The past two decades, 1990-2010, have been something of a “golden age” for stratospheric chemical observations. The Odin satellite from SNSB, the ENVISAT mission from ESA and NASA missions UARS and EOS-Aura have provided an unprecedented coverage (spatial, temporal) of the stratosphere chemistry and dynamics. These missions were designed with a focus on addressing the effect of man-made changes in atmospheric composition and its implication to climate change. These missions have provided measurements of a large number of chemical species, both long-lived and short-lived, that are critical to conduct scientific studies. The integration of measurements and atmospheric predictive models can be done through a technique known as data assimilation. It is quite remarkable that although data assimilation has been applied to a wide range of geophysical problems, the assimilation of those observations into chemical transport models has been rather scarce and has hindered the additional value those observations could provide.

This team brings scientists from observation studies, chemical modeling and processes, and data assimilation experts together to answer the question: “What is the added value of stratosphere and upper-troposphere chemistry data assimilation”.

* The animation above shows the evolution of Ozone at 520 K between Sept 1 to 30, 2008 with a frequency of 6 hours from Aura MLS Observations (left), BASCOE 4D-Var analysis (center) and BASCOE CTM run (right). Color ranges are from 0 (blue) to 4 (red) ppmv.