2004年河南北中部冷冬的气候特征

Study on the Climatic Characteristic in Cold Winter of North-central Henan

分析结果发现：2004年河南北中部出现的冷冬年气候特点是寒冷时间长，日平均气温低，逐日气温日较差较小，极端低温出现少；历史上冷冬出现的气候演变有连续性，一般≥4年；2004年冬季（12月～翌年2月）亚洲中高纬地区500hPa高度距平北高南低，西风带纬向环流占优势，成海到巴尔喀什湖间较长时间维持冷低中心，是造成当年冬季寒冷的大气环流特征。

The climatic characteristics in cold winter of Henan north - central region are the increasing of cold days and decreasing of mean daily temperature. The daily range is obviously decreasing and extreme low temperature appears very seldom. There is some continuity of climatic evolution in cold winter and it is more than 4 year. Asia region at mid - high latitude 500hPa altitude anomaly is high - north - low - south in winter 2004. Westerly belt zonal circulation is predominant. The cold center is maintaining for a long time between Salk Sea and Balkash Lake. Above mentioned are the appearance causes of circulation characteristics in cold winter.