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引用次数: 7
摘要
在埃尔斯米尔岛和格陵兰岛北部之间的纳尔斯海峡,强烈的低空南风很常见。纳尔斯海峡陡峭的地形导致了通道效应,导致了海峡沿岸的水流。本研究提出了COSMO-CLM气候模式模拟的30年流态气候学。模拟可用于1987/88年至2016/17年的冬季(11月至4月),因此覆盖的时间足够长,可以提供纳雷斯海峡的长期特征。15 km的水平分辨率足以真实地反映复杂的地形和气象条件。30年气候学研究表明,与间隙流相关的llj是纳雷斯海峡的一个气候特征。10 m平均风速最大值约为12 m s-1,位于史密斯湾南出口。风速与压力梯度密切相关。单次事件的日平均风速可达40 m s-1。在稳定的分层条件下,LLJ与海峡最狭窄部分的间隙流动有关,主要LLJ发生在100-250 m高度。随着山弗鲁德数的增加,LLJ风速和高度增加。10米级大风事件的频率(日平均为20 m s-1)表现出强烈的年际变化,平均每年冬季为15次。通道风对北水冰湖的形成有很强的影响。
A climatology of wintertime low-level jets in Nares Strait
Intense, southward low-level winds are common in Nares Strait, between Ellesmere Island and northern Greenland. The steep topography along Nares Strait leads to channelling effects, resulting in an along-strait flow. This research study presents a 30-year climatology of the flow regime from simulations of the COSMO-CLM climate model. The simulations are available for the winter periods (November–April) 1987/88 to 2016/17, and thus, cover a period long enough to give robust long-term characteristics of Nares Strait. The horizontal resolution of 15 km is high enough to represent the complex terrain and the meteorological conditions realistically. The 30-year climatology shows that LLJs associated with gap flows are a climatological feature of Nares Strait. The maximum of the mean 10-m wind speed is around 12 m s-1 and is located at the southern exit of Smith Sound. The wind speed is strongly related to the pressure gradient. Single events reach wind speeds of 40 m s-1 in the daily mean. The LLJs are associated with gap flows within the narrowest parts of the strait under stably stratified conditions, with the main LLJ occurring at 100–250 m height. With increasing mountain Froude number, the LLJ wind speed and height increase. The frequency of strong wind events (>20 m s-1 in the daily mean) for the 10 m wind shows a strong interannual variability with an average of 15 events per winter. Channelled winds have a strong impact on the formation of the North Water polynya.
期刊介绍:
Since 1982, Polar Research has been the international, peer-reviewed journal of the Norwegian Polar Institute, Norway''s central institution for research, environmental monitoring and mapping of the polar regions. Aiming to promote the exchange of scientific knowledge about the Arctic and Antarctic across disciplinary boundaries, Polar Research serves an international community of researchers and managers. As an open-access journal, Polar Research makes its contents freely available to the general public.
Original primary research papers comprise the mainstay of Polar Research. Review articles, brief research notes, letters to the editor and book reviews are also included. Special issues are published from time to time.
The scope of Polar Research encompasses research in all scientific disciplines relevant to the polar regions. These include, but are not limited to, the subfields of biology, ecology, geology, oceanography, glaciology and atmospheric science. Submissions from the social sciences and those focusing on polar management and policy issues are welcome. Contributions about Antarctica are particularly encouraged.