Objectives of the Working Group
The GCSS (GEWEX Cloud System Study) Boundary Layer Cloud Working Group aims to improve physical parameterizations of clouds and cloud related processes, and their interactions. We conduct careful intercomparisons between observational or laboratory case studies, 3D large-eddy-simulation models, single-column-model (SCM) versions of climate and numerical weather prediction (NWP) models of cloud-topped boundary layers. Most of the leading groups modelling boundary layer clouds have participated in our annual workshops, held every 12-18 months. The BLCWG is currently chaired by Adrian Lock of the Met Office, UK.
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Recent announcements
| 30th March | Provisional date for next Pan-GCSS meeting is 2-6 June at Meteo-France in Toulouse, France |
Current GCSS BLCWG activities
Precipitating trade cumulus off Antigua during RICO.
- Case coordinators: Margreet van Zanten (LES) and A. Pier Siebesma (SCM) of KNMI. Case specifications. Initial submissions were due 1 September 2006. A revised case specification will be released in October 2006 and new submissions are welcome.
- All presentations from GCSS/GPCI/RICO workshop at GISS, NYC, Sept. 2006, including preliminary results from RICO case and RICO observational presentations.
Controlled Microphysics Case
- As an outcome of the DYCOMS RF02 nocturnal drizzling stratocumulus intercomparison case there is a strong need for a simple case that can evaluate microphysics schemes used in GCM’s in isolation as to disentangle errors due to dynamics and errors due to microphysics. The actual construction for such a case is still under debate.
- Contact Person: Ulrike Lohmann of the Institute for Atmospheric and Climate Science, Switzerland
Related links to current GEWEX activities
- GABLS (the GEWEX Atmospheric Boundary Layer Study), whose mission is to coordinate research on boundary layer physics to improve the representation of the atmospheric boundary layer in numerical models.
- GPCI (the GCSS Pacific Cross-Section Intercomparison), which is comparing the observed thermodynamic structure and clouds along a vertical cross-section from the California coast to the central Pacific ITCZ during July 1998 and 2003 with simulations from regional and global simulations.
- An Ad Hoc activitity called DIME has the goal to provide “test kits” for model evaluation based on the GCSS Model Intercomparison Projects, including detailed results from the participating Cloud Resolving Models. William Rossow, NASA, GISS, is the chairperson.