Forecasting Strong Southward Magnetic Fields Associated with Coronal Mass Ejections: Ejecta, Sheaths, and Shocks Inside CME
Wednesday, 13 February 2019: 11:10
Fountain I/II (Westin Pasadena)
Noé Lugaz1, Reka Moldovan Winslow2, Charles J Farrugia3, Tarik Mohammad Salman3, Christina O Lee4 and Antoinette Broe Galvin3, (1)University of New Hampshire Main Campus, Space Science Center, Durham, NH, United States, (2)University of New Hampshire Main Campus, Durham, United States, (3)University of New Hampshire Main Campus, Durham, NH, United States, (4)Space Science Laboratory, UCB, Berkeley, United States
Abstract:
Coronal mass ejections (CMEs) are the main cause of intense geomagnetic storms, while CME-driven shocks are one of the primary drivers of radiation belt variability. Under these two general categories, there are, in fact, a number of different physical entities: magnetic clouds, complex ejecta, interacting CMEs, CME-CIR hybrids, shocks inside CME, and series of shocks. Here, we discuss how the predictability and effects on Earth vary depending on the type of structures impacting Earth. We focus, particularly, on how most of the largest events, as measured based on the ability to drive geomagnetic storms and on their ability to affect the radiation belts appear to be caused by "ideal" circumstances, and how this fact affect their predictability.
We then present two specific ideas to advance our space weather forecasting capability. The first is based on the well-know fact that most periods of intense southward magnetic fields are preceded by a fast-forward shock. This allows the development of a tool to obtain, on average, a 12-hour advanced warning of impeding southward periods. The second is the development of sub-L1 monitors, as proposed now for several decades. Before relying on such measurements in an operational setting, numerous space weather research investigations are needed. In particular, little is known on 1) how most shocks and CMEs evolve in the few hours before they impact Earth, and 2) the reliability of measurements away from the Sun-Earth line. We present some results and discuss some future work on these aspects.
