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On the relation between sunspot area and sunspot number
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hathaway, David H. Wilson, Robert M. |
| Copyright Year | 2006 |
| Description | Often, the relation between monthly or yearly averages of total sunspot area, A, and sunspot number, R, has been described using the formula A = 16.7 R. Such a simple relation, however, is erroneous. The yearly ratio of A/R has varied between 5.3 in 1964 to 19.7 in 1926, having a mean of 13.1 with a standard deviation of 3.5. For 1875-1976 (corresponding to the Royal Greenwich Observatory timeframe), the yearly ratio of A/R has a mean of 14.1 with a standard deviation of 3.2, and it is found to differ significantly from the mean for 1977-2004 (corresponding to the United States Air Force/National Oceanic and Atmospheric Administration Solar Optical Observing Network timeframe), which equals 9.8 with a standard deviation of 2.1. Scatterplots of yearly values of A versus R are highly correlated for both timeframes and they suggest that a value of R = 100 implies A=1,538 +/- 174 during the first timeframe, but only A=1,076 +/- 123 for the second timeframe. Comparison of the yearly ratios adjusted for same day coverage against yearly ratios using Rome Observatory measures for the interval 1958-1998 indicates that sunspot areas during the second timeframe are inherently too low. |
| File Size | 846035 |
| Page Count | 24 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20060020186 |
| Archival Resource Key | ark:/13960/t1bk6bh5k |
| Language | English |
| Publisher Date | 2006-02-01 |
| Access Restriction | Open |
| Subject Keyword | Solar Physics Observatories United States Standard Deviation Solar Cycles Sunspots Predictions Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
