Table 3 Years of Aa cycles and their corresponding ascending and descending phases
From: New perspectives on contributing factors to the monthly behavior of the aa geomagnetic index
Cycle number | Complete cycles | Ascending phase | Descending phase |
|---|---|---|---|
11 | 1868–1879 | 1868–1872 | 1872–1879 |
12 | 1879–1890 | 1879–1882 | 1882–1890 |
13 | 1890–1901 | 1890–1892 | 1892–1901 |
14 | 1901–1913 | 1901–1910 | 1910–1913 |
15 | 1913–1924 | 1913–1919 | 1919–1924 |
16 | 1924–1934 | 1924–1930 | 1930–1934 |
17 | 1934–1945 | 1934–1943 | 1943–1945 |
18 | 1945–1954 | 1945–1951 | 1951–1954 |
19 | 1954–1965 | 1954–1960 | 1960–1965 |
20 | 1965–1980 | 1965–1974 | 1974–1980 |
21 | 1980–1987 | 1980–1982 | 1982–1987 |
22 | 1987–1997 | 1987–1991 | 1991–1997 |
23 | 1997–2009 | 1997–2003 | 2003–2009 |
24 | 2009–2015 | 2009–2012 | 2012–2015 |