FTIR_schneider by mudoc123

VIEWS: 8 PAGES: 46

									                              Forschungszentrum Karlsruhe
                              in der Helmholtz-Gemeinschaft



   Water vapour profiles by ground-based FTIR Spectroscopy:
          study for an optimised retrieval and its validation
                      by M. Schneider, F. Hase, and T. Blumenstock




1. Inversion on a logarithmic scale, why ?
2. Error characterization (… towards an optimal strategy for UT H2O retrieval)
3. 7-year record of water vapour above Izaña observatory
4. Summary and outlook

                                                                     published in ACP:
                                                                     Atmos. Chem. Phys.,
                                                                     6, 811-830, 2006
                              NDACC H2O workshop, Bern, July 2006
                                     Forschungszentrum Karlsruhe
                                     in der Helmholtz-Gemeinschaft
                                                                     1. Inversion on a logarithmic scale, why ?



Examination of a-priori distribution. χ2 test checks for a normal distribution:
 2  ( x  xa ) T S1 ( x  xa )
                    a




                     99,5
   probability [%]




                      98
                      90                                               2
                                                           theoretical  cdf
                      70                                     2
                      50                                    cdf for assumption of
                      30                                    normal distributed vmrs
                                                             2
                      10                                    cdf for assumption of
                        2                                   log-normal distributed
                      0,5                                   vmrs
                      0,1
                            0   10      20           30        40          50
                                                 2
                                                

                                     NDACC H2O workshop, Bern, July 2006
                               Forschungszentrum Karlsruhe
                               in der Helmholtz-Gemeinschaft
                                                               1. Inversion on a logarithmic scale, why ?


The cost function

 2 ( y  Kx) T ( y  Kx)  ( x  xa ) T Sa 1 ( x  xa )
                                           




is only correctly posted if state vector is transformed on a logarithmic
scale !


On a linear scale a wrong a-priori distribution is assumed !
Then the term
              
( x  xa ) T Sa 1 ( x  xa )

provides for an overestimation of small x and an underestimation of
large x !


                               NDACC H2O workshop, Bern, July 2006
                         Forschungszentrum Karlsruhe
                         in der Helmholtz-Gemeinschaft
                                                                 2. Error estimations


Error estimation is performed by a „Monte Carlo“ method. Analytic error
   estimation like proposed by Rodgers (1990) is not appropriate due to non-
   linearities.

1. Forward calculation of assumed H2O profile
2. Introducing of errors (measurement noise, temperature profile, ILS,
    spectroscopic parameter, …)
3. Inversion of the simulated spectra


This „Monte Carlo“ error estimation works only if we apply a large ensemble of
   H2O profiles, which obey the real H2O statistics ! We apply 500 ptu-sonde
   measurements of the years 1999 and 2000.



                          NDACC H2O workshop, Bern, July 2006
                          Forschungszentrum Karlsruhe
                          in der Helmholtz-Gemeinschaft
                                                                      2. Error estimations


Errors are commonly presented as a mean (systematic error) and variance
(random error).


Here we present them in a more general manner: by least squares fits
→ difference of regression curve from diagonal: offset + slope of regression line
(mean + sensitivity as systematic error)


→ scattering around the regression curve (residual variance as random error):
                                                                   _ reg
                                                                            1  2
                                                                  x


                           NDACC H2O workshop, Bern, July 2006
                                                       Forschungszentrum Karlsruhe
                                                       in der Helmholtz-Gemeinschaft
                                                                                                                               2. Error estimation
                  Error estimation by means of linear least squares fit
                  Why? — there are two kind of systematic errors:                                                1. mean error (bias)
                                                                                                                 2. sensitivity error
                                                                                                                 (slope≠1 or no linear
                  8
                                                                                                                 correlation)
                          slope: x/x
                                  ^
                                                                                 2
                                              x
                                               ^

                                         x
erroneous value




                  6



                                                               remaining error
                                                                                 1


                  4                              ___
                                                 ^                               0
                                         offset: x-x

                  2
                                                                                 -1



                  0                                                              -2
                      0   2        4               6      8                           0        2        4        6         8

                              correct value                                               bias corrected erroneous value


                                                       NDACC H2O workshop, Bern, July 2006
                          Forschungszentrum Karlsruhe
                          in der Helmholtz-Gemeinschaft



In the following the errors of lower, middle, and upper tropospheric H2O are


1. estimated by Monte Carlo simulations


and


2. validated by comparing H2O from FTIR measurements with daily ptu-sondes




                           NDACC H2O workshop, Bern, July 2006
                                                           Forschungszentrum Karlsruhe
                                                           in der Helmholtz-Gemeinschaft
                                                                                                                   2. Error estimations


Estimation of total FTIR error (2.3-3.3km):

                                   linear scale                                        logarithmic scale

                                  30   lower troposphere (2.3-3.3km)              30
 retrieved part. col. [10 /cm ]
-2
21




                                  20                                              20



                                  10                                              10



                                   0                        =0.98; m=0.98         0                          =0.98; m=0.98

                                       0          10         20             30         0          10         20             30
                                                                  21   -2                                         21   -2
                                           real partial column [10 /cm ]                   real partial column [10 /cm ]



                                                            NDACC H2O workshop, Bern, July 2006
                                                              Forschungszentrum Karlsruhe
                                                              in der Helmholtz-Gemeinschaft
                                                                                                                         2. Error estimations

FTIR vs. ptu-sondes at 2.3-3.3km. Problem: detection of different
regions (FTIR: boundary layer; sonde: free troposphere)

                                      linear scale                                       logarithmic scale

                                 30    lower troposphere (2.3-3.3km)               30
retrieved part. col. [10 /cm ]
-2
21




                                 20                                                20




                                 10                                                10



                                                              =0.91; m=1.03                                   =0.88; m=0.96
                                  0                                                 0

                                       0           10         20             30         0           10         20                30
                                                                   21   -2                                          21      -2
                                           sonde partial column [10 /cm ]                   sonde partial column [10 /cm ]


                                                              NDACC H2O workshop, Bern, July 2006
                                                          Forschungszentrum Karlsruhe
                                                          in der Helmholtz-Gemeinschaft
                                                                                                                   2. Error estimations


Estimation of total FTIR error (4.3-6.4km):

                                      linear scale                                       logarithmic scale
                                 20                                                    20
                                       middle troposphere (4.3-6.4km)
retrieved part. col. [10 /cm ]
-2




                                 15                                                    15
21




                                 10                                                    10


                                  5                                                     5

                                                                =0.97; m=0.83                                     =0.97; m=0.86
                                  0                                                     0
                                       0        5        10         15        20            0        5        10        15         20
                                                                   21    -2                                           21     -2
                                           real partial column [10 /cm ]                        real partial column [10 /cm ]


                                                              NDACC H2O workshop, Bern, July 2006
                                                                Forschungszentrum Karlsruhe
                                                                in der Helmholtz-Gemeinschaft
                                                                                                                          2. Error estimations


                FTIR vs. ptu-sonde at 4.3-6.4km:

                                      linear scale                                            logarithmic scale

                                 20                                                  20
                                          middle troposphere (4.3-6.4km)
retrieved part. col. [10 /cm ]
-2




                                 15                                                  15
21




                                 10                                                  10



                                  5                                                   5


                                                               =0.95; m=0.96                                    =0.94; m=1.01
                                  0                                                   0

                                      0          5        10        15        20          0         5       10       15          20
                                                                   21    -2                                          21     -2
                                          sonde partial column [10 /cm ]                      sonde partial column [10 /cm ]


                                                                 NDACC H2O workshop, Bern, July 2006
                                                           Forschungszentrum Karlsruhe
                                                           in der Helmholtz-Gemeinschaft
                                                                                                                 2. Error estimations


                    Estimation of total FTIR error (7.6-10.0km):

                                     linear scale                                       logarithmic scale


                                 2   upper troposphere (7.6-10.0km)                 2
retrieved part. col. [10 /cm ]
-2




                                                      21   2
                                     (LT-slant < 10x10 /cm )
21




                                 1                                                  1




                                                           =0.74; m=0.43                                        =0.74; m=0.41
                                 0                                                  0

                                     0                1                  2              0                1                  2
                                                               21   -2                                            21   -2
                                         real partial column [10 /cm ]                      real partial column [10 /cm ]
                                                            NDACC H2O workshop, Bern, July 2006
                                                          Forschungszentrum Karlsruhe
                                                          in der Helmholtz-Gemeinschaft
                                                                                                                2. Error estimations


         FTIR vs. ptu-sonde at 7.6-10.0km:

                                     linear scale                                     logarithmic scale

                                     upper troposphere (7.6-10.0km)               2
                                 2
retrieved part. col. [10 /cm ]
-2




                                                      21   2
                                     (LT-slant < 10x10 /cm
                                      and S/N > 200)
21




                                 1                                                1




                                                          =0.64; m=0.41                                       =0.56; m=0.51
                                 0                                                0

                                     0               1                2               0                1                   2
                                                           21    -2                                             21    -2
                                         sonde part. col. [10 /cm ]                       retrieved part. col. [10 /cm ]


                                                          NDACC H2O workshop, Bern, July 2006
                                                                              Forschungszentrum Karlsruhe
                                                                              in der Helmholtz-Gemeinschaft
                                                                                                                             2. Error estimations
          Can we reduce the error of the retrieved UT H2O amount ?
          Case A: Yes, when absorption lines are unsaturated !

                                                                                       H2O
                                         4                    H2O
absolute radiances [W/(cm sterad cm )]




                                                                                                          H2O
-1




                                                                                                                H2O


                                         3
2




                                         2



                                                                      measurement
                                         1                            retrieval
                                                                      residuum
                                                                                                   x 10
                                                x 10                                   x 10


                                         0


                                         1110          1111         1112            1117.5                 1121       1122
                                                                                              -1
                                                                           wavenumber [cm ]


                                                                               NDACC H2O workshop, Bern, July 2006
                                                              Forschungszentrum Karlsruhe
                                                              in der Helmholtz-Gemeinschaft
                                                                                                                      2. Error estimations


Upper troposphere (Case A): Estimation of total FTIR error for LT slant
below 10 x 1021cm-2 (7.6-10.0km):
                                     linear scale                                        logarithmic scale

                                 2    upper troposphere (7.6-10.0km)                 2
retrieved part. col. [10 /cm ]




                                                       21   2
-2




                                      (LT-slant < 10x10 /cm )
21




                                 1                                                   1




                                 0                            =0.90; m=0.69         0                           =0.91; m=0.79

                                       0                  1                  2            0                  1                  2
                                                                  21    -2                                           21    -2
                                           real partial cololumn [10 /cm ]                    real partial cololumn [10 /cm ]


                                                              NDACC H2O workshop, Bern, July 2006
                                                            Forschungszentrum Karlsruhe
                                                            in der Helmholtz-Gemeinschaft
                                                                                                                    2. Error estimations


Upper troposphere (Case A): FTIR vs. ptu-sonde at 7.6-10.0km for LT
slant below 10 x 1021cm-1:
                                     linear scale                                       logarithmic scale

                                 2    upper troposphere (7.6-10.0km)                2
retrieved part. col. [10 /cm ]
-2




                                                       21   2
                                      (LT-slant < 10x10 /cm
                                       and S/N > 200)
21




                                 1                                                  1




                                                             =0.81; m=0.60                                    =0.81; m=1.02
                                 0                                                  0

                                      0                1                    2           0                1                   2
                                                                 21    -2                                          21   -2
                                          sonde partial column [10 /cm ]                    sonde partial column [10 /cm ]


                                                             NDACC H2O workshop, Bern, July 2006
                                                            Forschungszentrum Karlsruhe
                                                            in der Helmholtz-Gemeinschaft
                                                                                                                   2. Error estimations


Upper troposphere (Case A): Estimation of total FTIR error for LT slant
below 5 x 1021cm-2 (8.8-11.2km):
                                       linear scale                                     logarithmic scale

                                        tropopause (8.8-11.2km)
retrieved part. col. [10 /cm ]




                                                        21   2
-2




                                        (LT-slant < 5x10 /cm )
                                 0,4                                              0,4
21




                                 0,2                                              0,2




                                 0,0                        =0.89; m=0.61        0,0                        =0.94; m=0.66

                                        0,0         0,2           0,4                   0,0         0,2           0,4
                                                                  21    -2                                       21     -2
                                          real partial cololumn [10 /cm ]                 real partial cololumn [10 /cm ]


                                                             NDACC H2O workshop, Bern, July 2006
                                                           Forschungszentrum Karlsruhe
                                                           in der Helmholtz-Gemeinschaft
                                                                                                                    2. Error estimations


Upper troposphere (Case A): FTIR vs. ptu-sonde at 8.8-11.2km for LT
slant below 5 x 1021cm-1:
                                    linear scale                                         logarithmic scale

                                  0,6   tropopause (8.8-11.2km)                    0,6
                                                        21   2
 retrieved part. col. [10 /cm ]




                                        (LT-slant < 5x10 /cm
 -2




                                         and S/N > 200)
 21




                                  0,4                                              0,4




                                  0,2                                              0,2




                                  0,0                        =0.83; m=0.53        0,0                        =0.86; m=0.90

                                        0,0       0,2        0,4             0,6         0,0       0,2        0,4              0,6
                                                                   21   -2                                          21    -2
                                          sonde partial column [10 /cm ]                   sonde partial column [10 /cm ]


                                                           NDACC H2O workshop, Bern, July 2006
                                                                                      Forschungszentrum Karlsruhe
                                                                                      in der Helmholtz-Gemeinschaft
                                                                                                                                    2. Error estimations
                     Can we reduce the error of the retrieved UT H2O amount ?
                     Case B: Yes, when strong and moderately strong lines are fitted simultaneously !
                                           5
                                                                                                H2O
                     [W/(cm sterad cm )]




                                                                                                                 H2O
                     -1
absolute radiances




                                           4                                                                           H2O
                                                                 H2O
                                           3

                                           2
                     2




                                                  meaurement              x10
                                           1      retrieval
                                                  residuum x10
                                           0


                                           1110           1111            1112           1113      1117,9         1121       1122
                                                                                                            -1
                                                                                         wavenumber [cm ]

                                           5
                                               CH4
                     [W/(cm sterad cm )]
                     -1
absolute radiances




                                           4     HDO
                                                         CH4             HDO
                                           3                                             HDO
                                                                           N2O
                                           2
                     2




                                           1
                                                                  CH4
                                           0


                                                  1221            1252           1253       1325
                                                                                 -1
                                                                 wavenumber [cm ]

                                                                                        NDACC H2O workshop, Bern, July 2006
                                                              Forschungszentrum Karlsruhe
                                                              in der Helmholtz-Gemeinschaft
                                                                                                                     2. Error estimations


                                 Upper troposphere (Case B): FTIR vs. ptu-sonde at 7.6-10.0km (LT
                                 slant below 25 x 1021cm-2):
                                          strong lines                                    strong and moderately strong lines

                                  2                                                   2
retrieved part. col. [10 /cm ]
-2
21




                                  1                                                   1




                                                             =0.67; m=0.71                                         =0.84; m=0.89
                                  0                                                   0

                                      0                  1                 2               0                1                  2
                                                                 21   -2                                             21   -2
                                           real partial column [10 /cm ]                       real partial column [10 /cm ]


                                                               NDACC H2O workshop, Bern, July 2006
                                                                Forschungszentrum Karlsruhe
                                                                in der Helmholtz-Gemeinschaft
                                                                                                                        2. Error estimations


                                 Upper troposphere (Case B): FTIR vs. ptu-sonde at 10.0-12.4km (LT
                                 slant below 5 x 1021cm-2):
                                        strong lines                                      strong and moderately strong lines
retrieved part. col. [10 /cm ]
-2




                                  0,2                                                  0,2
21




                                  0,1                                                  0,1




                                                                =0.75; m=0.57                                          =0.78; m=0.45
                                  0,0                                                  0,0

                                        0,0              0,1             0,2                 0,0              0,1             0,2
                                                                    21    -2                                             21    -2
                                              real partial column [10 /cm ]                        real partial column [10 /cm ]


                                                                 NDACC H2O workshop, Bern, July 2006
                           Forschungszentrum Karlsruhe
                           in der Helmholtz-Gemeinschaft
                                                                    2. Error estimations


Recipe for retrieval of upper tropospheric H2O:
•   Only retrieval on a logarithmic scale provides for a correctly posted cost
    function → this reduces the systematic errors if compared to a retrieval on
    linear scale. It leads to consistent time series and a good sensitivity for UT
    H2O amounts
•   Simultaneous fit of strong and moderately strong lines provides for best
    exploitation of spectra → makes continuous observation of UT H2O feasible
•   Most important errors are: smoothing error, ILS, line parameter, and
    temperature profile




                           NDACC H2O workshop, Bern, July 2006
                                                                                    Forschungszentrum Karlsruhe
                                                                                    in der Helmholtz-Gemeinschaft
                                                                                                      3. 7-year record of water vapour above Izaña observatory
                                         tropopause (10.0-12.4km)
                                   0,2                      21
                                         for LT slant < 5x10 cm
                                                                -2                                           0,06                           Above 9km retrieval requires
                                                                                                             0,04                           unsaturated H2O lines → LT slant
                                   0,1
                                                                                                             0,02                           below 5 x 1021 cm-2 (in Izaña only
                                   0,0                                                                       0,00                           for 10% of all measurements)
partial column amounts [10 /cm ]
2




                                         UT (7.6-10.0km)
                                    2                        21
                                         for LT slant < 25x10 cm
                                                                 -2                                                                         Above 7.5km retrieval requires
21




                                                                                                             0,5
                                                                                                                                            moderate LT H2O amounts and




                                                                                                                    preciptible H 2O [mm]
                                    1
                                                                                                                                            simultaneous fit of strong and
                                    0                                                                        0,0                            moderately strong lines
                                   20
                                         MT (4.3-6.4km)                                                      5
                                   15

                                   10

                                    5

                                    0                                                                        0
                                                                                                                                            Up to 7km retrieval possible under
                                         LT (2.3-3.3km)
                                                                                                                                            all measurement conditions
                                   20
                                                                                                             5

                                   10


                                    0                                                                        0
                                           1999        2000           2001   2002     2003    2004    2005


                                                                                    NDACC H2O workshop, Bern, July 2006
                        Forschungszentrum Karlsruhe
                        in der Helmholtz-Gemeinschaft
                                                               4. Summary and outlook

Our study shows the following:


1. FTIR well-suited for continuous monitoring of lower and middle
   tropospheric H2O amounts.


2. For upper tropospheric H2O amounts a continuous monitoring is tricky, but
   feasible by FTIR, if:
       A: the inversion is perform on a log-scale
       B: strong and moderately strong lines are fitted simultaneously




                         NDACC H2O workshop, Bern, July 2006
                            Forschungszentrum Karlsruhe
                            in der Helmholtz-Gemeinschaft
                                                                  4. Summary and outlook

Future work:
1. Produce continuous time series of UT water vapour from many historic
   FTIR measurements (e.g. measurements at Jungfraujoch or Kitt Peak could
   produce unique continuous 20-year records !)
2. Further improvements are still possible for dryer or higher situated sites:
      we could apply stronger H2O lines → improved sensitivity at higher
      altitudes. Detection of lower stratospheric water vapour variability
      from Jungfraujoch ?

   3. Retrieval of HDO/H2O




                            NDACC H2O workshop, Bern, July 2006
Forschungszentrum Karlsruhe
in der Helmholtz-Gemeinschaft




         Thank You !!!!!!!!!




NDACC H2O workshop, Bern, July 2006
                                  Forschungszentrum Karlsruhe
                                  in der Helmholtz-Gemeinschaft
                                                                                       2. Error estimations


Summary of differences between FTIR and ptu sonde data (sum of errors of
sonde and FTIR). Theoretical estimations of FTIR errors are in brackets:

linear scale:
                total             2.3-3.3km           4.3-6.4km           7.6-10.0km        8.8-11.2km

random                  25 (4)             40 (21)             32 (24)           54 (50)               56 (47)
systematic(A)           +6 (0)             +3 (-3)              -4 (-6)         -40 (-31)            -47 (-38)


logarithmic scale:
                total             2.3-3.3km           4.3-6.4km           7.6-10.0km        8.8-11.2km
random                   25 (4)            47 (22)             33 (24)           58 (49)               51 (42)

sytematic(A)            +6 (-1)             -4 (-4)            +1 (-1)           +2 (-23)            -10 (-33)


(A): systematic spectroscopic line parameter errors are not considered
                                   NDACC H2O workshop, Bern, July 2006
                    Forschungszentrum Karlsruhe
                    in der Helmholtz-Gemeinschaft
                                                                  2. Error estimations


Upper troposphere (Case B): Estimation of total FTIR error at 7.6-
10.0km (LT slant below 25 x 1021cm-2):
     strong lines                             strong and moderately strong lines




                     NDACC H2O workshop, Bern, July 2006
                    Forschungszentrum Karlsruhe
                    in der Helmholtz-Gemeinschaft
                                                                 2. Error estimations


Upper troposphere (Case B): Estimation of total FTIR error at 7.6-10.0km
(LT slant below 25 x 1021cm-1):
     strong lines                            strong and moderately strong lines




                    NDACC H2O workshop, Bern, July 2006
                          Forschungszentrum Karlsruhe
                          in der Helmholtz-Gemeinschaft

What about the averaging kernels ?                              3. Vertical resolution

In the case of water vapour the averaging kernels only contain limited
    information about the sensitivity of the measurements.
Reason:
1. Non-linearities (kernels depend strongly on actual H2O profile)
2. variability of H2O decreases with height by 4 orders of magnitude
   → comparison of kernels for different heights is not straight forward !


Alternative representation of sensitivity:
Correlation matrices (correlation between original profiles and inverted
   profiles). The matrices give a realistic overview of the detectable
   atmospheric regions. Furthermore, they allow us to perform this sensitivity
   analysis for a realistic error scenario.
                          NDACC H2O workshop, Bern, July 2006
                                                   Forschungszentrum Karlsruhe
                                                   in der Helmholtz-Gemeinschaft
                                                                                                                             3. Vertical resolution


Estimation for LT slant column below 10 x 1021cm-2:

                                 linear scale                                                           logarithmic scale
                            15                                                                     15
retrieved atmosphere [km]




                                                                       retrieved atmosphere [km]
                            10                                                                     10

                                                               -0,64                                                                   -0,64
                                                               -0,52                                                                   -0,52
                                                               -0,40                                                                   -0,40
                                                               0,40                                                                    0,40
                                                               0,52                                                                    0,52

                             5                                 0,64                                 5                                  0,64
                                                               0,76                                                                    0,76
                                                               0,88                                                                    0,88
                                                               1,00                                                                    1,00



                                      5             10            15                                       5            10                15

                                       real atmosphere [km]                                                real atmosphere [km]



                                                    NDACC H2O workshop, Bern, July 2006
                                                   Forschungszentrum Karlsruhe
                                                   in der Helmholtz-Gemeinschaft
                                                                                                                              3. Vertical resolution


FTIR vs. sonde for LT slant below 10 x 1021cm-2:

                                  linear scale                                                           logarithmic scale
                             15                                                                     15
 retrieved atmosphere [km]




                                                                        retrieved atmosphere [km]
                             10                                                                     10

                                                                -0,64                                                                   -0,64
                                                                -0,52                                                                   -0,52
                                                                -0,40                                                                   -0,40
                                                                0,40                                                                    0,40
                                                                0,52                                                                    0,52
                              5                                 0,64                                 5                                  0,64
                                                                0,76                                                                    0,76
                                                                0,88                                                                    0,88
                                                                1,00                                                                    1,00



                                        5           10             15                                        5           10                15

                                       sonde atmosphere [km]                                                sonde atmosphere [km]



                                                    NDACC H2O workshop, Bern, July 2006
                                                   Forschungszentrum Karlsruhe
                                                   in der Helmholtz-Gemeinschaft
                                                                                                                                 3. Vertical resolution

Estimation for LT slant column below 5 x 1021cm-2:

                                 linear scale                                                              logarithmic scale

                            15                                                                        15
retrieved atmosphere [km]




                                                                          retrieved atmosphere [km]
                            10                                                                        10
                                                              -0,64                                                                    -0,64
                                                              -0,52                                                                    -0,52
                                                              -0,40                                                                    -0,40
                                                              0,40                                                                     0,40
                                                              0,52                                                                     0,52

                             5                                0,64                                     5                               0,64
                                                              0,76                                                                     0,76
                                                              0,88                                                                     0,88
                                                              1,00                                                                     1,00



                                      5            10                15                                       5            10                 15

                                      real atmosphere [km]                                                    real atmosphere [km]


                                                    NDACC H2O workshop, Bern, July 2006
                                                   Forschungszentrum Karlsruhe
                                                   in der Helmholtz-Gemeinschaft
                                                                                                                                 3. Vertical resolution


FTIR vs. sonde profiles for LT slant < 5 x 1021cm-2:

                                  linear scale                                                              logarithmic scale
                             15                                                                        15
 retrieved atmosphere [km]




                                                                           retrieved atmosphere [km]
                             10                                                                        10
                                                               -0,64                                                                      -0,64
                                                               -0,52                                                                      -0,52
                                                               -0,40                                                                      -0,40
                                                               0,40                                                                       0,40
                                                               0,52                                                                       0,52

                              5                                0,64                                     5                                 0,64
                                                               0,76                                                                       0,76
                                                               0,88                                                                       0,88
                                                               1,00                                                                       1,00



                                        5           10                15                                       5            10                   15

                                       sonde atmosphere [km]                                                   sonde atmosphere [km]


                                                    NDACC H2O workshop, Bern, July 2006
                                                                                                                       Forschungszentrum Karlsruhe
                                                                                                                       in der Helmholtz-Gemeinschaft
                                                                                           Slide from talk “Ground-based remote sensing of tropospheric HDO/H2O ratio profiles”

                        Empirical validation of H2O profiles: ptu-sonde vs. FTIR:
                                                             common approach                                                  PROFFIT v9.4
                                               15
                                                    H2O profiles: sonde vs. FTIR
                                                                                                                       15
                                                                                                                                                                    Inter-species constraint not
                                                                                                                                                                    only improves quality of δD
-2
 LT slant < 2.5x10 cm
                        FTIR atmosphere [km]




                                                                                                FTIR atmosphere [km]
                                                                                                                                                                    profiles but also quality of H2O
22




                                               10                                                                      10

                                                                                   1,00
                                                                                   0,88
                                                                                                                                                       1,00
                                                                                                                                                       0,88         profile:
                                                                                   0,76                                                                0,76
                                                                                   0,64                                                                0,64
                                                                                                                                                       0,52

                                                5
                                                                                   0,52
                                                                                   0,40
                                                                                   -0,40
                                                                                                                        5
                                                                                                                                                       0,40
                                                                                                                                                       -0,40
                                                                                                                                                                    H2O retrieval benefits from
                                                                                                                                                       -0,52
                                                                                   -0,52
                                                                                   -0,64
                                                                                                                                                       -0,64
                                                                                                                                                                    additional information present
                                                         5                10               15                                 5             10                 15   in HDO lines
                                                          sonde atmosphere [km]                                               sonde atmosphere [km]



                                               15                                                                      15

                                                                                                                                                                    Detection of UT/LS H2O with
-2
 LT slant < 5x10 cm




                                                                                                                                                                    the proposed lines ?
                        FTIR atmosphere [km]




                                                                                                FTIR atmosphere [km]
21




                                               10                                                                      10
                                                                                   1,00
                                                                                   0,88
                                                                                   0,76
                                                                                                                                                      1,00
                                                                                                                                                      0,88          For a definitive conclusion we
                                                                                                                                                      0,76
                                                                                   0,64
                                                                                   0,52
                                                                                   0,40
                                                                                                                                                      0,64
                                                                                                                                                      0,52
                                                                                                                                                      0,40
                                                                                                                                                                    need a larger ensemble of
                                                5                                  -0,40
                                                                                   -0,52
                                                                                   -0,64
                                                                                                                        5                             -0,40
                                                                                                                                                      -0,52
                                                                                                                                                      -0,64
                                                                                                                                                                    compared profiles (the
                                                                                                                                                                    correlation shown here bases
                                                         5                10               15                                 5             10                 15

                                                          sonde atmosphere [km]                                               sonde atmosphere [km]
                                                                                                                                                                    on only 7 profiles) !

                                                                                                                       NDACC H2O workshop, Bern, July 2006
                                                    Forschungszentrum Karlsruhe
                                                    in der Helmholtz-Gemeinschaft
                                                                                                            3. Validation of FTIR profiles with ptu-sondes


FTIR versus sonde profiles for all measurement days:

                                   linear scale                                                             logarithmic scale
                              15                                                                       15
  retrieved atmosphere [km]




                                                                           retrieved atmosphere [km]
                              10                                                                       10
                                                                  -0,64                                                                         -0,64
                                                                  -0,52                                                                         -0,52
                                                                  -0,40                                                                         -0,40
                                                                  0,40                                                                          0,40
                                                                  0,52                                                                          0,52

                               5                                  0,64                                  5                                       0,64
                                                                  0,76                                                                          0,76
                                                                  0,88                                                                          0,88
                                                                  1,00                                                                          1,00



                                          5           10              15                                           5              10                15

                                         sonde atmosphere [km]                                                     sonde atmosphere [km]



                                                     NDACC H2O workshop, Bern, July 2006
                                                    Forschungszentrum Karlsruhe
                                                    in der Helmholtz-Gemeinschaft
                                                                                                                                   3. Error estimations


Corresponding theoretical sensitivity assessment (whole ensemble):

                                   linear scale                                                             logarithmic scale
                              15                                                                       15
  retrieved atmosphere [km]




                                                                           retrieved atmosphere [km]
                              10                                                                       10
                                                                  -0,64                                                                     -0,64
                                                                  -0,52                                                                     -0,52
                                                                  -0,40                                                                     -0,40
                                                                  0,40                                                                      0,40
                                                                  0,52                                                                      0,52

                               5                                  0,64                                  5                                   0,64
                                                                  0,76                                                                      0,76
                                                                  0,88                                                                      0,88
                                                                  1,00                                                                      1,00



                                          5            10             15                                         5            10                15

                                          real atmosphere [km]                                                   real atmosphere [km]



                                                     NDACC H2O workshop, Bern, July 2006
                                                    Forschungszentrum Karlsruhe
                                                    in der Helmholtz-Gemeinschaft
                                                                                                                                   2. Error estimations


Corresponding theoretical sensitivity assessment (LT slant < 5 x 1021cm-2):

                                  linear scale                                                               logarithmic scale
                             15                                                                         15
 retrieved atmosphere [km]




                                                                            retrieved atmosphere [km]
                             10                                                                         10
                                                                -0,64                                                                      -0,64
                                                                -0,52                                                                      -0,52
                                                                -0,40                                                                      -0,40
                                                                0,40                                                                       0,40
                                                                0,52                                                                       0,52

                              5                                 0,64                                     5                                 0,64
                                                                0,76                                                                       0,76
                                                                0,88                                                                       0,88
                                                                1,00                                                                       1,00



                                        5            10                15                                       5             10                  15

                                        real atmosphere [km]                                                     real atmosphere [km]



                                                     NDACC H2O workshop, Bern, July 2006
                                                                                                                       Forschungszentrum Karlsruhe
                                                                                                                       in der Helmholtz-Gemeinschaft
                                                                                           Slide from talk “Ground-based remote sensing of tropospheric HDO/H2O ratio profiles”

                        Empirical validation of H2O profiles: ptu-sonde vs. FTIR:
                                                             common approach                                                  PROFFIT v9.4
                                               15
                                                    H2O profiles: sonde vs. FTIR
                                                                                                                       15
                                                                                                                                                                    Inter-species constraint not
                                                                                                                                                                    only improves quality of δD
-2
 LT slant < 2.5x10 cm
                        FTIR atmosphere [km]




                                                                                                FTIR atmosphere [km]
                                                                                                                                                                    profiles but also quality of H2O
22




                                               10                                                                      10

                                                                                   1,00
                                                                                   0,88
                                                                                                                                                       1,00
                                                                                                                                                       0,88         profile:
                                                                                   0,76                                                                0,76
                                                                                   0,64                                                                0,64
                                                                                                                                                       0,52

                                                5
                                                                                   0,52
                                                                                   0,40
                                                                                   -0,40
                                                                                                                        5
                                                                                                                                                       0,40
                                                                                                                                                       -0,40
                                                                                                                                                                    H2O retrieval benefits from
                                                                                                                                                       -0,52
                                                                                   -0,52
                                                                                   -0,64
                                                                                                                                                       -0,64
                                                                                                                                                                    additional information present
                                                         5                10               15                                 5             10                 15   in HDO lines
                                                          sonde atmosphere [km]                                               sonde atmosphere [km]



                                               15                                                                      15

                                                                                                                                                                    Detection of UT/LS H2O with
-2
 LT slant < 5x10 cm




                                                                                                                                                                    the proposed lines ?
                        FTIR atmosphere [km]




                                                                                                FTIR atmosphere [km]
21




                                               10                                                                      10
                                                                                   1,00
                                                                                   0,88
                                                                                   0,76
                                                                                                                                                      1,00
                                                                                                                                                      0,88          For a definitive conclusion we
                                                                                                                                                      0,76
                                                                                   0,64
                                                                                   0,52
                                                                                   0,40
                                                                                                                                                      0,64
                                                                                                                                                      0,52
                                                                                                                                                      0,40
                                                                                                                                                                    need a larger ensemble of
                                                5                                  -0,40
                                                                                   -0,52
                                                                                   -0,64
                                                                                                                        5                             -0,40
                                                                                                                                                      -0,52
                                                                                                                                                      -0,64
                                                                                                                                                                    compared profiles (the
                                                                                                                                                                    correlation shown here bases
                                                         5                10               15                                 5             10                 15

                                                          sonde atmosphere [km]                                               sonde atmosphere [km]
                                                                                                                                                                    on only 7 profiles) !

                                                                                                                       NDACC H2O workshop, Bern, July 2006
                                                   Forschungszentrum Karlsruhe
                                                   in der Helmholtz-Gemeinschaft

                                                                                                                                2. Error estimations

Whole ensemble:

                                  linear scale                                                            logarithmic scale
                             15                                                                      15
 retrieved atmosphere [km]




                                                                         retrieved atmosphere [km]
                             10                                                                      10
                                                                -0,64                                                                    -0,64
                                                                -0,52                                                                    -0,52
                                                                -0,40                                                                    -0,40
                                                                0,40                                                                     0,40
                                                                0,52                                                                     0,52

                              5                                 0,64                                  5                                  0,64
                                                                0,76                                                                     0,76
                                                                0,88                                                                     0,88
                                                                1,00                                                                     1,00



                                        5            10             15                                        5            10                15

                                        real atmosphere [km]                                                  real atmosphere [km]


                                                    NDACC H2O workshop, Bern, July 2006
                                                         Forschungszentrum Karlsruhe
                                                         in der Helmholtz-Gemeinschaft
                                                                                                                                               2. Error estimation
                          Error estimation by means of linear least squares fit
                          Why? — there are two kind of systematic errors:                                                       1. mean error (bias)
                                                                                                                                2. sensitivity error
                  5
                                                                                                                                (slope≠1)

                                                                                         1
                  4




                                                             error (erroneous-correct)
erroneous value




                  3
                                                                                         0
                                x
                  2        x
                            ^


                                           slope:
                  1                        x / x
                                             ^
                                                                                         -1


                  0
                      0         1      2      3      4   5                                    0       1      2       3      4        5

                                     correct value                                                eroneous value (retrieved value)




                                                         NDACC H2O workshop, Bern, July 2006
                                                    Forschungszentrum Karlsruhe
                                                    in der Helmholtz-Gemeinschaft
                                                                                                                                2. Error estimations

Slant column of lower troposphere (2.3-4.3km) below 10 x 1021cm-2:

                                   linear scale                                                           logarithmic scale
                              15                                                                     15
  retrieved atmosphere [km]




                                                                         retrieved atmosphere [km]
                              10                                                                     10

                                                                 -0,64                                                                  -0,64
                                                                 -0,52                                                                  -0,52
                                                                 -0,40                                                                  -0,40
                                                                 0,40                                                                   0,40
                                                                 0,52                                                                   0,52
                               5                                 0,64                                 5                                 0,64
                                                                 0,76                                                                   0,76
                                                                 0,88                                                                   0,88
                                                                 1,00                                                                   1,00



                                         5            10            15                                        5            10              15

                                         real atmosphere [km]                                                 real atmosphere [km]




                                                     NDACC H2O workshop, Bern, July 2006
                                         Forschungszentrum Karlsruhe
                                         in der Helmholtz-Gemeinschaft
                                                                                      2. Error estimations

Summary of random error component of smoothing + measurement noise
error:
                     linear scale                             logarithmic scale


                10                                      10
altitude [km]




                                           whole ensemble
                                           LT slant
                5                               22     -2 5
                                         <10x10 cm
                                           LT slant
                                              22    -2
                                         <5x10 cm

                     0              50            100         0                50     100
                         random error [%]                          random error [%]

                                         NDACC H2O workshop, Bern, July 2006
                                         Forschungszentrum Karlsruhe
                                         in der Helmholtz-Gemeinschaft
                                                                                       2. Error estimations


           Summary of random error component parameter error (whole ensemble):


                     linear scale                           logarithmic scale


                10                                         10
                                           pressure
altitude [km]




                                         broadening
                                           phase error
                                           T profile
                                         (no retr. of T)
                5                                          5
                                           T profile
                                         (simultaneaous
                                         retrieval of T)

                     0              50             100          0              50       100
                          random error [%]                          random error [%]
                                         NDACC H2O workshop, Bern, July 2006
                                         Forschungszentrum Karlsruhe
                                         in der Helmholtz-Gemeinschaft
                                                                                        2. Error estimations



    Summary of random error component parameter error (LT slant below
    10 x 1021cm-1):

                     linear scale                               logarithmic scale


                10                                         10
                                           pressure
altitude [km]




                                         broadening
                                           phase error
                                           T profile
                5                        (no retr. of T)   5
                                           T profile
                                         (simultaneaous
                                         retrieval of T)

                     0              50              100         0               50      100
                         random error [%]                            random error [%]
                                          NDACC H2O workshop, Bern, July 2006
                                         Forschungszentrum Karlsruhe
                                         in der Helmholtz-Gemeinschaft
                                                                                       2. Error estimations

       Summary of random error component parameter error (LT slant below 5
       x 1021cm-1

                     linear scale                           logarithmic scale


                10                         pressure      10
                                         broadening
altitude [km]




                                           phase error
                                           T profile
                                         (no retr. of T)
                5                          T profile      5
                                         (simultaneaous
                                         retrieval of T)


                     0              50             100        0                 50     100

                          random error [%]                          random error [%]
                                          NDACC H2O workshop, Bern, July 2006

								
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