*************************** ** THE GEM MESSENGER ** *************************** Volume 15, Number 33 June 6, 2005 -------------------------------------------------------------------------- CEDAR Workshop: HLPS - Plasma Structures in the Cusp Regions and Their Electrodynamics and Plasma Dynamics -------------------------------------------------------------------------- From: Lie Zhu 2005 July 01, 0800-1000 AM, Eldorado Zia Room, Eldorado Hotel, Santa Fe, New Mexico In the HLPS (High-Latitude Plasma Structures) Working Group of the CEDAR Program, experimentalists, theoreticians, and modelers join their efforts to study various issues of high-latitude plasma processes, including polar cap auroras, plasma patches, and traveling convection vortices. Over the past decade, numerous observational campaigns have been conducted by the group and several special issues of HLPS research progresses have been published. For the 2005 HLPS workshop, we plan to expand the HLPS study into a new research area: the plasma strudtures in the cusp regions. This workshop will address recent results on merging, coupling, electrodynamics, and the role of the underlying ionosphere of the cusp region. The cusp can be understood as a region that maps to the magnetopause. The importance of this region resides in the participation of some of the cusp fiels lines in antiparallel merging. The main effect of the merging process is the generation of convection cells in both polar caps and the transferring of solar wind energy, momentum and particles into the magnetosphere and ionosphere. The ionospheric cusp is also a region where electron and ion precipitation can produce elevated densities. Similarly, the prevailing large electric fields are able to increase recombination rates and decrease the local density. these two mechanisms working in concert can generate unique patterns of enhancement and depletions. Polar cap patches, seen under IMF Bz negative conditions, can be produced by the above mentioned mechanisms, but also by the transient and sporadic nature of the reconnection process. Concurrently, decameter scale-size irregularities are typically observed in the ionospheric cusp. The objective of this session is to better understand the control that the solar wind IMF, the dynamic pressure and magnetic activity exert on the optical displays of the cusp aurora and on the occurrence of plasma structuring seen at the cusp and then at subsequent times convecting throughout the polar cap. Results will be welcome from ground based and satellite borne imagers, scanning photometers, radars, magnetometers, and from modeling/theoretical investigations, on the dynamics, electrodynamics, and manifestations of cusp coupling processes of the solar wind-magnetosphere-ionosphere system and its conjugacy. The objective is to to unite the CEDAR and GEM communities in a discussion forum of the physics of the cusp region. The workshop will mainly consist of short-presentations. At the beginning, there will be a mini-introductory talk and at the end, we will hold an informal round-table discussion to plan future HLPS campaigns. If you want to give a presentation at the workshop, please send an email with presentation title and approximate time to the workshop conveners Lie Zhu (zhu@cc.usu.edu) or Cesar Valladares (valladar@bc.edu). Graduate students are especially encouraged to join this workshop. Conveners: Cesar Valladares, Boston College Jan Sojka, Utah State University Lie Zhu, Utah State University +-------------------------------------------------------------------------+ |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 | +-------------------------------------------------------------------------+