This suite of IDL programs provides identification and comprehensive characterization of the dynamical features of the jet streams in the upper troposphere, the lower stratospheric polar night jet, and the tropopause. The output of this software not only provides comprehensive information on the jets and tropopause, but also gives this information in a form that facilitates studies of observations in relation to the jets and tropopauses.

The programs use data from gridded meteorological analyses (including, currently, GEOS-5/MERRA and NCEP/GFS, but are designed to easily adapt to others) to identify the locations and characteristics (wind speed, temperature, wind components, potential vorticity, equivalent latitude, potential temperature, relative vorticity, and other fields) at the jet maximum and the edges of the jet regions. It also compiles detailed tropopause information based on several commonly used definitions of the tropopause, including cataloging times/ locations with multiple tropo pauses. These products are calculated for the complete gridded meteorological data sets, and the differences between jet locations/characteristics and measurement locations/characteristics cataloged for several satellite (currently, Aura MLS, ACE, and HIRDLS) and aircraft (currently START-08, Winter Storms, SPURT) datasets.

These products are currently being used in studies compiling jet and tropopause climatologies, and to characterize trace gas observations in relation to the jets and tropopauses. The output products will be made available to other collaborators, and eventually will be publicly available.

This work was done by Gloria L. Manney and William H. Daffer of Caltech for NASA’s Jet Propulsion Laboratory.

This software is available for commercial licensing. Please contact Daniel Broderick of the California Institute of Technology at This email address is being protected from spambots. You need JavaScript enabled to view it.. NPO-47709

This Brief includes a Technical Support Package (TSP).
Jet and Tropopause Products for Analysis and Characterization (JETPAC)

(reference NPO-47709) is currently available for download from the TSP library.

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This article first appeared in the September, 2012 issue of Software Tech Briefs Magazine.

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