Convection Electric Field Patterns for Quiet and Disturbed Periods

Thursday, 18 December 2014
Simon G Shepherd, Dartmouth College, Hanover, NH, United States and Ellen D. P. Cousins, National Center for Atmospheric Research, Boulder, CO, United States
Statistical models of ionospheric convection have been made using numerous
techniques and datasets. These models capture the climatology of
magnetosphere-ionosphere coupling in the high-latitude and serve as useful
inputs to various models of the magnetosphere-ionosphere-theremosphere system.
In this study, data from the Super Dual Auroral Radar Network (SuperDARN) are
used to determine global-scale convection electric field patterns in the
northern hemisphere for a variety of IMF and disturbance-level conditions.
A five-year period from 2009-2013 has been chosen for this study and includes
observations that extend from the geomagnetic pole to below 50 degrees.
Inclusion of data from mid-latitude and polar radars serves to augment
observations from the 'traditional' high-latitude SuperDARN radars, extending
the activity range over which global-scale patterns can be derived. Generally,
a larger cross polar cap potential (CPCP) and linear dependence on the Kp
index is observed in the new models, which is likely due to the more
consistent observations in the polar cap and from the contribution of
mid-latitude flows. Another notable difference in the new models is the
extent to which westward flows are observed at lower latitudes. Sub-auroral
flows and westward flows extending far into the post-midnight sector are
observed at almost all activity levels. With the increased range of
observations, these models represent an improvement in the
description of ionospheric convection electric field climatology.