【摘要】：本文基于12年(2003-2014)的衛(wèi)星遙感數(shù)據,分析了夏季舟山沿岸上升流區(qū)海表溫度(SST)、葉綠素和上升流強度的變化,以及海面風場對上升流強度的影響;進一步,基于Delft3D模型,模擬了 2014年舟山群島海域的溫度、鹽度、海流等水文、動力要素,通過控制試驗和改變影響因子的敏感性試驗,探討了夏季誘導舟山沿岸上升流的動力機制。衛(wèi)星遙感數(shù)據分析結果表明:不同年份夏季舟山沿岸上升流的強度變化很大,呈現(xiàn)4～5年的周期,分別于2004、2009、2013年達到峰值;夏季偏南風對舟山沿岸上升流區(qū)SST的變化影響很大,尤其是7月份,上升流強度與經向風應力呈現(xiàn)較好的線性關系,相關系數(shù)高達0.87;上升流區(qū)的葉綠素濃度較高,與SST的變化呈現(xiàn)負相關�；贒elft3D數(shù)值模型的控制試驗與實測站點的潮位吻合良好,海表溫度均方根誤差在1℃以內,鹽度均方根誤差在2ppt左右,模擬SST水平分布表明:2014年的夏季舟山沿岸上升流,6月份較弱,7、8月份逐漸加強,9月份明顯減弱,與2014年遙感觀測的結果基本一致�？刂圃囼灲Y果較為準確,模型能夠用來進行上升流研究。同時,本文分別進行了無風與偏北風、無長江徑流、改變斜坡地形、無潮4個敏感性數(shù)值試驗,以探討誘導夏季舟山沿岸上升流的動力機制。無風與偏北風模擬的結果表明夏季舟山沿岸上升流低溫中心仍然存在,上升流強度無風時較偏南風時稍弱,偏北風時較前兩種情況下更弱,風場對上升流的形成貢獻不大,但綜合衛(wèi)星遙感數(shù)據的分析結果,可以得出風場的變化對上升流強度的變化具有顯著的影響,其中偏南風有利于夏季舟山沿岸上升流強度的增加,偏北風則會削弱上升流的強度;無長江徑流模擬結果表明,舟山上升流強度略有減弱,長江徑流對舟山上升流強度有一定的影響;去除海底斜坡地形的數(shù)值試驗結果表明,在地形平緩的情況下,舟山上升流幾乎消失不見,而地形坡度較陡時則能產生明顯的上升流現(xiàn)象。由此可見,斜坡地形對舟山上升流有顯著的誘導作用;無潮數(shù)值試驗中,從SST分布上看不到上升流跡象,斷面溫鹽分布上也無明顯的等值線抬升現(xiàn)象,表明潮汐對舟山上升流的產生有顯著的誘導作用。綜上所述,夏季舟山沿岸上升流是在多種動力要素的共同作用下產生的。其中,潮汐和地形的作用較大,風場和徑流的作用較小。底層海水在潮流產生的混合效應和斜坡地形的誘導下,向上爬升形成上升流。風場對上升流的形成貢獻較小,但對上升流強度的短期與長期變化有較為顯著的影響。
[Abstract]:Based on the satellite remote sensing data of 12 years (2003-2014), the variation of (SST), chlorophyll and upwelling intensity in the upwelling zone along Zhoushan coast in summer and the influence of sea surface wind field on the upwelling intensity are analyzed. Furthermore, based on the Delft3D model, the hydrological and dynamic factors such as temperature, salinity and current in the Zhoushan Islands in 2014 were simulated. The dynamic mechanism of induced upwelling along Zhoushan coast in summer is discussed. The results of satellite remote sensing data analysis show that the intensity of the upwelling along Zhoushan coast in summer varies greatly in different years, showing a period of 4 ~ 5 years, which reached its peak in 2009 and 2013, respectively. The southerly wind in summer has a great influence on the variation of SST in the upwelling zone along the Zhoushan coast, especially in July, there is a good linear relationship between the upwelling intensity and the meridional wind stress, and the correlation coefficient is as high as 0.87; The chlorophyll concentration in upwelling region was higher and negatively correlated with the change of SST. The control test based on Delft3D numerical model is in good agreement with the measured tidal level. The root mean square error of sea surface temperature is less than 1 鈩，

本文編號：2416230