Spatial variability of snow chemistry in western Dronning Maud Land, Antarctica

Annals of Glaciology, Vol. 27, p. 378-384, 1998 

M. Stenberg, W. Karlén
Department of Physical Geography, Stockholm University, S-106 91 Stockholm, Sweden.
E. Isaksson
Norwegian Polar Institute, Middlethuns gt. 29, Box 5072-Majorstua, N-0301 Oslo, Norway.
M. Hansson
Department of Meteorology, Stockholm University, S-106 91 Stockholm, Sweden.
P.A. Mayewski, M.S. Twickler, S.I. Whitlow
Glacier Research Group, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH 03824, USA.
N. Gundestrup
Departement of Geophysics, The Niels Bohr Institute of Astronomy, Physics and Geophysics, University of Copenhagen.

ABSTRACT.
During the austral summer of 1993-94 a number of 1-2 m deep snow pits were sampled in connection with firn-coring in western Dronning Maud Land, Antarctica. The traverse went from 800 to about 3000 m a.s.l. upon the high-altitude plateau. Profiles of cations (Na⁺, K⁺, Mg²⁺, Ca²⁺), anions (Cl^-, NO^3-, SO₄^2-, CH₃SO₃^-) and stable oxygen isotopes (d¹⁸O) from 11 snow pits are presented here. Close to the coast 2 m of snow accumulates in about 2-3 years, whilst at sites on the high-altitude plateau 2 m of snow accumulates in 10-14 years. The spatial variation in ion concentration shows that the ions can be divided into two groups, one with sea-salt elements and methane sulfonate and the other with nitrate and sulfate. For the sea-salt elements and methane sulfonate the concentrations decrease with increasing altitude and increasing distance from the coast, as well as with decreasing temperature and decreasing accumulation rate. For nitrate and sulfate the concentrations are constant or increase with respect to these parameters. This pattern suggests that the sources for sea-salt elements and methane sulfonate are local, whereas the sources for nitrate and sulfate are a mixture of local and long-range transport.