环辽东湾地区冬季平均气温对渤海海冰面积的影响

Impact of Average Winter Temperatures around Liaodong Gulf Region on the Sea Ice Area of Bohai Sea

利用环辽东湾地区的大洼、锦州、绥中、熊岳、营口、旅顺6个站1960年～2007年48年间冬季（12月～次年2月）平均气温资料及1996年～2004年9年间渤海海冰面积资料，分析了辽东湾沿岸冬季平均气温与渤海海冰面积之间的相关关系，得出除1996年和1997年两年外，其余各年6站冬季平均气温与渤海海冰面积的变化呈现很好的负相关，相关系数达-0．85565。之后分析了环辽东湾地区冬季平均气温年变化规律及其影响因素，从而利用环辽东湾地区冬季平均气温年变化规律，根据二者的负相关关系推测出渤海海冰面积的年变化规律。研究结果显示，1960年～2007年渤海海水结冰日数年变化呈现明显的两段分布：1960年～1988年间渤海海水结冰日数以73天为中心上下振荡；1989年～2007年间以55天为中心上下振荡。研究结果还显示，在海冰面积相对较小的1989年～2007年间，未出现海冰面积逐年减小的趋势，并对产生这种年变化规律的影响因素进行了初步分析。探讨渤海海冰面积的年变化规律及其影响因素，对将渤海海冰作为淡水资源加以开发利用的研究具有有益的参考价值。

In order to identify the patterns of annual change in ice area in the Bohai Sea and ease the pressure on freshwater resources, we analyze the correlation between average winter temperatures in the areas around Liaodong Gulf and the ice area in Bohai Sea. This is done using average temperature data from six stations between 1960 and 2007 and data on ice area in the Bohai Sea between 1996 and 2004. Our analysis found a strong correlation except for the years of 1996 and 1997. The ice area in the Bohai Sea shows a strong relationship with the average winter temperature of the areas around Liaodong Gulf, with a significant negative correlation of - 0. 85565. We also analyzed the trends in annual changes of average winter temperatures and influencing factors, and deduced annual change principles by use of the strong negative correlation. The conclusion is very similar with the patterns of annual change in the average temperature in the areas around Liaodong Gulf, and the distribution of ice sea days appears in two different stages. Between 1960 and 1988, the number of ice days fluctuates around 73 days, while the number fluctuates around 55 days between 1989 and 2007. During the last 19 years when the ice area in Bohai Sea was relatively small, the area of sea ice does not appear to follow a trend of decreasing year by year. The trends in annual change of ice area and related factors are discussed in a preliminary analysis. On the basis of the study, we forecast that the ice situation in the 2007/2008 winter is serious, while in the 2008/2009 winter it will be lighter. The forecasting of the ice situation in the 2007/2008 winter matched up to the actual situation. Also, the annual change of ice days in the Bohai Sea for 1960 - 2007 is similar to the annual change of average winter temperatures in the areas around Liaodong Gulf. The discussion of changes in the ice area in Bohai Sea and the factors affecting temperature will provide useful background for research on exploitation of ice in the Bohai Sea for freshwater resources.