Drastic weather changes due to volcanic eruptions have long been documented by scientists. The air is cooled by the spew of particles from the eruptions blocking the solar energy. Some scientists believe that extended lengths of “volcanic winters” resulting from large eruptions were reason behind the extinction of Neanderthals and dinosaurs.

It is documented that frost resulting from Indonesia's 1815 Tambora eruption destroyed crops even in New England. The explosion of Philippines' Mount Pinatubo in 1991 resulted in decreasing the global temperatures by 0.7 degrees Fahrenheit. This is believed to be sufficient to camouflage the greenhouse gas effects for over a year. The recent study funded by the National Science Foundation (NSF)'s Division of Atmospheric and Geospace Sciences, scientists discovered that the eruptions also have effect on rainfall. The study was conducted over the Asian monsoon region as the seasonal storms in the region water crops consumed by nearly half the population of the world.

Gigantic eruptions affect most parts of Central Asia as much of the water tends to dry up. However, Tree-ring researchers at Columbia University's Lamont-Doherty Earth Observatory (LDEO) believe that the same eruptions are the result of increased rain for the Southeast Asian countries. Thailand, Vietnam, Cambodia, Laos and Myanmar receive extensive rainfall due to this very reason. The research conclusions are in direct conflict to many of the climate model’s prediction. The paper is published in the online version of the American Geophysical Union (AGU) journal Geophysical Research Letters.

Tree-ring researchers believe that the growth rings of some of the tree species can be directly correlated with the rainfall in the region. Tree rings procured from 300 sites across Asia were measured to understand the practical effects of 54 volcanic eruptions dating back nearly 800 years.

"We might think of the solid Earth and the atmosphere as two different things, but everything in the system is interconnected," said Kevin Anchukaitis, the paper's lead author. "Volcanoes can be important players in climate over time."

Till recently climate models incorporate the changes in the sun and the atmosphere to predict volcanic explosions and the disruption of the monsoon. This research however, found the opposite.

"The data only recently became available to test the models," said Rosanne D'Arrigo, one of the paper's co-authors. "There's a lot of work to be done to understand how all these different forces interact."

“Such studies should help scientists refine models of how natural and man-made forces might act together to shift weather patterns. A vital question for all areas of the world,” said Anchukaitis.

Published by Medicaldaily.com