We've heard much about Spaceship Earth in recent years—the growing realization that all of humanity is marooned on a relatively small hunk of rock surrounded by airless space. But only now is the general public beginning to realize that natural events in any part of this lonely planet may affect areas thousands of miles distant. Among such happenings with importance for the Chihuahuan Desert is El Niño, a phenomenon of the tropical Pacific Ocean that brings wet weather to the desert.
In non-El Niño times, trade winds pile up warm water in the
western Pacific, allowing cold water to well up along the western coast of South
America. In fact, at such times, the sea level in Indonesia is about one and a half
feet higher than at the coast of Ecuador in South America. Periodically, the trade
winds lessen, and the warm, western waters slosh eastward. Warmer water off of South
America means increased evaporation and significant changes in air circulation. The
result? More rain across southern North America, including our normally parched desert
region.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.