Temperature inversion in the Taiwan Strait during northeast monsoon

Hydrographic data from three cruises during 2006 and 2008 and historical temperature data from Japan Oceanographic Data Center (JODC) were used to study temperature inversion (TI) in the Taiwan Strait during northeast monsoon. The result shows that TI occurs almost in the whole strait except Taiwan Bank and shallow waters along western coast of the strait. The magnitude (occurrence frequency) of TI is large (high) in the western strait, but small (low) in the eastern strait and the coastal waters of Guandong. The start depths of TI layers are deeper in spring than that in autumn and winter. The area where TI occurs frequently (ATOF) with occurrence frequency above 60% has a southnorth movement with seasons. The southern edge of ATOF locates around Xiamen coastal sea in autumn and extends southward to the north of Taiwan Bank in winter, and then recedes northward to Pingtan coastal sea in spring. The seasonal southnorth migration of ZheMin Coastal Water (ZMCW) is found to induce ATOF’s movement. Besides seasonal variability, there was a distinct difference of TI between 2006 and 2007 winter. TI only occurred in the coastal area of western strait during 2006 winter, but in the western and eastern strait and the coastal waters of Guandong during 2007 winter. The lateral shift of ZMCW is suggested to be the major causative factor.