Conveners:
Mike Ruohoniemi (JHU/APL, mike.ruohoniemi@jhuapl.edu)
Ray Greenwald (JHU/APL)
John Foster (Millstone Hill/Haystack Observatory)
2004 Thursday 01 July 0330-0530 PM
The first workshop on Mid-Latitude Plasma Structuring (MLPS) was held on Thursday afternoon. About 50 people attended. The convenors were Mike Ruohoniemi and Ray Greenwald of JHU/APL and John Foster of Millstone Hill/Haystack Observatory. This tutorial workshop introduced the electrodynamics of the mid-latitude ionosphere as a specific study topic for CEDAR. Recent work has turned up exciting results on the occurrence of irregularities, intense electric fields, and the penetration of auroral effects. Observations with GPS are giving dramatic views of the structuring and transport of ionospheric plasma on global scales. Concern about the societal impact of ionospheric disturbance at mid-latitudes is giving added impetus to this research. Moreover, the characterization and understanding of variability in the mid-latitude ionospheric has been recognized as a primary objective of the upcoming NASA/LWS Ionosphere-Thermosphere Storm Probes mission. The workshop was motivated by a desire to focus the attention of the CEDAR community on these developments and to identify promising directions for research and collaboration.
The invited speakers included Bob Robinson (NSF) and John Foster, who reviewed the range of ionospheric effects at mid-latitudes. These presentations related the perturbations to the penetration of high-latitude sources and to the dynamics of the plasmasphere. Jan Sojka (USU) described the inadequacy of the current modeling efforts to account for the impressive TEC perturbations seen in the GPS observations and suggested that elucidation of the critical physics in the mid-latitude region will require extending the observations and modeling to the highest latitudes. Dave Hysell (Cornell) showed new results on the structuring of sporadic E layers and the sources of small-scale irregularities in plasma instabilities. Sundanda Basu (Boston University) spoke to the impact of auroral disturbance in causing scintillations and GPS effects during magnetospheric storms. Larry Paxton (JHU/APL) presented results of effects in neutral winds and densities seen by satellite, similar to the IMAGE and TIMED O/N2 changes during 1-4 Oct 2002 prepared by Yongliang Zhang. During the brief presentations session, Mike Ruohoniemi described a project to extend SuperDARN capabilities to mid-latitudes with the construction of an HF radar at Wallops Island. Nick Zabotin (NOAA) interpreted dynasonde observations of small-scale irregularities in terms of plasma instabilities.
Many instructive comments were received from the audience in the course of the presentations. A consensus emerged that the variety of new results and the prospects for further discoveries points to a need to reprise MLPS at future CEDAR meetings. The 2005 meeting at Santa Fe would be particularly apt as it will be possible to engage GEM researchers in an expanded discussion of the solar wind and magnetospheric drivers of mid-latitude disturbance. Accordingly, we will propose to coordinate a session of MLPS next year with the GEM M-I coupling campaign.