gov.noaa.ngdc.stp.solar:G005321700In 1848 the Swiss astronomer Johann Rudolph Wolf introduced a daily measurement of sunspot number. His method, which is still used today, counts the total number of spots visible on the face of the sun and the number of groups into which they cluster, because neither quantity alone satisfactorily measures sunpsot activity.An observer computes a daily sunspot number by multiplying the number of groups he sees by ten and then adding this product to his total count of individual spots. Results, however, vary greatly, since the measurement stongly depends on observer interpretation and experience and on the stability of the Earth's atmosphere above the observing site. Moreover, the use of Earth as a platform from which to record these numbers contributes to their variability, too, because the sun rotates and the evolving spot groups are distributed unevenly across solar longitudes. To compensate for these limitations, each daily international number is computed as a weighted average of measurements made from a network of cooperating observatories.To provide long-term scientific data stewardship for the Nation's geophysical data, ensuring quality, integrity, and accessibility.17000101UnknownUnknownIn workmonthlyNASA/Global Change Master Directory (GCMD) Earth Science KeywordsEARTH SCIENCE > Sun-earth Interactions > Solar Activity > Solar EventsNASA/GCMD Location KeywordsPhotosphereUncontrolled Location KeywordsSunRestriction Code: otherRestrictions; DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of CommerceSolar Data Managerphysical and mailing NOAA/NESDIS/NGDC E/GC2 325 Broadway BoulderCO80305303.497.6133 or 303.497.6323solar.ngdc@noaa.govUnknown 20111117Solar Data ManagerDOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commercemailing and physical NOAA/NESDIS/NGDC E/GC2 325 Broadway BoulderCO80305303.497.6133 or 303.497.6323solar.ngdc@noaa.govContent Standard for Digital Geospatial Metadata: Extensions for Remote Sensing MetadataFGDC-STD-012-2002