1. Cabauw Experimental Site for Atmospheric Research - CESAR - Henk Klein Baltink Atmospheric Research Section

2. 27 may 2002Cloudnet Workshop Paris2 Outline Overview Instruments at Cabauw Status 35 GHz Cloud Radar examples from BBC-campaign

3. 27 may 2002Cloudnet Workshop Paris3 CESAR (Cabauw) Objective: to set-up and operate at the Cabauw site an observational facility with a comprehensive set of remote sensing and in-situ equipment to characterize the state of the atmosphere, its radiative properties and interaction with the land surface, for the study of physical processes, climate monitoring, and validation studies

4. 27 may 2002Cloudnet Workshop Paris4 Remote Sensing Site Profiler Sonic GPS Cabauw Tower

5. 27 may 2002Cloudnet Workshop Paris5 Status May 2002 (1) Tower (10, 20, 40, 80, 140, 200 m agl): wind speed, direction, temp, dew temp (temp also at 0.6,1.6 m) turbulent fluxes at 180 m. (in progress) particle counters (in progress) Surface: incoming/outgoing short & longwave radiation (BSRN in 20??) rain rate and duration DSD (in progress) soil temp. & hum. turbulent fluxes (at 4.5 m and 1 m. agl)

6. 27 may 2002Cloudnet Workshop Paris6 Status May 2002 (2) Remote Sensing (passive) IR-radiometers microwave radiometer (Univ.-Bonn, until ?) Remote Sensing (active) 1290 MHz windprofiler/RASS 3.3 GHz FM-CW radar (TARA) 35 GHz Cloud Radar ceilometers (CT75,LD40) 1042 nm lidar GPS-receiver

7. 27 may 2002Cloudnet Workshop Paris7 KNMI 35 GHz Radar CT75 ceilometer Heimann IR-radiometers Video camera

8. 27 may 2002Cloudnet Workshop Paris8 peak power 100 W (TWT transmitter) polarisation capability on receive spectral processing pulse-coding to enhance sensitivity 1.8 m antenna (0.36º beam angle) flexible parameter setting via GUI automated, unattended operation Main Characteristics 35 GHz

9. 27 may 2002Cloudnet Workshop Paris9 Status 35 GHz Cloud Radar In continuous operation since August 2001 2 week interrupt due to hardware failure (August) some minor software interrupts up to November no calibration and X-pol. (mid January - mid March) power output decreased by  10% since August absolute values not reliable when water on shroud plan 2002: upgrade DSP-board, fast V-H switch

10. 27 may 2002Cloudnet Workshop Paris10 Acquisition cycle 0 5000 10000 20 s BBC 16 s PRESENT acquisition processing uncoded coded coded X-pol

11. 27 may 2002Cloudnet Workshop Paris11 Sensitivity 2 modes: - 8-bit code (red) - uncoded (black) ARM-SGP mode 2 -54 dBZe @ 5 km -42 dBZe @ 5 km

12. 27 may 2002Cloudnet Workshop Paris12 Examples from BBC-campaign TARA 35 GHz MIRACLE MICCY

13. 27 may 2002Cloudnet Workshop Paris13 Ice Cloud Reflectivity Vertical Velocity

14. 27 may 2002Cloudnet Workshop Paris14 Water Cloud

15. 27 may 2002Cloudnet Workshop Paris15 35 GHz vs. TARA in rain -70 -60 -50 -40 -30 -20 -10 0 Minutes after start time (00:48:04) Height [m] KNMI, 19 Sep 2001 1020304050607080 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 -70 -60 -50 -40 -30 -20 -10 0 Minutes after start time (00:48:04) Height [m] TARA, 19 Sep 2001 10203040506070 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Before rain event: good agreement -30 -20 -10 0 10 20 30 Time [min] Height [m] 35GHz radar 0306090120150180210 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 -30 -20 -10 0 10 20 30 Time [min] Height [m] 3.3GHz radar 306090120150180210 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 During rain event: 20 – 30 dB difference 205080110140170200230 -40 -30 -20 -10 0 10 20 30 40 Comparison between TARA and KNMI (Height: 2240m) Minutes (start time: 05:09UTC) Reflectivity factor (dBZ) KNMI TARA Onset of precipitation at surface

16. 27 may 2002Cloudnet Workshop Paris16 Model comparison BBC 18/9/01

17. 27 may 2002Cloudnet Workshop Paris17 Cloud Boundaries? super cooled layer

18. 27 may 2002Cloudnet Workshop Paris18 Ceilometer Courtesy of Hannelore Bloemink, KNMI

19. 27 may 2002Cloudnet Workshop Paris19 Spectra at 17:15 super cooled layer noise snr signal

20. 27 may 2002Cloudnet Workshop Paris20 Outlook (to do) Optimize acquisition cycle Calibration procedure (is it accurate enough?) Mode-intercomparison and merging Water on shroud: no easy solution(?) Analysis of (all that) data