Water 20Cycle - PowerPoint - PowerPoint

							Water Cycle
    Importance of the Water Cycle
   “The vitality of all life on Earth and our economic
    prosperity depend on water.” – Call for Proposals NSF Water
    Cycle Research

   “The cycling of water among the three phases is
    overwhelming important for Earth, driving not just the
    atmospheric general circulation but also the very
    existence of life as we know it” -- A Plan for a New Science
    Initiative on the Global Water Cycle, USGCRP

   “Deficiencies in our understanding of the global water
    cycle severely handicap efforts to improve climate
    prediction and guide water resource management.” –
    Robert Corell A Plan for a New Science Initiative on the Global Water
    Cycle, USGCRP
    Impacts of Water Cycle Variations
   In the U.S., flood damage is typically of order of ~$10-20 billions per
    year

   Flood damage varies from year to year : $200 billion in 1991-1995
    and 40% of economic damage from disasters in that period

   1998 Carolina drought -- $6 – 9 billion

   1988 Midwest drought -- $40 billion

   Recently the largest number of weather fatalities are due to flooding
    (not really true)

   Advanced knowledge of local events and year-to-year variations
    beneficial to society
     Water Cycle Research
   GEWEX – Global Energy and Water Cycle
      Experiment

   US Global Change Research Program’s (USGCRP) –
       Global Water Cycle Initiative

   NSF – Water Cycle Research

   NOAA – Water Cycle Program  NAME


   NASA – Water and Energy Cycle
          Water Cycle Research
 NCAR    has a Strategic Initiative called
    “Water Cycle Across Scales”
        http://www.rap.ucar.edu/projects/watercycles/

   The across the scales aspect is partly motivated by the
    societal impacts of water cycle (floods, droughts, water
    pollution) are local or regional, while many key aspects
    of the water cycle toward global scales (climate change,
    El Nino.) Also, many of the uncertainties in global
    modeling are due to problems treating subgrid scale
    processes.
         My Reading Homework
   Earliest work on the water cycle appears in Book 21 of
    the Iliad, Homer (~810 B.C.): Oceanus source of all
    rivers, sea, springs and wells

   Thales (~600 B.C.) and Plato (~400 B.C.): Water
    eventually returns to the sea by various routes

   Perrault and Mariotte (1600s): 1st Water budget: Seine
    runoff approximately balanced by rainfall and snowmelt
    in the Basin

   Modern planning documents (Hornberger report, NCAR
    water cycle, papers in the literature, NASA documents,
    etc.)
   1st Possible Research Themes and
   Corresponding Measurement Needs



 Watervapor, which is a key aspects of the
 water cycle is not measured accurately
 enough for research needs
                               Monitoring results of relative humidity in low cloud
                                Values shown for relative humidity bias are [100-
                                5          average value for 2 years]

                                4

                                3                         H Sensor
                                2                                                     Camb night bias
Relative humidity [per cent]




                                                                                      Camb day bias
                                                                                      Lerw night bias
                                1
                                                                                      Lerw day bias


                                0      A sensor                                       Augh night bias
                                                                                      Augh Day bias
                                                                                      Storn night bias
                                                                                      Storn day bias
                               -1
                                                                                      Hills night bias
                                                                                      Hills day bias
                               -2                                                     Boul night bias
                                                                                      Boul day bias

                               -3                                                     Hems night bias
                                                                                      Hems day bias

                               -4

                               -5

                               -6

                               -7
                                1990        1995           2000      2005
                                                   Year

                                                           From J. Nash, ATD seminar
      Motivations



1. Individual errors
    and biases
2. Temporal and
    spatial
    inhomogeneity
3. Temporal and
    spatial
    sampling –
    Satellite
    (calibrated by
    radiosonde)




NCAR Atmospheric Technology Division
            1ST Possible Theme
   Attempt to contribute to the measurement and research
    gap of accurate water vapor measurements for climate
    purposes

   Evaluate impact of NWS sonde “upgrades”

   One effort: Reference radiosonde with technology
    transfer and asssistance in long-term monitoring

   General effort to better measure water vapor and water
    vapor fluxes in surface, sounding, remote sensing and
    from aircraft (weather, climate, carbon cycle, etc.)
         The reference radiosonde for IHOP_2002
 •S/W chilled-mirror DP hygrometer
    – reference humidity sensor
 •Carbon hygristor                       Vaisala RS80
 •Copper-constantan thermocouple
 •Hypsometer                             NWS VIZ B-2




Reference
radiosonde


400MHz transmitter
GPS receiver
Cirrus clouds detected by
SnowWhite – thick cirrus

Surface Report: Cirrus anvil
(moon visible through cirrus)




                *




                                Satellite image from UW-Madison CIMSS web page
2nd Research Theme and Corresponding
         Measurement Needs

   Predictive models have widely varying
    degrees of sensitivity to surface properties

   This variation is often not reasonable and may
    be traced to the need for a greater
    understanding of the details of surface
    characteristics and surface exchanges in
    complex environments.
Ωp (S - W)




             Koster et al. 2003
             GLACE website
             June-August run
IHOP Surface
Tracks

From Lemone
et al.
From Lemone et al.
2nd Theme and Measurement Need
   Improved attack on surface exchanges and
    impact on boundary layer

   Surface in-situ measurements

       Fluxes and means, vegetation (NDVI, LAI, PAR,
        stomal conductance, etc.), soil measurements (soil
        composition, conductivity, shallow and deep soil
        moisture), long-term capability, do we need to go into
        the canopy
2nd Theme and Measurement Need
 Ground-based    remote sensing to look at
 response of atmosphere (Radar
 refractivity, water vapor lidar, better
 observations of early clouds)

 HIAPER    remote sensing to complement
 surface obs (better areal coverage,
 satellite “calibration”)
Refractivity: One Day After Heavy Rainfall
            Aircraft In-situ data
                                    Northern edge of
                                    aircraft track
                                    Ts=45,
                                    Theta60=307,
                                    q60 = 8.5


                                     Southern edge of
                                     aircraft track
                                     Ts=32,
                                     Theta60=306.2,
                                     q60 = 11
                                       Weckwerth
                                       and LeMone
                                       also Fabry
    3rd Measurement and Observing
               Theme
   Models have poor triggering of convection

   Diurnal cycle of precipitation and clouds wrong
    over the central US but getting (slightly) better

   Remote sensing and surface mentioned
    previously plus sounding/profiling supporting obs
    sufficient

   Current focus of water cycle but still likely to be
    the focus
    4th Measurement and Observing
               Theme
   Regional water cycle experiments that include
    hydrology (NAME, esp AMMA, etc.)
       Need precipitation radar and current technologies,
       Hydrology (can we build it?),
       HIAPER as a water cycle platform
         • Ability to profile water vapor, clouds, surface properties
       HIAPER as a satellite evaluation, platform for
        prototype satellite sensors and platform for
        understanding of and from these measurements
        (TRMM, GPM, EOS-Aura, EOS-Terra, EOS-Aqua,
        CloudSAT, CALIPSO, GRACE, AMSR, GIFTS,
        NAST etc) – allows us to scale up to global obs
Water Cycle