1. BBC2 Overview Scientific aims Atmospheric conditions Events

2. Scientific aims Measured three dimensional LWC fields for radiative transfer calculations –Victor Venema (Uni Bonn), Clemens Simmer (Uni. Bonn), Markus Quante (GKSS) Getting infrared images of cloud top and base with ground and aircraft based infrared imager –Jean-François Millot (CELAR) Error quantification of in-situ validation measurements for cloud retrievals with ground based remote sensing –Victor Venema (Uni Bonn), Clemens Simmer (Uni. Bonn), Markus Quante (GKSS) Scattering of radar waves by small scale cloud structures –Victor Venema (Uni Bon)

3. Microphysical cloud properties for correction algorithms of remote sensing data –Dagmar Nagel,(GKSS) Combining balloon-borne drop microphysical with aircraft and ground-based radiation measurements –Manfred Wendisch(Uni. Leipzi) Aircraft observations of solar radiation, turbulence and chemistry in shallow cumulus clouds –Han van Dop (IMAU), Keith M. Wilson (IMAU) Balloon-borne Lagrangian Study of the Indirect Aerosol Effect upon Cloud Microphysical Properties –Michael H Smith(Uni. Leeds) Validation of cloud parameter retrievals from MSG and AVHRR –Arnout Feijt (KNMI, Rob Roebeling (KNMI) Clear-sky shortwave radiation closure –Wouter Knap (KNMI), Piet Stammes (KNM)

4. Turbulent structure of the convective boundary layer including the entrainment zone –Fred Bosveld (KNMI), Henk Klein Baltink (KNMI), Cindy Werner G&NS), Jordi Vila WUR), Eddy Moors (WUR), Alex Vermeulen (ECN) Quality of Water Vapour Profiles and Boundary layer height observations –Iwan Holleman (KNMI), Sylvia Balag (KNMI) Validation of combined lidar and radar derived Ice Cloud radiative and micophysical properties. –Dave Donovan (KNMI) Occurance of oriented ice crystals. –Dave Donovan (KNMI), S. Crewell (Uni. Bonn) Rain –Remco Uijlenhoet (WUR) Cloud microphysics and radiation –Frederique Parol (Uni Lille)

5. Validation of cloud and aerosol data products from SCIAMACHY –Piet Stammes (KNMI), Juan Acarreta (KNMI) Entrainment in cumulus clouds –A. Pier Siebesma (KNMI), Stephan de Roode (IMAU) Evaluating Statistical Cloud Schemes –A. Pier Siebesma (KNMI) Trigger Function of Cumulus Convection –A. Pier Siebesma (KNMI) Top-Entrainment of the (Clear and) Scu topped boundary Layer –A. Pier Siebesma (KNMI) Measurements of aerosol particle size distributions and lidar profiles during BBC2 –Gerrit de Leeuw (TNO-FEL)

6. Scientific aims Cloud measuring techniques (ground based and satellite) Cloud-radiation interactions Cloud free radiative transfer Cloud process studies (atmospheric modeling, precipitation)

7. Scientific aims Focus aircraft flights –Water clouds with no cirrus on top stratified cumuli > 5 octa’s –Cloud free conditions

8. Overview Atmospheric Conditions BBC2

9. Front 2km = 0 o C Front Cirrus shield Front Cloud free Cirrus shield Clear Trailing cirrus Cu Cu 5+ Subsidence inversion

10. name: Erik van Meijgaard date: 2003-05-08 06:24 UTC Situation and Forecast for Thursday May 8th A rather inactive cold front is approaching from Britain and is expected to cross the Netherlands the coming night. High clouds associated with the front are currently over the North Sea touching North Holland but have a tendency to move NE. A warm front regenerated from an earlier frontal zone over Central Europe is moving NNE across France. Scattered thin cirrus associated with this front is already over the south east of the Netherlands.

11. Front Cu 5+ Front Subsidence inversion Unstable air showers Unstable air BBC Unstable air Front Unstable air Front Unstable air StCuClear Cu Old StCu Cu

12. Unstable air Cu in unstable air Unstable air Front StCu M

13. 2km = 0 o C Cloud free ClearCu Cu 5+ Subsidence inversion M: testD: test D M P: 8-9:309 May event

14. Communicating with the press Communicating with high level in the ministry Have a social event for Rotterdam/Cabauw/De Bilt 9 May Event at Cabauw

15. 9 May event

16. Cu 5+ Unstable air StCuClear Cu Old StCu Cu D M P D P: 10-12P D M P M: NS-CabauwScience Meeting De Bilt

17. Cu in unstable air Cu StCu M P: NS-Cabauw M M Science Meeting Cabauw BBC2 - BBQ

19. Summary We were very lucky with the weather (good choice …) We had magnificant support from outside –Meteorologist (FP, De Bilt, Rotterdam) –Air trafic control (Schiphol and the Army) –Army for radiosonde launches, security, radiocar We have a great set of measurements comparible to the ARM-site data sets that should be brought into an easily accessible data base

20. Summary To make the efforts worthwhile –We should do the research we planned ++ –The actual research has only started Outlook –We are bound to meet again in the next few years