Revisiting two-step Forbush decreases

Details Revisiting two-step Forbush decreases Revisiting two-step Forbush decreases

Nov 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011jgra..11611103j&link_type=abstract

Journal of Geophysical Research, Volume 116, Issue A11, CiteID A11103

Physics

Interplanetary Physics: Coronal Mass Ejections (4305, 7513), Interplanetary Physics: Cosmic Rays, Interplanetary Physics: Ejecta, Driver Gases, And Magnetic Clouds, Interplanetary Physics: Interplanetary Magnetic Fields, Interplanetary Physics: Interplanetary Shocks

Scientific paper

Interplanetary coronal mass ejections (ICMEs) and their shocks can sweep out galactic cosmic rays (GCRs), thus creating Forbush decreases (FDs). The traditional model of FDs predicts that an ICME and its shock decrease the GCR intensity in a two-step profile. This model, however, has been the focus of little testing. Thus, our goal is to discover whether a passing ICME and its shock inevitably lead to a two-step FD, as predicted by the model. We use cosmic ray data from 14 neutron monitors and, when possible, high time resolution GCR data from the spacecraft International Gamma Ray Astrophysical Laboratory (INTEGRAL). We analyze 233 ICMEs that should have created two-step FDs. Of these, only 80 created FDs, and only 13 created two-step FDs. FDs are thus less common than predicted by the model. The majority of events indicates that profiles of FDs are more complicated, particularly within the ICME sheath, than predicted by the model. We conclude that the traditional model of FDs as having one or two steps should be discarded. We also conclude that generally ignored small-scale interplanetary magnetic field structure can contribute to the observed variety of FD profiles.

Affiliated with

Also associated with

No associations

Rating

Revisiting two-step Forbush decreases 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 Revisiting two-step Forbush decreases, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Revisiting two-step Forbush decreases will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-742358