Atmospheric energy change in the Arctic troposphere under Arctic warming

The atmospheric energy is an essential property of atmosphere, mainly composed of internal, potential and latent energies, and could be changed by energy balance processes. The recent Arctic warming and wetting could have direct impacts on the internal and latent energies, and indirect impacts on energy transport and transformation. It is necessary to understand if and how the Arctic atmosphere, described by energy, has been changed under Arctic warming. This study attempts to analyse and discuss the changes of tropospheric energy over the Arctic (north of 66 degrees N) from 1979 to 2018, including the general status, seasonal variation, long-term trend, interannual variability and extremes. Three latest reanalysis products, ERA5, CFSR and JRA55, are used in this study, with acceptable reliability in validation with radiosonde observations. The reanalysis products exhibit high consistence in energy changes over the Arctic. The main results are obtained as (a) the Arctic troposphere has a total energy of 3.42 x 10(22) J, dominated by internal energy; (b) an increase of total energy in the Arctic troposphere is found on annual basis, with a trend of 7.20 +/- 5.47 x 10(19) J center dot decade(-1), and possibly enhanced in last 20 years, mainly contributed by internal energy; (c) the tropospheric energy over the Arctic had a interannual variability of 1.95 x 10(20) J, mainly supported by internal and potential energies, and the extremes of high energies were gradually enhanced. Therefore, the Arctic atmosphere, described by energy, has been changed under Arctic warming, evidenced by significant increases of total energy and its components in the Arctic troposphere on annual basis.