*************************** ** THE GEM MESSENGER ** *************************** Volume 17, Number 13 May 18, 2007 ---------------------------------------------------------------------------- GEM 2007 Workshop FG3 Breakout Session: A campaign concerning fine structure on the sun surviving to 1 AU and hitting the magnetosphere ---------------------------------------------------------------------------- From: Joe Borovsky Nick Arge Discussion of a Campaign to Determine (A) How Structure in the Solar Wind Is Related to Structure on the Sun and (B) How that Structure in the Solar Wind Affects the Magnetosphere FG3 Breakout: Wednesday, June 20, 1:30-3:15 led by Joe Borovsky and Nick Arge Evidence is being gathered indicating (a) that some discontinuities seen in the solar wind at 1 AU have their origins at the sun and (b) that magnetic and plasma structures seen in the solar wind at 1 AU are the open-flux bundles that penetrate through the magnetic carpet from the photosphere into the corona. If true, then there is an underlying pattern in the solar wind and the pattern may depend on the type of region on the solar surface giving rise to the solar wind. At Earth this pattern results in brief intervals of steady driving of the magnetosphere (corresponding to flux-tube interiors) punctuated by rapid changes (corresponding to flux-tube walls). And if true, then detailed in situ measurements of these solar-wind structures could be used to remotely sense processes ongoing within the chromospheric magnetic carpet, such as footpoint motion and interchange reconnection. In the "Foreshock, Bowshock, and Magnetosheath" Focus Group at GEM, there will be discussions to assess the feasibility and usefulness of a campaign to focus high-resolution telescopes onto the solar footpoints of L1 and to coordinate those telescope observations with in situ measurements made by the ACE and Wind spacecraft and with analysis of the driving of the magnetosphere by the observed solar wind. A similar discussion will be held at SHINE. A strawman campaign is the following. (1) Use the Wang-Sheeley-Arge mapping technique to specify two locations on the solar surface: (i) the location right now where a magnetic-field line from L1 has its footpoint on the sun and (ii) the location right now where plasma is lifting off the sun that will hit L1 in 3 or 4 days. (2) Point high-resolution telescopes right now at those two points and collect observations. The telescopes may be TRACE, Hinode, KPVT, SST, EIT subfield, etc. With (1) and (2), determine what phenomena on the surface of the sun (magnetic-carpet dynamics, granulation, activations) are associated with what features in the solar wind (velocity, ionic composition, shrahl, entropy density, core electrons, magnetic structures, helicities, Alfven-wave flux, etc.). (3) Bring the GEM community and their data sets into this campaign to look at the reaction of the Earth's magnetosphere and ionosphere to the solar-wind structures. (4) Using CCMC, simulate the heliosphere (ENLIL) and the solar-wind-driven magnetosphere (BATSRUS and OpenGGCM). The ENLIL simulations could provide insight into the L1-to-Sun mapping and the BATSRUS and OpenGGCM simulations could provide information about the effects of solar-wind structure (arising from various types of regions on the sun) on the near-Earth environment. These simulations could be run by SHINE and GEM students, with various students signing up to simulate various time intervals. Possible goals of the campaign: (A) Compare the temporal and spatial phenomena on the sun with the temporal and spatial phenomena in the solar wind -- versus the region type on the sun and versus the type of solar wind. (B) Learn about the dynamics ongoing in the magnetic carpet. (C) Learn about the birth of the solar wind and structure in the solar wind. (D) Learn about the importance of patterns in the solar wind on the solar-wind driving of the magnetosphere. (E) Learn how to predict the nature of these patterns days before they reach the Earth. At GEM, the discussion will be focused upon (a) What science could be done, (b) What questions might be answered, and (c) How such a campaign should be properly coordinated and managed. Joe Borovsky Los Alamos National Laboratory (505)667-8368 jborovsky@lanl.gov Nick Arge Air Force Research Laboratory Nick.Arge@hanscom.af.mil +-------------------------------------------------------------------------+ |To subscribe GEM Messengers, send an e-mail to | | with the following command in the body of your e-mail message: | | subscribe gem | |To remove yourself from the mailing list, the command is: | | unsubscribe gem | | | |To broadcast a message to the GEM community, please contact Peter Chi at | | | |Please use plain text as the format of your submission. | | | |URL of GEM Home Page: http://www-ssc.igpp.ucla.edu/gem/Welcome.html | |Workshop Information: http://gem.rice.edu/~gem | +-------------------------------------------------------------------------+