  In 2008 a sequence of geomagnetic storms occurred triggered by high-speed
solar wind streams from coronal holes. Improved estimates of precipitating
fluxes of energetic electrons are derived from measurements on board the
NOAA/POES 18 satellite using a new analysis technique. These fluxes are used to
quantify the direct impact of energetic electron precipitation (EEP) during
solar minimum on middle atmospheric hydroxyl (OH) measured from the Aura
satellite. During winter, localized longitudinal density enhancements in the OH
are observed over northern Russia and North America at corrected geomagnetic
latitudes poleward of 55$^{\circ}$. Although the northern Russia OH enhancement
is closely associated with increased EEP at these longitudes, the strength and
location of the North America enhancement appear to be unrelated to EEP. This
OH density enhancement is likely due to vertical motion induced by atmospheric
wave dynamics that transports air rich in atomic oxygen and atomic hydrogen
downward into the middle atmosphere, where it plays a role in the formation of
OH. In the Southern Hemisphere, localized enhancements of the OH density over
West Antarctica can be explained by a combination of enhanced EEP due to the
local minimum in Earth's magnetic field strength and atmospheric dynamics. Our
findings suggest that even during solar minimum, there is substantial
EEP-driven OH production. However, to quantify this effect, a detailed
knowledge of where and when the precipitation occurs is required in the context
of the background atmospheric dynamics.
