M3-I2 Session 2 - Recap and Organize
Notes by Shasha Zou and the M3-I2 session leaders. Vince Eccles moderated the session.
Robert Strangeway (UCLA) (invited speaker): presented the importance of understanding the ion outflow physics in the terrestrial environment as well as other planets. He briefly reviewed observations from the terrestrial observations, highlighting that precipitating electron density is the single best controlling factor for ion outflow but also the hardest to parameterize in models. He then talked about several areas that progresses should be made in order to further advance our understanding of ion outflow physics.
Naritoshi Kitamura (ISAS/JAXA): presented the comparison between the GPW model results and the Akabono data. He found that the model prediction was 30-500 smaller than data. He also gave an important caution that the H neutral profile of MSIS is wrong. The H + O+ <--> H+ + O resonant reaction will be wrong in the models depending on MSIS.
Vince Eccles (USU): gave a brief introduction to the Generalized Polar Wind (GPM) model. He announced our AGU session “SM014: Ion upflow/outflow physics and their effects on the coupled magnetosphere-ionosphere system” and encouraged submission from the community. He requested community input for the 5-year plan for the M3-I2 focus group. Three subgroups have been suggested within this focus group, including (1) ring current area, (2) plasma sheet/substorm dynamics, and (3) ionospheric boundary layer and upflow/outflow conversion.
Open floor discussion:
Discussions during the open floor part have been focused on three topics.
The first is the effects of ion outflow in the magnetospheric dynamics, including key science questions and necessary methodologies. (1) Particle energy and location of the outflow from the ionosphere is important because it determines where the particle lands in the magnetosphere. Delcourt Ion tracing code would be required for this effort. (2) George Kazhanov commented that anisotropic particle distribution needs kinetic approach and heat flux along magnetic field line in MHD can advance the modeling but it is difficult because of higher order moments needs another equation to close the set. (3) Bob Strangeway commented that it is important to understand “why MHD so successful?”(4) Ion outflow species are important because they determine the ring current lifetime. People working on substorms, plasma sheet will be invited to contribute to these discussions in the future.
The second topic discussed was the ion upflow and outflow from the ionosphere. Ionosphere as important lower altitude boundary has been recognized. Kinetic versus fluid modeling issues and energization processes have been discussed. No fundamental physics modeling studies are currently being performed on the wave-particle energization processes.
The third topic was individual storm period chosen for a focused study. There should be continued studies using older data sets from Cluster, Polar, LANL, Akebono, Themis, Geotail. These should be compared with new satellite data sets for similar conditions to insure continuity of interpretation. MMS HPCA summer 2016 data are suitable for plasma sheet, ring current, and warm plasma cloak formation. Need comparisons with Van Allen probes in inner magnetosphere.
One issue noted was the lack of communication of the different groups (experimentalist and modelers) when discussing energy flow and sources. The best units for experimentalists are eV/cm/cm/s for flow and eV/cm/cm/cm/s for deposition or sources.
Model-Measurement Comparisons:
TOPSIDE ALTITUDES (500-2000km): Ion upflow/outflow models should first compare against solar angle climatologies for proper topside ionosphere modeling. Some data periods for these tests can also be 2000 Oct 24, 1998 Jan 27, and 2002 Jan 20 (ISR & FAST conjunction).
MIDDLE ALTITUDES (2000-5000km): Polar Satellite is a good source of data for these altitudes. 1997 Jan 10-11 has good comparisons with Geotail, Wind, FAST, Freia. 2000 Apr 6-7 has Akebono, FAST, POLAR.
MAGNETOSPHERE (beyond 2 Re): 2015 Dec 31, 2016 Jan 20, 2016 Mar 6-8, 2015 Jun 22-23. All have multi-satellite support.
Ion Outflow Subgroup Items:
Magnetosphere Subgroup Items:
