Elemental carbon distribution in Svalbard snow

Abstract

[1] The concentration of apparent elemental carbon (EC a , based on a thermal-optical method) in the snow was investigated in Svalbard (European Arctic) during spring 2007. The median EC a concentration of 81 samples was 4.1 mg l À1 and the values ranged from 0 to 80.8 mg l À1 of melt water. The median concentration is nearly an order of magnitude lower than the previously published data of equivalent black carbon (BC e , based on an optical method), obtained from Svalbard snow in the 1980s. A systematic regional difference was evident: EC a concentrations were higher in east Svalbard compared to west Svalbard. The observations of snow EC a cover spatial scales up to several hundred kilometers, which is comparable to the resolution of many climate models. Measurements of atmospheric carbonaceous aerosol (2002)(2003)(2004)(2005)(2006)(2007)(2008) at Zeppelin station in Ny-Å lesund, Svalbard, were divided to air mass sectors based on calculated back trajectories. The results show that air originating from the eastern sector contains more than two and half times higher levels of soot than air arriving from south to west. The observed east-west gradient of EC a concentrations in snow may be because of a combination of the atmospheric concentration gradient, the orographic effect of the archipelago, and the efficient scavenging of the carbonaceous particles through precipitation.

Light-absorbing impurities in Arctic snow

“…The values we obtain for Svalbard, with medians 7-20 ng g −1 , are higher than those obtained by Forsström et al (2009) using the TO method. Their median for 81 samples across Svalbard was 4 ng g −1 .…”

“…Snow on the Greenland Ice Sheet is the cleanest snow of the Arctic, and these values represent the free tropospheric BC content at an elevation of ∼2600 m, so it is of interest to examine evidence from lower-elevation sites where only seasonal snow, rather than ice cores, is available. BC in the near-surface atmosphere has been monitored continuously since 1989 at Alert on Ellesmere Island (82.4 • N, 62.3 • W, 210 m) (Gong et al, 2010), and at Barrow, Alaska (Sharma et al, 2006), and since 1998 at the Zeppelin station above Ny-Ålesund (79 • N, 12 • E, 474 m) (Eleftheriadis et al, 2009;Forsström et al, 2009). All three locations document the seasonal cycle with BC concentrations peaking in winter, and all three show a multi-year decline of the wintertime peak.…”

Advances in understanding and parameterization of small-scale physical processes in the marine Arctic climate system: a review

“…As black carbon (BC) effectively absorbs visible radiation, it causes acceleration in the growth of snow grains, and therefore an overall decrease in albedo. In particular, Hansen et al (2005) suggested that the effect of BC on snow albedo contributes substantially to rapid warming and sea ice loss in the Arctic, although recent measurements (Forsström et al, 2009(Forsström et al, , 2013Doherty et al, 2010) have shown substantially lower levels of BC than was observed in the 1980s (Clarke and Noon, 1985). In view of these findings, parameterizations of BC and soot concentration in snow have been recently developed (Flanner and Zender, 2006;Yasunari et al, 2011;Aoki et al, 2011).…”

Measuring Organic Carbon and Black Carbon in Rainwater: Evaluation of Methods

“…This method is commonly used for the analysis of filter-based aerosol samples (Birch and Cary 1996) and it has been used to measure EC in precipitation (Hadley et al 2007;Forsstrom et al 2009;Cerqueira et al 2010). The method applied to rainwater analysis required the filtration of liquid and the collection of particulate carbon on quartz fiber filters, which are the only filters that can withstand the high temperatures of the TOA.…”