NDLI: A Comparison Between Global Proxies of the Sun’s Magnetic Activity Cycle: Inferences from Helioseismology

Content Provider	Springer Nature Link
Author	Broomhall, A. M. Nakariakov, V. M.
Copyright Year	2015
Abstract	The last solar minimum was, by recent standards, unusually deep and long. We are now close to the maximum of the subsequent solar cycle, which is relatively weak. In this article we make comparisons between different global (unresolved) measures of the Sun’s magnetic activity to investigate how they are responding to this weak-activity epoch. We focus on helioseismic data, which are sensitive to conditions, including the characteristics of the magnetic field, in the solar interior. Also considered are measures of the magnetic field in the photosphere (sunspot number and sunspot area), the chromosphere and corona (10.7 cm radio flux and 530.3 nm green coronal index), and two measures of the Sun’s magnetic activity closer to Earth (the interplanetary magnetic field and the galactic cosmic-ray intensity). Scaled versions of the activity proxies diverge from the helioseismic data around 2000, indicating a change in relationship between the proxies. The degree of divergence varies from proxy to proxy, with sunspot area and 10.7 cm flux showing only small deviations, while sunspot number, coronal index, and the two interplanetary proxies show much larger departures. In Cycle 24 the deviations in the solar proxies and the helioseismic data decrease, raising the possibility that the deviations observed in Cycle 23 are just symptomatic of a 22-year Hale cycle. However, the deviations in the helioseismic data and the interplanetary proxies increase in Cycle 24. Interestingly, the divergence in the solar proxies and the helioseismic data are not reflected in the shorter-term variations (often referred to as quasi-biennial oscillations) observed on top of the dominant 11-year solar cycle. However, despite being highly correlated in Cycle 22, the short-term variations in the interplanetary proxies show very little correlation with the helioseismic data during Cycles 23 and 24.
Starting Page	3095
Ending Page	3111
Page Count	17
File Format	PDF
ISSN	00380938
Journal	Solar Physics
Volume Number	290
Issue Number	11
e-ISSN	1573093X
Language	English
Publisher	Springer Netherlands
Publisher Date	2015-07-09
Publisher Place	Dordrecht
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Helioseismology, Observations Integrated Sun Observations Oscillations, Solar Solar Cycle, Observations Astrophysics and Astroparticles Atmospheric Sciences Extraterrestrial Physics, Space Sciences
Content Type	Text
Resource Type	Article
Subject	Astronomy and Astrophysics Space and Planetary Science

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

The Sun’s Interior Structure and Dynamics, and the Solar Cycle

Solar Magnetic Atmospheric Effects on Global Helioseismic Oscillations

A Full-Sun Magnetic Index from Helioseismology Inferences

Performance of the Birmingham Solar-Oscillations Network (BiSON)

A Comparison Between Global Proxies of the Sun's Magnetic Activity Cycle: Inferences from Helioseismology

On the Relation Between Solar Activity and Clear-Sky Terrestrial Irradiance

A Helioseismic Perspective on the Depth of the Minimum Between Solar Cycles 23 and 24

Multi-Ridge Fitting for Ring-Diagram Helioseismology

Effects of Magnetic Fields in the Solar Atmosphere on Global Oscillations

A Comparison Between Global Proxies of the Sun’s Magnetic Activity Cycle: Inferences from Helioseismology

Similar Documents

The Sun’s Interior Structure and Dynamics, and the Solar Cycle

Solar Magnetic Atmospheric Effects on Global Helioseismic Oscillations

A Full-Sun Magnetic Index from Helioseismology Inferences

Performance of the Birmingham Solar-Oscillations Network (BiSON)

A Comparison Between Global Proxies of the Sun's Magnetic Activity Cycle: Inferences from Helioseismology

On the Relation Between Solar Activity and Clear-Sky Terrestrial Irradiance

A Helioseismic Perspective on the Depth of the Minimum Between Solar Cycles 23 and 24

Multi-Ridge Fitting for Ring-Diagram Helioseismology

Effects of Magnetic Fields in the Solar Atmosphere on Global Oscillations

A Comparison Between Global Proxies of the Sun’s Magnetic Activity Cycle: Inferences from Helioseismology