by
P.S. McIntosh, E.C. Willock, and R.J. Thompson
UAG Report 101, World Data Center A for Solar-Terrestrial Physics NOAA, E/GC2 325 Broadway, Boulder, Colorado 80303-3328 USA. National Academy of Sciences. 188 pages.
Long-lived patterns of solar magnetic-field polarity and coronal holes are revealed in a collection of stackplots - vertical time series of segments of solar synoptic charts. The plots, based upon a 21-year collection of h-alpha synoptic charts compiled at the Space Environment Laboratory (SEL) of the National Oceanic and Atmospheric Administration, portray the long-term, large-scale evolution of solar magnetic features from late in 1966 through to the end of 1987. This interval includes two complete sunspot cycles (most of cycles 20 and 21, and the start of cycle 22.). Coronal hole data are available from the X-ray images obtained by Skylab (1973-74) and from HeI (10 830A) observations for 1975-1987.
Several types of stackplot are included in this collection. These include a series of plots displaying 10 degree zones of solar latitude, stepped from 70 degree N through the solar equator to 70 degree S. Three further series of stackplots show a wider band of latitude (1 degree N-50 deg N, 25 deg S - 25 deg N, 1 deg S to 50 deg S). Two types of large-scale plots are also included, both being formed from the 10 deg latitude zones. The first combines data from each 10 deg zone for the entire interval of time. The second, a fold-out page, combines the data from all zones to provide an overview of the entire 21-year database.
The maps are extensively cross referenced by date, rotation number, and latitude range to allow researchers easy access to periods of special interest. The plots are also accompanied by overlays and grids to measure rotation rates of drifting patterns.
Application for these data include: studies of variable rates of rotation for magnetic field and coronal hole patterns; inference of the general circulation of the solar atmosphere; definition of the solar cycle from large-scale parameters, independent of sunspots; improved studies of the reversal of polar magnetic fields; and meridional motions of large-scale features.
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