Observational aspects of cloud microstructures. Po-Hsiung Lin November 20, 2006

Transcription

1 Observational aspects of cloud microstructures Po-Hsiung Lin November 20, 2006

2 Outline Motivation Cloud microstructure parameters observed in laboratory, field and used in models Laboratory observations Field observations Aircrafts popular on-bard instruments and fleets in different countries Polarization radar and Lidar Satellite (CERES,GOES) Integration experiments

3 Motivation Civil Aviation Administration (Taiwan) will release a Kingair 350 aircraft Cloud seeding proposal at Taiwan needs observation of cloud microphysics What is the linkage between the flight observation of cloud microphysics and cloud model simulations, or what are the major observed parameters that cloud models care?

4 Cloud microstructure parameters observed in Laboratory and Field Diameters (of raindrop,snow, hail) ---Lab./Field Size distribution--- Field Habit (shape vs. air temperature & RH) ) ---Lab./Field Growth rate---lab. Terminal velocity ---Lab. LWC,IWC,TWC --- Field

5 UCLA cloud tunnel (1960s) Flow tube condenser

6 UCLA

7 Germany Mainz vertical wind tunnel (Z tunnel) vacuum pumps ultra-sonic nozzle experimental section contraction section nets honeycombs particle filter plenum chamber heating/cooling humidifying/drying

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9 Desert Research Institute Chamber Hydrometeor Imaging Laboratory Ice Physics Laboratory No detail information released

10 Japan MRI cloud simulation chamber

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12 DRI Bailey and Hallett (2004)

13 Cloud physics in WISCDYMM Parameterizations linked with D,S,H,G,T information (page 4)

14 in-situ cloud measurements 1943/ open cockpit of a single engine reconnaissance Heinkel aircraft (Weickmann,1947) 1951/ ice particle image by camera from the aircraft (McCullough and Perkins, 1951) Formvar on a slice

15 Vediosonde with (tethered) balloon (Takahashi,1990) Tethered balloon Vediosonde

16 Meteorological balloon & PPIS TOGA/COARE(Takahashi,1995) Precipitation Particle Image Sensor (New version of vediosonde) Height Diameter temperature Number density

17 Family of PMI (particle metrics Inc.) optical array probe aerosol cloud raindrop FSSP

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19 Cloud particle Imager CPI (SPEC inc. ) Under the wingset or on the cabin roof

20 CPI data sample TRMM validation experiment 1999/08/19

21 NASA DC-8 NASA-ER2 pod NASA-WB57

22 DOE Gulfstream-1 CIRPAS ( the Center for Interdisciplinary Remotely Piloted Aircraft Studies ) Twin Otter

23 NSF/NCAR HIAPER High-performance Instrumented Airborne Platform for Environmental Research (March, 2005) Specific Pods under design

24 NSF/NCAR C130

25 University of North Dakota (UND) Cessana Citation II *Unfortunately, this aircraft was lost in 2005

26 University of Wyoming (UW) Kingair-200

27 South Dakota School of Mines & Technology--- T28 *The aircraft has been moved to the Strategic Air and Space Museum near Omaha, NE (2005)

28 Next generation for storm-penetrating airplane A10 Thunderbolt (after 2008)--- for continuing T28 missions

29 Deutsches Zentrum fü r Luft- und Raumfahrt e.v. (DLR) Donier 228 Falcon 20

30 Germany Helicopter-borne ACTOS (airborne cloud turbulence observing system) 200kg

31 UK-FAAM (Facility for Airborne Atmospheric Measurement) the Met Office(TM) and the Natural Environment Research Council (NERC) BAE-146

32 France SAFIRE Service des Avions Franç ais Instrumentés pour la Recherche en Environnement ATR-42 Falcon-20

33 Airborne Research Australia (ARA) is a Research Centre at Flinders University and Australia's National Research Aircraft Facility Grob G520T Egrett. Diamond Aircraft ECO-Dimona

34 Canada National Research Council CONVAIR-580 LWC/TWC probe LWC

35 Israel Cheyenne-II cloud physics aircraft

36 Japan Diamond Air service Gulfstream G-2 Cloud Radar

37 Best spot for airplane in-situ measurement Weather Modification Inc. (Lerjet)

38 UAV (Unmanned Aerial Vehicle)--Altair

39 Cloud particle imager UAV (Unmanned Aerial Vehicle) --Aerosonde + micro CPI

40 CSU-CHILL Doppler polarimetric radar (11cm) The coexistance of a wide variety of hydrometeor shapes and sizes within a radar pulse volume lowers the zero lag correlation between the H and V signal returns (RhoHV(0) Fig. 5 To a first approximation, the RhoHV(0)'s generally dropped below.92 near the perimeter of the enhanced LDR area. (Note: the RhoHV(0) values shown in the image have been multiplied by 10). These regions of low RhoHV(0) may indicate areas where the signal returns from the hail and rain precipitation components were approximately equal. Distrometer

41 NOAA P3 Cloud radar

42 UW W-band cloud Radar Weather-tight, liquid cooled enclosures. 1.5 kw peak power with pulse-to-pulse polarization agility on transmit. 80 W average pwer at Ka-band, up to 45 W average power at W-band. Two-channel receiver for simultaneous reception of orthogonal polarizations. Receiver LNA noise figures of 3 db at Ka-band, 4.5 db at W-band. PC-based digital receiver with real-time full spectrum processing.

43 Satellite remote sensing on cloud physics

44 AIRS/ 13km (at nadir) channels MODIS/ 250m (at nadir), 36 bands Effective cloud amount Effective cloud size Cloud classification (water/ice, low-level/high-level)

45 MODIS natural color MODIS classification mask ClrSfc Midcld Lowcld Lowcld Lowcld

46 polarization Lidar is used to estimate ice/raindrop shape. sky ER2 Lidar Lidar on ground

47 CALIPSO: Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation CloudSat and CALIPSO were launched into a 705-kilometer circular. fly just 15 seconds apart. This pairing sets a new standard in terms of precision placement of Earth-orbiting satellites. The reason for this is simple: both satellites will look at the same clouds in the atmosphere.

48 Cloudsat+ CLIPSO The Cloud Profiling Radar (CPR) 3D cloud strcture The Cloud Profiling Radar (CPR) is a 94-GHz nadir-looking radar which measures the power backscattered by clouds as a function of distance from the radar. The overall design of the CPR is simple, well understood, and has strong heritage from many cloud radars already in operation in ground-based and airborne applications. Most of the design parameters and subsystem configurations are nearly identical to those for the Airborne Cloud Radar, which has been flying on the NASA DC-8 aircraft since 1998.

49 CRYSTAL-FACE (Florida/ Key West, July,2002) The Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment Aircrafts used: NASA: ER-2 and WB-57 Northrop Grumman :Proteus CIRPAS :UV-18A, Twin Otter UND: Cessna Citation II NRL: P-3

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53 TWP-ICE (Tropical Warm Pool-International Cloud Experiment) Feb.,2006 (Darwin, Australia)

54 summaries Laboratory and airborne observations provide microstructure information of cloud Aircraft is a flexible and worldwide platform to provide information of aerosol/cloud/precipitation particles Small cloud Radar is under developed on aircraft and satellite Airborne polarization Lidar is used to estimate ice/raindrop shape. Ground Doppler/polarization Radar + distrometer on surface estimate the ice/raindrop shapes in air and collect raindrop size distribution on ground Integration experiments are necessary to combine different instruments/platform to observe the same cloud system