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-------- Original Message --------
NCEP Model Evaluation Subscribers,
The Environmental Modeling Center (EMC) has proposed an upgrade to
the Real Time Ocean Forecast System (RTOFS). These changes are expected
to improve the performance of the Atlantic Forecast and Assimilation
System.
The changes include:
1. Change Sea Surface Height (SSH) assimilation quality control criteria
and mask to expose more of the region to SSH data.
2. Reset basin average SSH and update mean dynamic topography to better
match open boundary conditions.
3. Add bogus SSH anomaly data offshore of the mid Atlantic bight to
control gulf stream data.
4. Update tidal evaluations and transport boundary conditions from the
global inverse tide model, TPX07.
The combined effect of these changes has resulted in the following
improvements to model performance:
1. Significant reduction in spurious currents and eddies in the tropical
Atlantic and equatorial zones.
2. More realistic gulf stream and loop current in the Gulf of Mexico
which compares well with observed paths.
3. Better agreement with measured transports from AOML cable data near
27N from Florida to the Bahamas.
4. Significantly better representation of water temperature and salinity
at the World Ocean Circulation Experiment, WOCE, sections.
5. Reduction in SST errors when compared to INSITU data.
6. Significant improvement in reproduction of mesoscale features near
U.S. coast as shown in independent SSH analysis based on Jason-1 and
Jason-2 altimeter data.
Data format, volume and delivery will not be impacted by this
implementation.
Near Real-Time Parallel Data
FTP:
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/ofs/para/ofs.YYYYMMDD
HTTP:
http://www.ftp.ncep.noaa.gov/data/nccf/com/ofs/para/ofs.YYYYMMDD
We will make the model output available for 30 days starting Wednesday,
16 September so that end-users of the RTOFS data can verify that no
unforeseen changes have been introduced. Any comments on this proposed change will be appreciated. Any feedback you wish to provide during the evaluation period should be emailed to NCEP.List.ModelEvalFeedback@xxxxxxxx <mailto:NCEP.List.ModelEvalFeedback@xxxxxxxx>, prior to 23 October, 2009. The Environmental Modeling Center, EMC, has a publicly available website which can provide users with more information concerning the RTOFS: http://polar.ncep.noaa.gov/ofs/index.shtml Thanks Dan Starosta
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