Long-Range Atmospheric Transport and its Relationship to Air/Snow/Ice Chemistry at Summit, Greenland

这是四个协调项目之一，这些项目将利用格陵兰内陆冰盖上建立的营地设施，作为GISP-2冰芯钻探工作的一部分，以调查大气痕量元素是如何沉积在冰上的，以及它们被并入冰中时会经历什么样的变化。为了正确解释可以从冰芯中恢复的替代气候数据，有必要了解这些过程。虽然最近在提取和分析冰芯方面取得了重大进展，但在了解活性化学物质的空气到雪的转移过程方面的进展仍然滞后。该项目的目标是详细了解影响格陵兰冰盖上降水化学的大气输送过程。在有可靠的全球气象档案的时间内检查空气-雪-冰化学测量的变化，将能够将冰芯化学-大气传输联系在时间上反向推算到不存在气象信息的时期。大气远距离输送的知识是大气-雪输送过程的基础。回收的冰芯含有来源遥远的杂质和成分，并由大气环流携带到格陵兰内陆。沿岩心的冰的物理和化学成分的变化在很大程度上反映了大气环流模式的变化。作为该项目的一部分，将编制长期大气轨迹气候学，并检查观测到的运输模式的季节和年际变化。

This is one of four coordinated projects that will make use of the camp facilities established on the ice sheet in the interior of Greenland as part of the GISP-2 ice core drilling effort, in order to investigate how atmospheric trace elements are deposited on the ice and what kind of changes they undergo as they are being incorporated into the ice. An understanding of such processes is necessary in order to properly interpret the proxy climate data that can be recovered from ice cores. While significant progress has been made recently in extracting and analyzing ice cores, progress in understanding the air to snow transfer process for reactive chemical species has lagged behind. The goal of this project is to provide a detailed understanding of the atmospheric transport processes that influence the precipitation chemistry over the Greenland ice sheet. The examination of variations in air-snow-ice chemistry measurements during the time for which reliable global meteorological archives are available will allow the extrapolation of the ice core chemistry-atmospheric transport link backward in time to periods for which meteorological information does not exist. Knowledge of long-range atmospheric transport is basic to the air- snow transfer process. The recovered ice cores contain impurities and components whose sources are distant, and which were carried by the atmospheric circulation to the interior of Greenland. Variations in the physical and chemical composition of the ice along the core reflects to a large extent variations in atmospheric circulation patterns. As part of this project a long-term atmospheric trajectory climatology will be prepared as well as an examination of the seasonal and interannual variability of observed transport patterns.