Ionospheric signatures of magnetic reconnection in Earth’s magnetosphere

Magnetic reconnection is the primary mode by which the solar wind couples to Earth's magnetosphere, driving dynamics on an enormous range of scales. At the macroscale (tens of Earth radii), reconnection powers the Dungey Convection Cycle that transports magnetic energy from the solar wind to the magnetotail and back to the dayside magnetosphere. Reconnection in the magnetotail drives magnetic storms and substorms. At the mesoscale (several Earth radii), reconnection generates structures like Flux Transfer Events (FTEs) at the dayside magnetopause and Bursty Bulk Flows (BBFs) in the magnetotail. At the microscale (particle Larmor radii), reconnection generates structure and dynamics (e.g., field-aligned currents, particle precipitation, gyro-viscosity, turbulence) that feed back on the larger scales to shape the global structure of the magnetosphere. Understanding this interplay of reconnection physics on multiple scales is made challenging by the sparsity of our observations. Spacecraft sample tiny subsets of the magnetosphere at any given time, leaving huge gaps for our global models to fill. Ground observations from radars and multispectral imagers contain information spanning multiple scales, but there is a wide gap between these observations and state of the art global models. Bridging this gap will be one of the great challenges for the next decade of heliophysics research.

The goal of this Research Topic is to address the gap between our ground and Low Earth Orbit (LEO) spacecraft observations and our state of the art global magnetosphere models. Accomplishing this will require: 1) understanding the ionospheric signatures of magnetic reconnection on multiple scales, 2) assessing the current capabilities of global models in predicting the ionospheric signatures of magnetic
reconnection, and 3) prioritizing the advances in global modeling that will be needed to take full advantage of the ground and LEO observations that will be available in the next decade.

In this Research Topic, we'd like to address the following questions:

1. What ground and LEO spacecraft observations do we need to understand the ionospheric signatures of mesoscale (several Earth radii) and microscale (particle Larmor radii) reconnection in Earth's magnetosphere?
2. What are the ionospheric signatures of mesoscale and microscale reconnection structures at the magnetopause?
3. What are the ionospheric signatures of mesoscale and microscale reconnection structures in the magnetotail?
4. How capable are current state of the art global models of predicting the ionospheric signatures of mesoscale
and microscale reconnection?
5. What advances in global modeling are needed to take full advantage of the ground LEO spacecraft observations that will be available in the next decade?

We would like to invite contributions to these topics in the form of Perspective and Opinion articles. Reviews, Mini Reviews, Original Research and Brief Research Reports are also welcome.

Keywords: Magnetic Reconnection, Magnetosphere, Ionosphere, Polar Cusp, Aurora

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.