June 15, 2018, 1:00 pm - 2:00 pm

July 20, 2018, 1:00 pm - 2:00 pm, SED Director's Seminar, Hosted by the Heliophysics Science Division (670)

Connecting the corona to solar wind structure and magnetospheric impact using modeling and remote and in situ observations

Nicki Viall-Kepko (671)

Connecting solar wind structures and dynamics observed throughout the heliosphere - and especially near Earth - back to their origins in the Sun?s atmosphere has long been one of the central goals of heliophysics. Making this link is fundamental to determine the origin and formation of the solar wind. Achieving this goal is essential for understanding the basic physical processes driving solar and heliospheric activity, for fully understanding space weather, and for developing predictive space weather models. Under the new ISFM program we brought together an ambitious, cross-disciplinary, cross-laboratory, GSFC-focused work package team of world-class experts on the solar atmosphere, inner heliosphere, and Earth?s magnetosphere. We combine remote and in situ observations with modeling to yield fundamentally new insights into the dynamic connection between the corona and the heliosphere, and how it drives Earth?s magnetosphere. Our project is crucial for the ultimate space weather goal of deterministically forecasting geoeffective structures in the solar wind. Furthermore, by determining where and under what conditions spatial structure vs. temporal dynamics in the corona controls the resultant solar wind, this research will significantly advance and potentially fundamentally alter our understanding of solar wind release and acceleration. The Sun-heliosphere connection is also directly relevant to the goals of the upcoming Parker Solar Probe (PSP) and Solar Orbiter (SO) missions, and the GSFC-lead proposed CODEX and ISAT missions, making this proposed project extremely timely. The results of our research will be breakthrough science discoveries for all inner heliospheric datasets, and a critical theoretical framework for understanding and interpreting data from PSP and SO.

Understanding the role of magnetic reconnection, turbulence and magnetosphere-ionosphere coupling in the large scale structure and dynamics of Earth?s magnetosphere

John Dorelli (673)

Magnetic reconnection is the primary mode by which the solar wind couples to Earth?s magnetosphere, making possible the transport of energy and plasma across dayside magnetopause and into the magnetotail. In the tail, magnetic reconnection causes the sudden release of magnetic energy that drives substorms and the aurora. Our understanding of the local physics of reconnection has improved dramatically over the last several decades, culminating in NASA?s Magnetospheric Multiscale (MMS) mission. MMS is the first mission to fully resolve the ion and electron kinetic scales and put local kinetic simulations to the experimental test. While many of the features predicted by local reconnection simulations have now been observed, we do not yet understand how these local features impact the global structure and dynamics of the magnetosphere. There are several major problems that need to be addressed: 1) How does the structure of ion-scale current sheets impact the global convection and field-aligned current patterns? 2) What is the role of turbulence in the transport of magnetic energy into the tail lobes and in the generation of bursty flows in the plasma sheet? 3) How does non-local electron transport between the magnetosphere and ionosphere contribute to energy flow across the magnetopause, convection in the plasma sheet and the conductivity of the ionosphere? With support from the new Internal Scientist Funding Model (ISFM), we have assembled an interdisciplinary team to address these problems using a combination of high performance simulations and data analysis. Our results so far point to a new picture of global convection in Earth?s magnetosphere in which kinetic scale processes play an essential role not captured in our best fluid models.