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Abstract One of the most significant observations associated with a sharp enhancement in solar wind dynamic pressure,, is the poleward expansion of the auroral oval and the closing of the polar cap. The polar cap shrinking over a wide range of magnetic local times (MLTs), in connection with an observed increase in ionospheric convection and the transpolar potential, led to the conclusion that the nightside reconnection rate is significantly enhanced after a pressure front impact. However, this enhanced tail reconnection has never been directly measured. We demonstrate the effect of a solar wind dynamic pressure front on the polar cap closure, and for the first time, measure the enhanced reconnection rate in the magnetotail, for a case occurring during southward background Interplanetary Magnetic Field (IMF) conditions. We use Polar Ultra‐Violet Imager (UVI) measurements to detect the location of the open‐closed field line boundary, and combine them with Assimilative Mapping of Ionospheric Electrodynamics (AMIE) potentials to calculate the ionospheric electric field along the polar cap boundary, and thus evaluate the variation of the dayside/nightside reconnection rates. We find a strong response of the polar cap boundary at all available MLTs, exhibiting a significant reduction of the open flux content. We also observe an immediate response of the dayside reconnection rate, plus a phased response, delayed by ∼15–20 min, of the nightside reconnection rate. Finally, we provide comparison of the observations with the results of the Open Geospace General Circulation Model (OpenGGCM), elucidating significant agreements and disagreements.
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Mapping Solutions for Geomagnetic Conjugate Observations in the Arctic and Antarctic (iPoster/Lightning Presentation)
Access the original poster here: https://agu24.ipostersessions.com/default.aspx?s=56-AC-77-47-70-EA-25-74-40-80-19-49-D4-CA-D6-A7 Link to conference program: https://agu.confex.com/agu/agu24/meetingapp.cgi/Paper/1538608 This is an interactive poster, which was presented at AGU24 as a Lightning presentation. To view HTML files, download locally and open in browser. Abstract: The polar regions are uniquely valuable in geospace science, in part because much of the solar wind's energy enters the system in polar regions and their magnetospheric, ionospheric, and atmospheric connections are markedly different from the lower latitudes. Geomagnetic conjugate points in the northern and southern hemispheres – i.e., points linked by Earth's magnetic field, including both points connected by closed magnetic field lines and points in open-field line regions that are in similar magnetic domains – have been shown to alter each other’s environment on the order of minutes. Space weather conditions in Antarctica, therefore, influence and are influenced by the conditions in the northern hemisphere. This has been observed in the formation of auroral structures. However, the magnetic conjugate relationship is not straightforward to visualize with many common mapping tools, which commonly focus on midlatitude-oriented map projections. Related visualization difficulties also arise from the counterintuitive vertical scale of the geospace environment. Here, we present Python-based tools for mapping multiple instrumentation networks, including ground-based instruments, radars and satellites, to observe geospace events such as the polar eclipses of 2021, and discuss approaches to make the data presentation more flexible and intuitive. In particular, we highlight regions of potential interest for future instrument deployments.
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- Award ID(s):
- 2218996
- PAR ID:
- 10562843
- Publisher / Repository:
- Zenodo
- Date Published:
- Format(s):
- Medium: X
- Location:
- Washington, DC
- Right(s):
- Creative Commons Attribution 4.0 International
- Institution:
- American Geophysical Union Fall Meeting
- Sponsoring Org:
- National Science Foundation
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