An Eddy Perspective of Global Air–Sea Covariation

Mesoscale eddies are widely distributed in the global ocean. They affect the ocean flow field and material transport, and play an important role in the energy transfer between the ocean and the atmosphere. With the development of high-resolution satellite observations, many regional studies are emerging on the coupling effects between mesoscale eddies and the atmosphere. In this study, each identified global eddy (2010–2016, about 13 million eddies) is collocated and normalized with sea surface temperature (SST, 2010–2014), sea surface wind (2010–2016), sea surface air temperature at 2 m (2010–2016), water vapor (2010–2014), evaporation rate (2010–2016), cloud liquid water (2010–2014), and rainfall rate (2010–2014). Four normalization methods are used: non-rotated normalization, and normalizations based on wind direction, flow direction, and eddy egg direction alignment. Furthermore, the eddy explained variations of the air–sea parameters are calculated to obtain their spatial distribution. The eddy explained variation ranges of the seven parameters are 24%–78%, 12%–21%, 3%–35%, 8%–22%, 9%–18%, 0–53%, and 0–58%, respectively. The influence of mesoscale eddies on the air–sea interface can be summarized as a vertical mixing mechanism. This study is novel in that it explores the overlying air–sea distribution from the perspective of glo-bal eddies. The numerical distributions of climatological air–sea parameters are determined by utilizing the multiyear composite overlying air–sea distribution over global eddies using the eddy coordinate system, and the contribution of eddies to this pattern is analyzed. This study is important for the investigation of global climate change.