[A-CG41] Satellite Earth Environment Observation

[ACG41-P16] Intercomparisons of sea surface temperature products focusing on the recent summers with record highs on global average

*Eri Yoshizawa¹, Misako Kachi¹ (1.Japan Aerospace Exploration Agency)

Keywords:Sea surface temperature, AMSR

Sea surface temperature (SST) is one of the most vital climate indices for monitoring oceanic thermal conditions affected by global warming, obtained from in situ and satellite observations or reanalysis systems. Its global average shows an annual cycle with bimodal peaks corresponding to boreal and austral summers. Surprisingly, it was reported that the worldwide average hit a record high in the boreal summer of 2023, as well as the atmospheric temperature average, and that anomalous warm conditions continued to the subsequent austral summer. However, this warming is underestimated/overestimated depending on the products used as an index; for example, we compared passive microwave SST from the Advanced Microwave Scanning Radiometer 2 (AMSR2) onboard the Global Change Observation Mission-Water (GCOM-W) and Merged satellite and in situ data Global Daily SST (MGDSST) and found that the former tends to underestimate the summer SST rises compared with the latter during the last two decades. In the presentation, we will show detailed results of the space-time intercomparisons and discuss what causes the differences among the products.