NDLI: Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data

Content Provider	Springer Nature Link
Author	Lockwood, M. Owens, M. J. Barnard, L. Scott, C. J. Usoskin, I. G. Nevanlinna, H.
Copyright Year	2016
Abstract	We compare four sunspot-number data sequences against geomagnetic and terrestrial auroral observations. The comparisons are made for the original Solar Influences Data Center (SIDC) composite of Wolf/Zürich/International sunspot number [ $R_{\text{ISNv}1}$ ], the group sunspot number [ $R_{\mathrm{G}}$ ] by Hoyt and Schatten (Solar Phys. 181, 491, 1998), the new “backbone” group sunspot number [ $R_{\mathrm{BB}}$ ] by Svalgaard and Schatten (Solar Phys., DOI , 2016), and the “corrected” sunspot number [ $R_{\mathrm{C}}$ ] by Lockwood, Owens, and Barnard (J. Geophys. Res. 119, 5172, 2014a). Each sunspot number is fitted with terrestrial observations, or parameters derived from terrestrial observations to be linearly proportional to sunspot number, over a 30-year calibration interval of 1982 – 2012. The fits are then used to compute test sequences, which extend further back in time and which are compared to $R_{\text{ISNv}1}$ , $R_{\mathrm{G}}$ , $R_{\text{BB}}$ , and $R_{\mathrm{C}}$ . To study the long-term trends, comparisons are made using averages over whole solar cycles (minimum-to-minimum). The test variations are generated in four ways: i) using the IDV(1d) and IDV geomagnetic indices (for 1845 – 2013) fitted over the calibration interval using the various sunspot numbers and the phase of the solar cycle; ii) from the open solar flux (OSF) generated for 1845 – 2013 from four pairings of geomagnetic indices by Lockwood et al. (Ann. Geophys. 32, 383, 2014a) and analysed using the OSF continuity model of Solanki, Schüssler, and Fligge (Nature, 408, 445, 2000), which employs a constant fractional OSF loss rate; iii) the same OSF data analysed using the OSF continuity model of Owens and Lockwood (J. Geophys. Res. 117, A04102, 2012), in which the fractional loss rate varies with the tilt of the heliospheric current sheet and hence with the phase of the solar cycle; iv) the occurrence frequency of low-latitude aurora for 1780 – 1980 from the survey of Legrand and Simon (Ann. Geophys. 5, 161, 1987). For all cases, $R_{\mathrm{BB}}$ exceeds the test terrestrial series by an amount that increases as one goes back in time.
Starting Page	2811
Ending Page	2828
Page Count	18
File Format	PDF
ISSN	00380938
Journal	Solar Physics
Volume Number	291
Issue Number	9-10
e-ISSN	1573093X
Language	English
Publisher	Springer Netherlands
Publisher Date	2016-06-15
Publisher Place	Dordrecht
Access Restriction	One Nation One Subscription (ONOS)
Subject Keyword	Sunspots, Statistics Magnetosphere, Geomagnetic Disturbances Astrophysics and Astroparticles Atmospheric Sciences Space Sciences (including Extraterrestrial Physics, Space Exploration and Astronautics)
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

Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data

Tests of Sunspot Number Sequences: 1. Using Ionosonde Data

Investigation of Sunspot Area Varying with Sunspot Number

The New Sunspot Number: Assembling All Corrections

Comparison of New and Old Sunspot Number Time Series

The Discontinuity Circa 1885 in the Group Sunspot Number

The Revised Brussels–Locarno Sunspot Number (1981 – 2015)

Tests of Sunspot Number Sequences: 3. Effects of Regression Procedures on the Calibration of Historic Sunspot Data

Uncertainties in the Sunspot Numbers: Estimation and Implications

Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data

Similar Documents

Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data

Tests of Sunspot Number Sequences: 1. Using Ionosonde Data

Investigation of Sunspot Area Varying with Sunspot Number

The New Sunspot Number: Assembling All Corrections

Comparison of New and Old Sunspot Number Time Series

The Discontinuity Circa 1885 in the Group Sunspot Number

The Revised Brussels–Locarno Sunspot Number (1981 – 2015)

Tests of Sunspot Number Sequences: 3. Effects of Regression Procedures on the Calibration of Historic Sunspot Data

Uncertainties in the Sunspot Numbers: Estimation and Implications

Tests of Sunspot Number Sequences: 2. Using Geomagnetic and Auroral Data