Black carbon in Arctic snow and ice and its effect on surface albedo

北极冰雪中的黑碳及其对地表反照率的影响

• 批准号: 0612636
• 负责人: Stephen Warren
• 金额: $ 92.57万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0612636&HistoricalAwards=false
• 关键词: Black; carbon; Arctic; snow; ice

Warren 0612636Two decades ago, measurements of the black carbon (BC) content of snow on land and sea in the western Arctic suggested that BC was responsible for possible reductions of albedo of 0-4%. However, more recent measurements suggest that the BC content of snow in the Arctic Ocean may have changed. The PIs propose an updated, pan-arctic survey, during which samples will be taken near the time of maximum snow depth on the Arctic Ocean, in tundra areas of Russia, Alaska, and Canada, in both wet-snow and dry-snow zones of the Greenland Ice Sheet, and on ice caps in Iceland. Both project personnel and volunteer researchers will be involved in the sampling. Glacier ice will be sampled in summer in the ablation zone of the Greenland Ice Sheet, since there is evidence that its albedo is reduced by BC. Snow samples will be taken at several vertical levels through the snowpack. At one or more locations snow samples will be collected over the course of the melting season, to document the vertical redistribution of BC. BC is usually hydrophobic. As the snow melts, BC may tend to concentrate at the surface, where it has a greater effect on albedo than if uniformly distributed. The effect of BC on the surface albedo will be estimated both regionally and seasonally. Air sampling concurrent with snowfall events will be carried out at one or more locations, to determine the scavenging ratio, which is needed in atmospheric transport models that link emissions of aerosols to deposition in precipitation.The distribution of BC throughout the arctic snowmass and its seasonal variability may have important effects on climate variability due to their influence on albedo. The information provided by this project will be useful both for the further development and for the skill assessment of climate models.

Warren 0612636 二十年前，对北极西部陆地和海洋雪中黑碳 (BC) 含量的测量表明，BC 可能导致反照率降低 0-4%。 然而，最近的测量表明，北冰洋雪中的BC含量可能已经发生了变化。 PI提议进行更新的泛北极调查，调查期间将在北冰洋最大积雪深度附近、俄罗斯、阿拉斯加和加拿大的苔原地区的湿雪和干雪地区采集样本格陵兰冰盖和冰岛的冰盖上。 项目人员和志愿者研究人员都将参与采样。 夏季，我们将在格陵兰冰原消融区对冰川冰进行采样，因为有证据表明，BC 的反照率有所降低。将通过积雪在几个垂直高度采集雪样。 在融化季节期间，将在一个或多个地点收集雪样本，以记录 BC 的垂直重新分布。 BC通常是疏水性的。 随着雪融化，BC 可能会集中在地表，与均匀分布相比，它对反照率的影响更大。 BC 对地表反照率的影响将按区域和季节进行估计。 与降雪事件同时进行的空气采样将在一个或多个地点进行，以确定清除率，这是将气溶胶排放与降水沉积联系起来的大气传输模型所需要的。BC在整个北极雪体的分布及其季节性由于其对反照率的影响，变率可能对气候变率产生重要影响。 该项目提供的信息将有助于气候模型的进一步开发和技能评估。