Water Mass Properties, Variabilities And Origins In Northern Borneo

Abstract

We present a definition of water mass properties, variabilities and origins along the coast of northern Borneo based on 55 CTD casts taken during cruises in July 2009. We also studied data from four Argo profiling floats in the surrounding seas. The temperature salinity (TS) relation in the South China Sea, Sulu Sea and Celebes Sea show the existence of eight water masses. Earlier studies defined the surface mixed layer water masses as Open Sea Water (OSW), Continental Shelf Water (CSW) and Seasonal Thermocline Water (STW). Below the layer of this active mixing are subsurface zones of rapid transition called the Tropical Surface Water (TSW) and Maximum Salinity Water (MaxSW). Permanent Thermocline Water (PTW), Minimum Salinity Water (MinSW) and Deep Water (DW) are at the intermediate layer to about 1000 m. BLUElink ReANalysis (BRAN) global ocean models demonstrated how current circulations influence the exchange of water masses between the three seas. The Sulu Sea sits in the middle, and has very limited connections between the other two seas. Connection with the Celebes Sea occurs at a depth of 200m.