Radar-lidar synergy for the retrieval of water cloud parameters Herman Russchenberg, Oleg Krasnov February 25, 2019 International Research Centre for Telecommunication and Radar

Ground based observations radar lidar radiometry February 25, 2019

Dropsize distribution Very sensitive to tail of dsd Are power laws useful? Dropsize distribution Very sensitive to tail of dsd February 25, 2019

Common opinion: No, there is too much scatter due to drizzle unless we can identify the drizzle droplets somehow... February 25, 2019

drizzle “transition” drizzle non-drizzling A million droplets of 10 micron give the same radar reflection as one droplet of 100 micron! A million droplets of 10 micron contain a thousand times as much water as one one droplet of 100 micron... And so: one drizzle droplet changes the reflectivity significantly without changing the liquid water content non-drizzling February 25, 2019

Radar reflection Drizzling Non-drizzling Coarse classification February 25, 2019

Radar and lidar observables in relation to microphysics of water clouds Radar-lidar ratio vs effective radius Radar reflectivity vs liquid water content February 25, 2019

Example: June 19, 2003, Chilbolton February 25, 2019

February 25, 2019

February 25, 2019

Statistics of cloud types, Cabauw 7.9 % 27.1 % 65.0 % February 25, 2019

Statistics of cloud types, Chilbolton 9.3 % 29.3 % 61.4 % February 25, 2019

Statistics of cloud types, Palaiseau 8.7 % 27.8 % 63.5 % February 25, 2019

Statistics of cloud types, all sites 8.7 % 27.8 % 63.5 % -35 dBZ -20 dBZ February 25, 2019

Climatology or calibration? Site-specific thresholds Averaged CloudNet thresholds February 25, 2019

February 25, 2019

After filtration out values of both LWP > 400 g/m^2 The difference between the radar/lidar LWP retrievals and microwave radiometer After filtration out values of both LWP > 400 g/m^2 February 25, 2019

The comparative statistic for the Cloudnet LWP datasets February 25, 2019

observations February 25, 2019

The difference between the Radar/lidar retrievals and ECMWF NWPM LWP After filtration out values of both LWP > 400 g/m^2 February 25, 2019

February 25, 2019

Outlook Refine statistics Refine thresholds Application to ARM data Apply to CloudSat – Calipso Combine with IPT February 25, 2019