Accuracy of Global Geospace Simulations: How much of the error arises
from solar wind input uncertainties?
Abstract
In this study, we examine the accuracy of global geospace simulations by
analyzing the relationship between the solar wind and its propagation
parameters and the errors in auroral electrojet index AU and AL, ring
current index SYM-H and the cross-polar cap potential (CPCP) in
simulations. We show that generally the error distributions are wider
for higher level of solar wind driving. Our results also show that the
observing solar wind monitor distance from the Sun-Earth line and the
phase front normal angle produce only minor effects on the error
distributions, however, for oblique angles (<0.4) of the phase
front normal there are noticable effects on the error distributions.
Furthermore, we show that the results hold true also when using two
magnetometer station recordings, one at subauroral and the other at
auroral latitudes, which speak to the similarity of the error sources in
local and global activity measures. These results are important elements
in assessing the accuracy of the timing and magnitude of space weather
events recorded on ground.