CCMP

Products / Announcements / Citations/References / Related Publications

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 July 1, 1987 through December 31, 2008, with wide ranging research applications in meteorology and oceanography. This product was a result of an investigation funded by NASA's Making Earth Science data records for Use in Research Environments (MEaSUREs) Program.

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.

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

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

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.

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 User Manual	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 User Manual	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 User Manual	Comments:		Derived using the Level 3.0 product. Contains time averaged, 5-day and monthly, gridded wind vector fields. Only those grid points containing observations that passed quality control are used in the average in order to approximate a satellite-only climatology. Soon to come will be “Level 3.5b”, which will utilize the complete analysis within the Level 3.0 product.

Announcements
As of May 11, 2009, CCMP has been migrated from the experimental ‘Preview’ FTP stage to an anonymous FTP stage. Consequently, this dataset is classified as fully vetted and validated by the Ocean Vector Winds science community, thereby enabling PO.DAAC staff to provide full technical support to all current and future users of this dataset. However, this product is still fairly new to the community and so the PO.DAAC staff is still welcoming you to share your concerns regarding CCMP and its specific sub-products. Please direct your comments and inquiries 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.