Statistical Comparison of Magnetopause Distances and CPCP Estimation by
Global MHD Models
Abstract
Acquiring quantitative metrics-based analysis regarding the performance
of most first-principle space physics modeling approaches is key in
understanding the solar and space weather. As established by the
successive the Geospace Environment Modeling Challenges, quantification
of performance help set a precedent in understanding the science behind
the various phenomena observed naturally in addition to elucidating the
merits and demerits of a space weather prediction method. In this study,
the performance of three magnetohydrodynamic models (SWMF/BATS-R-US, LFM
and OpenGGCM) in estimating the Earth’s magnetopause location and the
ionospheric cross polar cap potential (CPCP) have been studied. Using
the Community Coordinated Modeling Center’s Run-on-Request system and
extensive database on results of various magnetospheric scenarios run
during a variety of solar weather patterns, the aforementioned model
predictions have been compared with magnetopause standoff distance
estimations obtained from six empirical models, and with cross polar cap
potential estimations obtained from AMIE and SuperDARN. The events
considered in this study contain a spectrum of possibilities – solar
storms, substorms, constant solar wind events, which have been
categorized using the Kp index as high, moderate and low magnitude solar
events. Several of these storms have been well documented as part of the
Geospace Environment Modeling (GEM) Challenges and other studies. The
root-mean-square difference (RMS), prediction efficiency (PE) and
maximum amplitude (Max Amp) metrics are used to quantify the model
performances for the solar events considered. A separate metric called
Wrong Prediction (WP) has also been used to study the models’ hit and
miss rates with the empirical data. While almost all the cases
considered for the magnetopause standoff distances have a satisfactory
performance, there is huge deviation for the CPCP data both in the
physics based models and the empirical data. The metric data is
therefore valid for the magnetopause location comparisons, while not
being that thorough for the CPCP comparative study.