QBO-dependent relation between electron precipitation and wintertime surface temperature

[1] Recent research has shown that energetic particle precipitation into the upper atmosphere can change ion and neutral chemistry, e.g., by enhancing NOx concentration in the mesosphere, which, in turn, can affect stratospheric ozone balance under appropriate conditions. It has been suggested that this may affect the surface temperatures at high latitudes by modulating tropospheric circulation. Motivated by such results, we compare here the wintertime energetic electron precipitation (EEP) with North Atlantic Oscillation (NAO) and surface air temperature (SAT) in the Northern Hemisphere. We use the recently recalibrated energetic electron data from the Medium Energy Proton and Electron Detector instrument of the National Oceanic and Atmospheric Administration (NOAA)/Polar Orbiting Environment Satellites in two energy ranges (30―100 keV and 100-300 keV), the NAO index from NOAA, and the NASA Goddard Institute for Space Studies surface temperature analysis for years 1980―2010. We find a statistically significant correlation between EEP and the NAO index and also between EEP and SAT in certain geographic regions. The strongest negative correlation is found in Northeast Canada/Greenland, while the strongest positive correlation is found in North Siberia/Barents Sea, in agreement with similar studies using global geomagnetic activity as a proxy for particle precipitation. We find higher correlation when the two winters (1984/1985 and 2003/2004) of unprecedentedly strong sudden stratospheric warmings are excluded. We also find that the different phases of quasi-biennial oscillation (QBO; observed at 30 hPa) lead to dramatically different correlation patterns, with easterly QBO producing considerably stronger and spatially wider correlation and larger temperature response than westerly QBO.