Assimilation of scatterometer winds into surface pressure fields using a variational method
A variational formulation was used to assimilate Seasat-A scatterometer (SASS) surface wind measurements near and during a severe storm in the North Atlantic into conventional National Meteorological Center sea level pressure fields. An estimate of the relative vorticity at every point on a grid was...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19860061741 2023-05-15T17:33:26+02:00 Assimilation of scatterometer winds into surface pressure fields using a variational method Harlan, J., Jr. Obrien, J. J. Unclassified, Unlimited, Publicly available Jun 20, 1986 http://ntrs.nasa.gov/search.jsp?R=19860061741 unknown http://ntrs.nasa.gov/search.jsp?R=19860061741 Accession ID: 86A46479 Copyright Other Sources 47 Journal of Geophysical Research; 91; 7816-783 AD-A173462 1986 ftnasantrs 2012-02-15T16:50:31Z A variational formulation was used to assimilate Seasat-A scatterometer (SASS) surface wind measurements near and during a severe storm in the North Atlantic into conventional National Meteorological Center sea level pressure fields. An estimate of the relative vorticity at every point on a grid was calculated using each of these two data sets. A solution to a modified geostrophic stream function is found subject to the constraints that (1) the relative vorticities calculated from the data agree as closely as possible with the relative vorticities from the variational solution, and that (2) the average kinetic energy is a minimum. Results are obtained which support the idea that averaged satellite data can be treated as synoptic data. Direct substitution rather than a time-weighted insertion made from SASS winds generally resulted in more accurate pressure analyses. In addition, this relatively simple model provides surface pressure fields which agree extremely well with surface truth and the results of other investigators who required additional sources of input data into more complex models. It will be possible to obtain improved wind field maps from future scatterometer pressure fields in mid-latitudes. Other/Unknown Material North Atlantic NASA Technical Reports Server (NTRS) |
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NASA Technical Reports Server (NTRS) |
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47 |
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47 Harlan, J., Jr. Obrien, J. J. Assimilation of scatterometer winds into surface pressure fields using a variational method |
topic_facet |
47 |
description |
A variational formulation was used to assimilate Seasat-A scatterometer (SASS) surface wind measurements near and during a severe storm in the North Atlantic into conventional National Meteorological Center sea level pressure fields. An estimate of the relative vorticity at every point on a grid was calculated using each of these two data sets. A solution to a modified geostrophic stream function is found subject to the constraints that (1) the relative vorticities calculated from the data agree as closely as possible with the relative vorticities from the variational solution, and that (2) the average kinetic energy is a minimum. Results are obtained which support the idea that averaged satellite data can be treated as synoptic data. Direct substitution rather than a time-weighted insertion made from SASS winds generally resulted in more accurate pressure analyses. In addition, this relatively simple model provides surface pressure fields which agree extremely well with surface truth and the results of other investigators who required additional sources of input data into more complex models. It will be possible to obtain improved wind field maps from future scatterometer pressure fields in mid-latitudes. |
format |
Other/Unknown Material |
author |
Harlan, J., Jr. Obrien, J. J. |
author_facet |
Harlan, J., Jr. Obrien, J. J. |
author_sort |
Harlan, J., Jr. |
title |
Assimilation of scatterometer winds into surface pressure fields using a variational method |
title_short |
Assimilation of scatterometer winds into surface pressure fields using a variational method |
title_full |
Assimilation of scatterometer winds into surface pressure fields using a variational method |
title_fullStr |
Assimilation of scatterometer winds into surface pressure fields using a variational method |
title_full_unstemmed |
Assimilation of scatterometer winds into surface pressure fields using a variational method |
title_sort |
assimilation of scatterometer winds into surface pressure fields using a variational method |
publishDate |
1986 |
url |
http://ntrs.nasa.gov/search.jsp?R=19860061741 |
op_coverage |
Unclassified, Unlimited, Publicly available |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Other Sources |
op_relation |
http://ntrs.nasa.gov/search.jsp?R=19860061741 Accession ID: 86A46479 |
op_rights |
Copyright |
_version_ |
1766131938795454464 |