Collaborative Research: SNOWpack Photodenitrification from the Antarctic and Arctic Cryosphere (SNOWPAAC)

合作研究：南极和北极冰冻圈的 SNOWpack 光脱氮 (SNOWPAAC)

• 批准号: 1244958
• 负责人: Daven Henze
• 金额: $ 5.72万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1244958&HistoricalAwards=false
• 关键词: Collaborative; Research; SNOWpack; Photodenitrification; Antarctic

The importance of knowing the different sources of atmospheric nitrate to the polar ice sheets of Antarctica and Greenland, along with their transport paths, is of intrinsic interest to the atmospheric chemistry of polar NOx species. In turn, surface photolysis of snowpack nitrate renders these ice sheets as strongly oxidizing surfaces during sunlight. Attempts to derive past conditions or variability of atmospheric NOx (= NO + NO2 +?) species from ice core records will need to take photodenitrification and source transfer function effects into account. The approach willcontinue to use a inverse chemical transfer model (adjoint GEOS-Chem) to test the sensitivity of nitrate deposition to the Antarctic continent from various possible sources. The following questions are posed: 1) what are the important sources of nitrate to Antarctia (and Greenland) in the present and in the pre-industrial Holocene? 2) How does the recycling of reactive nitrogen at the atmosphere-snow interface redistribute nitrate across large polar ice sheets? and 3) are their implications for nitrate preservation in ice cores and their interpretation?Goals being pursued in this modeling study include the reconstruction of past (polar) atmospheric composition and a better contemporary understanding of the variability of atmospheric reactive nitrogen compounds as may be discerned from measurements of nitrate concentrations retained in snow, firn and possibly ice cores in polar regions.

了解南极洲和格陵兰岛极地冰盖大气硝酸盐的不同来源沿着传输路径的重要性，对极地NOx物种的大气化学具有内在的意义。反过来，积雪硝酸盐的表面光解使这些冰盖在阳光照射下成为强氧化表面。 试图推导出过去的条件或大气氮氧化物的变化（= NO + NO2 +？）冰芯记录中的物种需要考虑到光脱氮作用和源转移函数效应。 该方法将继续使用逆化学转移模型（伴随GEOS-Chem）来测试各种可能来源的硝酸盐沉积对南极大陆的敏感性。提出了以下问题：1）在现代和前工业化全新世，对舌尖（和格陵兰）硝酸盐的重要来源是什么？2)在大气-雪界面上活性氮的循环是如何将硝酸盐重新分布到极地大冰原上的？3）它们对冰芯中硝酸盐保存的意义及其解释？在这一建模研究中追求的目标包括重建过去（极地）的大气成分和更好的当代理解大气活性氮化合物的变异性，可以看出，从测量保留在雪中的硝酸盐浓度，积雪和可能的冰芯在极地地区。