DOI: 10.7910/dvn/kf96b2
title: MWO polar faculae count calibrated to WSO polar fields and SOHO/MDI polar flux

description: &lt;h2&gt;Citation and Acknowledgements&lt;/h2&gt;

&lt;p&gt;&lt;br&gt;Please cite both this database the paper describing it, as well as adding the following acknowledgement:

&lt;p&gt;&lt;br&gt;&lt;b&gt;"MWO calibrated polar faculae data were downloaded from the solar dynamo dataverse (https://dataverse.harvard.edu/dataverse/solardynamo), maintained by Andrés Muñoz-Jaramillo." &lt;/b&gt;&lt;/p&gt;

&lt;p&gt;&lt;br&gt; Database citation format is shown at the top of this page, underneath the database title. It can be downloaded in a variety of formats directly from this page&lt;/p&gt;

&lt;p&gt;&lt;br&gt;The paper describing this database is&lt;/p&gt;

&lt;p&gt;&lt;br&gt;&lt;b&gt;A. Muñoz-Jaramillo, N. R. Sheeley Jr., J. Zhang, & E. E. DeLuca, Calibrating 100 years of polar faculae measurements: Implications for the evolution of the heliospheric magnetic field, ApJ, 753, 146 (2012).&lt;/b&gt; &lt;a href="http://adsabs.harvard.edu/abs/2012ApJ...753..146M"&gt;http://adsabs.harvard.edu/abs/2012ApJ...753..146M&lt;/a&gt;
&lt;/p&gt;

&lt;h2&gt;Main Limitations&lt;/h2&gt;

&lt;p&gt;The main limitations of these data are:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;Polar field measurements are limited to a cadence of one measurement per year, and&lt;/li&gt;
&lt;li&gt;Polar faculae are a strictly possitive quantity. Prior to 1976, magnetic polarity has been assigned by assuming that reversal takes place when facular counts reach a minimum .&lt;/li&gt;
&lt;/ol&gt;


&lt;h2&gt;Description&lt;/h2&gt;

&lt;img src="http://solardynamo.org/images/PFaculae_Data.jpg" alt="MWO Faculae" width="840"&gt;


&lt;p&gt;Faculae counted by hand on the best 5 images during the periods of maximum pole coverage (August 15-September 15 for the North pole and February 15-March 15 for the South pole) and averaged. Standard deviation has been turned into standard error by dividing it by sqrt(5). Years with multiple observations have been averaged as well as their their standard errors.&lt;/p&gt;

&lt;p&gt;Calibration between campaigns was made taking advantage of the overlaps between them. All campaigns were standardized to the values of the 3rd campaign in order to reduce error propagation.&lt;/p&gt;

&lt;p&gt;Original papers reporting the different data reduction campaigns are:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;
&lt;p&gt;1st Campaign:&lt;br&gt;
Sheeley N. R. Jr. 1964 ApJ 140 731&lt;br&gt;
Sheeley N. R. Jr. 1966 ApJ 144 723&lt;/p&gt;
&lt;/li&gt;

&lt;li&gt;
&lt;p&gt;2nd Campaign:&lt;br&gt;
Sheeley N. R. Jr. 1976 J. Geophys. Res. 81 3462&lt;/p&gt;
&lt;/li&gt;

&lt;li&gt;
&lt;p&gt;3rd Campagin:&lt;br&gt;
Sheeley N. R. Jr. 1991 ApJ 374 386&lt;/p&gt;
&lt;/li&gt;

&lt;li&gt;
&lt;p&gt;4th Campagin:&lt;br&gt;
Sheeley N. R. Jr. 2008 ApJ 680 1553&lt;/p&gt;
&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Calibration factors used were:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;To turn 1st campaign values into 2nd campaign: 0.8733 +/- 0.0343&lt;/li&gt;

&lt;li&gt;To turn 2nd campaign values into 3rd campaign: 0.7293 +/- 0.1918&lt;/li&gt;

&lt;li&gt;To turn 4th campaign values into 3rd campaign: 1.6601 +/- 0.1861&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Unification of all campaigns is performed by averaging overlapping years between the calibrated campaigns as well as their standard errors.&lt;/p&gt;

&lt;p&gt;Calibration to MDI magnetic flux is performed by using MWO, WSO, and MDI data only during periods of maximum polar coverage and the overlap between the unified WSO facular count, WSO, and MDI data.&lt;/p&gt;

&lt;p&gt;The calibration factors used were:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;To turn MWO facular counts to MDI magnetic flux: (1.045 +/- 0.1638)*10^21 Mx &lt;/li&gt;

&lt;li&gt;To turn WSO facular counts to MDI magnetic flux: (10.61 +/- 0.6410)*10^21 Mx/Gauss &lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Details on the consolidation and calibration of the different campaigns can be found in:&lt;/p&gt;

&lt;p&gt;A. Munoz-Jaramillo, N. R. Sheeley, Jr., J. Zhang, and E. E. DeLuca
CALIBRATING 100 YEARS OF POLAR FACULAE MEASUREMENTS: IMPLICATIONS
FOR THE EVOLUTION OF THE HELIOSPHERIC MAGNETIC FIELD
ApJ, 753, 146. (2012) doi:10.1088/0004-637X/753/2/146&lt;/p&gt;

&lt;p&gt;Paper available from: &lt;a ="http://www.solardynamo.org/docs/Munoz-Jaramillo_etal_ApJ2012.pdf"&gt;http://www.solardynamo.org/docs/Munoz-Jaramillo_etal_ApJ2012.pdf&lt;/a&gt;&lt;/p&gt;

&lt;hr&gt;

&lt;p&gt;&lt;h2&gt;Available Products:&lt;/h2&gt;&lt;/p&gt;

&lt;p&gt;&lt;h3&gt;File: e_PField_MWO_WSO_2.0.dat&lt;/h3&gt;&lt;/p&gt;
&lt;img src="http://solardynamo.org/images/e_MWO_WSO_PField.svg" alt="MWO calibrated to WSO Field" width="840"&gt;

&lt;p&gt;&lt;h3&gt;File: f_PFlux_MWO_WSO_MDI_2.0.dat&lt;/h3&gt;&lt;/p&gt;
&lt;img src="http://solardynamo.org/images/f_MWO_WSO_MDI_PFlux.svg" alt="MWO calibrated to WSO Field" width="840"&gt;

&lt;p&gt;&lt;h3&gt;Files: aN_Polar_Fac_Raw_North.dat and aS_Polar_Fac_Raw_South.dat&lt;/h3&gt;&lt;/p&gt;
&lt;img src="http://solardynamo.org/images/a_Raw_Data.svg" alt="MWO calibrated to WSO Field" width="840"&gt;

&lt;p&gt;&lt;h3&gt;Files: bN_Polar_Fac_Consolidated_North_2.0.dat and bS_Polar_Fac_Consolidated_South_2.0.dat&lt;/h3&gt;&lt;/p&gt;
&lt;img src="http://solardynamo.org/images/b_Consolidated_Data.svg" alt="MWO calibrated to WSO Field" width="840"&gt;

&lt;p&gt;&lt;h3&gt;Files: cN_Polar_Fac_Calibrated_North_2.0.dat and cS_Polar_Fac_Calibrated_South_2.0.dat&lt;/h3&gt;&lt;/p&gt;
&lt;img src="http://solardynamo.org/images/c_Calibrated_Data.svg" alt="MWO calibrated to WSO Field" width="840"&gt;

&lt;p&gt;&lt;h3&gt;File: d_Polar_Fac_Unified_2.0.dat&lt;/h3&gt;&lt;/p&gt;
&lt;img src="http://solardynamo.org/images/d_Unified_Data.svg" alt="MWO calibrated to WSO Field" width="840"&gt;