Here is the latest info on the SEAFLUX intercomparison project and Workshop.

If you haven't checked the SEAFLUX web page recently (http://paos.colorado.edu/~curryja/ocean/), there continues to be more data added to the page under Intercomparison. Also, there are new data sets on the Links page. The new satellite flux data sets on the Links page include data sets from Kubota and Jones.

The SEAFLUX Intercomparison Workshop will be held in May 17-18, 2001, in San Diego, CA. The Workshop will be held in conjunction with the American Meteorological Society Conferences on Air/Sea Interactions and Polar Meteorology and Oceanography. Further information on the AMS meetings can be found at http://www.ametsoc.org/AMS/.

The Workshop (and Conferences) will be held at the Catamaran Resort Hotel, 3999 Mission Boulevard, San Diego, CA 92109. A block of rooms has been reserved at the hotel for conference and Workshop attendees at a special rate of $145/singe or $155/double room, plus tax. Government rates are also available. To receive these special rates, attendees must request a room under the American meteorological Society room block. Reservations must be made prior to 6 April and must be accompanied by a one-night deposit. Reservations made after that date will be on a space available basis. For reservations, call 800-288-0770 or 858-488-1081.

There is a limited amount of travel funds available for the workshop. If you need funds, please contact Bill Rossow at wrossow@giss.nasa.gov

If you plan to attend the Workshop, please reply to me via email at curryja@cloud.colorado.edu by April 6. (You can of course attend if you don't reply by this date, but need this info to organize the workshop). If we do not already have your contact info on the SEAFLUX web page under participants, please include your mailing address, phone, and email. If you would like to make a brief presentation on any of the agenda topics (see below), please email a brief description and title.

Here is a draft agenda for the Workshop. The idea is to keep the workshop very focused, towards making recommendations for proceeding with developing improved gobal flux products. The presentations should be brief (say 5 tansparencies) and specifically targeted at the intercomparison project. Lengthier science presentations will be given at the AMS Conferences. If the group would like to have some lengthier science presentations at the workshop, perhaps we can arrange for this on Thursday eve.

The relative length of the sessions on the different topics will depend somewhat on how many people want to give presentations on a topic and how many discussion issues are identified.

We have pencilled in a few specific speakers and topics, based upon people who we have already heard something from.

Please send comments/suggestions on the agenda, including discussion topics (and of course send in a brief abstract if you want to give a presentation).

8:30 am: Introduction (J. Curry)

8:35 am: News from GEWEX (W. Rossow)

8:50 am: News from JSC/SCOR Working Group (S. Gulyev)

9:05 am: In situ data sets

10:15 am: Break

10:30 am: Bulk turbulent flux models

12:00 pm: Lunch

1:30 pm: SST

2:30 pm: Surface winds

3:30 pm: Break

4:00 pm: Surface air temperature and humidity

5:30 pm: Dismiss

8:30 am: Satellite and NWP fluxes

10:15 am: Break

10:30: Breakout groups

11:45 am: Lunch

1:00 pm: Final Plenary Discussion

3:00 pm: Dismiss

WCRP/SCOR Workshop on Intercomparison and Validation of Ocean-Atmosphere Flux Fields (Washington DC area, USA, 21-25 May 2001).

The WCRP/SCOR Workshop on Intercomparison and Validation of Ocean-Atmosphere Flux Fields, to be held in Washington DC, USA, (21-25 May 2001), is the second meeting encouraging interaction and dialogue between the diverse scientific communities involved in producing and using air-sea fluxes.

The Final Report of the Working Group is a substantial document assessing the present state of the art in regard to air sea flux determination ("Intercomparison and Validation of Ocean-Atmosphere Energy Fluxes" shortly to be published in the WCRP report series). The report can be accessed at http://www.soc.soton.ac.uk/JRD/MET/WGASF.

Workshop organisers (Frank Bradley, Sergey Gulev - organizing committee chair, David Legler - local organizing committee chair, Roger Newson, Joerg Schulz, Peter Taylor, and Glenn White) invite all interested scientists to send statements of interest, abs tracts of papers (if you are going to present one) and submittal information (name, address, Email, telephone, fax) on Email, mail or fax by the deadline of 31 January 2001 to:

Sergey Gulev
P.P. Shirshov Institute of Oceanology
RAS
36 Nakhimovsky Ave.
117851, Moscow
Russia
Phone: +7-095-1247985
Fax: +7-095-1245983
Email: gul@gulev.sio.rssi.ru

Further information about the Workshop will be available shortly at: http://www.soc.soton.ac.uk/JRD/MET/WGASF and http://www.sail.msk.ru.

SEAFLUX REPORT TO GEWEX
SEAFLUX: Ocean Surface Turbulent Fluxes Study
Report Presented to GEWEX, 1/25/01

Judith Curry and William Rossow

The need for high-resolution, accurate surface turbulent fluxes (heat, water vapor, momentum) over the global ocean has been articulated by numerous groups within the global climate community. In August 1999, the GEWEX Radiation Panel and sponsored a workshop to review the analysis methods and data sets currently available and organize an intercomparison activity that includes in situ data, flux algorithms, satellite-derived input parameters and fluxes, and NWP products, which has been named SEAFLUX. An overview of the SEAFLUX study is found at http://paos.colorado.edu/~curryja/ocean/. We note here that SEAFLUX is coordinating with the JSC/SCOR Working Group on Air/Sea Fluxes.

The SEAFLUX intercomparison project is now underway (http://paos.colorado.edu/~curryja/ocean/intercomparison-cg.html). During 2000, we have assembled an extensive web-based library of in situ data sets from research ships and buoys that includes direct turbulent flux measurements, skin and bulk sea surface temperature, wave information, and surface air temperature, humidity, and vector winds (http://paos.colorado.edu/~curryja/ocean/valdata-cg.html). The total number of deployments in the data set numbers 50, with the individual deployments totalling over 300 months of measurements. A total of 13 deployments include direct turbulent flux measurements, 5 deployments include wave information, and 7 include skin SST measurements. A total of 15 deployments are from the tropics (20oN to 20oS), 14 deployments are from the subtropics (20o to 35o), 16 are from the mid latitudes (35o to 55o) and 5 are from high latitudes (55o to 80o). One case over sea ice (SHEBA) is included; although the sea ice obviously has different roughness characteristics than the open ocean, this case is deemed very valuable for evaluating bulk flux algorithms under statically stable conditions. All of the different data sets have been rewritten in a common format and using the same units, for ease of interpretation and use. Metadata is included for each of the different data sources.

We have colocated the following satellite data and NWP analyses with the in situ measurements: SSM/I brightness temperatures, TRMM brightness temperatures, the Wentz SSM/I and TRMM retrieved products, AVHRR GAC data for cases with skin SST measurements, ISCCP and TOVS products, and the NCEP analyses of surface turbulent fluxes and the input variables. Colocation with scatterometer wind products will be undertaken in 2001. The evaluation of the NCEP analyses against the in situ validation data is well underway. We are evaluating ECMWF analyses since July 1999, when the new wave model was incorporated; a more extensive evaluation of the ECMWF analyses will be undertaken once the ERA-40 is available.

We have made available on the project web site the codes for 10 different bulk flux algorithms that are used either in satellite retrievals or GCMs. These codes are currently be evaluated using the in situ data that includes direct turbulent flux measurements.

A number of different satellite flux data sets have been made available during 2000 by SEAFLUX participants:

• Schulz: The Hamburg Ocean Atmosphere Parameters from Satellite Data (HOAPS) data set (latent and sensible heat fluxes), globally at grid resolutions of 1o by 1o and 2.5o by 2.5o as pentad and monthly fields for July 1987-December 1998
• Chou: Global flux product for July 1987-December 1994 with resolution of 2.5o and 1 day.
• Curry: All flux components for TOGA COARE, 3 hr and 50 km resolution
• Jones: Daily latent heat fluxes for the tropical Pacific Ocean 1988-1999
• Lin: Tropical latent heat fluxes using TRMM data
• And the global tropical oceans for 1998 (Lin et al., 2000; Schluessel and Albert, 2000)
• Kubota: Global monthly latent heat fluxes, 1 degree spatial resolution
• Katsaros: Global daily latent heat fluxes using NSCAT (October 96-June 97)

During 2001, we have the following specific plans:

• Complete the assembly of the satellite data sets for the intercomparison
• Complete the evaluation of the NCEP analyses and the bulk flux algorithms
• Complete the evaluation of satellite skin SST retrieval methods
• Conduct the first intercomparison workshop in conjunction with the AMS Conference on Air/Sea Interactions, during May 2001 in San Diego, CA
• Participate in the JSC/SCOR Workshop in May 2001
• Begin evaluating the ECMWF fluxes
• Begin evaluating the satellite flux products

An outcome of the first intercomparison workshop will be recommendations for improved methods of determining global, high-resolution ocean surface turbulent fluxes. The second intercomparison workshop (2002 or 2003) will include evaluation of improved retrievals against a more extensive in situ data set (including more recent data that overlaps with the most recent satellite observations), and evaluation of the performance of the flux products in applications such as constraining the budget and mean transports of heat and freshwater in the global ocean, diagnosing regional and time variations of the coupled atmosphere-ocean system, evaluating the surface fluxes in coupled atmosphere-ocean models and weather forecasting models, and surface forcing for ocean models.

Even if the accuracy goal of 1o spatial resolution, 3-6 h time resolution, and accuracy of 5 W m-2 for individual components of the surface heat budget is not achievable with currently available measurements, the results of the intercomparison project will substantially improve global flux products and will highlight the obstacles to achieving the required accuracy. In any case, the results should be useful for determining the dominant scales of variability and identifying responsible processes. Carefully characterized errors in the fluxes allows an imperfect data set to be used at some level for the target applications.