Intercomparison - Newsletter, October 2000

October 2000

In the last SEAFLUX email newsletter (dated 5/26/00), the guidelines and schedule for the SEAFLUX intercomparison were established. For details on the intercomparison, see the project web site at http://paos.colorado.edu/~curryja/ocean/intercomparison-cg.html This e-mail is an update on the intercomparison, including status of the data sets, revised schedule (including dates for workshops), and some proposed activities for the intercomparison.

Assembly of the data for the intercomparison project is underway. All of the data that we have prepared to date is posted on the web page, with ftp sites. There is some metadata, but these files are not yet complete. Randy Reeder and Mat Rothstein at CU are coordinating the assembly of the data sets. This effort is being funded by a NASA EOS IDS project, P. Webster, PI (but we are way overspent, looking for other sources of funds!). Your feedback on the organization and utility of the website and data would be most appreciated. We have tried to make this as user-friendly as possible.

Thanks to Chris Fairall, Bob Weller, Mark Bourassa and Shawn Smith, Bill Emery, and Joerg Schulz for providing in situ data sets. We have 48 in situ case studies ready, with another 18 under preparation. This corresponds to over 300 months of measurements. 13 case studies include direct turbulence measurements and 7 include skin SST measurements. There is a surprisingly good latitudinal distribution for the measurements (no they are not all in the tropics!).

Satellite data sets are being assembled, but this involves reading a huge number of tapes and is utilizing a lot of tape drives. This is our limiting factor at present. To date, some of the SSM/I and Wentz retrievals are posted on the web page (thanks to Mat Rothstein). Some of the AVHRR data is nearly ready (thanks to Dan Baldwin and Bill Emery), and also the ISCCP and TOVS products (thanks to Bill Rossow).

The in situ measurements are being matched with ECMWF and NCEP grid cells (thanks to Randy Reeder). So far, about half of the NCEP data set is completed.

In addition, there are now two global satellite flux data sets available: Shulz and Chou.

In terms of a revised schedule:

12/31/00:	completion of in situ data sets
12/31/00:	completion of ISCCP, SSM/I, Wentz retrievals, AVHRR data
2/28/01:	completion of other satellite data sets
5/16-18/01	SEAFLUX Workshop in Washington DC (Bill Rossow handling logistics)
5/21-25/01	WCRP Air/Sea Flux Workshop in Washington DC

The colocation of the SEAFLUX workshop with the WCRP Flux workshop was designed to minimize travel costs. Re: travel funds for the workshop, we are hoping to obtain some funds from U.S. funding agencies and also from WCRP. Will keep you posted on this.

In considering the schedule and rethinking what we can do with this data, it seems that 2 intercomparison workshops will be needed. At the first intercomparison workshop, it seems like the group can accomplish the following:

Evaluation of NWP and existing flux data sets using the in situ data
Evaluation of bulk flux algorithm using the direct turbulence measurements.
Other individual projects are likely to emerge

To get things moving, I would like to propose the following specific activities:

Preparation of a BAMS article describing the SEAFLUX project, the in situ data, and evaluation of the NWP products. This paper would involve the workshop organizing committee, people who have contributed in situ data, relevant people from the NWP centers, and people at CU helping assemble the relevant data sets. This would then provide a reference for the in situ data set (and credit for those who provided the in situ data).
Evaluation and intercomparison of bulk flux algorithms (for an eventual JGR paper?). So far, we have bulk flux models from Zeng, Clayson, FSU, and Fairall-Bradley (Mark Bourassa, we can't get your code to run). We are hoping to get codes also from ECMWF, Jones, Chow, Schulz, Lin and anyone else who has a code that is being used in satellite retrievals or a large-scale model. Xubin Zeng has previously offered to take the lead on such a project (Xubin are you still interested?)
Evaluation of skin SST satellite retrieval algorithms. Rossow and Emery have expressed interest in organizing this. If others have satellite skin SST retrieval algorithms and are interested in participating, pls contact Rossow and Emery.
Evaluation of existing satellite flux products (Schulz, Chou, Jones, Lin) and possible intercomparison of the different products in the tropics. Any one interested in coordinating this?
Any other smaller projects that anyone is interested in coordinating on the time scale of the first workshop?

This already seems like an ambitious agenda for the first workshop. It seems like the task of actually improving the satellite flux products would be appropriate for a second intercomparison workshop.

Your comments and further input would be greatly appreciated.