Karin Muglach (Goddard Space Flight Center)

Properties of Coronal Hole Jets and Outflows as Observed With SDO and Hinode
When Sep 18, 2014 from 11:00 AM to 12:00 PM
What
  • Special Seminar
  • Colloquium
Where SH, Lecture Hall
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Solar coronal holes are known to be the source of the fast solar wind (as observed with in-situ instruments near Earth). Although generally darker than surrounding quiet and active regions, they contain small-scale bright areas. In  low-resolution coronal images these areas were called bright points, but modern high-resolution images show that they consist of tiny loop-like coronal structures with a bipolar magnetic field distribution at their photospheric footpoints. X-ray and EUV imaging instruments have shown in the past that these bright points undergo episodic ejection of mass, coronal hole jets.

In this presentation I will show an analysis of these coronal hole jets observed with Hinode/EIS and SDO. Coronal velocities of up to 200 km/s and enhancements in line width are measured. On the other hand, some of these jets are hardly visible in imaging data like SDO/AIA and Hinode/XRT.

I will also discuss the photospheric signatures at the footpoint of these jets using SDO/HMI magnetograms and the plane-of-sky flow field derived with local correlation tracking. Both the evolution of the magnetic field and the flows allow us to study the photospheric drivers of these jets. I will give both a summary of all events observed in a 44h time series and a discussion of a couple of events in detail. This allows us to address the question of the origin of the solar wind and its relation to the magnetic field.

This work is funded by the National Science Foundation.