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The Wyoming King Air and Mixed-Phase Clouds

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The Wyoming King Air and Mixed-Phase Clouds The Wyoming King Air and Mixed-Phase Clouds Zhien Wang University of Wyoming University Wyoming King Air A part of USA NSF low atmospheric facility since 1987 Examples of N2UW missions •BL Studies •Turbulence Studies •Satellite Validation •Cloud Physics & •Aerosol Studies •Airborne Remote Dynamics Sensing •Air/Sea Interaction •Radiative Fluxes & •Air Pollution Forcing •Air Chemistry •Tropospheric Profiling University Wyoming King Air A unique platform for Cloud Study Provide extended cloud microphysical properties for GVR WCR cloud physics study 2D-C • Remote sensors LWC 100 WCL-I – Cloud radar – Cloud lidar WCL-II – Microwave radiometer • In situ sensors – Aerosol – Cloud – H2O,CO2 Cloud Property Retrieval Algorithms Ice clouds Water Clouds Mixed-phase clouds IWC LWC, effective IWC and D for ice Retrieval ge Properties and General radius (reff), and phase effective radius drizzle flux LWC and reff for water (Dge) phase Lidar input Extinction Extinction Extinction Depolarization ratio Radar input Radar reflectivity Radar reflectivity Radar reflectivity or and Doppler Doppler spectrum velocity Radiometer LWP LWP References Wang and Sassen 2002; Sassen et al. 2000; Wang and Sassen 2001; Wang Comstock et al. 2007; Wang 2007; Turner et 2007; Wang et al. 2004, Wang Deng et al. 2010. al. 2007 and Zhao 2007 High Occurrence of possible mixed- phase clouds Possible mixed-phase: Tbase > -38 C and Ttop < 0 C All ICE phase - Water Possible mixed Possible The Importance of Mixed-phase Cloud Representation in GCMs • Contribution to cloud feedback uncertainty in GCMs. Net LW SW The spread of TOA cloud forcing changes among 17 AR4 coupled GCMs Cloud phase Distribution Mixed Ice Water December-January-February Cloud-phase Dependent and Regional Inter-model CRF Spread JJA Mean Net CRF MAM Net CRF STD Example of Ground-based Mixed-phase Cloud Retrieval Inputs MMCR MPL Outputs Water Phase Ice Phase Mixed-phase clouds observed at the Barrow site on 10 October 2004 by combining Radar (MMCR), Lidar (MPL), MWR, and radiosonde data. Cloud top temperature ~ -13.3 °C. - Wang and Zhao, 2007 WCR • “3”-D cloud structure • Cloud scale dynamics Wyoming Cloud Lidar (WCL) • A simple elastic lidar with depolarization measurements • Working together with the WCR to improved cloud microphysical property profiles • 355 or 351 nm laser– eye safe Receiver • The nearest usable bin: ~15 m • First deployed on NCAR C-130 2007 during Optics Transmitting ICE-L Lidar Radar GVR • A G-band (183 GHz) water Vapor Radiometer (GVR) from ProSensing Inc. • Four double-sideband receiver channels, centered at 183.31 ±1, 3 and 7, and 14 GHz • Operate from a standard 2-D PMS probe canister • Provide precipitable Water Vapor (PWV) and Liquid Water Path (LWP) up to 20 Hz But It is not available now ! Wyoming King Air Observation Example WCR WCL 2-DC FSSP PCASP GVR LWP Airborne Observation Example of Wave Clouds Leg1 Radar reflectivity Leg2 Radar reflectivity Doppler velocity Doppler velocity Lidar Backscatter Lidar Backscatter Lidar depolarization Lidar depolarization 2DC N(D) Ice 2DC N(D) Ice FSSP N(D) Liquid FSSP N(D) Liquid PCASP N(D) Aerosol PCASP N(D) Aerosol Time Time Heterogeneous and homogeneous ice nucleation cases -31°C at the flight level -41°C at the flight level Ice Microphysical Property Retrieval and Validation STORMVEx/CAMPS 02/17/2011 Mean Ratio= 1.09 Radar Lidar Power Lidar Dep. Extinction IWC CLH, L-R at 30 m We lack LWP measurements to characterize liquid phase! Stratiform Mixed-phase Clouds As Natural Targets to Study Ice Generation • Simple cloud dynamics. • Known thermodynamical environments. • Predicable ice growth history. • High occurrence From Maximum Ze to Nice C) ° C) ° CTT( CTT( Ze_max (dBZ) Ze_max (dBZ) Modeled Z with 1/L ice e Observed Ze concentration ? Ice concentration in stratiform clouds globally! Comparison between Retrievals and In Situ Measurements Upward and Downward Radar Upward and Downward Lidar Lidar Collocated Airborne remote sensing and in situ measurements offer an effective way to evaluate the approach A Global View of Dust Impact on Ice Generation • Dust has up to factor 7 impacts on ice generation in stratiform mixed-phase clouds. • Need to link Ice concentration with aerosol properties to improve parameterization Summary • We have excellent airborne remote sensing capabilities for mixed-phase cloud study. • But reliable and fast responding LWP measurements are still missing. • Other efforts to improve King Air (for other NSF aircraft too) remote sensing capabilities In Wyoming —Could be good synergies with microwave radiometer measurements . New King Air Remote Sensing Capabilities Compact Raman Lidar Raman lidar Dry-line Structure Integrated Lidar Design New King Air Remote Sensing Capabilities Multi-function Airborne Raman Lidar • Profile water vapor, aerosol/cloud, and temperature simultaneously. Applications 1. Boundary layer structure 2. Cold pool development 3. Entrainment and detrainment 4. Air-sea interactions 5. … Funded by NSF MRI 2013 New King Air Remote Sensing Capabilities Ka-band Precipitation Radar (PMS mounted) Funded by NASA, Being built by ProSensng .
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