Satellite Remote Sensing of Glaciers and Ice Caps in Svalbard, Eurasian High Arctic

汉密尔顿0221292最近与气候有关的观测汇编表明，北极高地正在发生重大变化，这可能是对过去约250年来人为温室气体排放的一种反应。这些变化包括对流层变暖，海冰覆盖减少，积雪覆盖面积减少，冻土带永久冻土变暖，以及冰川和冰帽的负质量平衡。在许多情况下，观察到的变化持续时间相对较短或空间范围较小。首席调查人员将在斯瓦尔巴群岛上研究过去大约80年来的冰川和冰盖变化，并进行大规模的研究。这些岛屿拥有欧亚大陆北部最大范围的冰川冰，相当于约0.03米的海平面相当于储存的水。自1966年以来，对斯瓦尔巴群岛冰川变化和物质平衡的测量一直在进行，但大多数调查仅限于斯瓦尔巴群岛西北部的小冰川。大多数大型冰川和冰盖的行为和现状在很大程度上是未知的。这项提案中包含的工作包括使用高分辨率的现代卫星图像来绘制当前冰川和冰盖范围的地图。这些地图将与档案信息进行比较，以评估变化的速度和方式。将使用的主要现代图像类型将来自Terra上携带的高级星载热发射和反射辐射计(ASTER)仪器。档案信息来源包括大地测量地图、解密情报卫星摄影(DISP)图像和陆地卫星MSS(多光谱扫描仪)图像。拟议工作的总体目标是了解斯瓦尔巴群岛目前冰块的质量平衡，以及它们目前和未来对海平面变化的贡献。方案有几个目标：1)使用卫星图像绘制斯瓦尔巴特群岛冰川和冰帽的现代界线，并将这些界线与档案资料进行比较，以评估50年或更长时期的变化；2)利用遥感数据建立雪相范围和夏末雪线位置的时间序列，以确定短期和中期的变异性；3)绘制冰流变化图，以确定流动不稳定性的重要性；4)利用观测到的变化评估整个群岛冰川和冰帽质量平衡的空间变异性；5)解释观测到的变化的原因。

Hamilton0221292Recent compilations of climate-related observations show that important changes are now underway in the High Arctic, probably as a response to anthropogenic greenhouse gas emissions over the last approximately 250 years. These changes include warming of the troposphere, reductions in sea ice cover, decreases in snow cover area, warming of tundra permafrost, and negative mass balances of glaciers and ice caps. In many instances, observations of change are relatively short in duration or sparse in spatial extent. The Principal Investigators will study glacier and ice cap variations over the approximately last 80 years and at a large scale on Svalbard. The islands contain the largest extent of glacier ice in northern Eurasia, amounting to about 0.03 meters of sea level equivalent water in storage. Measurements of glacier variations and mass balance have been conducted continuously on Svalbard since 1966, but most investigations are restricted to small glaciers in northwestern Svalbard. The behavior and current status of most large glaciers and ice caps is largely unknown. The work contained in this proposal involves using high resolution, modern satellite imagery to map current glacier and ice cap extents. These maps will be compared with archival information to assess rates and styles of change. The primary type of modern imagery to be used will be from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument carried onboard Terra. Archival sources of information include geodetic maps, Declassified Intelligence Satellite Photography (DISP) imagery and Landsat MSS (Multi-spectral Scanner) imagery. The overall aim of the proposed work is to understand the current mass balance of ice masses in Svalbard and their current and future contribution to sea level change. There are several objectives: 1) mapping modern boundaries of glaciers and ice caps in Svalbard using satellite imagery and comparing those with archival information to assess changes over a 50 or longer year period; 2) constructing time series of snow facies extent and late summer snowline positions using remotely sensed data to determine short- and medium-term variability; 3) mapping changes in ice flow to determine the importance of flow instabilities; 4) using observed changes to assess spatial variability in glacier and ice cap mass balance across the archipelago; and 5) interpreting the causes of observed changes.