21世纪海上丝绸之路海洋上层热含量及热比容海平面异常变化

The variations of the upper ocean heat content and thermostatic sea level around 21st century Marine Silk Road

气候变暖背景下,全球平均海洋变暖和海平面上升显著,为人类社会的可持续发展带来巨大挑战。上层海洋热力状况是海平面变化的主导因子之一。本文围绕"21世纪海上丝绸之路"途经海区(文中简称为丝路海区)上层海洋热含量异常的区域性时空特征,分析探讨了丝路海区热比容海平面异常的时空变化、演变特征及可能影响,以期为"21世纪海上丝绸之路"海洋环境安全保障提供服务支撑。结果表明,自20世纪70年代中后期,丝路海区上层(0~700m)海洋已明显变暖,尤其20世纪90年代中后期增暖幅度显著加大。近60年来,在丝路海区热带海洋中,西太平洋的北赤道流区及以北海域、东海黑潮流域以及南海北部和南部海区、阿拉伯海西北部海域、马来西亚西北部海域及南印度洋部分海域具有长期增暖趋势。热带西太平洋暖池区整体增暖不明显,主要与印度洋中部海域呈反位相变化,且明显受到季节和年际变化的调制。长江口附近沿岸、南海北部沿岸、中南半岛南部沿岸以及阿拉伯海西北部沿岸的近岸海域长期增暖明显,自20世纪90年代中后期,中南半岛东部和西部沿海、澳大利亚西部沿海以及我国东南沿海热比容海平面上升明显。近岸热比容海平面的季节演变对沿海地区社会和经济发展会造成一定影响。此外,东亚夏季风与东海、黄海和渤海热比容海平面的上升显著相关,同时,ENSO、太平洋年代际振荡和印度洋偶极子的发生也均与我国东南沿海和印度洋西部沿海热比容海平面上升明显关联。特别是,气候变暖情形下,各种区域性致灾因子和气候变率的协同影响会对丝路海区海岸带和沿海地区的防灾减灾与社会经济发展带来较大挑战,开展海岸带和沿海地区全球变化综合风险研究成为当前首要任务。

Under the background of climatic warming,the global ocean temperature increased and the sea level rose significantly,imposing enormous challenges to the sustainable development of human society.The upper ocean heat condition is one of the dominant factors of sea level change.Focusing on the 21 st century Silk Road Maritime Region（SRMR）,the local spatial and temporal characteristics of the upper ocean heat content were analyzed,furthermore,the change and evolution characteristics of thermosteric sea level and associated impaction were discussed,in order to give the services supporting for marine environment security of＂21 st century Maritime Silk Road＂.The analysis results show that,since the 1970 s,the upper layer（0-700 m）ocean of SRMR began to warm obviously,and especially presented significant larger warming from the middle of 1990 s.Recently 60 years,in tropical oceans of the SRMR,the North Equatorial Current and its north sea area in the western Pacific,the China seas including the north and the south of the South China Sea（SCS）and the Kuroshio valley in East China Sea,the northwest coastal waters in Arabian sea,the sea area of northwest of Malaysia and south part of the Indian Ocean had a longterm heating trend.The warming of the whole region of tropical western Pacific warm pool was not obvious,and presented mainly anti-phase change with the central Indian Ocean,which were modulated by seasonal and interannual variability.The coastal zones of the eastern China seas near the Changjiang River Estuary,the north of the SCS,the southern of Indo-China Peninsula,the northwestern of Arabian Sea had an obviously long-term warming.Since the middle of the 1990 s,the thermosteric sea level in costal zones of the east and west of Indo-China Peninsula,the west of Australia and the China seas have rose obviously.The seasonal evolution of thermosteric sea level rising can cause a certain degree of impact on social and economic development in coastal zones.In addition,the East Asian summer monsoon was significantly associated with the thermosteric sea level rising in eastern China seas,at the same time,the ENSO,the PDO and the IOD also related distinctly to the thermosteric sea level rising in coastal zones in China seas and the western Indian Ocean.Particularly,in climate warming scenario,due to the synergy impaction of regional disaster-causing factors and climate variability,the social and economic development and the disaster prevention and mitigation in coastal zones in SRMR would be subject to huge challenges.The study of comprehensive risk of coastal zones by global change has become the top priority.