Accession Number:

ADA626831

Title:

The Hunt for the Missing Modes: Revealing the True Nature of the Solar Wind

Descriptive Note:

Final rept. 15 Mar 2013-31 Aug 2014

Corporate Author:

NORTHUMBRIA UNIV NEWCASTLE UPON TYNE (UNITED KINGDOM)

Personal Author(s):

Report Date:

2015-01-29

Pagination or Media Count:

7.0

Abstract:

This effort produced a novel image-processing algorithm which has allowed successful identification and accurate track of solar plumes in Solar Dynamics ObservatoryAtmospheric Imaging Assembly SDOAIA data and, moreover, enabled the first direct measurements of transverse waves in solar polar plumes. This image-processing technique has allowed direct measurement of the transverse displacements, periods and velocity-amplitudes of 596 distinct oscillations in the 171 channel over a 4 hour period which displayed a non-uniformly distributed range of parameters. Furthermore, the measurements allow us to take into account the whole of observed non-uniform parameter distribution, permitting the calculation of a more accurate time-averaged energy flux than previously reported. Crucially, this allowed the calculation of an energy flux of 9-24 W m 2, which is 4-10 times below the energy requirement for solar wind acceleration. Hence, the results indicate that transverse magnetohydrodynamic waves as resolved by SDOAIA cannot be the dominant energy source for fast solar wind acceleration in the open-field corona. The development of this robust, versatile wave-tracking image-processing algorithm can also be applied to a whole range of different solar structures and in principle to other data sets that display oscillation behaviour. For example, we took advantage of the recent High-resolution Coronal Imager Hi- C data and applied the image-processing algorithm to measure the fine-scale structure in transition region moss which led to the first direct observation of transverse wave behaviour of moss in an active region.

Subject Categories:

  • Astrophysics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE