Estimating source regions of European emissions of trace gases from observations at Mace Head

A technique is described for identifying probable source locations for a ra nge of greenhouse and ozone-depleting trace gases from the long-term measur ements made at Mace Head, Ireland. The Met. Office's dispersion model NAME is used to predict concentrations at Mace Head from all possible sources in Europe, then source regions identified as those which consistently lead to elevated concentrations at Mace Head. Estimates of European emissions and their distribution are presented for a number of trace gases for the period 1995-1998. Estimated emission patterns are realistic, given the nature and varied applications of the species considered. The results indicate that w hilst there are limitations, useful information about source distribution c an be extracted from continuous measurements at a remote site. It is probab le that much improved estimates could be derived if observations were avail able from a number of sites. The ability to assess emissions has obvious im plications in monitoring compliance with internationally agreed quota and p rotocols. Crown Copyright (C) 2001 Published by Elsevier Science Ltd. All r ights reserved.