From SUMMARY OF PROGRESS AND MAIN ACTIONS/RECOMMENDATIONS FROM THE EIGHTH MEETING OF THE GEWEX CLOUD SYSTEM STUDY (GCSS) SCIENCE TEAM
 

Working Group-4 Action List

(a) It was agreed that the results of the work that had been undertaken by WG4 from both WG-4 Case 1 (TOGA COARE, based squall line case) and Case 2, which utilized data from the TOGA COARE Intensive Flux Array (IFA) in a model evaluation exercise, should both be cited for significantly improving the scientific benefit of the CRM/Cloud Physics component of TOGA-COARE. The work by WG1 in conjunction with the TOGA-COARE cases was also acknowledged. The action is to insure these cases are documented and the data sets developed for the analyses are preserved for future applications. Connection with DIME (see below) is necessary to complete this action.

(b) The experience gained in the context of the GCSS test cases utilizing TOGA-COARE data should be specifically documented. The findings uniquely associated with these data sets should form the basis for a specific statement as to the appropriate methodology for conducting other studies with this data and a discussion of what additional possible benefits could accrue from such analyses, if any. The WG4 Chair will provide such a statement in 2000.

(c) Work should proceed, in 2000 with development of an idealized diurnal cycle case over land.

(d) Prescription of surface fluxes should be instituted in test case runs so that there can be a more realistic coupling with land surface schemes in larger scale models.

(e) WG4 Case 3 may be enhanced with support from DIME and this link should be established in 2000. This case is a continental deep convection case drawn from data taken at the ARM Southern Great Plains experimental site during July 1997 (Leaders: Steve Krueger and Kuan-Man Xu). Specialized instrumentation including a millimeter cloud radar (MMCR) and an extensive array of other meteorological instruments were operational at that time. This case will be done in collaboration with the ARM Single Column Modelling Group as a means of involving more of the SCM community to participate in the process and to gain support of the ARM Data and Science Integration Team (DIST) in the provision of forcing data and the compilation of results submitted by the modelling groups.

DIME will be able to lend expertise and resources to develop the necessary data sets and, in addition, to format them for other studies.

(f) At the breakout session on the view of GCSS within the context of larger scale modelling and prediction concerns, it was noted that the form of the initiatives within WG4 should shift to "parallel processing" of various studies (undertaken individually). There was agreement that the issues of importance, from the NWP/GCM perspective, included the need for more microphysical complexity, convection over land/diurnal cycle as referenced in Item (c) above, a representation of convection at a horizontal resolution of 5 to 10 km and how to represent mesoscale organization of convection.

 GCSS "Ad Hoc" Data Integration for Model Evaluation (DIME) Effort

More work is required on plans to make all GCSS test case study data sets available to other groups and to the scientific community at large. An effort to form an "ad hoc" Data Integration for Model Evaluation (DIME) Effort working group has advanced and resources are now available at the Goddard Institute of Space Science (GISS), to undertake the collection, cataloguing, critique and dissemination of specific GCSS case study datasets. This concept is being investigated as a possible joint initiative with the GRP and the GEWEX Hydrometeorolgy Panel (GHP) where related data set development activities could benefit from a focused data integration activity. The plans for initiating such an effort were discussed and action is being undertaken by the Working Group Chairs to benefit from the availability of these resources for the organization of appropriate test case data sets. Further progress on this
proposal will be reported at the next GCSS meeting.