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A tabular summary provides key details. Additional information is given in written descriptions following the table.
The names of the products in the table are linked to the written descriptions. These descriptions include contact information, sites from which the data is available (or email contact with the people who will send the data), links to documentation, links to read routines, and references.
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Definitions for Symbols All scatterometer derived wind and pseudostress quantities are equivalent neutral values, unless explicitly stated otherwise.
Further explanations for the winds, pseudostresses, and stresses are available.
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Field |
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u |
West-to-East component of the wind (positive Eastward). |
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v |
South-to-North component of the wind (positive Northward). |
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w |
Wind speed. Note that wind speeds can be averaged as vectors or scalars, and that the differences can be substantial. See the detailed product description for the type of averaging. |
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UW |
West-to-East component of the pseudostress (positive Eastward). |
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VW |
South-to-North component of the pseudostress (positive Northward). |
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t x |
West-to-East component of the surface stress (positive Eastward). |
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t y |
South-to-North component of the surface stress (positive Northward). |
Global, daily, vector averaged maps of QuikSCAT winds, derived from daily bins the Level 2/50 km wind vectors, on 0.25 degree by 0.25 degree grids. Winds are available only where there were observations. Reference height is 10m. A table describing this and other gridded products is at the top of this page.
Four times daily fields of pseudostress are produced using a variational approach (direct minimization) with tuning parameters objectively determined using Generalized Cross Validation (GCV). This method greatly reduces spurious curl and divergence that occur near swath edges. These products are on either 0.5 x 0.5 or 1 x 1 degree grids. Data fields are pseudostress components. Rain-contaminated scatterometer measurements are excluded from the blending product. Reference height is 10m. A table describing this and other gridded products is at the top of this page.
Deliverables:
Tools are available for converting NetCDF files to ASCII at http://www.coaps.fsu.edu/nscat/html/conv_progs.html Free read software for UNIX, Macs, and PCs is available from Unidata. Additional information is available at http://www.unidata.ucar.edu/packages/netcdf/.
Pegion, P. J., M. A. Bourassa, D. M. Legler, and J. J. O'Brien, 2000: Objectively-derived daily "winds" from satellite scatterometer data. Mon. Wea Rev., in press.
Blended Winds from Morzel, Milliff, and Chin
Global 6-hourly maps of ocean surface winds are derived from a space and time blend of QSCAT scatterometer observations and NCEP analyses. This blending method creates global fields by retaining QSCAT wind retrievals in swath regions, and in the unsampled regions (nadir and interswath gaps) augmenting the low-wavenumber NCEP fields with a high-wavenumber component that is derived from monthly regional QSCAT statistics. Rain-contaminated scatterometer measurements are excluded from the blending product. Reference height is 10m. A table describing this and other gridded products is at the top of this page.
Deliverables:
Data: Global, 6-hourly blended QSCAT/NCEP wind vectors on 0.5x0.5 grid.
Read Software: FORTRAN
Document: Detailed information about Data is available at
http://www.colorado-research.com/~morzel/blendedwinds.qscat.ku2000.html
Where to Get the Data and Software:
To get the data, please go to
http://dss.ucar.edu/datasets/ds744.4/Contact:
Jan Morzel
Phone: (303) 415-9701 x206
Email:
References:
The details of the blending methology are the subject of
Chin, T.M., R.F. Milliff, and W.G. Large, 1998:
Basin-Scale High-Wavenumber Sea Surface Wind Fields from
Multiresolution Analysis of Scatterometer Data.
Journal of Atmospheric and Oceanic Technology, 15, 741-763.
Global maps of wind stress curl have been computed from the NSCAT blended product, and compared with curl from NCEP analyses in Milliff, R.F., and J. Morzel, 2001: The Global Distribution of the Time-average Wind Stress Curl from NSCAT. Journal of the Atmospheric Sciences, Vol. 58, No. 2, 109-131.
The QSCAT blended wind product provides a useful compromise between ubiquitous but coarse and contaminated NCEP, and intermittent by high-resolution QSCAT surface wind products, as described in Morzel, J., R.F. Milliff, M. Freilich, and B. Vanhoff, 2001: Global Annual Average Wind Stress Curl and Divergence from QSCAT: Comparisons between QSCAT, NCEP, and a Blended Product. This web page is based on a presentation at the NASA Oceanographic Scientific Conference, April 2001, Miami Beach, FL.
Twice daily global wind fields produced by successive corrections using scatterometer winds, with QuikSCAT monthly averaged wind data as the initial fields. This product is based on the near real-time data from NOAA, rather than the delayed product from JPL or RSS. Rain-contaminated data are not removed. Spatial grid is 0.5 degree by 0.5 degree. The gridded products are wind components. A table describing this and other gridded products is at the top of this page.
