摘要
利用一个全球海冰气耦合模式模拟结果,选取冬季年际变率最大的海冰区———格陵兰海海冰区中的一个4年海冰剧烈变化过程展开分析,试图探讨此个例过程中海冰剧烈变化的原因。结果表明,在此个例中,该区域海冰年际变异主要是由大气环流异常驱动的,海表面温度和海冰密集度变化主要是对大气环流变化的响应。海表面温度变化决定着海冰范围及海冰密集度的变化,但海冰变化时通过相变潜热的释放或吸收反过来对海表面温度变化有一定影响。
Using results of numerical simulation of sea-sea ice-air interaction in high northern latitudes from an ocean-sea ice-atmosphere coupled model, a case of 4-year strong variations of sea ice in Greenland Sea where the biggest variability occurs in winter is studied. The case is subtracted from the last 30-year result of a 50-year integration experiments with LASG/NCC （State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences/China National Climate Centre） global coupled model. Within the 4-year variation, there are two positive anomalies and two negative anomalies of sea ice in winter whereas sea ice extents are almost the same in October each year. The aim of the study is to try to find the reason of strong interannual variation of sea ice in this special case and to understand the features of sea - sea ice- air interaction in the duration. The methods of analysis employed here are simple comparison of averages of important fields for different time spans and difference attributions. It is shown that, in this special case, atmospheric circulation plays a dominant role. The detailed reason for sea ice anomalies can be illustrated below. In winter, when the intensity of the Icelandic low weakens/strengthens, the strength of northward advection of relatively warm and humid air decreases/increases, air in Greenland Sea becomes colder and dryer/warmer and wetter, losses of sensible heat flux and latent heat flux from sea surface grow/reduce. As a result, sea ice there has a positive/negative anomaly. In summer, when the strength of prevailing southward currents over Greenland Sea weakens/strengthens, low level atmosphere there becomes warmer and wetter/colder and dryer, losses of sensible heat flux and latent heat flux from sea surface reduce/grow, the sea surface temperature increases/decreases, the melting speed of sea ice become faster/slower. It is also shown that it is the variation of atmospheric circulati
出处
《大气科学》
CSCD
北大核心
2005年第5期795-804,共10页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金重点项目40233031
关键词
耦合模式
海冰变化
数值模拟
格陵兰海
coupled model, sea ice variation, numerical simulation, Greenland Sea
