We examined the relationships between the dynamics of surface inflow into Lake Baikal and the runoff of the main tributaries of the Baikal drainage basin and regional and global circulation parameters to determine the role of certain of the meteorological factors in the current low water level within the Baikal catchment area. A decrease or an increase in the runoff of Baikal’s rivers in the summer months depends on the synoptic situation in the south of East Siberia and in the north of Mongolia where southern cyclones provide the main influx of moisture to the Baikal region. We used different indices as climatic and circulation factors which characterize the specific features in the forms of atmospheric circulation in high and low latitudes of the northern hemisphere (NAO, AO, SCAND, and others) as well as the anomalies of mean monthly values of surface pressure and geopotential heights of isobaric surface AT-500 in the zone of 43–50°N and 90–115°E. It was found that the low water level within the Lake Baikal drainage basin has persisted since 1996 but it has manifested itself particularly clearly due to the lake stage reduction. In the south of Siberia and in the north of Mongolia, since the early 21st century there has been an enhancement in anticyclogenesis processes accompanied by an increase in air temperature, surface pressure and geopotential altitudes at the level of the mid-troposphere (5 km). The more favorable conditions for river runoff formation are created during the development of the ridge of elevated and low pressure over Ural and the associated ridge of low pressure over Siberia, with cyclogenesis processes occurring in front of them over the territory of Mongolia and the south of East Siberia at the Earth’s surface. Elevated precipitation and runoff are observed at the time of blocking anticyclones over Transbaikalia and the Far East, which are responsible for a long-lasting persistence of Mongolian cyclones.

中文翻译：

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贝加尔湖流域内当前低水位的循环因素

我们研究了贝加尔湖地表流入动态与贝加尔湖流域主要支流径流以及区域和全球环流参数之间的关系，以确定某些气象因素在贝加尔湖当前低水位中的作用集水区。夏季月份贝加尔湖河流径流的减少或增加取决于东西伯利亚南部和蒙古北部的天气情况，南部气旋为贝加尔湖地区提供了主要的水分流入。我们使用不同的指数作为气候和环流因子，表征北半球高低纬度大气环流形式的具体特征（NAO、AO、SCAND、和其他）以及 43-50°N 和 90-115°E 区域内等压面 AT-500 的地表压力和位势高度的月均值异常。研究发现，贝加尔湖流域内低水位自1996年以来一直持续存在，但由于湖水位减少，低水位表现得尤为明显。在西伯利亚南部和蒙古北部，自 21 世纪初以来，随着气温、地表压力和对流层中层（5 公里）的位势高度升高，反气旋形成过程有所增强. 在乌拉尔上空高压和低压脊以及西伯利亚上空相关的低压脊发展期间，为河流径流形成创造了更有利的条件，在蒙古领土和东西伯利亚南部在地球表面发生的气旋过程在它们面前发生。在阻止外贝加尔和远东上空的反气旋时观察到降水和径流升高，这是蒙古气旋长期持续存在的原因。