1 In some months, the Ides is on the 15th, and in others, it is the 13th. 2  It's supposed to be on the day of the full moon. [See Roman Calendar.]. 3  March's Ides marked the beginning of the consular year: The two annually-elected Roman consuls took office on the Ides from c. 220 B.C. to 153.
In the case of Mount Pinatubo, the result was a measurable cooling of the Earthâs surface for a period of almost two years. Because they scatter and absorb incoming sunlight, aerosol particles exert a cooling effect on the Earthâs surface.The Pinatubo eruption increased aerosol optical depth in the stratosphere by a factor of 10 to 100 times normal levels measured prior to the eruption.ecause they scatter and absorb incoming sunlight, aerosol particles exert a cooling effect on the Earthâs surface. The Pinatubo eruption increased aerosol optical depth in the stratosphere by a factor of 10 to 100 times normal levels measured prior to the eruption.
Ash column generated by the eruption of Mount Pinatubo, a volcano in the Philippines Luzon volcanic arc, on June 12, 1991. The climactic eruption of Mount Pinatubo occurred three days later on June 15, 1991, and was one of the largest eruptions of this century.sually, the hazards from volcanic gases are most severe in the areas immediately surrounding volcanoes, especially on volcano flanks downwind of active vents and fumaroles. But these hazards can persist for long distances downwind following large eruptions, or from volcanoes erupting gas-rich magma.