Feasibility of reconstructing the basin-scale sea surface partial pressure of carbon dioxide from sparse in situ observations over the South China Sea
Shen, Samuel S. P.
- 海洋环境－科研数据 
Sea surface partial pressure of CO2 (pCO2) data with high spatial-temporal resolution are important in studying the global carbon cycle and assessing the oceanic carbon uptake capacity. However, the observed sea surface pCO2 data are usually limited in spatial and temporal coverage, especially in marginal seas. This study provides an approach to reconstruct the full sea surface pCO2 field in the South China Sea (SCS) with a grid resolution of 0.5º×0.5º over the period of 2000-2017 using both remote-sensing derived pCO2 and observed pCO2. Empirical orthogonal functions (EOFs) were computed from the remote sensing derived pCO2. Then, a multilinear regression was applied to the observed pCO2 as the response variable with the EOFs as the explanatory variables. EOF1 explains the general spatial pattern of pCO2 in the SCS. EOF2 shows the pattern influenced by the Pearl River plume on the northern shelf and slope. EOF3 is consistent with the pattern influenced by coastal upwelling along the north coast of the SCS. The reconstructions always agree with observations. When pCO2 observations cover a sufficiently large area, the reconstructed fields successfully display a pattern of relatively high pCO2 in the mid-and-southern basin. The rate of sea surface pCO2 increase in the SCS is 2.383 uatm per year based on the spatial average of the reconstructed pCO2 over the period of 2000-2017.