Ten years(from 2005 to 2014) of satellite sea surface temperature(SST) data from the Advanced Very High Resolution Radiometer(AVHRR) are analyzed to reveal the monthly changes in surface cold patches(SCPs) in the main areas of the Northern Yellow Sea(NYS). The Canny edge detection algorithm is used to identify the edges of the patches. The monthly changes are described in terms of location, temperature and area. The inter-annual variations, including changes in the location and area of the SCPs from 2010 to 2014, are briefly discussed. The formation mechanisms of the SCPs in different periods are systematically analyzed using both in situ data and numerical simulation. The results show that from May to October, the location and area of the SCPs remain stable, with a north-south orientation. The SCPs altogether cover about 1? of longitude(124?E–125?E) in width and 2? of latitude(37.5?N–39.5?N) in length. In November, the SCP separates from the Jangsan Cape and forms a closed, isolated, and approximately circular cold patch in the central NYS. From May to October, the upwelling that leads to the formation of the SCP is mainly triggered by the headland residual current, wind field, climbing movement of the current and secondary circulation at the tide front. In November, cyclonic circulation in the NYS is primarily responsible for generating the upwelling that leads to the formation of the closed and isolated SCP.
HU JingwenSHI MaochongZHANG TingluCHEN ShuguoWU Lunyu
依据2012年1月至2013年12月2年的GOCI（Geostationary Ocean Color Imager）卫星总悬浮体数据,分析了长江口毗邻水域的表层悬浮体锋面（浓度≥2mg/L）的周、月变化特征,并对其机制进行了初步分析。研究结果显示,长江口毗邻水域表层悬浮体锋面变化可基本分为4个阶段,即：1~3月的外输稳定阶段、4~5月的向岸退缩阶段、6~8月的内储稳定阶段、9~12月的向海扩张阶段。4月由输变退,9月由退变输,1月向外海扩散面积最为广阔,6月向岸退缩得最近。春夏交替时期悬浮体锋面的退缩速度较秋冬交替时的扩张速度快约1倍。一年中,退缩最快的时段约在第15~17周,扩张最快的时段约为第38~39周。结果还表明悬浮体锋面的变化速度与风速的变化速度有很大的相关性。
