Collaborative Research: Present and future contribution of glacial runoff to freshwater discharge into the Gulf of Alaska

合作研究：冰川径流对阿拉斯加湾淡水排放的当前和未来贡献

• 批准号: 0943599
• 负责人: Eran Hood
• 金额: $ 8.47万
• 依托单位: University of Alaska Southeast Juneau Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0943599&HistoricalAwards=false
• 关键词: Collaborative; Research; Present; future; contribution

Freshwater influx to the Gulf of Alaska (GOA) is strongly influenced by glacier runoff as roughly one fifth of its drainage basin is covered by glacier ice. During the last decades GOA glaciers have generally thinned and retreated and hence precipitation stored in the glaciers as snow and ice has been released augmenting streamflow and freshwater influx to the Gulf of Alaska. Glaciers draining to the GOA are highly sensitive to climate warming and mass loss rates are expected to increase. It is hypothesized that runoff from glaciers will initially increase by more than 50% as wastage accelerates, but then will reach a turning point upon which runoff will decrease as the glaciers shrink and partly disappear. Hence, the changes in the hydrological cycles due to glacier wastage are substantially larger than expected changes in any other component of the water budget in this region.The research will quantify these changes in runoff. A glacier runoff model is used to simulate the current magnitude and timing of runoff from glaciers that drain to the Gulf of Alaska and project how glacial runoff along the Gulf of Alaska will change by 2100 in response to future climate scenarios in Alaska downscaled by a high resolution regional climate model. Further, potential changes to the biogeochemical fluxes into freshwater and marine ecosystems associated with the projected changes in glacier runoff are assessed. Results provide regional scale estimates of glacier runoff changes and associated impacts on biogeochemical fluxes for the GOA. A modeling strategy is developed that can be used to evaluate glacier runoff changes and hydrologic ?tipping points? in other heavily glacierized regions. Moreover, the downscaled climate scenarios we develop will be available for other impact studies. Visualization products of the results are made available to the Mendenhall Glacier visitor center, which is visited by approximately 350,000 people each year.

冰川径流对阿拉斯加湾（果阿）的淡水涌入受到强烈的影响，因为大约五分之一的排水盆地被冰川冰覆盖。在过去的几十年中，果阿冰川通常已经变薄和退缩，因此随着冰雪的释放，冰川储存在冰川中，增强了溪流和淡水涌入阿拉斯加湾。排入果阿的冰川对气候变暖高度敏感，预计质量损失率将增加。假设冰川的径流最初会随着浪费的加速增加50％以上，但是随着冰川缩小并部分消失，径流会减少的转折点。因此，由于冰川浪费而引起的水文循环的变化大大比该地区水预算的任何其他组成部分的预期变化大得多。该研究将量化径流中的这些变化。冰川径流模型用于模拟从冰川流向阿拉斯加湾的径流的当前幅度和时机，并预测阿拉斯加湾沿线的冰川径流将如何在2100年变化，以应对阿拉斯加未来的气候场景，而高分辨率的气候气候模型降低了。此外，评估了与冰川径流预计变化相关的淡水和海洋生态系统的生物地球化学通量的潜在变化。结果提供了冰川径流变化的区域尺度估计以及对果阿生物地球化学通量的相关影响。开发了一种模型策略，可用于评估冰川径流的变化和水文？临界点？在其他重冰川的地区。此外，我们开发的缩小的气候场景将用于其他影响研究。结果的可视化产品可提供给门登霍尔冰川游客中心，该中心每年约有35万人访问。