Recent changes in the frequency of freezing precipitation in North America and Northern Eurasia
Recent changes in the frequency of freezing precipitation in North America and Northern Eurasia
复制标题
DOI：
10.1088/1748-9326/11/4/045007
复制
发表时间：
2016-04
影响因子：
6.7
通讯作者：
P. Groisman;O. Bulygina;Xungang Yin;R. Vose;S. Gulev;I. Hanssen‐Bauer;E. Førland
中科院分区：
文献类型：
--
作者：
P. Groisman;O. Bulygina;Xungang Yin;R. Vose;S. Gulev;I. Hanssen‐Bauer;E. Førland
冻雨和冻雨事件是世界许多地区的一个重要特征。即使在低强度下，这些事件也经常导致自然灾害，对住房、通信线路和其他人造基础设施造成破坏。这些事件通常发生在0 °C等温线附近。在不断变化的气候中，这种等温线不会消失，但它在空间和时间上的位置可能会改变，冰冻降水的地理位置也会改变。从海洋进入大陆的大量水蒸气也可能增加冰冻降水事件的数量和频率。本文评估了我们目前对美国、加拿大、挪威和俄罗斯最近冰冻降水变化的理解。该研究是一个更大的GEWEX横切项目的一部分，该项目旨在解决“0 ° C附近的冷/肩季节降水”。利用这四个国家874个长期时间序列（40年的数据）的天气观测档案，我们记录了每日冻雨和冻雨发生的气候学以及其中的趋势。冻雨频率最高的地区（每年3至8天）位于美国的东北象限和加拿大东南部50 °N以南的邻近地区以及大东欧平原的南部和西南部。各地冻雨发生频率均超过冻雨发生频率。在过去的十年中，美国东南部冻雨事件的频率有所下降。在北极圈以北的北美洲，它增加了约1天。在挪威，冻雨的出现大幅增加，特别是在挪威的北极地区。在俄罗斯欧洲部分和西伯利亚西部，冻雨的频率有所增加（除了最南端的草原地区和北极地区），而整个俄罗斯的冻雨频率则有所减少。
Freezing rain and freezing drizzle events represent a critical feature of many regions of the world. Even at low intensities, these events often result in natural hazards that cause damage to housing, communication lines, and other man-made infrastructure. These events usually occur near the 0 °C isotherm. In a changing climate, this isotherm will not disappear, but its position in space and time will likely change as will the geography of freezing precipitation. A larger influx of water vapor into the continents from the oceans may also increase the amount and frequency of freezing precipitation events. This paper assesses our current understanding of recent changes in freezing precipitation for the United States, Canada, Norway, and Russia. The research is part of a larger GEWEX Cross-Cut Project addressing ‘cold/shoulder season precipitation near 0 °C’. Using an archive of 874 long-term time series (40 years of data) of synoptic observations for these four countries, we document the climatology of daily freezing rain and freezing drizzle occurrences as well as trends therein. The regions with the highest frequency of freezing rains (from 3 to 8 days per year) reside in the northeastern quadrant of the conterminous United States and adjacent areas of southeastern Canada south of 50 °N and over the south and southwest parts of the Great East European Plain. The frequency of freezing drizzle exceeds the frequency of freezing rain occurrence in all areas. During the past decade, the frequency of freezing rain events somewhat decreased over the southeastern US. In North America north of the Arctic Circle, it increased by about 1 day yr−1. Over Norway, freezing rain occurrences increased substantially, especially in the Norwegian Arctic. In European Russia and western Siberia, the frequency of freezing rain somewhat increased (except the southernmost steppe regions and the Arctic regions) while freezing drizzle frequency decreased over entire Russia.