Trends And Inter-annual Variability Of The South China Sea Surface Winds,Surface Height And Surface Temperature

The monthly products of the surface winds(SW, from 1988 to 2011), sea surface height(SSH, from 1993 to 2014) and sea surface temperature(SST, from 1982 to 2015) of the South China Sea(SCS) are used to analyze trends and inter-annual variability. The linear trends of the regional mean east and north components of SW, SSH and SST are 0.005±0.005(m/s)/yr,-0.003±0.005(m/s)/yr, 0.420±0.107cm/yr, 0.006±0.004℃/yr, respectively. The inter-annual variability of the regional mean east and north components of SW, SSH and SST correlates with inverse EMI(El Ni?o Modoki Index), NINO3, inverse NINO3.4 and NINO3 with coefficient of about 0.570, 0.682, 0.518 and 0.538, and with lag of 9, 1, 4 and 5 months, respectively. The warming rate of the SCS SST is slowing down, which is consistent with the global warming hiatus since the end of the last century. Empirical Orthogonal Function(EOF) analysis is performed to evaluate the inter-annual variability. Results indicate that the first EOF mode of the SW is characterized by a basin-wide anti-cyclonic pattern. The correlation coefficient between the corresponding time coefficient function(TCF) and NINO3 index is 0.871 with a lag of 1 month. The first EOF mode of the SSH is characterized by a low sea level along the eastern boundary. The correlation coefficient between the corresponding TCF and the EMI index is 0.721 with a lag of 7 months. The first EOF mode of the SST is characterized by a basin-wide warming. The correlation coefficient between the corresponding TCF and the NINO3 index is 0.588 with a lag of 5 months, indicating that the entire SCS is warmed up following the El Ni?o events.