DOI: 10.5194/tc-14-199-2020
论文题名: Impact of exhaust emissions on chemical snowpack composition at Concordia Station, Antarctica
作者: Helmig D. ; Liptzin D. ; Hueber J. ; Savarino J.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 1 起始页码: 199
结束页码: 209
语种: 英语
英文关键词: ambient air
; atmospheric chemistry
; atmospheric plume
; chemical composition
; exhaust emission
; ice sheet
; nitrogen oxides
; ozone
; photochemistry
; snowpack
; Antarctica
; Concordia Station
; Dome Concordia
; East Antarctica
英文摘要: The chemistry of reactive gases inside the snowpack and in the lower atmosphere was investigated at Concordia Station (Dome C), Antarctica, from December 2012 to January 2014. Measured species included ozone, nitrogen oxides, gaseous elemental mercury (GEM), and formaldehyde, for study of photochemical reactions, surface exchange, and the seasonal cycles and atmospheric chemistry of these gases. The experiment was installed ≈ 1 km from the station main infrastructure inside the station clean air sector and within the station electrical power grid boundary. Ambient air was sampled continuously from inlets mounted above the surface on a 10m meteorological tower. In addition, snowpack air was collected at 30 cm intervals to 1.2m depth from two manifolds that had both above- and belowsurface sampling inlets. Despite being in the clean air sector, over the course of the 1.2-year study, we observed on the order of 50 occasions when exhaust plumes from the camp, most notably from the power generation system, were transported to the study site. Continuous monitoring of nitrogen oxides (NOx) provided a measurement of a chemical tracer for exhaust plumes. Highly elevated levels of NOx(up to 1000 × background) and lowered ozone (down to ≈ 50 %), most likely from reaction of ozone with nitric oxide, were measured in air from above and within the snowpack.Within 5-15 min from observing elevated pollutant levels above the snow, rapidly increasing and long-lasting concentration enhancements were measured in snowpack air. While pollution events typically lasted only a few minutes to an hour above the snow surface, elevated NOx levels were observed in the snowpack lasting from a few days to ≈1 week. GEM and formaldehyde measurements were less sensitive and covered a shorter measurement period; neither of these species data showed noticeable concentration changes during these events that were above the normal variability seen in the data. Nonetheless, the clarity of the NOx and ozone observations adds important new insight into the discussion of if and how snow photochemical experiments within reach of the power grid of polar research sites are possibly compromised by the snowpack being chemically influenced (contaminated) by gaseous and particulate emissions from the research camp activities. This question is critical for evaluating if snowpack trace chemical measurements from within the camp boundaries are representative for the vast polar ice sheets. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164476
Appears in Collections: 气候变化与战略
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作者单位: Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, United States; Université Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble, 38000, France
Recommended Citation:
Helmig D.,Liptzin D.,Hueber J.,et al. Impact of exhaust emissions on chemical snowpack composition at Concordia Station, Antarctica[J]. Cryosphere,2020-01-01,14(1)