In recent decades, Arctic surface temperature increases much faster than that in other regions, which is so called Arctic amplification (AA). A robust feature for AA is that AA reaches its maximum (minimum) in autumn-winter (summer), while it reaches its secondary peak in spring. Based on our previous studies (Dai, 2021, GRL; Dai et al., 2022, JGRA; Wu and Dai, under review), most of the additional solar radiation induced by sea-ice loss is stored as seasonal heat storage (SHS) in subsurface ocean, which leads to AA minimum in summer. In autumn-winter, SHS is released due to colder surface air and warmer sea surface, which leads to AA maximum without additional solar radiation. For SHS formation/discharge anomaly, it is mainly completed by vertical diffusion, which is induced by enhanced wind stress over the current via sea-ice loss or wind acceleration and/or strengthened turbulence via denser water formation.

Arctic amplification,seasonal heat storage,energy budget