Enhanced Relationship between Central Tropical Pacific Sea Surface Temperature and Eurasian Surface Air Temperature during Boreal Summers

Abstract This study investigates the relationship between central tropical Pacific (CTP) sea surface temperature (SST) and air (SAT) variability un-related to canonical El Niño-Southern Oscillation (ENSO) over mid-to-high latitude Eurasia during boreal summers past half-century. The results show that their experienced a decadal shift around early 1980s. Before 1980s, Eurasian SAT-CTP SST connection was weak; after time, became stronger, SAT anomalies exhibited significant wave-like pattern Eurasia. Such change in could be attributed changes mean state of CTP SST. warmer enhanced 1980s reinforced convective activities Pacific, leading significantly anomalous divergence/convergence Rossby wave sources North Pacific. outcome further excited train propagating along Northern Hemisphere zonal jet stream northern then affected heat fluxes atmospheric circulations region, resulting SATs However, period before had weak impact on circulation consequently not able excite SATs. physical processes linking are confirmed by numerical simulations. this valuable understanding summer