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