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In recent years techniques have been developed to obtain integrated water vapor along slant paths between ground-based Global Positioning System (GPS) receivers and the GPS satellites. Results are presented of an observing system simulation (OSS) to determine whether three-dimensional water vapor fields could be recovered from a high-resolution network(More)
A Space and Time Mesoscale Analysis System (STMAS) has been developed at Forecast Systems Laboratory (FSL) to generate a gridded analysis of surface observations. It is a three-dimensional variational analysis (3DVAR) of horizontal space and time instead of pressure or height levels. It is used to detect boundary layer phenomena, frontal zones, and various(More)
The importance of narrow zones of boundary layer convergence (or boundaries) for thunderstorm development and evolution has been recognized since the days of the Thunderstorm Project. Boundary detection and characterization are primary objectives of automated nowcasting systems, which employ surface data, radar and satellite observations of current storms(More)
Correlation scales have been used in the traditional scheme of three-dimensional variational data assimilation (3DVAR) to estimate the background (or first guess) error covariance matrix (the B matrix in brief) for the numerical forecast and reanalysis of ocean for decades. However, it is challenging to implement this scheme. On the one hand, determining(More)
A recursive filter or parameterized curve fitting technique is usually used in a three-dimensional variational data assimilation (3DVAR) scheme to approximate the background error covariance, which can only represent the errors of an ocean field over a predetermined scale. Without an accurate flow-dependent error covariance that is also local and time(More)
tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised(More)
Through idealized experiments, this study is to test the performance of multi-grid three-dimensional variantional (3D-Var) on three-dimensional (3D) Doppler radar radial velocity data assimilation, and to what degree the 3D Doppler radar radial velocity can improve the conventional (in situ) wind observation analysis. A two-scale idealized wind field is(More)
A Space and Time Mesoscale Analysis System (STMAS) has been developed at Forecast Systems Laboratory (FSL) to generate a grid analysis of surface observations. It is a three-dimensional variational analysis (3DVAR) of horizontal space and time instead of pressure or height levels. It is used to detect boundary layer phenomena, frontal zones, and various(More)
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