As storms pound drought-stricken California, what is El Ni帽o anyway?
Forecasters have predicted rain over parched California over the next two weeks, thanks to El Ni帽o storms.
The El Ni帽o effect brings warmer ocean temperatures and increased rainfall to the West coast of the Americas for many months. These episodes can be irregular, occurring every two to seven years for nine to 12 months, sometimes stretching on for years.
So what drives these shifting weather patterns across the Pacific Ocean?
Globally, ocean temperatures . Over warmer sections of the ocean, more clouds form and more rain falls in that region.聽
Especially near the equator, the sun heats up sea surface temperatures. Most of the time, the Pacific trade winds push that warm water away from Central and South America toward Indonesia. Cold water from the depths of the ocean rises into that warm water's place, bringing drier weather to the Americas.
But when that wind weakens or changes direction, usually in the fall or winter, the water along the west coast of the Americas gets warmer again. That is El Ni帽o.
El Ni帽o has a counterpart, La Ni帽a. Together, they form the , or ENSO. El Ni帽o is the warm phase, while La Ni帽a appears as its cold opposite.
The current El Ni帽o is predicted to soak the west coast, bringing hope of relief from the region's four-year drought.聽
Bill Patzert, climatologist with NASA鈥檚 Jet Propulsion Laboratory in La Ca帽ada Flintridge, Calif., told the Los Angeles Times, 鈥淚鈥檓 quite optimistic that the entire state is going to ."
But such a downpour could shock the parched California dirt, leading to mudslides and flooding.聽And Dr. Patzert says it's unlikely that El Ni帽o will deliver enough of a punch to knock out California's drought.聽
"Over a 25-year period, over the long term, El Ni帽o provides only 7% of our water. So as much as we鈥檙e hyping it, it鈥檚 not a big player," Patzert said. "It鈥檚 fast and furious, but it鈥檚 too irregular 鈥� the gap between El Ni帽os is too long to build any statues to El Ni帽o to be a drought-buster."聽
Still, any rain , as groundwater, reservoirs, and snowpack are dwindling.聽
El Ni帽o was named by South American fishermen in the 1600s. When unusually warm water appeared where they were fishing in the ocean, they noticed many of the fish disappear or move. The name means The Little Boy or Christ Child, in Spanish, named for proximity to Christmas.
