what happen to the climate when the suns rays are blocked from reaching the earth after a volcanic eruption?

Answer 1

When a volcano erupts it throws out large volumes of sulphur dioxide (SO2), water vapour, dust, and ash into the atmosphere. Although the volcanic activity may last only a few days, yet the large volumes of gases and ash can influence climatic patterns for years. Millions of tonnes of sulphur dioxide gas can reach the upper levels of the atmosphere (called the stratosphere) from a major eruption. The gases and dust particles partially block the incoming rays of the sun, leading to cooling. Sulphur dioxide combines with water to form tiny droplets of sulphuric acid. These droplets are so small that many of them can stay aloft for several years. They are efficient reflectors of sunlight, and screen the ground from some of the energy that it would ordinarily receive from the sun. Winds in the upper levels of the atmopshere, called the stratosphere, carry the aerosols rapidly around the globe in either an easterly or westerly direction. Movement of aerosols north and south is always much slower. This should give you some idea of the ways by which cooling can be brought about for a few years after a major volcanic eruption.

Answer 2

apparently after a volcanic eruption, the sky will be dark showing that the sun's rays are already blocked.as a result, there might be some irregularities in the climate (the time of changing seasons etc,,,) this is because the sun's rays directly affects the temperature of the atmosphere.

Answer 3

From Discovery Channel:
"During the summer of 1816, unexpected climate changes left countries in the Northern Hemisphere suffering from devastating famine and epidemic outbreaks. These weather patterns were the result of the volcanic eruption of Mount Tambora in Sumbawa, Indonesia, on 10th April 1815.

Over the following year, heavy ash-fall filled the air across the globe, preventing sunrays from reaching the earth. The resulting frost and rains devastated crops and caused the “Year without Summer”.

The death toll outside Indonesia ran into hundreds of thousands. With the 117,000 victims who died in the original cataclysm in Indonesia, this was one of the deadliest disasters in history."

From Wikipedia:
"The unusual climatic aberrations of 1816 had the greatest effect on the American northeast, New England, the Canadian Maritimes, Newfoundland, and northern Europe. Typically, the late spring and summer of the northeastern U.S. are relatively stable: temperatures (average of both day and night) average about 68–77 °F (20–25 °C), and rarely fall below 41 °F (5 °C). Summer snow is an extreme rarity, though May flurries sometimes occur.

In May 1816,[4] however, frost killed off most of the crops that had been planted, and in June two large snowstorms in eastern Canada and New England resulted in many human deaths. Nearly a foot of snow was observed in Quebec City in early June, with consequent additional loss of crops—most summer growing plants have cell walls which rupture in a mild frost, let alone a snowstorm coating the soils. The result was widespread localized famines, and further deaths from those who, in a hunger-weakened state, then suffered disease as well in their less resistant condition.

In July and August, lake and river ice were observed as far south as Pennsylvania. Rapid, dramatic temperature swings were common, with temperatures sometimes reverting from normal or above-normal summer temperatures as high as 95 °F (35 °C) to near-freezing within hours. Even though farmers south of New England did succeed in bringing some crops to maturity, maize (corn) and other grain prices rose dramatically. Oats, for example, rose from 12¢ a bushel the previous year to 92¢ a bushel—a nearly eightfold increase—and oats are a necessary staple for an economy dependent upon horses for primary transportation. Those areas suffering local crop failures then had to deal with the lack of roads in the early 19th century, preventing any easy importation of bulky food stuffs."

Similar, though not as severe climate changes were caused by the eruption of Krakatoa in 1883, Mt. St. Helens in 1980, and Mount Pinatubo in 1991