The impact of high-frequency atmospheric forcing on the Yellow Sea Warm
Current and warm salty water intrusion in the Southern Yellow Sea
Abstract
The impact of high-frequency atmospheric forcing on the Yellow Sea (YS)
circulation with emphasis on the Yellow Sea Warm Current (YSWC) was
investigated by comparing model simulations with and without
high-frequency atmospheric processes. By including the high-frequency
atmospheric forcing at the synoptic scale in an atmosphere reanalysis
used to force the ocean model, the simulated intensity of the mean YSWC
is increased by 40-100%. The mean temperature is decreased by up to
1°C, and the mean salinity along the YSWC pathway is increased by up to
0.2-0.5 psu. Additional simulations in which either the wind or other
atmospheric fields were filtered revealed that the high-frequency wind
forcing is more important in the YSWC and relates mean temperature with
the other atmospheric variables that play relatively minor roles. In
winter, the high-frequency wind forcing associated with frequent winter
storm bursts and relaxation is able to excite coastal trapped waves
propagating cyclonically around the Bohai Sea and Yellow Sea coast; this
forcing is a very important factor influencing the synoptic variability
in the YSWC and drives intermittent warm and salty water intrusion into
the southern YS. The results from this study provide a basis for a new
understanding of how transient atmospheric phenomena, such as winter
storms, impact regional circulation and water transport in the YS.