Recent trends in Canadian lake ice cover
Recent trends in Canadian lake ice cover
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DOI：
10.1002/hyp.6131
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发表时间：
2006-03-15
影响因子：
3.2
通讯作者：
Ménard, P
中科院分区：
文献类型：
--
作者：
Duguay, CR;Prowse, TD;Ménard, P
最近的研究表明，由于全球变暖，北半球湖泊和河流的冰期在19世纪和20世纪有所减少。然而，加拿大的湖冰趋势并没有得到很好的记录。由于它的大小，在全国范围内，冻裂日期和冻裂日期可能存在相当大的差异。在这篇论文中，分析了最近加拿大各地（1951-2000）冻结和破裂日期的趋势结果。在包括20世纪90年代在内的分析期间，观察到大多数湖泊有提早破裂日期的趋势。另一方面，与分手日期相比，冻结日期几乎没有明显的趋势，时间一致性也很低。这些结果与1966- 1995年秋季和春季0摄氏度等温线日期的趋势进行了比较。观察到类似的时空格局，在加拿大西部大部分地区，春季/破裂日期普遍有明显的提前趋势，而在加拿大大部分地区，秋季等温线和冻裂日期变化不大。在全国许多地方，0℃等温线日期和冰冻/破裂日期之间的强相关关系（或> -5）揭示了这些变量的高度同步性。这些结果也与最近对其他冰冻圈和大气变量的观测结果相一致，这些观测结果特别表明，在20世纪后半叶出现了春季提前的总体趋势。本研究的结果进一步证明了湖冰作为气候变率和变化的代理指标的稳健性。版权所有(c) 2006约翰威利父子有限公司
Recent studies have shown that ice duration in lakes and rivers over the Northern Hemisphere has decreased over the 19th and 20th centuries in response to global warming. However, lake ice trends have not been well documented in Canada. Because of its size, considerable variability may exist in both freeze-Lip and break-Lip dates across the country. In this paper, results of the analysis of recent trends (1951-2000) in freeze-up and break-up dates across Canada are presented. Trends toward earlier break-up dates are observed for most lakes during the time periods of analysis which encompass the 1990s. Freeze-up dates, on the other hand, show few significant trends and a low degree of temporal coherence when compared with break-up dates. These results are compared with trends in autumn and spring 0 degrees C isotherm dates over the time period 1966-95. Similar spatial and temporal patterns are observed, with generally significant trends toward earlier springs/break-up dates over most of western Canada and little change in isotherm and freeze-Lip dates over the majority of the country in autumn. Strong cot-relations (r > 0-5) between 0 degrees C isotherm dates and freeze-up/break-up dates at many locations across the Country reveal the high synchrony of these variables. These results ire also consistent with more recent observations of other cryospheric and atmospheric variables that indicate, in particular, a general trend toward earlier springs in the latter part of the 20th century. The results of this study provide further evidence of the robustness of lake ice as a proxy indicator of climate variability and change. Copyright (c) 2006 John Wiley & Sons, Ltd.