Using GOME NO2 satellite data to examine regional differences in TOMCAT model performance N. H. Savage1, K. S. Law1,*, J. A. Pyle1, A. Richter2, H. Nüß2, and J. P. Burrows2 1Centre for Atmospheric Science, Chemistry Department, University of Cambridge, UK 2Institute of Environmental Physics, University of Bremen, NW1, Kufsteiner Strasse 1, D-28359 Bremen, Germany *Now at: Service d’Aeronomie, CNRS/IPSL, Paris, France
Abstract. This paper compares column measurements of
NO2 made by the GOME instrument on ERS-2 to model
results from the TOMCAT global CTM. The overall correlation
between the model and observations is good (0.79 for the
whole world, and 0.89 for North America) but the modelled
columns are larger than GOME over polluted areas (gradient of 1.4 for
North America and 1.9 for Europe). NO2 columns in the
region of outflow from North America into the Atlantic
are higher in winter in the model compared to the GOME results,
whereas the modelled columns are smaller off the coast of Africa
where there appear to be biomass burning plumes in the satellite data.
Several hypotheses are presented to explain these
discrepancies. Weaknesses in the model treatment of vertical
mixing and chemistry appear to be the most likely explanations.
Citation: Savage, N. H., Law, K. S., Pyle, J. A., Richter, A., Nüß, H., and Burrows, J. P.: Using GOME NO2 satellite data to examine regional differences in TOMCAT model performance, Atmos. Chem. Phys., 4, 1895-1912, doi:10.5194/acp-4-1895-2004, 2004.