Remote-sensing of the environment (RSE) ATMOS Analysis of the Composition of Clouds with Extended Polarization Techniques L. Pfitzenmaier, H. Russchenbergs group (TU Delft) TROPOS, Germany KNMI METEK, Germany

ATMOS Delft University of Technology 2 Remote-sensing of the environment (RSE) Ice particle within mixed-phase clouds  growth processes(L. Pfitzenmaier, TU Delft)  shape categorisation(A. Myagkov, TROPOS, Germany) Why? Process important for precipitation formation Gap between theory and observations of those processes/clouds Improve mixed-phase cloud observations  Measuring in Cabauw Motivation < 0 ⁰C > 0 ⁰C

ATMOS Delft University of Technology 3 Remote-sensing of the environment (RSE) Ice crystals Shape: not spherical Pristine ice crystals Aggregates Graupel Phase: solid Size: mm – cm Lower concentration  < 100 cm -3 Super cooled cloud droplets Shape: spherical Phase: Liquid Size: ~ 10 mm High concentration  100 – 1000 cm -3 Microphysical description of mixed-phase clouds Liquid phase & ice crystals Mixed phase clouds: Mid-level clouds (~3 – 7 km) -40 ⁰ C < Temperature < 0 ⁰

ATMOS Delft University of Technology 4 Remote-sensing of the environment (RSE) Ice crystals Shape: not spherical Pristine ice crystals Aggregates Graupel Phase: solid Size: mm – cm Lower concentration  < 100 cm -3 Super cooled cloud droplets Shape: spherical Phase: Liquid Size: ~ 10 mm High concentration  100 – 1000 cm -3 Microphysical description of mixed-phase clouds Liquid phase & ice crystals Mixed phase clouds: Mid-level clouds (~3 – 7 km) -40 ⁰ C < Temperature < 0 ⁰  Synergy of instruments to measure the whole cloud system

ATMOS Delft University of Technology 5 Remote-sensing of the environment (RSE) Why Cabauw..? Instrumentation at Cabauw: TARA  ice phase & growth categorization processes CAELI  liquid layer detection Cloud radar  ice and liquid Radiometer  liquid layer Wind profiler  vertical dynamic (Doppler spectra?)

ATMOS Delft University of Technology 6 Remote-sensing of the environment (RSE) Transportable Atmospheric Radar – TARA S-band profiler: f=3.298 GHz, =9.09 cm (Rayleigh-scattering) Fully polarimetric  Shape/orientation of particles Doppler capability  Velocity of hydrometeors High temporal (> 3.5 s) and spatial resolution (> 3 m)  small scale processes Sensitive to large hydrometeors (size) Precipitation (drizzle, rain, snow, hail) Ice crystals NOT TO CLOUD DROPLETS (~10  m)  Direct measurement of the ice phase  Use of a second instrument to get information about the liquid phase

ATMOS Delft University of Technology 7 Remote-sensing of the environment (RSE) CESAR cloud, aerosol, and water vapour liadr - CAELLI 3 wavelength Raman lidar 1064 nm, 532 nm, 355nm – 2 Raman channels: 387 nm and 607 nm Water vapor channel 407 nm Depolarization channel 532 nm extinction coefficient backscatter coefficient depolarization ratio High special resolution (7.5 m) Sensitive to small particles Aersols Cloud droplets  Information about liquid water layers within mixed phase clouds

ATMOS Delft University of Technology 8 Remote-sensing of the environment (RSE) Raman Lidar – CAELI  Sensitive to particle concentration Radar – TARA  Sensitive to particle size Measurement set up Cabauw  : extinction coefficient n(r) : droplet number concentration r : droplet radius Z : reflectivity Donovan and Lammeren, 2001 Y. Dufournet PhD Thesis Microwave radiometer  Gives values of the liquid water path (LWP)  the amount of liquid water present in the cloud system

ATMOS Delft University of Technology 9 Remote-sensing of the environment (RSE) Why Cabauw..? Instrumentation at Cabauw: TARA  ice phase & growth categorization processes CAELI  liquid layer detection Cloud radar  ice and liquid Radiometer  liquid layer Wind profiler  vertical dynamic (Doppler spectra?)  LACROS (Leipzig Aerosol and Cloud Observations System)  More information on the liquid phase Founded by ACTRIS-TNA and TROPOS More instruments needed

ATMOS Delft University of Technology 10 Remote-sensing of the environment (RSE) Leipzig Aerosol and Cloud Observations System - LACROS Cloud radar – Mira 35 STAR mode  scanning  shape categorization of ice particles  scanning strategy  liquid phase information Microwave radiometer  liquid phase information Ceilometer  Cloud base Distrometer  Rain droplet sizes Raman lidar – PollyXT (of zenith pointing)  liquid layer detection  runs automatically – 24/7 Doppler lidar  analyze the dynamic at cloud base Cloud radar – Mira35  vertical pointing  Comparison with other radars Radiosounds Aircraft...? TARA Caeli MWR Doppler- lidar LACROS Mira35

ATMOS Delft University of Technology 11 Remote-sensing of the environment (RSE) Goals of ACCEPT Categorization of the ice phase in mixed-phase clouds characterize of ice particle growth processes testing the Mira35 STAR mode radar Comparison of radar measurements comparison of particle shape measurements TARA and Mira35-STAR mode sensitivity studies Cloud measurements with CAELI compare with Polly XT measurements Creating a data set where also other studies could be done  Open data base  More about scientific work  Poster

Remote-sensing of the environment (RSE) ATMOS TARA – S-band precipitation radar CAELI – Raman lidar Wind profiler Cloud radar - KNMI Mira35 – STAR mode cloud radar Mira35 – LDA mode cloud radar PollyXT – Raman lidar Doppler lidar Microwave radiometer Distrometer Ceilometer Radiosounds date: 6-10 – Information about campaign: open data base o more radiosounds…? o Interested...? Contact us