21世纪以来全球变暖进入停滞时期,研究表明,大量热量进入海洋深层是导致全球平均表面温度暂缓上升的主要原因。本文估计和研究了2002.42014.12间由热膨胀导致的海平面变化趋势,以此来探测海洋热含量的变化情况。研究使用GRACE重力卫星CSR RL05数据计算了全球海洋的水质量变化,并结合海平面异常数据,计算了由热量变化导致的海平面变化(Net SLA)。将Net SLA与Ishii温度数据计算的海洋热含量进行相关性分析后表明, Net SLA与海洋热含量存在高度相关性,相关系数最大值达0.95。考虑到海洋观测只能表现海洋上层2000m的热含量变化,而除去水质量变化的海平面变化则反映了整层海洋的热含量变化,是估计海洋增暖趋势快慢的有利工具。经计算得出, 2002至2014年间南太平洋和南印度洋存在加速增暖趋势,而近年来南半球环状模的增强是导致其增暖的主要原因。
英文摘要:
Since the 21th century, global warming has turned into hiatus. Studies have shown that large amounts of heat sank into deeper ocean, which led to the global average surface temperature keeping constant. In order to detect the changes of ocean heat content, we estimated and studied the sea level anomaly caused by thermal expansion in the period of 2002.42012.12. In this paper, we used GRACE CSR RL05 data to calculate the ocean mass change. Combining the SLA data and ocean mass change, we calculated the thermal expansion component of sea level anomaly (Net SLA). The correlation analysis between ocean heat content and Net SLA shows a high correlation, the maximum correlation coefficient is 0.95. Considering that ocean observations could only represent the upper 2000m ocean heat content, whereas Net SLA can reflects the change in whole ocean column; therefore, Net SLA is a good tool to estimate the trend of ocean warming. We found that, South Pacific and South Indian have an enhanced warming trend from 2002 to 2014. And the enhancement of Southern Annual Mode in recent 20 years is the main reason for the Southern Hemisphere Ocean warming.