*************************** ** THE GEM MESSENGER ** *************************** Volume 19, Number 15 June 1, 2009 ---------------------------------------------------------------------------- DAP-2 Session "The Relationship Between Diffuse Aurora and the Dynamics and Structure of the Magnetosphere" at 2009 GEM Workshop ---------------------------------------------------------------------------- From: Eric Donovan Tu, 23 June, 3:30-5:00 PM DAP 2: The Relationship Between Diffuse Aurora and the Dynamics and Structure of the Magnetosphere Chair: Eric Donovan Co-Chairs Marilia Samara and Robert Mitchell GEM Session: A number of different types of aurora are classified as diffuse. These aurora are caused by a number of distinct precipitation mechanisms which sometimes overlap in space. Unlike discrete aurora, in most instances diffuse aurora is a more or less direct consequence of a process or processes in the magnetosphere, and so temporal variations of and spatial gradients in brightness are thought to convey significant information about those magnetospheric processes. Further, diffuse auroral precipitation plays some role in the loss of magnetospheric particles and in carrying large- and possibly small-scale currents, and so the diffuse aurora is important in the system-level behavior of geospace. In this session we will be exploring the use of diffuse aurora to remote sense magnetospheric dynamics, and the role of diffuse aurora in those dynamics. We encourage contributions about (1) the physical meaning (in terms of magnetospheric dynamics and topology) of diffuse auroral boundaries and their temporal evolution, variations in brightness, as well as (2) the importance of diffuse aurora in carrying large-scale currents and magnetospheric particle loss. We encourage presentations based on observational and theoretical/modelling work. We are hoping for presentations describing work that utilizes coordinated ground-based (ASIs, induction coil & fluxgate magnetometers, riometers, ISRs, etc) and in situ (THEMIS, FAST, Polar, Geotail, LANL, etc) observations. Topics for discussion will include 1. How is the motion of diffuse auroral structures related to magnetospheric convection? 2. The poleward boundary of the diffuse “redline” aurora has been widely used as a proxy for the open-closed field line boundary. In terms of the magnetosphere, what does the equatorward boundary of the redline aurora correspond to? 3. What is the "state of the art" in terms of using intensity ratios to infer characteristics of precipitating particles? 4. What is the instantaneous spatial extent of different types of diffuse aurora? 5. How do large-scale processes (eg., solar wind pressure pulses, ULF waves including Pi2s, etc) modulate diffuse auroral brightness? 6. How do diffuse aurora of different types relate to currents? 7. How do diffuse aurora of different relate to magnetospheric particle loss? +-------------------------------------------------------------------------+ |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://aten.igpp.ucla.edu/GemWiki | |Workshop Information: http://www.cpe.vt.edu/gem/index.html | +-------------------------------------------------------------------------+