Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/6649
Full metadata record
DC FieldValueLanguage
dc.contributor.authorPriyal, M-
dc.contributor.authorBanerjee, D-
dc.contributor.authorKarak, B. B-
dc.contributor.authorMunoz-Jaramillo, A-
dc.contributor.authorRavindra, B-
dc.contributor.authorChoudhuri, A. R-
dc.contributor.authorSingh, J-
dc.date.accessioned2014-09-29T09:15:28Z-
dc.date.available2014-09-29T09:15:28Z-
dc.date.issued2014-09-20-
dc.identifier.citationThe Astrophysical Journal Letters, Vol. 793, No. 1, L4en
dc.identifier.issn2041-8205-
dc.identifier.urihttp://hdl.handle.net/2248/6649-
dc.descriptionRestricted Accessen
dc.description.abstractThe Sun has a polar magnetic field which oscillates with the 11 yr sunspot cycle. This polar magnetic field is an important component of the dynamo process which operates in the solar convection zone and produces the sunspot cycle. We have direct systematic measurements of the Sun's polar magnetic field only from about the mid-1970s. There are, however, indirect proxies which give us information about this field at earlier times. The Ca-K spectroheliograms taken at the Kodaikanal Solar Observatory during 1904-2007 have now been digitized with 4k × 4k CCD and have higher resolution (~0.86 arcsec) than the other available historical data sets. From these Ca-K spectroheliograms, we have developed a completely new proxy (polar network index, hereafter PNI) for the Sun's polar magnetic field. We calculate PNI from the digitized images using an automated algorithm and calibrate our measured PNI against the polar field as measured by the Wilcox Solar Observatory for the period 1976-1990. This calibration allows us to estimate the polar fields for the earlier period up to 1904. The dynamo calculations performed with this proxy as input data reproduce reasonably well the Sun's magnetic behavior for the past century.en
dc.language.isoenen
dc.publisherIOP Publishingen
dc.relation.urihttp://iopscience.iop.org/2041-8205/793/1/L4/en
dc.rights© IOP Publishingen
dc.subjectMagnetic fieldsen
dc.subjectSun: activityen
dc.subjectSun: faculaeen
dc.subjectPlagesen
dc.titlePolar Network Index as a Magnetic Proxy for the Solar Cycle Studiesen
dc.typeArticleen
Appears in Collections:IIAP Publications

Files in This Item:
File Description SizeFormat 
Polar Network Index as a Magnetic Proxy for the Solar Cycle Studies.pdf
  Restricted Access
Restricted Access1.05 MBAdobe PDFView/Open Request a copy


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.