Title Seasonal variations of snow chemistry at NEEM, Greenland
Author Kuramoto, T.; Goto-Azuma, K.; Hirabayashi, M.; Miyake, T.; Motoyama, H.; Dahl-Jensen, D.; Steffensen, J.P.
Author Affil Kuramoto, T., National Institute of Polar Research, Tokyo, Japan. Other: University of Copenhagen, Denmark
Source Annals of Glaciology, 52(58), p.193- 200, . Publisher: International Glaciological Society, Cambridge, United Kingdom. ISSN: 0260-3055
Publication Date 2011
Notes In English. 41 refs. GeoRef Acc. No: 310192
Index Terms chemical composition; drilling; firn; hydrogen; ions; isotopes; mass balance; metals; oxygen; snow; water; Greenland; alkali metals; alkaline earth metals; Arctic region; calcium; chloride ion; chlorine; D/H; electrical conductivity; halogens; ice cores; isotope ratios; magnesium; NEEM project; nitrate ion; North Greenland Eemian Ice Drilling; O-18/O-16; pH; potassium; seasonal variations; sodium; stable isotopes
Abstract We conducted a pit study in July 2009 at the NEEM (North Greenland Eemian Ice Drilling) deep ice-coring site in northwest Greenland. To examine the seasonal variations of snow chemistry and characteristics of the drill site, we collected snow/firn samples from the wall of a 2 m deep pit at intervals of 0.03 m and analyzed them for electric conductivity, pH, Cl-, NO3-, SO42-, CH3SO3- (MSA), Na+, K+, Mg2+, Ca2+ and stable isotopes of water (delta 18O and delta D). Pronounced seasonal variations in the stable isotopes of water were observed, which indicated that the snow had accumulated regularly during the past 4 years. Concentrations of Na+, Cl- and Mg2+, which largely originate from sea salt, peaked in winter to early spring, while Ca2+, which mainly originates from mineral dust, peaked in late winter to spring, slightly later than Na+, Cl- and Mg2+. Concentrations of NO3- showed double peaks, one in summer and the other in winter to spring, whereas those of SO42- peaked in winter to spring. The winter- to-spring concentrations of NO3- and SO42- seem to have been strongly influenced by anthropogenic inputs. Concentrations of MSA showed double peaks, one in spring and the other in late summer to autumn. Our study confirms that the NEEM deep ice core can be absolutely dated to a certain depth by counting annual layers, using the seasonal variations of stable isotopes of water and those of ions. We calculated the annual surface mass balance for the years 2006-08. The mean annual balance was 176 mm w.e., and the balances for winter-to-summer and summer- to-winter halves of the year were 98 and 78 mm, respectively. Snow deposition during the winter-to-summer half of the year was greater than that during the summer-to-winter half by 10-20 mm for all three years covered by this study.
Publication Type journal article
Record ID 65007371