Seasonal mean circulation in the Yellow Sea - a model-generated climatology

The three-dimensional climatological circulation is computed for the Yellow and Bohai Seas in a series of six bimonthly realizations, The model (QUODD Y, Lynch et al., Continental Shelf Res, 16(7) (1996) 875) is nonlinear, tid e-resolving, and baroclinic with level 2.5 turbulence closure. Data inputs include seasonal hydrography, seasonal mean wind and river input, and ocean ic tides. Results for winter and summer exhibit two distinct circulation mo des. In winter, strong northerly wind drives southward flow at the surface and along both Korean and Chinese coasts. This is compensated by deep retur n flow - the Yellow Sea Warm Current - in the central trough of the Yellow Sea, penetrating to the Bohai. The Changjiang discharge exits to the southw est in winter, trapped alone the Chinese coast. In summer, a water mass pro duced by winter cooling - the Yellow Sea Cold Water - is isolated in the de ep central trough, setting up cyclonic circulation over the eastern Yellow Sea. Summer winds from the south drive northeastward flow along the Chinese coast. The net result is a qualitative reversal of the winter pattern. The Changjiang discharge is driven offshore toward the Korean Strait by the su mmer wind. The winter and summer circulations are partitioned dynamically a mong tidal rectification, baroclinic pressure gradients, wind response, and river input from the Changjiang. Wind dominates the winter pattern. In sum mer, baroclinic pressure gradients dominate the eastern Yellow Sea; with wi nd, tidal rectification, and input from the Changjiang dominant to the west of the cyclonic gyre, The seasonal cycle indicates that January and March exhibit the same basic winter pattern. May is quiescent, followed by July w hich defines the summer mode. September shows the same general summer patte rn, with features shifted westward. November is a transition period followe d by winter conditions, (C) 2001 Elsevier Science Ltd. All rights reserved.