New evidence of long distance pollen transport to southern Greenland in late spring

New observations of long-distance pollen transport to southern Greenland are recorded during the last 2 weeks of May, 2003. The results indicate northeastern North America as the source area of the transported pollen grains as shown in earlier investigations. Backward trajectories indicate that transport occurred twice during the first week corresponding to a time of maximum pollen flux emitted to the atmosphere in the source area. A large percentage of exotic pollen grains were identified, about 11% of the total counted. However, transport during the second week appears to have occurred during a single day at a time of reduced pollen emission into the atmosphere, which was subjected later to severe washout. As a result, only 1% of the total pollen spectra was identified as exotic grains. The back trajectories modeled by the HYSPLIT application differ somewhat from those previously identified in 2002. Although in both years air passing over southern Greenland at 3000 in carried out the main transport, additional transport could have occurred at a much lower altitude in 2003. (c) 2006 Elsevier B.V. All rights reserved.