On a New Interplanetary Origin of Two-Step Geomagnetic Storms

Details On a New Interplanetary Origin of Two-Step Geomagnetic Storms On a New Interplanetary Origin of Two-Step Geomagnetic Storms

May 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006agusmsm53a..06f&link_type=abstract

American Geophysical Union, Fall Meeting 2007, abstract #SM53A-06

Other

7954 Magnetic Storms (2788), 2111 Ejecta, Driver Gases, And Magnetic Clouds, 2778 Ring Current, 2784 Solar Wind/Magnetosphere Interactions

Scientific paper

A new view on how large disturbances in the magnetosphere may be prolonged and intensified further emerges from a recently discovered interplanetary (IP) process: the collision/merger of ICMEs (ejecta) within 1 AU. As shown in a pilot study, the merging process changes IP parameters dramatically with respect to values in isolated (pristine) ejecta. The resulting geoeffects of the coalesced ("complex") ejecta reflect a superposition of IP triggers which may result in, for example, 2-step, major geomagnetic storms. In two case studies, we isolate the effects on ring current enhancement when coalescing ejecta reached Earth. %on March 31, and October 21-25, 2001. In each case, the magnetosphere "senses" the presence of the two ejecta and responds with a re-activation of the ring current soon after it started to recover from the passage of first ejection, giving rise to a double-dip (DD), great storm. %(each min Dst < -250 nT). The very high (up to ~10 cm-3) plasma sheet density, but with a decreasing trend, is the major determining factor in the intense storm activity. The plasma sheet density correlates well with the solar wind density, suggesting the compression of the leading ejecta as the source of hot, superdense plasma sheet in these cases. This correlation is similar to that obtained in a previous investigation extending over several years, but the present case studies extend the range of plasma sheet densities from ~2 to ~ 10 cm-3. Idiosyncracies in the behavior of the magnetopause current during these extreme events are discussed. Saturation of cross-polar cap potential and dayside erosion are present during Earth passage of the coalescing ejecta, and this aspect is investigated using AMIE data and other techniques. We suggest that interacting ejecta may be a new, important IP source of DD, major storms. This work is supported in part by NASA Grants NNG05GG25G and NNG05GC75G

Affiliated with

Also associated with

No associations

Rating

On a New Interplanetary Origin of Two-Step Geomagnetic Storms 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 On a New Interplanetary Origin of Two-Step Geomagnetic Storms, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On a New Interplanetary Origin of Two-Step Geomagnetic Storms will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1027861