Mechanism and predictability of the blocking over Russian region, and its influence on the heat wave over Japan in the summer of 2010

本文利用再分析数据集和两种预测数据集，研究了2010年夏季俄罗斯上空强阻塞的机制和可预测性。结果表明：在7月底的阻塞维持期，阻塞的可预测性大大降低，阻塞上游槽加深引起的对流层上层水平辐散相关的反气旋涡度强迫是阻塞形成的重要因素；在8月初的另一个维持期，由气候水平辐合与欧亚大陆西部对流层上层共存的反气旋异常相互作用产生的反气旋涡度强迫是维持阻塞的关键。这些维护机制也被发现是俄罗斯封锁所固有的。

We investigate the mechanism and predictability of a strong blocking residing over Russia in the summer of 2010 using a reanalysis dataset and two kinds of forecast datasets. It is found that the following different mechanisms contributed to the enhancement of the blocking: During a maintenance period of the blocking in the end of July, when the predictability of the blocking was much reduced, an anticyclonic vorticity forcing associated with horizontal divergence in the upper troposphere due to a deepening trough upstream of the blocking was an important factor for the blocking formation; during another maintenance period in early-August, an anticyclonic vorticity forcing produced by the interaction between the climatological horizontal convergence and the coexisting anticyclonic anomaly in the upper troposphere over the western part of the Eurasian continent was a key to maintain the blocking. These maintenance mechanisms are also found to be inherent to the Russian blocking.