1. COPS Workshop, 27-29 February 2008 Long-term water vapour comparison at the ARM Mobile Facility S. Crewell, U. Löhnert, S. Kneifel (U Cologne) D. Turner (U Wisconsin)

2. COPS Workshop, 27-29 February 2008 Instrumentation at AMF  Radiosondes  IfT Lidar  Microwave Radiometers - MWRP 12ch. - HATPRO - Scanning (Köln) - MWRLOS 2ch. - MWRHF - DPR  GPS Vertical profiles MWRP MWRLOS MWRHF HATPRO DPHASE Integrated Water Vapor (IWV)

3. COPS Workshop, 27-29 February 2008 Data Set SourceOrg.Description tt Operation COSMO-DEDWDModel analysis/fore-cast at 3x3 gpoints 15 min04/01-12/ 31 RS-92ARMRadiosonde profiles 919 quality checked 4 / day04/01-12/ 31 GPSGFZ15 min, 93%15 min04/19-12/31 2CHARMStandard ARM dual channel radiometer 20 s04/01 - 12/31 MWRPARM12 freqs1 s04/01 - 12/31 MWRHFARM90/150 GHz1 s06/20-12/31 HATPROUKölnscanning 14 freqs04/20-12/31 DPRUKölndual pol at 150 GHz1s05/02-10/05 LidarIfTRamanCOPS MSGFUBIWV 3x3 grid15 min04/01-12/31

4. COPS Workshop, 27-29 February 2008 Microwave Signatures standard atmosphere liquid water path LWP=250 gm -2 temperature profile humidity profile ν / GHz 313690 90°91250

5. COPS Workshop, 27-29 February 2008 TB Intercomparison Difference in gas absorption from MonoRTM - Rosenkranz 22 GHz water vapor line continuum at higher freqs

6. COPS Workshop, 27-29 February 2008 Water vapour during COPS Water on Radome

7. COPS Workshop, 27-29 February 2008 Water vapour during COPS 15 min values new best estimate by D. Turner

8. COPS Workshop, 27-29 February 2008 Water vapour during COPS agreement between GPS and microwave is worse compared to other sites

9. COPS Workshop, 27-29 February 2008 Radiosonde intercomparison Only 12 UTC launches G

10. COPS Workshop, 27-29 February 2008 Radiosonde Dry Bias 0 UTC6 UTC12 UTC18 UTCAll N61666865263 RS - GPS0.3 1.1-0.1 0.8-1.5 1.3-0.3 0.8-0.4 1.2 RS - Profiler0.0 0.8-0.7 0.7-1.0 0.7-0.4 0.6-0.5 0.8 RS - 2 ch0.2 0.5-0.5 0.6-1.4 0.9-0.6 0.6-0.6 0.9 AMF April to June Bias/Std. Deviation in Integrated Water Vapor in kg m -2

11. COPS Workshop, 27-29 February 2008 Scanning Microwave Observations COPS: Azimuth scans every 15 min - fixed elevation angle (30°) - 355°- rotation with 5° resolution - beamwidth: HATPRO: ~4-2°, IR: ~1° - scan duration about 5 Min. Integrated Water Vapor (IWV), liquid water path (LWP) and IR-Temperatur along slant path for each azimuth angle

12. COPS Workshop, 27-29 February 2008 Exmple: 14 July 2007 30 deg azimuth scans  Morning strong asymmetry of the humidity field  Noon strong humidity reduction of about 5 kgm -2 (in zenith)  13:00-14:30 UTC Convection in the North West  after 15:00 humidity increase see Poster by S. Kneifel

13. COPS Workshop, 27-29 February 2008 Summary and Outlook  Water vapour absorption Poorly known at higher microwave frequencies  calibration analysis  Integrated Water Vapor  consistent analysis of all COPS microwave radiometers (calibration, filtering, quality flags, retrieval algorithms..)  Profiles  intercomparisons with IfT Lidar, DLR aircraft lidar  Spatial variabiity More than 10 % variabilty in IWV (see Poster by Kneifel  further analysis of volume scans