Evaluation of the ERA5 Sea Surface Temperature Around the Pacific and the Atlantic

Abstract

Sea surface temperature (SST) is a key factor for both climate and weather. Most studies focus on evaluation of satellite SSTs in different oceanic regions, but the performance of ERA5 reanalysis SST datasets (ERA5 SSTs) has not been systematically evaluated. In this article, buoy measurements from 46 National Data Buoy Center (NDBC) sites around the Pacific and the Atlantic are used to make an analysis of the deviations of the ERA5 SSTs on an hourly basis and its variations on a daily basis. Overall, ERA5 SSTs have a global coverage with a -0.04 °C bias and 4.60 °C standard deviation in the study area. It is worthwhile to notice that ERA5 SSTs exhibit significant differences in the amplitude and the phasing of their spatial patterns. The products are found to meet the accuracy criterion, except in near coastal areas, which may result from the near-coastal mixture effect and the warm SST. The results reveal that ERA5 SSTs completely capture the diurnal variability of SST under all wind speed conditions, especially in the situation when wind speed is above 6 m/s. There is a slight cold bias when wind speed is below 6m/s, indicating that ERA5 SSTs are not affected by solar radiation heating. These findings contribute to the sensible use of ERA5 SSTs around the Pacific and the Atlantic.

Keywords

• Accuracy evaluation
• buoy measurements
• ERA5
• reanalysis product
• sea surface temperature