A near absence of volcanically produced stratospheric aerosol during the years 1976 - 1980 allows an assessment of seasonally variable background tropospheric aerosol for that period, which is then compared with the volcanically active period after 1980 using 485 nights of photometric observations from 1972 through 1985. The 1982 eruption of the Mexican volcano El Chichón caused the largest long-lived global increase in atmospheric extinction since the 1963 eruption of Agung in the southern hemisphere. Measurements of extinction one or two nights ahead have little predictive value for photometric work, although a correlation with certain locally recorded meteorological variables can be demonstrated. However, knowledge of the normal seasonal variations, plus published stratospheric optical depths, offers a considerable improvement in accuracy - nearly a factor of 3 - over commonly adopted observatory "mean" extinction coefficients.
No takes yet. Share an insight, caveat, or question.
Lockwood et al. (1986) studied this question.