Jon Petch 26th July 2004 -------------------------- Meeting: GCSSWG4 members present at ICCP Date: Wednesday 21st July 2004 Time: 1730-1930 Introduction ------------ This is a brief summary (informal minutes) of the meeting of GCSS WG4 members present at ICCP 2004 in Bologna, Italy. About 12 people attended the meeting and a good discussion was had. Presentations ------------- Jon Petch presented an outline of a proposed new case which is focused on the transition of tropical convection. This talk is available for all to see on the WG 4 web site (www.convection.info). Chris Bretherton presented a discussion of an RCE or modified RCE case he is planning. This may be on the web site too. This case will involve some members of WG4 as funded participants and others are invited to become involved. Marat Khairoutdinov presented some amazing pictures from a very high resolution 3D simulation from the LBA case (case 4). Sadly there was limited time for this so I hope he can show more at our next meeting. Discussions/Actions ------------------- Steve Krueger questioned what the drift in T & q was in the new case. Jon Petch to look at drift of T and q in new case. Steve Krueger offered to work with Steve Woolnough in putting together some observations. Jon Petch to initiate this. It was agreed than on the whole 3D should be encouraged along with a resolution of 500 m. Ideally it would be nice to have a basic run of 2D and 500m and say 500 points which is quick and the same between different runs. There was general discussion of whether another period or more should be added. This makes sense as the current one may (TBC) be when the ships were on their holidays. Also, it might be nice to see how representative the case is. Finally it could be good to have the Case 2 repeated. These can all be considered. Marat questioned using DT and Dq due to vertical advection rather than w. There was no general agreement on this. Perhaps someone (Marat?) could do a sensitivity study on this. There was a general discussion of whether to use Zhang data. This again was undecided. We need to decide based on if we have time. Could consider adding additional case which used this data. Adrian Tompkins suggested a sensitivity experiment to what was suppressing the convection should be considered. He also suggested we look at the large scale during this period to check this was not a very localized suppression and was part of the MJO. Issues linked to differing surface fluxes was raised. Should we all use the same algorithm. Would need to provide this if this was decided. Marat suggested we should use ISCCP simulator code so models could submit this data. Steve Krueger will send me the paper where he has done this and can discuss this with Steve too. Actions ------- 1. Go ahead with current case but add new periods (if possible one of which should used Zhang data) - Jon Petch/Steve Woolnough to look for suitable new periods - 1 period similar to current one 2. Steve Krueger to work with Steve Woolnough to pull together more observations. 3. Agreed to have a quick 2D run along with a recommendation for 3D and 500m or better grid length. This will be up to participants though. 4. Add a link to find ISCCP simulator to case when it is ready. 5. Consider also adding a specified surface flux algorithm.