SGER: Snow Chemical Composition and Its Relation to Arctic Springtime Mercury Deposition and Ozone Depletion

SGER：雪的化学成分及其与北极春季汞沉积和臭氧消耗的关系

• 批准号: 0420205
• 负责人: William Simpson
• 金额: $ 9.09万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0420205&HistoricalAwards=false
• 关键词: SGER; Snow; Chemical; Composition; Its

This study will involve the systematic sampling of snow in northern Alaska during the critical springtime period when ozone depletion events (ODE) and mercury deposition events (MDE) take place. It has been known for sometime that unusual chemistry takes place during sunrise at high northern latitudes, in which chemistry involving bromine leads to boundary layer ozone destruction, and deposition of mercury. The details of the source of the bromine and the exact chemical mechanisms are still under study. The deposition of mercury is a potential environmental hazard, and thus it is important to understand the details of the processes. This study will attempt to quantify the functional dependence of mercury deposition and halogen abundance on distance from the ocean source region, meteorology, and other factors. This project leverages the existence of the Barrow Arctic Mercury Study (BAMS) that will provide infrastructure and detailed chemical and physical measurements at Barrow, Alaska, and will extend BAMS through geographical sampling of snow in the region south and west of Barrow. In addition, satellite observations of bromine monoxide (BrO) will be used to track the evolution of ozone depletion events and to help plan the snow sampling periods.The snow samples will be collected along three transects between Barrow, Wainwright, and Atqasuk. The three villages form a triangle with legs approximately 100 km long. Barrow and Wainwright sit on the shore of the Arctic Ocean, while Atqusuk lies inland. The hypothesis that the chemistry responsible for ozone depletion and mercury deposition is limited by availability of bromide ion in the snow will be rigorously tested by this experiment. Studies will be performed after sunrise, but well before the active ozone depletion period, near equinox when depletion chemistry is very active, and late in the spring when ozone depletion has ended but snow remains on the ground. The snow will be sampled for a number of quantities including mercury, ions and the deuterium and oxygen isotopic composition of water. These measurements will allow the quantification of the target quantities (mercury and bromide) as well as species that will aid in correlating specific snow layers at the different sites.This project will improve understanding of the mechanism of mercury deposition and be of benefit to the inhabitants of regions impacted by this springtime phenomenon. The spatial extent and intensity of mercury deposition will be studied in the region. This will lead to better understanding of the global mercury budget. The budget provides graduate student support, and the PIs intend to make presentations on their research at the three remote villages bounding the study region, thereby improving public understanding of the relevant issues.

这项研究将涉及在关键的春季期间，当臭氧消耗事件（ODE）和汞沉积事件（MDE）发生时，在北方阿拉斯加州的雪的系统采样。 人们知道，在北方高纬度地区的日出期间会发生不寻常的化学反应，其中涉及溴的化学反应会导致边界层臭氧破坏和汞的沉积。 溴的来源和确切的化学机制的细节仍在研究中。 汞的沉积是一种潜在的环境危害，因此了解这些过程的细节非常重要。 这项研究将试图量化汞沉积和卤素丰度与海洋源区距离、气象和其他因素的函数依赖关系。 该项目利用了巴罗北极汞研究项目，该项目将在阿拉斯加的巴罗提供基础设施和详细的化学和物理测量，并将通过对巴罗南部和西部地区的积雪进行地理采样来扩展北极汞研究项目。 此外，还将利用一氧化溴的卫星观测来跟踪臭氧消耗事件的演变情况，并帮助规划雪的取样周期，将沿巴罗、温赖特和阿特卡苏克之间的沿着三个断面收集雪样。 这三个村庄形成一个三角形，边长约100公里。 巴罗和温赖特坐落在北冰洋的海岸，而阿特库苏克则位于内陆。 该实验将严格验证以下假设：造成臭氧消耗和汞沉积的化学物质受到雪中溴离子可用性的限制。 研究将在日出后进行，但要早于臭氧消耗活跃期、接近秋分时臭氧消耗化学非常活跃、以及春季末臭氧消耗结束但地面仍有积雪时。 将对雪进行取样，以确定水的汞、离子、氘和氧同位素组成等数量。 这些测量将有助于量化目标数量（汞和溴）以及物种，这将有助于将不同地点的具体雪层联系起来，该项目将提高对汞沉积机制的理解，并有利于受这种春季现象影响的地区的居民。 将研究该区域汞沉积的空间范围和强度。 这将有助于更好地了解全球汞预算。 预算提供研究生支持，PI打算在研究区域边界的三个偏远村庄介绍他们的研究，从而提高公众对相关问题的理解。