"We absolutely need to use a model with a grid size at least as small as, or smaller than, 50-by-50 kilometers (31-by-31 miles) to look at where and when the stratospheric air reaches the surface," Lin said.
Lin's analysis, based on a GFDL model with 50-kilometer (31-mile) resolution, suggests that the impact on ground level ozone in the U.S. West from springtime intrusion events is two to three times greater than previously estimated. The study was published October 2012 in Journal of Geophysical Research.
Steven Pawson and Eric Nielsen, atmospheric scientists at NASA's Goddard Space Flight Center in Greenbelt, Md., are also in pursuit of improved model simulations of stratospheric ozone intrusions. The team set out to see if the Goddard Earth Observing System Model, Version 5 (GEOS-5) Chemistry-Climate Model could replicate stratospheric intrusions at 25-kilometer (16-mile) resolution.
They show that indeed, the model could replicate small-scale features, including finger-like filaments, within the apron of ozone-rich stratospheric air that descended over Colorado on April 6, 2012.
"High-resolution modeling is giving us the capability to examine these events comprehensively for the first time," Nielsen said.
High-resolution models are possible due to computing power now capable of simulating the chemistry and movement of gasses and pollutants around the atmosphere and calculating their interactions. The addition of chemistry to these models, however, is not without a computational cost. For example, a weather forecast that takes about one hour of computational t
|Contact: Kathryn Hansen|
NASA/Goddard Space Flight Center