Weather conditions and warm air masses during active fire-periods in boreal forests
Weather conditions and warm air masses during active fire-periods in boreal forests
复制标题
北方森林火灾活跃期的天气状况和暖气团
DOI：
10.1016/j.polar.2019.07.002
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发表时间：
2019
期刊：
影响因子：
1.8
通讯作者：
Naito Daisuke
中科院分区：
文献类型：
--
作者：
Hayasaka Hiroshi;Yamazaki Koji;Naito Daisuke
通过各种天气图和温度图检查了北方森林同时发生大面积火灾的天气条件。北方森林的四个研究区域是三个在东西伯利亚，一个在阿拉斯加。我们应用了作者提出的 Sakha 初步分析方法来证明我们方法的有效性。从卫星热点数据中发现了超过 12 个非常活跃的火灾周期。分析结果清楚地表明，随着来自南方的暖气团接近四个研究区域，所有火灾活跃期的火灾都变得非常活跃。这些暖气团的运动主要与大西风带的蜿蜒有关。为了解释火灾活跃期间每日热点（火灾）的大量增加，进行了初步的风分析。当温暖干燥的气团在低空的各种天气条件下接近、停滞并经过南萨哈时，就会出现强风情况。在南萨哈火灾顶峰期间，低空风速（925hPa）从约1米/秒变化至8米/秒，热点数量从约1000个增加至9000个。
Weather conditions for concurrent widespread fires in boreal forests were examined by various weather maps and temperature charts. The four study regions in boreal forests are three in East Siberia and one in Alaska. We applied preliminary analysis method for Sakha proposed by the authors to show the effectiveness of our approach. More than 12 very active fire-periods were identified from satellite hotspot data. Analysis results clearly showed fires during all active fire-periods became very active as warm air masses from south approached four study regions. These movements of warm air masses were mainly related to the meandering of large westerlies. To explain the large increase of daily hotspots (fires) during active fire-periods, a preliminary wind analysis was carried out. Strong wind conditions occurred when warm and dry air masses were approaching, stagnating, and passing over Southern Sakha under various weather conditions at lower air. During the top fire-period in Southern Sakha, wind velocity at lower air (925 hPa) changed from about 1 to 8 m/s while number of hotspot increased from around 1000 to 9000.