[A-OS12] Ocean Science Revealed by Global Observation System

[AOS12-02] Satellites Reveal Different Stories of the Marine Heatwaves: From Globe to Arctic

*Ning Zhao¹, Xuewei Zhang², Zhijun Dai², Zhen Han³ (1.Japan Agency for Marine-Earth Science and Technology,, 2.East China Normal University, 3.Shanghai Ocean)

Keywords:marine heatwaves, satellite, SST, Arctic

Prolonged extremely warm ocean temperatures have great impacts on both natural ecosystems and human communities. These phenomena (i.e., marine heatwaves) could be easily monitored globally by satellite-based sea surface temperatures; however, the choice of datasets may lead to potential uncertainties in the marine heatwave assessment. Here we compared the marine heatwaves using commonly used satellite products to illustrate the uncertainties, with specific attention on the Arctic Ocean. Distinct differences were found in the occurrence, duration, and long-term trend of marine heatwaves over both coastal and open waters in the global oceans, while some discrepancies could become comparable with the obtained metrics themselves. Specifically, in the Arctic region, inconsistent behaviors of marine heatwaves using different datasets became even larger when they showed opposite tendencies over regions with higher ice concentrations (> 50%) in recent years. Overall, our findings revealed our knowledge of marine heatwaves is facing challenges due to the significant influences of the algorithms used in different datasets and the sea ice, and our analyses in the Arctic region also suggest their results also varied in different versions, highlighting an urgent need for more in situ observations and consistent and reliable long-time datasets for the warming oceans.