Space Climate 7 Meeting Abstract
Effect of energetic particle precipitation on atmospheric dynamics and climate variations
Timo Asikainen (University of Oulu)
Antti Salminen (1), Ville Maliniemi (2,1) and Kalevi Mursula (1) (1) ReSoLVE Centre of Excellence, Space Climate Research Unit, University of Oulu, Finland (2) Birkeland Centre for Space Science, Department of Physics and Technology, University of Bergen, Norway
Recent research has given strong indications that energetic particle precipitation (EPP) from space into the atmosphere can have tangible effects on atmospheric dynamics throughout the middle-atmosphere down to ground level. It has been shown the EPP creates chemical species (e.g., NOx) which can catalytically destroy ozone either directly in the mesosphere or indirectly much lower in the stratosphere where the EEP created NOx can descend over the winter in polar darkness. Ozone loss can change radiative heating rates and thereby modify atmospheric circulation, temperature and winds. These changes lead to enhancement of the wintertime stratospheric polar vortex and can propagate down to the troposphere where they are seen as variations of dominant wintertime weather patterns, most notably the Northern Annular Mode (NAM) and North Atlantic Oscillation (NAO). We review here our recent research on the effects of EPP in the stratosphere and on ground using a wide collection of datasets. We show that the EPP effect can be observed at least for the past 100 year in long-term ground climate records as well as in atmospheric re-analysis datasets covering the past 40 years. Moreover, we demonstrate that the EPP effect is significantly modulated by internal atmospheric factors, most notably the Quasi-Biennial Oscillation (QBO) of equatorial stratospheric winds.
Mode of presentation: oral (Need to be confirmed by the SOC)