Solar White Light Faculae

Solar White Light Faculae are areas of bright plages on the solar disk. These were routinely measured at the Royal Greenwich Observatory in the UK from 1874 to 1976, producing a record of over 100 years of continuous monitoring of this solar phenomenon. Detailed positions and areas of sunspots and faculae for each day in the year are available. As part of a data rescue effort in 1999, NOAA had these analog records keyed into digital form.

The record includes photograph time, observing station (Greenwich, Cape of Good Hope, Kodaikanal, and Mauritius), group number, position of the spot group and/or faculae, area of the spots, and faculae area for each group. The dark sunspot group areas block the solar radiation from the Sun. The bright white light faculae enhance the solar radiation from the Sun. Models of the total solar irradiance include both these opposing forces of dark sunspot group areas and the bright white light faculae areas.

Greenwich data are also available via Solar Sunspot Regions in a different format, and compiled by Fred Ward, USAF AFCRL, in the 1960s and later updated by Doug Hoyt in the 1990s. The Greenwich data books have two sections and the data are somewhat different between the two sets.

1. Greenwich White Light Faculae and Sunspot Area data by group 1874-1955 (Data documentation)
   Download Data (TXT): Choose Year 1955 1954 1953 1952 1951 1950 1949 1948 1947 1946 1945 1944 1943 1942 1941 1940 1939 1938 1937 1936 1935 1934 1933 1932 1931 1930 1929 1928 1927 1926 1925 1924 1923 1922 1921 1920 1919 1918 1917 1916 1915 1914 1913 1912 1911 1910 1909 1908 1907 1906 1905 1904 1903 1902 1901 1900 1899 1898 1897 1896 1895 1894 1893 1892 1891 1890 1889 1888 1887 1886 1885 1884 1883 1882 1881 1880 1879 1878 1874

   Download Data (PDF): Choose Year 1955 1954 1953 1952 1951 1950 1949 1948 1947 1946 1945 1944 1943 1942 1941 1940 1939 1938 1937 1936 1935 1934 1933 1932 1931 1930 1929 1928 1927 1926 1925 1924 1923 1922 1921 1920 1919 1918 1917 1916 1915 1914 1913 1912 1911 1910 1909 1908 1907 1906 1905 1904 1903 1902 1901 1900 1899 1898 1897 1896 1895 1894 1893 1892 1891 1890 1889 1888 1887 1886 1885 1884 1883 1882 1881 1880 1879 1878 1874
2. Greenwich PhotoHeliographic Results -- Summary daily data (Data documentation) 1956-1976 -- daily projected umbral area and total sunspot area, daily projected faculae area for Eastern hemisphere, daily projected faculae area for the Western hemisphere, corrected umbral and total sunspot area, and corrected faculae areas for the Eastern and Western hemisphere.
   Download Data: Choose Year 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976