摘要:
根据珠江口及其附近海域2006年冬季(2006年12月至2007年1月)航次的CTD调查资料发现,由于表层水体冷却而产生的对流作用,以及东北季风、浪、流等强动力条件下,冬季陆架水体垂向混合均匀,但粤东近岸海域却存在显著的温跃层及逆盐跃层,其原因在于:东北季风的Ekman效应引起了陆架表层高温、高盐海水向岸输送,东北季风还驱动了西南向沿岸流,其底边界层的Ekman效应引起了沿岸底层低温、低盐海水离岸输送,这样就形成了陆架方向的次生环流,在沿岸海域则为下降流,并表现为沿岸海域的逆盐跃层及温跃层现象。在下降流显著的区域,溶解氧垂向分布均匀且浓度较高,这应归因于下降流将溶解氧浓度较高的表层水带入深层所致。
Abstract:
According to the obtained CTD data of Zhujiang River estuary and the surrounding waters during the winter cruise in 2006, it found that under the convection effect of the cooling surface water and the strong dynamical condition of northeast monsoon, wave and current act., the shelf water mixed uniform vertically, however, eastern Guangdong coastal waters has remarkable thermocline and inverse halocline, which caused by the transporting of high temperature and salinity surface water from shelf to coast under the Ekman effect of northeast monsoon, the offshore transporting of low temperature and salinity coastal bottom water under the Ekman effect of bottom boundary layer due to the southwest coastal current drived by northeast monsoon, these led to the secondary circulation in the shelf direction and downwelling in the coastal area which embodys in the phenomena of inverse halocline and thermocline in the costal area. In the area with remarkable downwelling, the dissolved oxygen concentration is uniform vertically and higher than other area. This should ascribe to downwelling effect which can bring the surface water with higher concentration dissolved oxygen to the deep layer.
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