Snow disappearance in Eastern Siberia and its relationship to atmospheric influences
Snow disappearance in Eastern Siberia and its relationship to atmospheric influences
复制标题
DOI：
10.1002/joc.1382
复制
发表时间：
2007-02
期刊：
影响因子：
--
通讯作者：
Y. Iijima;K. Masuda;T. Ohata
中科院分区：
文献类型：
--
作者：
Y. Iijima;K. Masuda;T. Ohata
在本研究中，我们研究了东西伯利亚勒拿河流域近15年（1986-2000）的气候特征和积雪消失的年际变化，以及积雪消失与大气条件的关系。从消雪日气候学来看，4月中旬至6月初，勒拿河流域消雪边界快速向北迁移，流域中部年际变化最小。此外，勒拿河流域中部也出现了明显的前期积雪消失现象。在某些大气条件下，勒拿河流域的积雪融化通常发生在积雪完全消失后的 30 天内：日平均气温超过 − 10 °C，水蒸气压力大于 2 hPa，因此在晴空条件下向下长波辐射超过 170 W m−2。使用再分析数据集的综合分析表明，伴随积雪融化而出现的气温和水蒸气增加是由于雪消失前 30 天内湿（暖）空气平流以及勒拿河流域中部水蒸气汇聚增强所致。版权所有© 2006 英国皇家气象学会。
In the present study, we examine the climatological features and interannual variations in snow disappearance within the Lena River Basin, Eastern Siberia, during a recent 15‐year period (1986–2000), and the relationship of snow disappearance to atmospheric conditions. According to the climatology of the day of the year on which snow disappears, the boundary of snow disappearance within the Lena River Basin migrates rapidly northward from mid‐April until early June, with minimum interannual variation occurring in the middle part of the basin. In addition, the preceding snow disappearance is apparent in the central Lena River Basin. Melting of snow within the Lena River Basin commonly occurs within 30 days of complete snow disappearance under certain atmospheric conditions: daily mean air temperature in excess of − 10 °C, greater than 2 hPa of water vapor pressure, and, hence, more than 170 W m−2 of downward longwave radiation under clear sky conditions. Composite analysis using a reanalysis dataset demonstrates that the increase in air temperature and water vapor that accompanies snow melting is due to wet (and warm) air advection in conjunction with enhanced water vapor convergence over the central Lena River Basin during the 30‐day period prior to snow disappearance. Copyright © 2006 Royal Meteorological Society.