Almost 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.
