Identification

Title

On the contribution of quiet-sun magnetism to solar irradiance variations: Constraints on quiet-sun variability and grand-minimum scenarios

Abstract

While the quiet-Sun magnetic field shows only little variation with the solar cycle, long-term variations cannot be completely ruled out from first principles. We investigate the potential effect of quiet-Sun magnetism on spectral solar irradiance through a series of small-scale dynamo simulations with zero vertical flux imbalance (< B-z > = 0) and varying levels of small-scale magnetic field strength, and one weak network case with an additional flux imbalance corresponding to a flux density of < B-z > = 100 G. From these setups, we compute the dependence of the outgoing radiative energy flux on the mean vertical magnetic field strength in the photosphere at a continuum optical depth tau = 1 (<vertical bar B-z vertical bar >(tau=1)). We find that a quiet-Sun setup with a mean vertical field strength of <vertical bar B-z vertical bar >(tau=1) = 69 G is about 0.6% brighter than a non-magnetic reference case. We find a linear dependence of the outgoing radiative energy flux on the mean field strength <vertical bar B-z vertical bar >(tau=1) with a relative slope of 1.4 x 10(-4) G(-1). With this sensitivity, only a moderate change of the quiet-Sun field strength by 10% would lead to a total solar irradiance variation comparable to the observed solar cycle variation. While this does provide strong indirect constraints on possible quiet-Sun variations during a regular solar cycle, it also emphasizes that potential variability over longer timescales could make a significant contribution to longer-term solar irradiance variations.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d70c500t

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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Temporal reference

Temporal extent

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End position

Dataset reference date

date type

publication

effective date

2020-05-15T00:00:00Z

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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