Cross‐Correlations of Solar Wind Parameters Using Monitoring Spacecraft

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Space weather predictive modeling currently utilizes real‐time data from the spacecraft ACE and DSCOVR, with SOLAR‐1 and IMAP recently online. This study assesses whether DSCOVR solar wind plasma and interplanetary magnetic field (IMF) data exhibit large‐scale discrepancies from the corresponding ACE data, and if so, whether these discrepancies can be accounted for in predictive models. We chose several month‐long intervals of ACE and DSCOVR when they were maximally separated in Y location and separately in X location. In general, DSCOVR measurements of solar wind density, velocity and magnetic field magnitude correlate quite well with ACE. However, although the measured IMF magnitude is essentially identical between the two platforms, the various IMF components show significant differences, particularly in B ZGSE . The data frequently display a significant (10–20 min) time offset between the two sets of measurements, consistent with the plasma structures being aligned with the Parker spiral. Comparison with MMS data taken in the solar wind confirm this variation from ballistic timing. Thus, space weather predicted by models relying on L1 monitors may be significantly impacted, representing a fundamental uncertainty in the prediction accuracy. Our results suggest that for the most accurate estimate of the IMF reaching the magnetopause, modelers should choose the spacecraft which is closest to the Sun/Earth line (−20 < Y GSE < 10 R E ) and nearest to Earth in X GSE . However, for predictions with the longest lead time, as for time sensitive space weather alerts, the realtime monitor used should be the one with the largest + Y GSE and X GSE location.

This publication has 15 references indexed in Scilit: