Here Comes the Rain...Again
March 18, 2005
It's raining again in Southern California, even though most of the west is having a drought. JPL oceanographer Dr. Bill Patzert studies the ocean's role in climate and has some opinions about these recent deluges and how they fit into the big climate picture. He approaches this wet season with characteristic dry wit.
Q: What's going on in the Pacific right now (image from Mar. 6)?
A: The latest Jason image shows a pool of higher-than-normal sea level, or warmer waters, centered at the Dateline in the mid-to west Pacific. Look at the red area at about 180 degrees west. But to the east, sea levels are lower, and the water is cooler, from the coast of Peru out to 150 degrees west. I'd call this situation neither an El Niño nor La Niña. It's la nada.
Q: What's causing all this rain?
A: Southern California is being battered by one low-pressure system after another. These storms start in the North Pacific. They break off from the polar jet stream and wander south. These storms are slow, they're wet and they're definitely cold.
Big rains from El Niños are usually much warmer. They normally hit the southwestern United States later in the season than these did and they come from the south and southwest. In contrast, this stuff is coming from the Gulf of Alaska.
Once again, it has been a mediocre year for surfing-that's another reason not to blame El Niño. El Niños are always a surfer's delight, dude.
We're getting Seattle's rain and we don't know exactly why. Mother Nature can be messy, and sometimes you just don't know all the answers. There is some good news, though. Southern Californian reservoirs and aquifers are brimming, giving us some relief from our six years of local drought.
Q: Does this mean the drought is over?
A: No, definitely not. The rainfall here is very local; most of the west is still locked in a multi-year drought. The big picture is that the drought is continuing.
Q: What is the ocean's role in climate?
A: The oceans are the memory of the climate system. Understanding these great heat reservoirs is a key to forecasting climate.
Media contact: Alan Buis (818) 354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Written by: Rosemary Sullivant
