ThecirculationofYellowSeaColdWaterMass(YSCWM)intheSouthernYellowSeaisinvestigatedusingadiagnostic2DMITgcmmodel.Theresolutionofthecomputationalgridis900minthehorizontaland2mintheverticalwhereaninitialtemperaturedistributioncorrespondingtoatypicalmeasuredYellowSeaColdWaterMasswasapplied.TheexistenceofYSCWMthatcausesfluiddensitydifference,isshowntoproducecounter-rotatingcyclonichorizontaleddiesinthesurfacelayer:theinneroneisanti-cyclonic(clockwise)andrelativelyweaker(8–10cms-1)whiletheouteroneiscyclonic(anti-clockwise)andmuchstronger(15–20cms-1).ThisresultisconsistentwiththesurfacepatternobservedbyPangetal.(2004),whohasshownthatamesoscaleanti-cycloniceddy(clockwise)existsintheupperlayerofcentralsouthernYellowSea,andabasin-scalecyclonic(anticlockwise)gyreliesoutsideoftheanti-cycloniceddy,basedonthetrajectoriesanddriftingvelocitiesof23drifters.Belowthethermocline,thereisananti-cyclonic(clockwise)circulation.ThiscomplexcurrenteddysystemisconsideredtobecapableoftrappingsuspendedsedimentsanddepositingthemnearthefrontbetweenYSCWMandthecoastalwatersofftheSubeicoast,providinganexplanationonthesedimentdepthandsizedistributionofmudpatchesintheSouthernYellowSea.Moreover,sensitivetestscenariosindicatethatvariationsofbottomfrictiondonotsubstantiallychangethemainfeaturesofthecirculationstructure,butwillreducethebottomcurrentvelocity,increasethesurfacecurrentvelocityandweakentheupwellingaroundthefrontalarea.
