Core Measurements at Summit, Greenland Environmental Observatory

This 5-year project supports continuing and expanding the collection of long-term measurements of the Arctic atmosphere, snow and other Earth system components at the Summit Greenland Environmental Observatory (GEOSummit), located at an elevation of 3100 m on the Greenland ice sheet. A core suite of measurements has been collected at GEOSummit since 1993 and this project provides for the continued operation of GEOSummit as long-term site for year-round disciplinary and interdisciplinary measurements and research. The location provides a compliment to lower-elevation sites and a Northern Hemisphere analog to South Pole station. Measurements include baseline meteorology, radiation, tropospheric chemistry, snow properties and snow chemistry, some measurements in cooperation with NOAA-CMDL and measurements initiated by individual investigators. Measurements are aligned with the objectives of the World Meteorological Organization's Global Atmospheric Watch (GAW) program. The atmospheric gas-phase and aerosol species being studied are all either sensitive indicators of anthropogenic impacts on regional and global atmospheric change, or are important chemically coupled species whose concentrations may be strongly influenced by changes in the Arctic, including changes in snow/ice surface temperatures, ice/snow cover, and atmospheric circulation. Related chemical measurements in the snow provide the needed link to investigate feedbacks between Arctic climate change, air-snow exchange, and atmospheric composition. Recent evidence indicates that important atmospheric chemical constituents undergo temperature-dependent exchange with ice/snow, and that some species are photochemically transformed and/or produced within the sunlit surface snowpack. Understanding arctic environmental change requires a quantitative understanding of the environmental controls (e.g., temperature, radiation, humidity, ozone concentration) on air-snow feedbacks, as well as the impact of these processes on the entire Arctic atmosphere. Because changes in Arctic atmospheric circulation are cyclic over 4-5 year or longer times, long-duration measurements are needed to understand circulation and to place observed changes in a long-term perspective. Data and results will be shared via the National Snow and Ice Data Center data archive.

本为期五年的项目支持对格陵兰冰盖之巅环境观测站（Summit Greenland Environmental Observatory, GEOSummit）的长期监测工作进行延续与拓展。该观测站坐落于格陵兰冰盖海拔3100米处，监测对象涵盖北极大气、积雪及其他地球系统组分。自1993年起，该观测站便已开展核心系列监测工作，本项目将保障其持续运行，作为常年开展单学科与跨学科监测及研究的长期站点。
该观测站的设立可作为低海拔监测站点的重要补充，同时也是北半球地区对标南极科考站的关键监测点位。监测内容涵盖基础气象、辐射、对流层化学、积雪特性与积雪化学等方向，部分监测工作与NOAA-CMDL合作开展，另有部分监测由独立研究者发起。所有监测工作均符合世界气象组织（World Meteorological Organization, WMO）全球大气观测（Global Atmospheric Watch, GAW）计划的目标要求。
本次研究关注的大气气相组分与气溶胶物种，要么是人为活动对区域及全球大气变化产生影响的敏感指示物，要么是具有重要化学耦合关系的物种——其浓度极易受北极地区环境变化影响，包括积雪/冰面温度、冰雪覆盖范围以及大气环流的改变。针对积雪开展的相关化学监测，可为探究北极气候变化、气雪交换与大气组分之间的反馈机制提供必要的关联纽带。
近期研究证据表明，重要的大气化学成分会与冰雪发生依赖于温度的交换过程，部分物种还会在受日照的表层积雪中发生光化学转化或生成。要深入理解北极环境变化，需定量阐明气雪反馈过程的环境控制因子（如温度、辐射、湿度、臭氧浓度），以及这些过程对整个北极大气系统的影响。由于北极大气环流的变化存在4-5年甚至更长周期的循环规律，因此需要开展长期监测以解析环流特征，并将观测到的变化置于长期时间尺度下进行审视。所有数据与研究成果将通过美国国家冰雪数据中心（National Snow and Ice Data Center）的数据存档平台进行共享。