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The Tropical Warm Pool International Cloud Experiment by chenmeixiu


									The Tropical Warm Pool International
         Cloud Experiment

        Darwin, Jan/Feb 2006

     Peter May, Jim Mather, Christian Jakob
            And a host of others…
                     A Few Acknowledgements

TWP-ICE Participants:     ARM, BOM, CSIRO, NASA, and many Universities

ACTIVE:                   Geraint Vaughan and Keith Bower

Our hosts:                 Northern Territory Regional Forecast Centre
                           Charles Darwin University
                           Darwin RAAF Base

Logistics coordination:       Andrew Hollis

Operations web site:         Tim Hume

Forecast team:                Lori Chappel and Mick Pope

Ground site maintenance:     Brad Atkinson and Anthony Noonan

And don’t forget all those contracts! (Bev Johnson and Margaret Hughes)
TWP-ICE Science Goals:
1) Make detailed measurements of the cirrus microphysics and how
   they relate to storm intensity and proximity (spatial and temporal) to the
   parent convection including high thin cirrus.

2) Verification of remotely sensed microphysical measurements.

3) Provide data sets for forcing cloud resolving and single column
   models that will attempt to simulate the observed characteristics and

4) Document the evolution of oceanic convective clouds from the early
   convection phase through to the remnant cirrus with particular emphasis
   on their microphysics.
 (Aerosol and Chemical Transport in Tropical Convection)

• Make direct measurements of a range of aerosol and chemical
  species in the low-level inflow and the high-level outflow of tropical

• Relate these to model simulations of the storms

• Place these results in context by comparing with measurements in the
  background TTL and predictions from larger-scale models.


        TWP-ICE Observation Network

               Proteus      Egrett (UK)

Twin Otter

             Dornier (UK)

         Darwin ARM site including        BOM radars: scanning 5 cm
         a 50 MHz profiler from U.        polarimetric radar (C-POL)
         Adelaide and a 14 Channel        and scanning operational
         microwave from U. Munich         weather radar

CSIRO Research Vessel              Surface         Radiosonde Network:
Southern Surveyor:               Observations      Darwin airport, four
remote sensing, fluxes,                            additional land sites, and
ocean state                                        the Southern Surveyor

           BOM profiler site including    Flux network with radiation
           50 MHz and 920 MHz             and turbulent flux sites
           profilers and NOAA’s 2.8       operated by Monash U.,
           GHz (S-band) profiler          Charles Darwin U., and PNNL

                        DOE Proteus: In-situ
             16 km      microphysics, remote sensing,
                        ARA Egrett: In-situ
             14 km      microphysics, aerosols (also

              3 km      Twin Otter: In-situ, upward-
                        looking remote
                        NERC Dornier: aerosols, state
             0.5-4 km   (also Nov-Dec)

                        ARA Dimona: Fluxes, BL
           20 m–2 km    structure
             Key Airborne Instruments

Proteus      CAPS                                   Size Spectra
             Cloud Particle Imager (CPI)            Hi-res images
             Cloud Integrating Nephelometer (CIN)   Extinction
             Cloud Spectral Imager (CSI)            Total Water
             Tunable Diode Laser (TDL)              Water vapor
             Broadband Radiometers

Twin Otter   Airborne Cloud Radar (CloudSat/JPL)
             Lidar (Whiteway/U. Toronto)
TWP-ICE Weather …

          active “dry” monsoon dry break
                                                ~7 mm/day

                         ~5 mm/day

                         45 mm in a day

            ~15 mm/day

                                          Courtesy Peter May
Radiosonde data also illustrates progression of meteorological regimes
                          TWP-ICE Aircraft Missions

               2 2      2 2   2   2   2   2   2   3   3   3   3   3    3    3   3 3   3   4   4   4   4   4
               1 2      3 4   5   6   7   8   9   0   1   2   3   4    5    6   7 8   9   0   1   2   3   4
Proteus                       A       A       S               H        A        H             H       A

Egrett             S T        A       A               S S         N             H     H       H       A H

Twin Otter         S T        A       A       S               H T               H     H H H           A

Dornier            S          N S S               N       S S N                 H     H H H           A

Dimona         L              L               L       L B H            O O O          H       H       A

                   Active                 Dry monsoon                 Dry             Break

    Active: Sampled outflow from active convective systems
    Dry monsoon: Sampled aged cirrus outflow from cyclone located south of Darwin
    Dry: Very clear conditions – no cirrus missions
    Break: Sampled afternoon convection over islands and along coasts

  A=ARM Site           T=Timor Sea            S=South of Darwin                 N= North of Darwin
  H=Hector             L=Land flux sites      O=Ocean flux sites                B=Boundary layer
   Coordination of day to day operations involved many people …

                                               Operations Center at Charles Darwin U.
 Mission Control at BOM
 Regional Forecast Center

         Operations Groups

Mission planning    Decision team
Operations office   Media coordinators
Aircraft groups     Ship scientists and crew
Sounding crews      ARM site staff
Satellite support   Report teams
                                                       Aircraft operations at RAAF
                       Flight mission schedule
Day prior to mission

3pm      Debrief of previous day’s flight

4pm      Daily weather briefing at Charles Darwin University (CDU)

5pm      Decision team meeting – general plans for following day (at CDU)

Day of mission

7-10am Follow-up decision team meeting – specific plans for the flight
       at Regional Forecast Centre (RFC)

1-3pm   Take off times

4pm      Daily weather briefing

6-7pm    Aircraft return to base

8-9pm    Mission control representatives meet with flight teams at RAAF
February 2, 2006: Thick anvil mission

The low to the south had weakened but there were still strong surface winds
so storms were expected to move quickly.

At 9:00 Local time, there was a band of quite thick cirrus moving to the
north and a line of convection to the NW coming towards Darwin.

Take-off times (LT): 1100 Proteus, 1130 Twin Otter, 1200 Dimona
                                      Scanning centimeter radar
                                      combined with satellite
                                      observations provide spatial
                                      context for missions.

Minnis et al.

       J. Cetrone and C. Schumacher
                               C-Pol Cross sections, 01:30 – 03:00 UTC

                        0130                               0200
Altitude (0 to 20 km)

                        0230                              0300

                          Horizontal Distance Along Cross Section (0 to 127 km)
                          (Courtesy Cetrone and Schumacher)
        95 GHz Airborne Cloud Radar: February 2 under Proteus spiral


                                                                              Reflectivity (-50 to 10 dBZ)
Altitude (km)

                     0224              0248                   0312


                            0336                           0400
                                   Time (UTC)

                                      Courtesy Steve Dinardo and Richard Austin
Analysis of 850 mb winds from BOM TXLAPS Model, 27 January 2006
January 27, aged cirrus case

MPL Backscatter at Darwin ARM site

                                     MTSAT-1R, 09:33Z
                                     IR window channel
                                     (Pat Minnis)
Jan 27 Cloud Particle Imager (CPI) composite from Proteus

                                                 McFarquhar and Um
Total water measured from Proteus over ARM site

                           Courtesy, G. McFarquhar and M. Freer
In addition to aged cirrus, the dry monsoon also brought high wind speeds…
CSIRO Research Vessel
The Southern Surveyor

                              Radiosonde launches
                              Surface fluxes
                              Ocean properties
                              Remote sensing

                        PARSL 94 GHz radar
                        January 24
     Flux Network: Significant Positive SW Cloud Effect

 Downwelling SW significantly greater than clear-sky          Courtesy Chuck Long
amount is not unusual in the TWP. Positive cloud effect (CE)
occurred at all sites during TWP-ICE (top).
 During January, CE greater than 20 Wm -2 occurred about
3% of the daylight hours, compared to about 20% of the
time in February at Garden Point, 13% at Cape Don and 28%
at Darwin ARM.
   NOAA S-Band Profiler

   Located for duration of
   wet season at profiler
   site in Darwin – near
   ARM site.

   Other guest instruments
   for TWP-ICE include The
   U. Adelaide 50 MHz
   profiler and the U.
   Munich 14 channel
   microwave radiometer –
   both at the ARM site.

Courtesy Chris Williams
                      The Darwin ARM Site Radar

Diurnal Cycle of Cloud Occurrence    Heating rates derived from ARM
                                     radar and microwave radiometer
                                     combined with BOM radiosondes

                                                McFarlane and Mather
Outreach (the other kind)

      TWP-ICE “Open Day” at
      Charles Darwin University

                                  K-12 Classroom visits
Science highlights:

In situ and remote sensing cloud data in aged tropical cirrus including in
situ spirals over the ARM site

Aircraft cloud data including thorough characterization of the convective
boundary layer in multiple convection cases – over 20 missions

High temporal resolution radiosonde data at multiple sites (~1000 flights)

14-channel microwave profiler within radiosonde network

Radiosonde network encompassing developing tropical cyclone (prior to
system crossing over land and becoming a landphoon).

Surface radiation and turbulent fluxes over a variety of representative
surface types

Extended low altitude (20m) aircraft surface flux missions

Airborne aerosol observations throughout the region courtesy ACTIVE
For more information:

And check out posters by: Chuck Long, Jay Mace, Jim
Mather, Peter May, Greg McFarquhar, Bob McCoy, Pat
Minnis, Courtney Schumacher, and Tim Tooman

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