Evaluation of Sea Surface Temperatures Derived From the HY-1D Satellite
Xiaomin Ye, Jianqiang Liu, Mingsen Lin, Jing Ding, Bin Zou, Qingjun Song, Yue Teng
Abstract
Global sea surface temperatures (SSTs) are detected by the Chinese ocean color and temperature scanner (COCTS) instruments aboard the HaiYang (HY)-1C and HY-1D satellites. In this study, the SSTs derived from the COCTS instrument on the HY-1D (COCTS/HY-1D) satellite and a nonlinear SST algorithm with corresponding coefficients were introduced. The COCTS/HY-1D SSTs recorded from April 26 to August 31, 2021, were evaluated against water temperature measurements taken at depths above 1 m from the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> Quality Monitor system; root-mean-square errors (RMSEs) of 0.65 and 0.71 °C and robust standard deviations (RSDs) of 0.51 and 0.47 °C were obtained for the daytime and nighttime SSTs, respectively, using a spatiotemporal matching window of 4 h and 2.5 km. Daily gridded SSTs derived from COCTS/HY-1D were compared with those obtained from the visible infrared imaging radiometer suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite in the same period, and RMSEs of 0.67 ± 0.06 and 0.81 ± 0.06 °C and RSDs of 0.49 ± 0.04 and 0.58 ± 0.05 °C were obtained for the daytime and nighttime SSTs, respectively. The COCTS/HY-1D-derived SSTs covering Gulf Stream waters were cross-validated against the VIIRS/S-NPP data as a case study, and RMSEs of 0.53 and 0.47 °C for the daytime and nighttime, respectively, were obtained.