The global magnetosphere-ionosphere-thermosphere (M-I-T) system is intrinsically coupled and susceptible to external drivers such as solar wind dynamic pressure enhancements. In order to understand the large-scale dynamic processes in the M-I-T system due to the compression from the solar wind, the 17 March 2015 sudden commencement was studied in detail using global numerical models. This data set is comprised of the simulation data
generated from these models. and NOTE: The following changes were made to this dataset on March 28, 2018. First, two mp4 files were added. Second, the symbol representing "degree" was not rendering properly in the README file. The symbols were removed and replaced with the word "degree". Third, the metadata in the "methodology" and "description" fields were revised for content and clarity. On April 16, 2018 a citation to the corresponding article was added to the metadata record.
The rapid increases in solar wind dynamic pressure, termed sudden impulses (SIs), compress Earth’s dayside magnetosphere and strongly perturb the coupled Magnetosphere-Ionosphere (M-I) system. The compression of the dayside magnetosphere launches magnetohydrodynamic (MHD) waves, which propagate down to the ionosphere, changing the Auroral Field Aligned Currents (FACs), and into nightside magnetosphere. The global response to the compression front sweeping through the coupled system is not yet fully understood due to the sparseness of the measurements, especially those with the necessary time resolution to resolve the propagating disturbances. That’s why a study including modeling is necessary. On 15 August 2015 at 7.44 UT, Advanced Composition Explorer measured a sudden increase in the solar wind dynamic pressure from 1.11 nPa to 2.55 nPa as shown in Figure-1.
We use the magnetospheric spacecraft in the equatorial magnetosphere to identify the signatures of magnetosphere response to this SI event and examine the interaction of the propagating disturbances with the M-I system. With the increased time resolution of Active Magnetosphere and Polar Electrodynamics Response Experiment (AMPERE), the FAC pattern and intensity change due to SI can also be studied in more depth. We further use measurements from ground based magnetometer stations to increase our tracking capability for the disturbances in the ionosphere and to improve our understanding of their propagation characteristics. This is the first step in a comprehensive multi-point observation and a global magnetohydrodynamic simulation based investigation of the response of the coupled M-I system to sudden impulses.
The modeling research conducted to produce this dataset focuses on the solar wind dynamic pressure drop events and how they affect the Earth's intrinsically coupled Magnetosphere, Ionosphere and Thermosphere systems. This study specifically focuses on the 11 June 2017 event, where the solar wind dynamic pressure dropped significantly following a period of higher pressure. We model the response to this pressure drop using University of Michigan Space Weather Modeling Framework ( http://csem.engin.umich.edu/tools/swmf/). The simulation results were created using BATS-R-US and GITM models. The observational data required for model comparisons were taken from OMNI ( https://omniweb.gsfc.nasa.gov) and CDAWeb ( https://cdaweb.gsfc.nasa.gov/sp_phys/) Databases.
Ozturk, D. S., Zou, S., Slavin, J. A., & Ridley, A. J. ( 2019). Response of the geospace system to the solar wind dynamic pressure decrease on 11 June 2017: Numerical models and observations. Journal of Geophysical Research: Space Physics, 124, 2613– 2627. https://doi.org/10.1029/2018JA026315
