Development of a High-Latitude Convection Model by Application of
Machine Learning to SuperDARN observations
Abstract
A new model of high-latitude convection derived using machine learning
(ML) is presented. The ML algorithm random forests regression was
applied to a database of velocity observations from the Super Dual
Auroral Radar Network (SuperDARN). The features used to train the model
were the IMF components Bx, By, and
Bz; the solar wind velocity, vsw; the
auroral indicies, Au and Al; and the
geomagnetic index, SYM-H. The SuperDARN velocities were separated into
north-south, and east-west components and sorted into a magnetic local
time - magnetic latitude grid that ran from 55° to the magnetic pole
with a bin size of 2° in latitude, and 1-hour in MLT. Separate models
were created for each velocity component in each bin of the grid. It is
found that even though the models in each bin are independent of one
another a coherent convection pattern is formed when the models are
viewed in aggregate. The resulting convection pattern responds to
changes in the auroral indicies by expanding and contracting in a way
that is consistent with expectations for a substorm cycle. Further it is
found that the mean-squared difference between predictions of the model
and observed values of the velocity are substantially lower than the
same quantity calculated for an existing climatology that was not formed
with ML techniques