49 / 2024-09-02 14:32:17

Role of ocean seasonal heat storage on seasonality of Arctic amplification

Arctic amplification,seasonal heat storage,energy budget

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.