Aspmo Katrine, Temme Christian, Berg Torunn, Ferrari Christophe, Gauchard L Pierre-Alexis, Fain Xavier, Wibetoe Grethe
Norwegian Institute for Air Research (NILU), Instituttveien 18, P.O. Box 100, N-2027, Kjeller, Norway.
Environ Sci Technol. 2006 Jul 1;40(13):4083-9. doi: 10.1021/es052117z.
Atmospheric mercury speciation measurements were performed during a 10 week Arctic summer expedition in the North Atlantic Ocean onboard the German research vessel RV Polarstern between June 15 and August 29, 2004. This expedition covered large areas of the North Atlantic and Arctic Oceans between latitudes 54 degrees N and 85 degrees N and longitudes 16 degrees W and 16 degrees E. Gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and mercury associated with particles (Hg-P) were measured during this study. In addition, total mercury in surface snow and meltwater ponds located on sea ice floes was measured. GEM showed a homogeneous distribution over the open North Atlantic Ocean (median 1.53 +/- 0.12 ng/m3), which is in contrast to the higher concentrations of GEM observed over sea ice (median 1.82 +/- 0.24 ng/m3). It is hypothesized that this results from either (re-) emission of mercury contained in snow and ice surfaces that was previously deposited during atmospheric mercury depletion events (AMDE) in the spring or evasion from the ocean due to increased reduction potential at high latitudes during Arctic summer. Measured concentrations of total mercury in surface snow and meltwater ponds were low (all samples <10 ng/L), indicating that marginal accumulation of mercury occurs in these environmental compartments. Results also reveal low concentrations of RGM and Hg-P without a significant diurnal variability. These results indicate that the production and deposition of these reactive mercury species do not significantly contribute to the atmospheric mercury cycle in the North Atlantic Ocean during the Arctic summer.
2004年6月15日至8月29日，在德国研究船“极星号”（RV Polarstern）上进行了为期10周的北大西洋北极夏季考察，期间对大气汞形态进行了测量。这次考察覆盖了北大西洋和北冰洋北纬54度至85度、西经16度至东经16度之间的大片区域。在本研究中，对气态单质汞（GEM）、活性气态汞（RGM）和与颗粒物相关的汞（Hg-P）进行了测量。此外，还测量了海冰浮冰上表层雪和融水池塘中的总汞。GEM在开阔的北大西洋呈现均匀分布（中位数为1.53±0.12纳克/立方米），这与在海冰上观测到的较高GEM浓度（中位数为1.82±0.24纳克/立方米）形成对比。据推测，这要么是由于春季大气汞消耗事件（AMDE）期间先前沉积在冰雪表面的汞的（再）排放，要么是由于北极夏季高纬度地区还原电位增加导致汞从海洋逸出。表层雪和融水池塘中测量的总汞浓度较低（所有样本<10纳克/升），表明这些环境介质中汞的积累较少。结果还显示RGM和Hg-P浓度较低，且无明显的日变化。这些结果表明，在北极夏季，这些活性汞物种的产生和沉降对北大西洋大气汞循环的贡献不大。
