With the trend of amplified warming in the Arctic, we examine the observed and modeled top-of-atmosphere (TOA) radiative responses to surface air-temperature changes over the Arctic by using TOA energy fluxes from NASA’s CERES observations and those from twelve climate models in CMIP5. Considerable inter-model spreads in the radiative responses suggest that future Arctic warming may be determined by the compensation between the radiative imbalance and poleward energy transport (mainly via transient eddy activities). The poleward energy transport tends to prevent excessive Arctic warming: the transient eddy activities are weakened because of the reduced meridional temperature gradient under polar amplification. However, the models that predict rapid Arctic warming do not realistically simulate the compensation effect. This role of energy compensation in future Arctic warming is found only when the inter-model differences in cloud radiative effects are considered. Thus, the dynamical response can act as a buffer to prevent excessive Arctic warming against the radiative response of 0.11 W m−2 K−1 as measured from satellites, which helps the Arctic climate system retain an Arctic climate sensitivity of 4.61 K. Therefore, if quantitative analyses of the observations identify contribution of atmospheric dynamics and cloud effects to radiative imbalance, the satellite-measured radiative response will be a crucial indicator of future Arctic warming.
Bibliographical noteFunding Information:
This work was supported by the “Development of Climate and Atmospheric Environmental Applications” project, funded by Electronics and Telecommunications Research Institute which is a subproject of the “Development of Geostationary Meteorological Satellite Ground Segment (NMSC-2019-01)” program funded by the National Meteorological Satellite Center of the Korea Meteorological Administration, and a National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2018R1A2B6006653). CY is supported by Korea Polar Research Institute by grant KOPRI-PN19081. Yuan Wang, Hui Su, and Jonathan Jiang acknowledge the support from the NASA ROSES ACMAP, MAP and CCST programs and are grateful for the support from the Jet Propulsion Laboratory, California Institute of Technology, under contract by NASA. Y.-S. Choi acknowledges the support of the JPL faculty visitation program.
© 2019, The Author(s).