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.
Pinatubo volcano exploded spectacularly on 15 June 1991. The Pinatubo eruption on 15 June 1991 was the second largest volcanic eruption of the 20th century. Pinatubo is a complex of lava domes located 100 km NW of Manila city, Luzon Island, Philippines. Prior to the eruption, Pinatubo was a little known volcano and it had been dormant for 400 years. There were no known historic eruptions. Before the eruption in 1991 Pinatubo was 1745 m high (ca. 250 m more than now), and was only 200 m higher than the nearby peaks, which are remnants of older volcanic edifices of Mt Pinatubo and hid it from views from distance.