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Small-Scale Irregularities Within Polarization Jet/SAID During Geomagnetic Activity
A A Sinevich1,2, A A Chernyshov1,2, D V Chugunin1
1Space Research Institute of the Russian Academy of Science Moscow Russia.
Geophysical Research Letters
|July 21, 2022
Summary
Polarization Jet/Sub-Auroral Ion Drift (PJ/SAID) structures were studied using satellite data. During geomagnetic storms, plasma parameter fluctuations increase, with larger-scale effects becoming more prominent.
Area of Science:
- Space Physics
- Plasma Physics
- Aerospace Engineering
Background:
- Polarization Jets/Sub-Auroral Ion Drifts (PJ/SAID) are key phenomena in Earth's magnetosphere.
- Understanding their spatial structure is crucial for space weather prediction.
- Previous studies lacked high-resolution in-situ measurements of PJ/SAID plasma parameters.
Purpose of the Study:
- To investigate the spatial structure of PJ/SAID during geomagnetic storms.
- To analyze plasma parameters and electron density spectra within PJ/SAID with unprecedented temporal resolution.
- To compare small-scale and large-scale irregularities and their behavior under varying geomagnetic activity.
Main Methods:
- Utilized data from NorSat-1 and Swarm satellites during a geomagnetic storm.
- Employed Langmuir probes on NorSat-1 for high-frequency (up to 1 kHz) plasma parameter measurements.
- Performed comparative analysis of plasma data and electron density spectra from both satellites.
Main Results:
- Observed increased fluctuations in plasma parameters at all scales within PJ/SAID with rising geomagnetic activity.
- Measured in-situ small-scale irregularities down to hundreds of meters.
- Found that large-scale effects within PJ/SAID become more significant than small-scale ones during high geomagnetic activity.
- Identified PJ/SAID structures approximately 0.2° in latitude, containing small-scale irregularities.
Conclusions:
- Geomagnetic activity significantly influences the spatial structure and dynamics of PJ/SAID.
- High-resolution satellite measurements reveal intricate small-scale and large-scale plasma irregularities within PJ/SAID.
- The interplay between small- and large-scale structures evolves with geomagnetic conditions, impacting the overall PJ/SAID morphology.
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