Scientific Applications of Satellite Data within the Geophysics Research Community

This report is made on behalf of the Geophysica community, which comprises about 30 research groups across Europe, and forms part of the APERCU initiative for the exploitation of ENVISAT data.During the APE-THESEO mission in 1999, members of the Geophysica team retrieved data from Meteosat-5, and used this in combination with data from the Geophysica, to unravel the sometimes subtle links between convection and high-level tropical clouds. Satellite and in-situ data were used to distinguish non-convective tropopause cirrus from underlying convective anvils. It was shown that tropopause cirrus could be generated by convective systems that do not in themselves reach to the tropopause.Scientific campaigns, primarily for validation, but also testing the use of ENVISAT data synergistically with Geophysica data, took place in Italy, in July and October 2002. Geophysica flights probed the upper troposphere and lower stratosphere over southern Europe and the Mediterranean, a region that has been little studied. Small-scale structure was seen in long-lived tracers, indicative of quasi-isentropic stirring in both the upper troposphere and lower stratosphere, and rapid vertical mixing in the troposphere. This small-scale structure is also seen in three-dimensional Lagrangian transport model results. Resolving such small-scale structure will be a severe test of the ENVISAT instruments, but the intention is to follow the structures that ENVISAT instruments can resolve, and that are seen by Geophysica instruments, in time and space, to improve our understanding of transport and chemistry in the region.