Fluxes of nitrates between snow surfaces and the atmosphere in the European high Arctic H. J. Beine1, F. Dominè2, A. Ianniello1, M. Nardino3, I. Allegrini1, K. Teinilä4, and R. Hillamo4 1C.N.R. – IIA, Roma, Italy 2CNRS – LGGE, Grenoble, France 3C.N.R. – ISAC, Bologna, Italy 4FMI – Air Quality Research, Helsinki, Finland
Abstract. Measurements of atmospheric and snow mixing ratios of nitrates and nitrites and their fluxes
above the snow surface were made during two intensive campaigns during spring time 2001 at
Ny-Ålesund, Svalbard as part of the EU project "`The NItrogen Cycle and Effects on the oxidation of
atmospheric trace species at high latitudes" (NICE).
At this coastal site close to the unseasonably unfrozen fjord, of the measured nitrogen species, only
HNO3 showed a significant flux on to the snow surface; a mean deposition of
-8.7 nmol h-1 m-2 was observed in late April / early May 2001. These fluxes may be due to the reaction of
HNO3 with sea salt, and especially NaCl, or may be simply uptake of
HNO3 by ice, which is alkaline because of the sea salt in our marine
environment. During snowfall periods dry deposition of HNO3 may contribute up to
10% of the N budget in the snow; however, the main source for N is wet deposition in falling snow.
The surface snow at Ny-Ålesund showed very complex stratigraphy; the NO3- mixing ratio in snow varied
between 65 and 520 ng g-1, the total NO3- content of the snowpack was on the order of
2700 ng cm-2. In comparison the atmospheric boundary layer column showed a
NO3- content of only 8 ng cm-2. The limited
exchange, however, between the snow and the atmosphere was attributed to low mobility of
NO3- in the observed snow.
Contrary to other Arctic sites (i.e. Alert, Nunavut or Summit, Greenland) deposition of sea salt and crustal
aerosols in this marine environment made the surface snow alkaline; snow
NO3- was associated with heavier cations and was not readily available for physical exchange or photochemical reactions.
Citation: Beine, H. J., Dominè, F., Ianniello, A., Nardino, M., Allegrini, I., Teinilä, K., and Hillamo, R.: Fluxes of nitrates between snow surfaces and the atmosphere in the European high Arctic, Atmos. Chem. Phys., 3, 335-346, doi:10.5194/acp-3-335-2003, 2003.