1. 1 H.W.J Russchenberg 1, C.L. Brandau 1, U. Loehnert 2 and K. Ebell 2 (1) International Research Centre for Telecommunication and Radar (IRCTR), Delft Technical University, The Netherlands (2) Institute for Meteorology and Geophysics, University of Cologne, Cologne, Germany Liquid water clouds in the Murg-valley

2. 2 Cloud Radar Microwave Radiometer Cloud radar based retrievals of liquid water content (LWC): Directly: simultaneous measurements of LWC and Z: Fox/Illingworth JPM 1997 In-situ observations Evaluation:

3. 3 Stratocumulus, Murg Valley Radar reflectivity Vertical velocity Spectral width Liquid water path

4. 4 One hour standard deviation vertical speed

5. 5 Link with liquid water path

6. 6 Some cloud statistics, Murg Valley

7. 7 Radar data analysis: approach, 1 ? Z LWC Comparison of independent techniques

8. 8 Radar data analysis: approach, 2 ? Z LWC Suppose: Which Z-LWC fits the equation?

9. 9 Case study: 26 October 2007, COPS LWP(radar)-LWP(radiometer)

10. 10 Case study: 26 October 2007, COPS Required Z-LWC relationships

11. 11 Evaluation of radar-based LWC retrieval in the Murg-valley from April-December single layer, cloud droplets only, LWP(max)=700gm-2, geometrical thickness(min)=2 radar bins (90m), broken clouds included Radar discrepancy

12. 12 Analysis of cloud structure increase of H results in a greater deviation from LWP(MWR) Effect on the derived LWP from radar-based Z-LWC relationships

13. 13 M M SOP2: 21/07/2007 M M Combination of different scales LWC in-situ (PVM) Radar reflectivity of 5 height bins due to changes in flight level Z > -50 Z < -17 no drizzle Is it always the case?

14. 14 Z-LWC relationship from in-situ data: SOP2: 21/07/2007 Z-LWC relationship from Fox/Illingworth and Atlas reproduces (albeit not perfect) radar observation on the ground

15. 15 Concluding remarks The observed reflectivity of stratocumulus tends to be less than expected We are looking for aerosol data Be careful with aircraft measurements