A model for regional‐scale estimation of temporal and spatial variability of active layer thickness and mean annual ground temperatures
A model for regional‐scale estimation of temporal and spatial variability of active layer thickness and mean annual ground temperatures
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DOI：
10.1002/ppp.449
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发表时间：
2003-04
影响因子：
5
通讯作者：
T. Sazonova;V. Romanovsky
中科院分区：
文献类型：
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作者：
T. Sazonova;V. Romanovsky
年平均地表温度在 0°C 左右或以下的高纬度生态系统对全球变暖高度敏感。这主要是因为这些地区有大面积的永久冻土，当年平均气温升至冰点以上时，永久冻土就开始融化。地球物理研究所永久冻土实验室开发了一种新的交互式地理信息系统（GIS）模型，用于估计永久冻土对气候变化的长期响应。分析方法用于计算活性层厚度 (ALT) 和年平均地面温度 (MAGT)。当应用于长期（十年或更长的时间尺度）平均值时，该方法显示 MAGT 的精度为 ±0.2–0.4°C，ALT 计算的精度为 ±0.1–0.3 m。 ALT 计算的相对误差不超过 32%，但通常在 10% 到 25% 之间。对西伯利亚 32 个地点的数据进行的空间统计分析表明，测量的 MAGT 与计算的 MAGT 之间的偏差为 0.2–0.4°C，置信度为 75%。对阿拉斯加和东西伯利亚的两个区域样带进行了详细分析，验证了该模型的使用。从该分析中获得的结果表明，在永久冻土空间和时间动力学的区域和全球尺度分析中，可以成功地使用更经济（就计算时间而言）的分析方法来代替全尺寸数值模型。该项目是对北极气候影响评估项目的成功贡献。版权所有 © 2003 约翰·威利父子有限公司
High‐latitude ecosystems where the mean annual ground surface temperature is around or below 0°C are highly sensitive to global warming. This is largely because these regions contain vast areas of permafrost, which begins to thaw when the mean annual temperature rises above freezing. The Geophysical Institute Permafrost Lab has developed a new interactive geographical information systems (GIS) model to estimate the long‐term response of permafrost to changes in climate. An analytical approach is used for calculating both active layer thickness (ALT) and mean annual ground temperatures (MAGTs). When applied to long‐term (decadal or longer time scale) averages, this approach shows an accuracy of ±0.2–0.4°C for MAGTs and ±0.1–0.3 m for ALT calculations. The relative errors do not exceed 32% for ALT calculations, but typically they are between 10 and 25%. A spatial statistical analysis of the data from 32 sites in Siberia indicated a confidence level of 75% to have a deviation between measured and calculated MAGTs of 0.2–0.4°C. A detailed analysis has been performed for two regional transects in Alaska and eastern Siberia that has validated the use of the model. The results obtained from this analysis show that a more economical (in terms of computational time) analytical approach could be successfully used instead of a full‐scale numerical model in the regional and global scale analysis of permafrost spatial and temporal dynamics. This project has been a successful contribution to the Arctic Climate Impact Assessment project. Copyright © 2003 John Wiley & Sons, Ltd.