CCMP

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Product Description
In collaboration with private and government institutions, a team led by Dr. Robert Atlas (PI; proposal originally solicited by REASoN, and currently funded by MEaSURES through NASA) has created a cross-calibrated, multi-platform (CCMP), multi-instrument ocean surface wind velocity data set (http://sivo.gsfc.nasa.gov/oceanwinds), for the period extending from 1987 through 2007, with wide ranging research applications in meteorology and oceanography. It represents a continuation and expansion of the SSM/I surface wind velocity data set that began under the NASA Pathfinder Program (see http://podaac.jpl.nasa.gov/PRODUCTS/p079.html). This data set combines data derived from SSM/I, AMSRE, TRMM TMI, Quikscat and other missions using a variational analysis method (VAM) to produce a consistent climatological record of ocean surface vector winds at 25km resolution. The VAM requires a background (first guess) analysis of gridded U and V winds as a starting estimate of the wind field. Analysis increments are added to this background to arrive at the final analysis. Background analyses for the ‘first-look’ (FLK) products utilize the ECMWF Operational Analysis (DS111.1), which are obtained from the Computation and Information Systems Laboratory (CISL) at the National Center for Atmospheric Research (NCAR): http://dss.ucar.edu/datasets/ds111.1/ . The next addition to the CCMP will be the ‘late-look’ (LLK) products, which may incorporate bias correction to the ECMWF backround wind vector field and ocean wind vector data from new satellite missions.

The methodology that is used to generate the CCMP has been previous published by Atlas et al. (1996) and is similar to that described by Hoffman (1984), with modifications to accommodate special attributes of the satellite surface wind data as well as some additional tuning of the data quality checking and filter weights.

Quikscat and TRMM measurements over hurricane Floyd on September 13, 1999.

Quikscat and TRMM measurements over Hurricane Floyd on September 13, 1999.

Satellite surface wind data are obtained from Remote Sensing Systems (RSS) under the DISCOVER project: Distributed Information Services: Climate/Ocean Products and Visualizations for Earth Research (http://www.discover-earth.org/index.html). RSS uses a more accurate sea-surface emissivity model resulting in much better consistency between wind speed retrievals from microwave radiometers (SSM/I, AMSR, TMI) and those from scatterometers (NSCAT and SeaWinds). All observations are referenced to a height of 10 meters.

CCMP TABLE

Products

	FTP	s/w	.bmap.gz	Y	Y	N	N	daily	25 km
Documentation: Related Publications	Comments:		Contains microwave radiometer derived wind speed data in swath, supplemented by VAM-derived wind directions. The satellite instruments covered by the L2.5 product include SSM/I, TMI, and AMSR-E.

	FTP	s/w	.nc.gz	Y	Y	N	N	6-hourly	0.25°
Documentation: Related Publications	Comments:		Contains gridded VAM ocean vector wind fields produced from all of the microwave radiometer data from the L2.5 product, blended with scatterometter data (NSCAT and SeaWinds on QuikSCAT/ADEOS-II).

	FTP	s/w	.nc.gz	Y	Y	Y	Y	5 days, monthly	0.25°
Documentation: Related Publications	Comments:		Contains a time-averaged version of the L3.0 product, including 5-day and monthly mean gridded fields.

Announcements
This product is currently in an experimental ‘preview’ stage and is being offered as-is, with no expressed provision of data-specific technical support to users by PO.DAAC staff. However, the PO.DAAC staff would like to know your opinions regarding this specific product, such as: how is it useful for your scientific needs, is it user friendly, does this product contain any bugs or errors, and what could be done to improve this product? Please direct your comments and concerns to: podaac@podaac.jpl.nasa.gov.

Citations/References
Atlas, R., R. N. Hoffman, S. C. Bloom, J. C. Jusem, and J. Ardizzone, 1996: A multiyear global surface wind velocity data set using SSM/I wind observations. Bull. Amer. Meteor. Soc., 77, 869–882.

Hoffman, R. N.s, 1984: SASS wind ambiguity removal by direct minimization. Part II: Use of smoothness and dynamical constraints. Mon. Wea.Rev., 112, 1829–1852.

Related Publications
Atlas R., S. C. Bloom, R. N. Hoffman, J. V. Ardizzone, and G. Brin, 1991: Space-Based Surface Wind Vectors to Aid Understanding of Air-Sea Interactions. EOS, 72, 201-208.

Atlas R., R. W. Hoffman, and S. C. Bloom, 1993: Surface Wind Velocity Over the Oceans. Atlas of Satellite Observations Related to Global Change Atlas, 129-139.

Atlas R., R., S. C. Bloom, R. N. Hoffman, E.Brin, J. Ardizzone, J. Terry, D.Bungato, and J. C. Jusem, 1999: Geophysical validation of NSCAT winds using atmospheric data and analyses. JGR., 104, 11405-11424.

Atlas R., R., and R. N. Hoffman, 1999: The use of satellite surface wind data to improve weather analysis and forecasting. Satellites, Oceanography, and Society.

Henderson, J. M., R. N. Hoffman, S. M. Leidner, J. V. Ardizzone, R. Atlas, and E. Brin, 2003: A comparison of a two-dimensional variational analysis method and a median filter for NSCAT ambiguity removal. J. Geophys. Res., 108, NO. C6, 3176, doi:10.1029/2002JC001307.

Hoffman, R. N., S. M. Leidner, J. M. Henderson, R. Atlas, J. V. Ardizzone, and S. C. Bloom, 2003: A two-dimensional variational analysis method for NSCAT ambiguity removal: Methodology, sensitivity, and tuning. J. Atmospheric Oceanic Technology, 20, 585-605.

Hoffman, R.N. and C. Grassotti, 1996: A technique for assimilating SSM/I observations of marine atmospheric storms. J. Applied. Meteorol., 35(8), 1177-1188.

Uppala, S.M., and Coauthors, 2005: The ERA-40 Re-analysis. Quart. J. Roy. Meteor. Soc., 131, 2961-3012.