The usual water level of Lake Powell on the Colorado River behind Glen Canyon Dam is marked by the white areas; the lake is less than half full due to the recent drought. Photo credit: Gabriel Gruionu

Experts at the Climate Modeling Group at the Lamont-Doherty Earth Observatory (LDEO), part of The Earth Institute at Columbia University, expect drought to worsen in the Plains and the West over the next several years due to La Niña-like conditions. LDEO's "Persistent Drought in North America" Web site provides an in-depth examination of drought in this region.

Using observations and models, LDEO scientists learned that all the major dry and wet events in the American West in the last century and a half were forced by slowing varying tropical Pacific sea surface temperatures (SSTs). On the Web site, Climate Modeling Group scientists show that decadal variations of these SSTs are predictable to a modest degree a few years in advance.

The group’s research on whether rising greenhouse gases will induce an El Niño-like (causing increased precipitation over the American West) or La Niña-like (causing less precipitation over the American West) response in the tropical Pacific Ocean provides additional insight on whether the American West is entering a more drought-prone period than any seen since European settlement.

The Climate Modeling Group plans to continue its research, including examining the causes of the severe droughts that occurred during the 12th and 13th centuries.

visit "Persistent Drought in North America" website