Electric currents are fundamental to the structure and dynamics of space plasmas, including our own near-Earth space environment (also called “geospace”). This recognition is one of the great achievements in space research, going back to the beginning of the last century. With the current multi-spacecraft missions, such as Cluster, THEMIS and Swarm, we have unprecedented opportunities to unravel many of the intriguing puzzles about electric currents, such as:
- How are electric currents generated, maintained, and dissipated?
- What is their three-dimensional spatial structure (topology)?
- What is the relationship among various scales?
- What is their temporal development, both short and long term?
- How do the currents affect their space environment?
- How much energy is transported and deposited in various regions by currents?
In addition to advances in our own geospace, much knowledge has been accumulated about planetary and solar current systems. Recent space missions that have provided data in the last decade or so to study current systems in planetary magnetospheres include: Cassini, MESSENGER, and Venus Express and now Maven. Juno will provide data on high latitude current systems at Jupiter when it arrives in July 2016. Two recent space missions, the Hinode satellite and the Solar Dynamics Observatory spacecraft, have provided new information on electrical currents at the level of the Sun’s photosphere, as well as high resolution X-ray and extreme-UV and X-ray images of solar activity powered by coronal currents.
There have also been tremendous advances in the capabilities of simulations to allow modeling of many of the relevant processes.
To build up a comprehensive picture, this Chapman conference will address electric currents in various space plasmas, including:
• Earth’s magnetosphere & ionosphere
• Planetary magnetospheres & ionospheres (other than Earth)
• Solar atmosphere and solar wind (including the heliospheric current sheet)
The main objective of this conference will be to develop a deeper understanding of the fundamental physics of electric currents in space plasmas and to give an up-to-date look on where research on currents stands: What are the new analysis methods? What do we know? What are unanswered questions? What else is needed to make progress?
The second objective is to stimulate cross-disciplinary discussions among scientists specializing in different areas, and will be an excellent opportunity for various communities to meet and learn from each other.
The third objective is to provide a historical review of electric currents in space. With the upcoming 150th and 100th anniversaries of Kristian Birkeland’s birth and death years (1867-1917), we will have several keynote speakers on the pioneers in this important field of space science.
Sadly, Olaf Amm, our fellow convener, passed away in December 2014. He was an accomplished scientist, especially in the fields of ionospheric electrodynamics and magnetosphere-ionosphere coupling processes. Olaf developed several new innovative approaches for creating regional maps of ionospheric currents, conductances and fields with adjustable space resolution from the basis of ground- or space-based magnetic and electric field measurements. The methods that Olaf developed are widely used by other scientists, and without any doubts, results will be shown at this Chapman conference.
Olaf was very enthusiastic about this conference, and he has and would have continued to contribute significantly to its success. We dedicate this conference to Olaf.