Geomagnetic disturbance intensity dependence on the universal timing of the storm peak

R. M. Katus, M. W. Liemohn, A. M. Keesee, T. J. Immel, R. Ilie, D. T. Welling, N. Yu Ganushkina, N. J. Perlongo, A. J. Ridley

Research output: Contribution to journalArticlepeer-review

Abstract

The role of universal time (UT) dependence on storm time development has remained an unresolved question in geospace research. This study presents new insight into storm progression in terms of the UT of the storm peak. We present a superposed epoch analysis of solar wind drivers and geomagnetic index responses during magnetic storms, categorized as a function of UT of the storm peak, to investigate the dependency of storm intensity on UT. Storms with Dst minimum less than −100 nT were identified in the 1970–2012 era (305 events), covering four solar cycles. The storms were classified into six groups based on the UT of the minimum Dst (40 to 61 events per bin) then each grouping was superposed on a timeline that aligns the time of the minimum Dst. Fifteen different quantities were considered: seven solar wind parameters and eight activity indices derived from ground-based magnetometer data. Statistical analyses of the superposed means against each other (between the different UT groupings) were conducted to determine the mathematical significance of similarities and differences in the time series plots. It was found that the solar wind parameters have no significant difference between the UT groupings, as expected. The geomagnetic activity indices, however, all show statistically significant differences with UT during the main phase and/or early recovery phase. Specifically, the 02:00 UT groupings are stronger storms than those in the other UT bins. That is, storms are stronger when the Asian sector is on the nightside (American sector on the dayside) during the main phase.

Original languageEnglish (US)
Pages (from-to)7561-7571
Number of pages11
JournalJournal of Geophysical Research: Space Physics
Volume121
Issue number8
DOIs
StatePublished - Aug 1 2016
Externally publishedYes

Keywords

  • geomagnetic indices
  • ground-based magnetometers
  • longitudinal dependence
  • magnetic storms
  • space weather

ASJC Scopus subject areas

  • Space and Planetary Science
  • Geophysics

Fingerprint

Dive into the research topics of 'Geomagnetic disturbance intensity dependence on the universal timing of the storm peak'. Together they form a unique fingerprint.

Cite this