Is Glacier Wastage Accelerating in Northwestern North America?

北美西北部几乎所有的冰川都在失去质量，而且在过去十年左右的时间里，其速度比过去几十年的速度快了近两倍。显而易见的问题是，这种加速是否还在继续。为了解决这个问题，一项为期三年的项目将继续对北美西北部的冰川进行海拔剖面分析，该项目将在2007年至2009年期间使用小型飞机激光测高仪系统进行。将有第四年进行分析。这些结果将为我们提供比目前更好的区域覆盖范围，并允许对该源区对平均海平面上升的贡献进行更准确和最新的估计。在所有年份，都将有一个解释性项目，重点关注冰川消耗对海平面的影响，特别关注趋势，以及冰川与气候之间的联系。其目标是：1)在国际极地年期间继续开展冰川分析项目；2)从这个项目和我们相关的（以及早期的）NASA项目中完整地还原、分析和存档冰川剖面数据；3)开发一种有效和准确的方法，将我们的飞行线高程变化和体积变化估算从测量的冰川外推到北美西北部所有冰川化地区，从而可以在适当的间隔更新这些冰川对海平面上升的区域贡献估算；4)根据冰川在气候系统中的作用来解释我们的结果。更广泛的影响：在气候变化的这段时间里，对北美西北部冰川流失的测量引起了公众的兴趣，并得到了很多媒体的报道。公众把冰川的消融看作是一种令人印象深刻的晴雨表和例证，是气候持续变化的结果，最实际的后果是冰川消融对全球平均海平面上升的贡献。因此，冰川流失是否继续加速的问题引起了相当大的兴趣。海平面上升对世界沿海人口的影响是巨大的，包括直接的洪水和相关现象，如冰川后隆起、海岸侵蚀加剧以及风暴潮的风险。

ABSTRACTLingleOPP-0612Almost all the glaciers of northwestern North America are losing mass, and at a rate that has accelerated by a factor of almost two during the past decade or so compared with the rate over several previous decades. The obvious question is whether this acceleration is continuing. To address this question, funds are requested for a three-year program to continue elevation profiling of the glaciers of northwestern North America, which will be carried out with a small-aircraft laser altimeter system from 2007 through 2009. There will be a fourth year for analysis. The results will give us better regional coverage than we have at present, and permit more accurate and updated estimations of the contribution to rising mean sea level from this source region. In all years, there will be an interpretative program that will focus on the effect of glacier wasting on sea level with special attention to trends, and on the connections between glaciers and climate. The objectives are to: 1) continue the glacier profiling and analysis program through the International Polar Year; 2) complete reduction, analysis and archiving of glacier profiling data from this and our related (and earlier) NASA projects; 3) develop an efficient and accurate method for extrapolating our flight-line elevation changes and volume change estimates from measured glaciers to all of the glacierized areas of northwestern North America, so estimates of the regional contribution from these glaciers to rising sea level can be updated at suitable intervals; and 4) interpret our results in terms of the role of glaciers in the climate system. Broader impacts: The measurement of glacier wastage in northwestern North America is of interest to the public during this time of climate change and has received much press coverage. The public sees the wastage of glaciers as an impressive kind of barometer and illustration and a consequence of continuing climate change, the most practical consequence being the contribution of glacier wastage, globally to rising mean sea level. Thus, the question of whether glacier wastage is continuing to accelerate is of considerable interest. The effects of rising sea level on the coastal populations of the world are enormous and include direct flooding and related phenomena such as post-glacial uplift, increasing coastal erosion, and risk from storm surges.