摘要
应用大气与海洋再分析资料和FVCOM-SWAVE区域海洋耦合模式,对2004—2009年长江口杭州湾冷季(11—3月)海洋热动能—主要为海流能和温差能进行特征分析,以及对北路及西路入海寒潮过程影响下的海洋热动能变化进行模拟研究。结果显示:该海域海流能主要受沿岸流和黑潮流系影响,此两流系强弱变化与南北季风的强弱变化,以及入海径流丰枯期的变化相关。2月海面温度SST低,且南北向水平温度梯度大,显示北方高纬冷海温的势力强盛。北路偏北寒潮大风在大陆近岸造成向南余流增强和余水位向岸增高。西路寒潮的偏西大风造成离岸向东的余流,在外海受地转力作用转为偏南流动,造成湾内负值余水位。海水表层温度的降低往往滞后于寒潮降温1—2 d。近海SST低于底层,其降温幅度大于底层,此种特征可持续3—5 d。外海站点寒潮影响造成的上下层海温迅速混合所需时间大约1—2 d,温度降幅小于近岸。增加波浪模式的耦合,增强了水位对寒潮的响应强度,显著改善模式产品质量。对3个SST海温槽脊系统的海流能与温差能比较显示,寒潮剧烈天气过程的影响,驱动自北向南的冷水团质量输送,造成海区热动能表现为短期迅速地显著增长。
Using air and sea reanalysis data and FVCOM-SWAVE coastal coupled model, during the cold season （Nov. -Mar.of 2004-2009）,the characteristics of ocean thermodynamic energy and their response to the cold wave events from the north and the west paths invaded into the Yangtze Estuary and Hangzhou Bay sea region are analyzed and simulated. The result shows that the current energy in the sea region are mainly influenced by both current systems of the Kuroshio current and the alongshore currents. The two current systems are impacted by the intensity of monsoon, the river runoff, especially its flooding and low-water periods. In Feb. the SST has a large temperature gradient in sea surface, which shows that the cold SST at northern Yellow sea is strong and powerful. The cold wave with the north path creates the sea residue current going to south and the water level increasing towards the coast. The cold wave with the west path creates the sea residue current going to the east and its Ekman mass transport towards the south. The type of cold wave results in the minus sea level in the Yangtze Estuary and Hangzhou Bay. The SST dropping down usually delays 1-2 d to cold wave invasion. The SST is lower than the sea temperature at bottom level, and the SST dropping extent is larger at near shore places than at off shore, such temperature vertical distribution can maintain 3-5 d. The sea temperature mixing of surface and bottom at offshore is quicker within 1-2 d after cold wave arriving, and the decreasing extent is larger at near-shore than at off shore. By coupling wave module, the response of water level to cold wave is stronger, and the quality of the modeling products is obviously improved. Furthermore the comparison is made for the sea current energy and sea temperature different energy among 3 systems of sea temperature trough and ridge, and the result shows that the strong cold wave process forces cold water mass from the north to the south and results in the sea thermodynamic energy increases rapidly, and the increasing amount is remarkable in the regional sea during cold season.
出处
《海洋预报》
2016年第4期58-70,共13页
Marine Forecasts
基金
国家自然科学基金面上项目(41276033)
国家科技支撑项目(2012BAH05B01)
气象公益性行业专项(201206068)
江苏科技支撑项目(BE2012774
BE2014729)
江苏高校优势学科建设工程资助项目(PAPD)
关键词
长江口杭州湾
冬半年
海洋热动能
寒潮过程
FVCOM-SWAVE耦合模式
the Yangtze estuary and Hangzhou bay
cold season
sea thermodynamic energy
cold wave process
FVCOM-SWAVE coastal coupled model
