Science Systems and Applications, Inc. - Science and Technology with Passion

Modeling & Simulation of atmospheric phenomena

The EPV field from the GEOS-5 data assimilation system, showong EPV in potential vorticity units. The shading shows regions of high EPV, typical of the polar vortex, in white, and regions of low EPV, typical of tropical air masses, in darker shades. Credit: NASA GSFC/GMAOThe EPV field from the GEOS-5 data
assimilation system, showing EPV in
potential vorticity units. The shading shows
regions of high EPV, typical of the polar
vortex, in white, and regions of low EPV,
typical of tropical air masses, in darker shades.
Credit: NASA/GSFC/GMAO
SSAI scientists are advancing NASA’s data assimilation and atmospheric modeling. Recent improvements in the GEOS-5 analysis and forecasting system presented an opportunity to examine the Sudden Stratospheric Warming (SSW) event of January 2013 at a level of detail that was not possible only a few years ago. The quarter-degree resolution GEOS-5 analyses depicted distortion and breakdown of the stratospheric polar vortex with unprecedented characterization of small-scale features. The accuracy of analyses and integrity of the underlying GEOS-5 model led to a successful prediction of this SSW event five days in advance, accurately forecasting the initial displacement of the vortex, followed by its dynamical breakdown into three smaller vortices.