SAR imaging and numerical simulation of upwelling processes near the coastal area of Qingdao in China

SST cooling episodes in the early Spring are often observed by various remote sensing measurement systems near the coast of Qingdao, a city in China's Shandong province (Figure 1). Several wind-SST interaction mechanisms that can cause colder deep water to force its way upward and drive away and subsequently replace the warmer surface water, also known as upwelling, have been previously documented. Most of the previous coastal upwelling work has been focused on the mechanism of upwelling processes on a large scale and caused by winds blowing parallel to the coast and Ekman transport. Upwelling on small local scales such as the one shown in Figure 1 has not been extensively studied. However, on a more local and smaller scale, not associated with Coriolis force or Ekman transport, winds blowing offshore can also push water mechanically away from land to produce upper level divergence and upwelling. But it is not clear if the recurring upwelling in Figure 1 can be attributed to the along-coast winds or the offshore winds or the local bathymetry, or a combination of several factors. We will look into the possible mechanisms.