渤海海冰外缘线候平均离岸距离的变化及其关键影响因子  

Variability of the Pentadly Average Distance Between the Sea Ice Edge and the Coast in the Bohai Sea and Its Key Impact Factors

作　　者：李彦青[1] 苏洁[1] 汪洋[2] 郭晓葭[1] 

机构地区：[1]中国海洋大学海洋环境学院,山东青岛266100 [2]中国科学院海洋环流与波动重点实验室,山东青岛266071

出　　处：《中国海洋大学学报（自然科学版）》2013年第7期7-16,共10页Periodical of Ocean University of China

基　　金：国家海洋局公益性行业科研专项(201105016);国家气象局公益性行业科研专项(201306091);国家自然科学基金面上项目(41176022)资助

摘　　要：以渤海海冰为研究对象,基于MODIS遥感数据,构建了辽东湾、渤海湾和莱州湾2001—2011年11个冬季的海冰外缘线离岸距离候平均时间序列,并对其年际和季节内变化特征进行了分析。研究表明,每年的海冰候平均离岸距离最大值通常发生在1和2月上旬,辽东湾最大值出现的时间比渤海湾和莱州湾晚,且具有发生时间越晚,该年度冬季冰情越重的特点。基于海冰离岸距离候平均时间序列,从季节内变化角度分析了影响渤海海冰的关键因子。结果指出,小的海区(渤海湾和莱州湾)的海冰对气温的响应更快,每候负积温是1个比候平均气温更好的预报因子;而大的海区(辽东湾)与1个月左右的前期气温因子相关更好;对3个海湾整体而言,前期副高面积、强度和脊线位置均与渤海海冰离岸距离呈明显负相关,海冰对副高面积的响应比其他副高指数更强、更快;500hPa位势高度的西风环流带上存在2个与渤海海冰距离呈明显负相关的关键区(东亚和西太),关键区的平均位势高度可以作为新的海冰预报因子。本文对这2个因子影响渤海海冰的机制进行了分析和解释。. Based on the MODIS remote sensing satellite data, the time series of pentadly averaged distance between sea ice edge and the coast in Bohai Sea from 2001 to 2011 is built. The interannual and seasonal variability of the series is studied. The analysis shows the largest distance happens in January and early February usually, and the time of the largest distance appearance in Liaodong Bay is later than that of the other two Bays. The later the largest distance happens, the heavier sea ice is. The key factors are analyzed as well based on the pentadly time series. The results show that sea ice in small area, such as Bo- hai Bay and Laizhou Bay, has a quicker response to air temperature, and pentadly negative accumulated temperature is a better predictor for sea ice than the pentadly average temperature for these two bays~ while sea ice in larger sea area, such as Liaodong Bay, has better correlation with prophase temperature. Sea ice of the whole Bohai Sea is negatively correlated with prophase area, intensity and ridge line of subtropical high, among these subtropical high indexes, the area is the factor with more quickly and intense effect on sea ice distance. We present two key factors from the 500 hPa geopotential height near westerly circulation zone. The averaged geopotential height of East-Asia and West-Pacific areas can act as new predictors for sea ice of the Bohai Sea. We also analysis and explain the influence mechanism of the two new factors.

关 键 词：渤海 MODIS数据 候平均时间序列 海冰外缘线离岸距离 关键影响因子 

分 类 号：P722.4[天文地球—海洋科学]