Physics
Scientific paper
Dec 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010agufmsm23b..08h&link_type=abstract
American Geophysical Union, Fall Meeting 2010, abstract #SM23B-08
Physics
[2101] Interplanetary Physics / Coronal Mass Ejections, [2102] Interplanetary Physics / Corotating Streams, [2778] Magnetospheric Physics / Ring Current, [2788] Magnetospheric Physics / Magnetic Storms And Substorms
Scientific paper
Geomagnetic storms - episodes of intense solar wind-magnetosphere coupling usually associated with extreme conditions in the solar wind such as coronal mass ejections (CMEs) or co-rotating interaction regions (CIRs) - cause large global disturbances in the Earth’s magnetosphere. During such storms, large amounts of energy are deposited in the magnetotail and inner magnetosphere, producing an enhanced ring current and energising plasma to relativistic levels by as yet unknown excitation mechanisms. By exploiting data from the Advanced Composition Explorer (ACE) spacecraft in conjunction with space- and ground-based measurements of geospace over the last solar cycle, a database of geomagnetic storms has been compiled and analysed. Here we present some statistical findings from a superposed epoch analysis of 143 events identified from the global SYM-H index. We find that the duration of the main phase of storms decreases for increasing storm size, as defined by the maximum negative excursion of SYM-H, contrary to the results of previous studies. We also discuss a comparison of CME and CIR driven storms in terms of storm size, phase duration and evolution, and the associated solar wind-magnetosphere coupling. Initial work has successfully identified characteristic radar backscatter observed by the Super Dual Auoral Radar Network (SuperDARN) and, in particular, the new lower-latitude StormDARN radar network during these storm-time conditions. Here we present early findings of a superposed epoch analysis of auroral imagery from the IMAGE spacecraft and ionospheric convection maps from the SuperDARN radar network. This work further illustrates the storm-time coupling between the solar wind and magnetosphere, and develops the relationship between auroral oval radius and the evolution of the storm-time SYM-H index first reported by Milan et al., (2009). Once completed, this will be the most complete superposed epoch analyses of storms to date, combining multiple datasets and analysis techniques. This will enable us to gain a better understanding of complex storm time processes such as the energisation of ring current plasmas.
Grocott Adrian
Hutchinson J. A.
Milan Stephen E.
Wright Darren M.
No associations
LandOfFree
A Superposed Epoch Analysis of Geomagnetic Storms over a Solar Cycle: Geomagnetic and Solar Wind Data, Radar Backscatter & Auroral Imagery does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Superposed Epoch Analysis of Geomagnetic Storms over a Solar Cycle: Geomagnetic and Solar Wind Data, Radar Backscatter & Auroral Imagery, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Superposed Epoch Analysis of Geomagnetic Storms over a Solar Cycle: Geomagnetic and Solar Wind Data, Radar Backscatter & Auroral Imagery will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1469740