The seasonal variation of the upper layers of the South China Sea (SCS) circulation and the Indonesian through flow (ITF): An ocean model study

•A high resolution ocean model resolves the interactions between the South China Sea through flow (SCSTF) and the Indonesian through flow (ITF).•The modeled volume transports through the SCSTF and ITF straits have strong seasonal variations and agree well with the observations.•The warming signal observed from the 60s to the 90s is reproduced in the simulation in the upper layers of the SCS.•Warming of the SCS is due to the increased local net heat flux rather than to the large scale circulation.