CEDAR email: CEDAR 2017 Grand Challenge Workshop: Storms and substorms without borders

Stanislav Sazykin sazykin at rice.edu
Thu Jun 8 12:22:57 MDT 2017

Dear Colleagues,

At the upcoming CEDAR workshop in Keystone, we will hold the third and  
final CEDAR Grand Challenge Workshop “Storms and substorms without  
borders” (SSWB). We would like to invite you to participate in our  
workshop and contribute to our focus study. Our goal is to make  
significant improvement of our scientific understanding of M-I-T  
coupling, and in particular with regard to convection and its  
consequences at sub-auroral latitudes. We need your help to accomplish  
our goal.

We will have two sessions: At the first two-hour session, we will  
present a refining round of model runs and observational comparisons  
centered on the ongoing community Sub-Auroral Polarization Streams  
(SAPS) Focus Study (see definition below).

The second two-hour session will start with a review of what we have  
learned, followed by community discussion on the status of our  
understanding of magnetosphere-ionosphere coupling with particular  
attention focused on SAPS electric fields, plasma transport,  
instabilities, and what are the outstanding questions needing to be  
addressed.  The outcome of this workshop will be one or more  
publications that review our understanding and point to the way forward.

Details on the “focus study” are included below and at the workshop  
description on the CEDAR web page. If you are interested, please let  
us know as soon as possible if you will attend, if you plan to  
contribute, and to which of the two sessions.

We encourage those who contributed to our sister AGU session  
"Geomagnetic Storms and Substorms and the SAPS  
Magnetosphere-Ionosphere-Thermosphere Science Challenge: Towards a  
Synthesis of Observations, Modeling, and Theory" to bring follow-on  
results and progress reports from that work.

If you have any questions, don’t hesitate to contact us.

Phil Erickson, Stan Sazykin, Naomi Maruyama, Mike Ruohoniemi, Simon  
Shepherd, Tony Mannucci, Jo Baker

Relevant links:
Complete description of the workshop:

Detailed modeling results based on the SAPS focused collaborative  
study, with background information on the selected intervals, is  
available at the following URL, which also serves as a repository for  
contributions and results:  

Description of the related GEM SIMIC focus group:


Session 1 of the workshop: SAPS Focus Study refined simulations

Session 1 will examine results of new or refined simulations (“round  
2”) of the sub-auroral ionosphere - thermosphere - magnetosphere  
response in the SAPS Focus Study. SAPS has been one of the more  
important problems that both GEM and CEDAR have in common, for both  
modeling and observations. The list of questions that emerged from our  
previous effort is summarized as follows: what are the key physical  
processes leading to SAPS, and how well do models of SAPS compare with  
actual observations? Does the mid-latitude trough exist in the  
preceding interval, and how do the trough and SAPS channel relate to  
each other? Does SAPS generate the trough, or is the trough a  
pre-existing condition for SAPS and does the SAPS then deepen the  
trough? What is the nature of the M-I-T feedback during events (i.e.,  
does the inner magnetosphere simply drive the ionospheric effects or  
does the ionosphere respond back on the magnetosphere in a significant  
way)? What is the relationship between SAPS and substorms? How do  
model predictions of SAPS under less disturbed conditions (i.e.,  
substorms only) differ?

The following targeted intervals have been selected based on available  
observations and on results presented at prior SSWB and AGU sessions:

(1) March 16, 2013 04-10 UT (pre-storm SAPS); (2) March 17, 2013 06-20  
UT (main phase SAPS); (3) March 20, 2013 04-10 UT (recovery phase SAPS).

Comparison with observations is critical to making further progress.  
We invite data analysis and modeling results relevant to any of the  
topics listed above, that specifically build on previous results  
presented at SSWB and AGU meetings.

Contributions of simulation results in this session should include, if  
possible, predicted sub-auroral electric fields in the afternoon to  
post-midnight MLT sector, relevant electrodynamic quantities such as  
ionospheric conductivities, inner magnetospheric particle and fields  
distributions, total electron content (TEC), field-aligned currents,  
magnetic field perturbations, or anything else that may help in  
unraveling the dynamics of plasma processes involved in the formation  
of SAPS.

Session 2: Synthesis and Identification of Future Challenges

In the second and summarizing session, we invite participants to  
engage in a robust discussion of the nature of SAPS, the role of  
plasma instabilities, the control of occurrence of SAPS by solar wind  
and IMF parameters, ionospheric preconditioning influence on SAPS  
appearance, and the role of the inner magnetospheric pressure-bearing  
plasma in determining SAPS lifetimes. In addition to numerical  
simulations, we welcome presentations that address observations of  
SAPS and related effects (both in the ionosphere and the  
magnetosphere) in the coupled M-I-T system relevant to the selected  

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