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: 0943742
• 负责人: Regine Hock
• 金额: $ 35万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Continuing 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=0943742&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.

流入阿拉斯加湾（果阿）的淡水受到冰川径流的强烈影响，因为其流域约有五分之一被冰川冰覆盖。在过去的几十年里，果阿冰川普遍变薄和退缩，因此，随着冰雪的释放，降水储存在冰川中，增加了流入阿拉斯加湾的径流和淡水。流向果阿的冰川对气候变暖高度敏感，预计质量损失率将增加。据推测，冰川的径流量最初将增加50%以上，随着浪费的加速，但随后将达到一个转折点，随着冰川的缩小和部分消失，径流量将减少。因此，由于冰川流失造成的水文循环变化远远大于该地区水收支任何其他组成部分的预期变化，研究将量化这些径流变化。冰川径流模型被用来模拟目前的规模和时间的径流从冰川流失到阿拉斯加湾和项目如何冰川径流沿着阿拉斯加湾将改变到2100年，在阿拉斯加的未来气候情景缩小的高分辨率区域气候模型。此外，潜在的变化到淡水和海洋生态系统的地球化学通量与冰川径流的预计变化进行了评估。结果提供了区域尺度的估计冰川径流变化和相关的影响地球化学通量的果阿。一个建模策略的开发，可用于评估冰川径流变化和水文？引爆点在其他严重冰川化的地区。此外，我们开发的缩小尺度的气候情景将可用于其他影响研究。结果的可视化产品提供给门登霍尔冰川游客中心，该中心每年约有35万人参观。