IRCTR - International Research Centre for Telecommunication and Radar ATMOS Ice crystals properties retrieval within ice and mixed-phase clouds using the Doppler polarimetric radar TARA. CSIP & COPS workshop 2009 Tuesday, October 27 th Y. Dufournet, C.M.H Unal, S. Placidi H.W.J Russchenberg

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 2 COPS status – TU Delft  Outlines :  Cloud microphysical Retrieval principle  Case study and main use of COPS facilities transmitterreceiver HHVV TARA 12 m  FMCW radar TARA - Located on Supersite H (Hornisgrinde) - measurements performed within:  ice or mixed-phase cloud (only the ice phase)  Precipitation (3.3 GHz – 10 cm)

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 3 Spectral polarimetric parameter - Principle Particles with different size, habit, orientation ≠ fall velocities, particle axis ratio 0 velocity Spectral reflectivity Doppler effect Polarimetric behavior radar + Spectral polarimetric parameters Isolate different group of particles

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 4 Microphysical retrieval : resulting parameters height time Polarimetric information Doppler information Radar cell  Numb. of particles types  Particle orientation  Particle habits  PSD for each particle type  radial wind, spectral broadening Assumption based Retrieved Parameters Forward model Detailed microphysical analysis

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 5 Measurement at a microphysical mode– 21/07/07 Precipitation Ice or mixed- phase cloud Melting layer Drizzle Boundary layer top Retrieval zone time height  Based on a retrieval technique !

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 6 Retrieval orientation and particle habit plates dendrites Mainly horizontal Mainly vertical No orientation No data Horizontally aligned plates (+ dendrites) and few aggregates Vertically aligned plates (+ dendrites) and few aggregates Strong aggregation Mainly aggregates and few plates orientation habits

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 7 Comparison particle habits  Radiosonde launch  ATR 42 flight Plate production region Cloud top region PMS 2D-C probes images

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 8 Retrieval PSD and ambient wind D0 agg. D0 pla. Nt agg. Nt pla. Vertical ambiant wind Obtained from modified gamma distribution Wind shear Convergence zone v0v0

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 9 Comparison PSD ATR 42 retrieved IWC Nt Good agreement

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 10 Cloud processes – possible explanation m.s -1 Mean vertical Doppler velocity from TARA Pristine ice prod. aggregation Orographic enhancement Strong updraft blocking area Only agg. precipitate Plates fully blocked v TARA = v particles

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 11 Main achievements using COPS data set microphysical retrieval: promising results on the cloud observation processes  assumptions tested and improved leading to good agreements when compared with other instruments 3D wind measurements: corrected and assessed with radiosondes measurements  within optically thick clouds and precipitation Conclusion What is next ? - Processing the remaining days - Full Assessment and validation of the microphysical retrieval

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 12 EarthCARE SIMulator - ECSIM Earth Cloud Aerosols Radiaton Explorer by ESA Launch date: 2013 EarthCARE mission end2end SIMulator – ECSIM Simulate all the 4 EarthCARE instruments and the satellite platform Model Atmosphere Model Atmosphere Forward Models Synthetic observations Synthetic observations Space-borne radar and lidar Ground-based / aircraft radar and lidar Satellite imager and broadband radiometer (Courtesy of Simone Placidi) cloud scene creation ( PSD, r eff, shape parameter, surface properties, cloud/aerosol information…) input from LES models, fractal cloud generator

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 13 Validation – assessment with ECSIM Microphysical data retrieved Comparison with COPS instrumentation (Courtesy of Simone Placidi) Optical Depth of original scene Simulated 94 GHz Radar Reflectivity (ground)‏ Synthetic observations

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 14 Thank you!

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 15 Example horizontal particle motion (COPS) Wind shear at 4000 m 10 days processed (Courtesy Christine Unal) 21 min averaged Observation of 3D particle motion at high resolution within ice/mixed-phase clouds and precipitation

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 16 EarthCARE SIMulator INPUT OUTPUTSIMULATIONS Cloud scene - Scene dimensions - Atmospheric properties - Surface properties - Clouds/aerosols info - Scattering regions - ext, LWC, Reff - Gamma / log- normal distribution - shape parameter - min/max value of Reff for DSD - From LES, CRM, fractal cloud generator Outputs - Radar Reflectivity - Lidar return/ extinction/ backscatter - COT - Reff – LWP - Fluxes Forward/Instruments models - ground - Radar (5GHz, 32Ghz, 94 GHz) - Lidar (0.353 nm) - Space: - Radar - Lidar - Multi Spectral Imager - Broadband radiometer

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 17 Radar measurement from TARA transmitterreceiver HHVV  Doppler and Polarimetric capabilities: - transmit and receive horizontally (H) or vertically (V)  change of the polarization state every 1ms: HH HV VV -Antennas at 45°  improve the polarimetric contrast  Other requirements for cloud observation: - High resolution  15 m range resolution  1 profile every 1.5 s - For mixed-phase clouds : at 3.3 Ghz, reflectivity of supercooled water droplets below the noise level – direct measurement of the ice crystals! TARA: Transportable Atmospheric RAdar (FMCW – S band) 12 m Spectral polarimetric parameter

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 18 Case study – 21/07/2007 (COPS – EUFAR) France Convective and Orographically-induced Precipitation Study Precipitation Ice or mixed- phase cloud Melting layer Drizzle Meteorological situation: Frontal activities and mesoscale convective system development with orographic inhancement Boundary layer top Retrieval zone Hornisgrinde Black Forest

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 19 Measurement type overview height time Polarimetric information Doppler information Radar cell Microphysical model  Simulated sZ DR (v) + sZ HH (v)  Numb. of particles types  Particle orientation  Particle habits Least square fit algorithm Signal improvement  PSD for each particle type  radial wind, spectral broadening Velocity Assumption based  Particle motion Cloud microphysical retrieval Mean Doppler velocity Doppler width

IRCTR - International Research Centre for Telecommunication and Radar ATMOS Delft University of Technology 20 Type of measurements height time Polarimetric information Doppler information Radar cell  Numb. of particles types  Particle orientation  Particle habits  PSD for each particle type  radial wind, spectral broadening Assumption based Wind mode : moment computation from 3 beams Microphysical mode : retrieval  Mean Doppler velocity  Doppler width Particle fall velocity, horizontal wind speed and direction