SEASONAL-VARIATIONS IN THE CONCENTRATION OF BE-10, CL-, NO3-, SO4(2)-, H2O2, PB-210, H-3, MINERAL DUST, AND DELTA-18O IN GREENLAND SNOW

A detailed snow pit study at Dye 3, South Greenland, has been carried out in order to investigate the seasonal variations of Be-10, Cl-, NO3-, SO42-, H2O2, Pb-210, H-3, Mn and delta-O-18. Special emphasis was placed on understanding the causes of Be-10 variations because this isotope can be used to trace the history of solar activity. A sampling interval of 5 cm was chosen to assure a mean time resolution of about 20 samples per year for the period 1978-1983. Four different categories of seasonal variations were identified: strong summer peaks (delta-O-18, H2O2, H-3), weak bimodal peaks (NO3-, SO42-, conductivity, Be-10), a fall peak (Pb-210) and a winter-spring peak (Cl-, Mn). Although we are still far from a detailed understanding of the mechanisms which control the measured compositions, there are indications that different processes dominate at different seasons. NO3-, SO42-, Mn and Cl- variations suggest that aerosol transport is most important during winter-spring. In summer-fall there seems to exist a second period of long range transport from low latitude continental areas resulting in enhanced concentrations of Pb-210, Be-10 and SO42-.