Pollen transport to southern Greenland: new evidences of a late spring long distance transport

Abstract. New observations of long distance transport of pollen to southern Greenland are recorded during two consecutive weeks, 19 May until 1 June 2003. These new results indicate again Northeastern America as the source area of the transported pollen grains. Backward trajectories studies indicate that transport occurred twice during the first week, which corresponds to the interval of maximum pollen flux emitted in the atmosphere. This is indicated by the large percentage of exotic pollen grains identified, about 11% of the total counted including the local vegetation. Conversely, the transport observed during the second week occurred during a single day, at a time of reduced pollen emission into the atmosphere in the source area, and experienced severe wash out and thus is indicated by a lower percentage of exotic grains, 1% of the total identified ones. The trajectories modeled by the HYSPLIT application show different patterns to those previously identified in 2002. Although air volumes passing over southern Greenland at 3000 m carried out the main transport, additional transport occurred at a much lower altitude leading producing a more complicated pattern of modeling than previously considered.