A Century-long Record of Trace Gases in the Northern Hemisphere from the NEEM Ice Core Drilling Project in Greenland

格陵兰岛 NEEM 冰芯钻探项目对北半球痕量气体长达一个世纪的记录

• 批准号: NE/F021194/1
• 负责人: William Sturges
• 金额: $ 53.54万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FF021194%2F1
• 关键词: Century; long; Record; Trace; Gases

An international effort is underway to drill a new ice core in Greenland: the North Greenland Eemian Ice Drilling project (NEEM). This presents an exciting and rare opportunity to obtain 'firn' air and ice cores from a Northern Hemispheric (NH) location. 'Firn air' is air trapped in the porous snow overlying solid ice. This air can be pumped out with a special drilling and pumping arrangement. As one moves deeper in to the snow, the older the air is: eventually representing the composition of air in the NH in the first half of the 20th century. Below the firn, even older air is trapped in individual bubbles in solid ice. We will also extract this air and analyse it, but the measurement is much more difficult and not as many chemicals can be analysed as in the firn. We nevertheless should be able to study the rise of numerous gaseous pollutants (carbon monoxide (CO) and its isotopic composition, hydrocarbons, halocarbons, organic nitrates, etc.) over the last century or more. Deep drilling will begin in the summer of 2008, with a second borehole drilled at that time to extract firn air. Large firn air volumes will be retrieved to enable an extensive suite of trace gases to be measured, and also to permit comprehensive analysis of the isotopes ratios of CO (delta13C, delta18O, and Delta17O). Measurements will concentrate on trace gases with anthropogenic sources, for which we expect to observe significant increases over the last century. We will further concentrate on gases that are relatively short-lived in the atmosphere (lifetimes of weeks to a few years), since prior Antarctic studies have only partly / or not at all - delivered trends of such gases which are emitted largely in the NH. The target gases include those of importance to stratospheric ozone, and those which are precursors of tropospheric ozone, or are proxies of other species (e.g. alkyl nitrates as proxies of reactive nitrogen, NOx: an important driver of global-scale chemistry). The trend and stable isotopic composition of CO will be determined to probe both the past sources of CO (e.g. biomass burning versus methane oxidation) from measurement of delta13C(CO), and past levels of hydroxyl radical (OH) by studying delta18O(CO) and Delta17O(CO). Hydroxyl radical is a crucial component of atmospheric chemistry: often referred to as the 'detergent' of the atmosphere. There is presently little consensus on whether OH has changed over the last hundred years as a result of increased pollution. Any significant decrease would be a cause for concern for future levels of this important molecule.

一项在格陵兰岛钻探新冰芯的国际努力正在进行中：北格陵兰岛伊米安冰钻探项目(NEEM)。这提供了一个令人兴奋和难得的机会，可以从北半球(NH)位置获得“降雪”空气和冰芯。Firn Air指的是被困在坚硬冰层上的疏松积雪中的空气。这种空气可以用一种特殊的钻孔和抽水装置抽出。一个人越深入到雪中，空气就越古老：最终代表了20世纪上半叶NH地区空气的组成。在积雪之下，即使是更老的空气也被困在固体冰中的单个气泡中。我们还将提取这些空气并对其进行分析，但测量要困难得多，可以分析的化学物质也不像在FIRN中那么多。然而，我们应该能够研究大量气态污染物(一氧化碳及其同位素组成、碳氢化合物、卤代烃、有机硝酸盐等)的上升。在过去的一个世纪或更长时间里。深井钻探将于2008年夏天开始，届时将钻第二个钻孔，以提取稀薄的空气。将回收大量的降温空气，以便能够测量广泛的痕量气体，并允许全面分析CO的同位素比率(增量13C、增量18O和增量17O)。测量将集中在具有人为来源的痕量气体上，我们预计在上个世纪将观察到这方面的显著增加。我们将进一步集中研究大气中寿命相对较短的气体(寿命从几周到几年)，因为以前的南极研究只有部分或根本没有提供这类气体的趋势，这些气体主要在NH排放。目标气体包括那些对平流层臭氧很重要的气体，以及那些是对流层臭氧前体的气体，或者是其他物种的替代品(例如，作为活性氮替代品的烷基硝酸盐，NOx：全球规模化学的重要驱动因素)。CO的趋势和稳定的同位素组成将被确定，以通过测量Delta13C(CO)来探索过去的CO来源(例如，生物质燃烧与甲烷氧化)，以及通过研究Delta18O(CO)和Delta17O(CO)来探索过去的羟基自由基(OH)水平。羟基自由基是大气化学的重要组成部分：通常被称为大气中的“洗涤剂”。目前，对于羟基磷灰石在过去一百年中是否由于污染增加而发生了变化，人们几乎没有达成共识。任何显著的下降都会引起人们对这一重要分子未来水平的担忧。

项目成果

Tropospheric observations of CFC-114 and CFC-114a with a focus on long-term trends and emissions

CFC-114 和 CFC-114a 对流层观测，重点关注长期趋势和排放

• DOI: 10.5194/acp-2016-610
• 发表时间: 2016
• 作者: Laube J

Atmospheric Abundances, Trends and Emissions of CFC-216ba, CFC-216ca and HCFC-225ca

CFC-216ba、CFC-216ca 和 HCFC-225ca 的大气丰度、趋势和排放

• DOI: 10.3390/atmos5020420
• 发表时间: 2014
• 期刊: Atmosphere
• 影响因子: 2.9
• 作者: Kloss C

Reconstruction of Northern Hemisphere 1950-2010 atmospheric non-methane hydrocarbons

• DOI: 10.5194/acp-14-1463-2014
• 发表时间: 2014-01-01
• 期刊: ATMOSPHERIC CHEMISTRY AND PHYSICS
• 影响因子: 6.3
• 作者: Helmig, D.;Petrenko, V.;Tans, P.
• 通讯作者: Tans, P.

Gas transport in firn: multiple-tracer characterisation and model intercomparison for NEEM, Northern Greenland

• DOI: 10.5194/acp-12-4259-2012
• 发表时间: 2012-01-01
• 期刊: ATMOSPHERIC CHEMISTRY AND PHYSICS
• 影响因子: 6.3
• 作者: Buizert, C.;Martinerie, P.;Blunier, T.
• 通讯作者: Blunier, T.

Accelerating growth of HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) in the atmosphere

• DOI: 10.5194/acp-10-5903-2010
• 发表时间: 2010-07
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: J. Laube;P. Martinerie;E. Witrant;T. Blunier;J. Schwander;C. Brenninkmeijer;T. Schuck;M. Bolder;T. Röckmann;C. Veen;H. Bönisch;A. Engel;G. Mills;M. Newland;D. Oram;C. Reeves;W. Sturges