Read at :
Rainfall in South Pacific Was More Variable Before 20th Century
Sep. 9, 2013 — A new reconstruction of climate in the South Pacific during the past 446 years shows rainfall varied much more dramatically before the start of the 20th century than after. The finding, based on an analysis of a cave formation called a stalagmite from the island nation of Vanuatu, could force climate modelers to adjust their models. The models are adjusted to match the current levels of climate variability that are smaller now than they were in the recent past for this region.
“In this case, the present is not the key to the past, nor the future,” says Jud Partin, a research scientist associate at The University of Texas at Austin’s Institute for Geophysics who led the study. The institute is part of the Jackson School of Geosciences. “Instead, the past is the key to what may happen in the future.”
The researchers also discovered a roughly 50 year cycle of rainfall in Vanuatu, toggling between wet and dry periods. Vanuatu lies within the largest rain band in the southern hemisphere, the South Pacific Convergence Zone and its rainy season is from November to April. In the 20th century, rainfall during wet periods was about 7 feet per rainy season and during dry periods about 4 ½ feet per rainy season.