Booth Id:
PHYS028T
Category:
Physics and Astronomy
Year:
2022
Finalist Names:
Lin, Hsin-Yu (School: Taipei First Girls High School)
Liu, Yu-Chen (School: Taipei First Girls High School)
Abstract:
A geomagnetic storm is a disturbance of Earth’s magnetic fields caused by solar wind
plasma and interplanetary magnetic field (IMF). Even a moderate storm can lead to
satellite loss, such as the falling down of 40 SpaceX Starlink satellites on 2022
February 4. It is believed that coronal mass ejections (CMEs) and coronal holes
(CHs) are major sources for geomagnetic storms. Therefore, determining the critical
solar parameters is very important for storm predictions by combining solar remote
observations, solar wind in-situ measurements, and geomagnetic indices. In this
study, the north-south component of IMF (Bz), dawn-dusk convection electric field
(Ey ), and dynamic pressure (P) are proposed to be the critical solar wind parameters.
The geomagnetic indices of disturbance storm time (Dst) and SYM-H are used to
define the storm magnitude. Those events during 2010-2019 together with the
corresponding solar wind parameters from OMNI database are adopted to derive an
equation of state in power-law form. We also identify the potential CMEs and CHs
based on the observations from SOHO, STEREO, and SDO spacecraft. Our results
show that in comparison with CHs, CMEs tend to accompany with stronger solar
wind conditions and thus cause larger magnitude of geomagnetic storms. Besides, our
equation of state indicates that Bz and Ey rather than P affect the storm magnitude
more significantly. We further apply the derived equation of state to predict the storm
events after 2019 and find that our predictions perform relatively well for the
moderate storms compared to intense cases.