Assessing Scales of Variability for Constituents Relevant to Future Geostationary Satellite Observations and Models of Air Quality

Establishing appropriate specifications for satellite observations of atmospheric composition is a difficult and inexact task since neither models nor field observations can provide both the resolution and spatial coverage required. Despite shortcomings in temporal and spatial coverage, field observations are unique in capturing atmospheric variability on scales down to and below those of satellite observations. Airborne field observations from NOAA and NASA-sponsored field campaigns offer dense observations focused on air quality across North America. Here we use variogram analyses to assess spatial variability in key constituents (NO2, O3, CO, and SO2) for a number of air quality focused field campaigns (ICARTT, TEXAQS2000 and 2006, ARCTAS-CARB). The resulting variograms provide a useful metric for evaluating resolution requirements for future geostationary satellite observations. Variograms also provide an assessment of subgrid variability expected to influence nonlinear ozone photochemistry within air quality models based on a chosen model resolution.