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.
It injected more particulate into the stratosphere than any eruption since Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 Â°C (0.9 Â°F) in the years 1991-93, and ozone depletion temporarily increased substantially.ear Mount Pinatubo, the United States maintained two large military bases in the region. The U.S. Naval Base Subic Bay was 37 km (23 mi) south of Pinatubo, and the extent of Clark Air Base was just 14 km (8.7 mi) east of the volcano's summit.