Modeling study on the polar middle atmospheric responses to medium energy electron (MEE) precipitation

Energetic particle precipitation (EPP) is an important source of chemical changes in the polar middle atmosphere during winter. Recently, it has been suggested from modeling study that EPP-induced chemical changes can cause dynamic changes of the atmosphere. In this study we investigate the atmospheric responses to medium-to high energy electron (MEE) precipitations during 2005-2013 by using Specific Dynamics Whole Atmosphere Community Climate Model (SD-WACCM). Results show that MEE precipitations significantly increase the amount of NO_x and HO_x, resulting in mesospheric and stratospheric ozone depletions during polar winter. The ozone depletion due to MEE precipitation induces warming in the polar lower mesosphere. Large ozone loss in the polar middle atmosphere leads to clear dynamic impacts, which causes warming by 3-11 K temperature increase and weakening of the zonal wind in the lower mesosphere. Our study show that the MEE precipitation induces not only the chemical effects such as ozone depletion but also clear dynamic effects in the polar middle atmosphere.