内蒙古冬季极端多雪气候事件环流演变特征及季节预测信号

Evolutionary Features of Atmospheric Circulation and Seasonal Forecast Signals for Extreme Snowy Climate Events during Wintertime in Inner Mongolia

文章研究关注了内蒙古冬季极端多雪气候事件的季节预测问题,在对大量降水观测资料、海温及大气环流场资料进行统计、分析、研究的基础上,确定了历史上58a(1960—2017年)内蒙古冬季极端多雪和少雪气候事件样本,通过对大气环流场的对比分析发现极端多雪或少雪冬季环流场特征显著不同,分析后确定了影响内蒙古冬季降雪的主要环流系统,包括西太平洋副热带高压、极涡、东亚大槽、环流E型及南方涛动等系统。同时,探索了对这些主要环流系统具有预测意义的来自海洋和大气场的预测信号,对预测信号关键区做了标准化定量提取,确定了预测信号综合指数分段判别阈值,给出了预测概念模型,取得了较好预测效果。

This study focuses on seasonal forecast of extreme winter snowy events in Inner Mongolia.Based on a lot of detailed statistical,analysis and research works on historical precipitation,sea surface temperature and the atmospheric circulation observation data,the samples of extreme rich or less snows have been identified for the period of 58 years(from 1960 to 2017).According to the outcomes of comparing analyses,some clearly different circulation characters were found existing between those two kinds of extreme snow events,and then,several circulation systems,including the western Pacific subtropical high,North Polar vortex,eastern Asian trough,E circulation pattern and the South Oscillation,were confirmed to be major impacting factors on the winter snow falls of Inner Mongolia.In addition,some meaningful forecast signals and their crucial regions of the major influential systems from the oceans and atmosphere have been explored.An evolutionary conceptual model for the seasonal snow prediction and some synthesized periodical thresholds were given out after extracting and standardized the forecast signals of the crucial regions.It has got satisfactory forecast efficiency.