Identification

Title

An observationally constrained 3D potential-field source-surface model for the evolution of longitude-dependent coronal structures

Abstract

The improvement of techniques for realistically modeling the solar magnetic field has been a priority in solar physics for decades. The challenge of creating synoptic maps of the photosphere that reliably reflect conditions at all locations concurrently is a major limitation to progress in this area. White-light coronal images, which contain morphological information about the 3D corona at the solar limb, have been largely overlooked as a resource for constraining or correcting synoptic maps. We explore a complementary approach to traditional magnetogram-based coronal field solutions that makes use of these images. Applying a modified 3D potential-field source-surface (PFSS) model, we investigate the use of MLSO white-light coronal images for deriving 3D coronal morphology by empirically fitting model solutions with observations only. Applying an iterative technique to coronal image data from the solar minima preceding Cycles 22, 23, and 24, and the ascending phase of Cycle 23, we obtain model solutions as linear combinations of low order and degree spherical harmonics. We find that the 3D morphology produced by our method agrees qualitatively with traditional magnetogram-based PFSS approaches for coronas that are dipole dominated. For more complex coronas, additional constraints are needed to account for polarity and correct interpretation of coronal structures. Estimates of the relative strength of dipoles versus multipoles in the coronal field also agree with traditional methods, but the contributions of specific multipoles do not, revealing nonuniqueness in our results. Future work will incorporate magnetogram-based solutions prior to applying the iterative technique.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7pg1vd8

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

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South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2017-11-28T00:00:00Z

Frequency of update

Quality and validity

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Conformity

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name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact