[1] New El Niño Heading For An Ocean Near You
El Niño conditions are returning to the equatorial Pacific and waters are expected to continue warming for some months to come, NOAA scientists announced last week.
Already, sea surface temperatures are more than 1 degree C above average in some areas. But a July 9 statement from NOAA's Climate Prediction Center said model forecasts didn't agree over how strong the warming trend will be.
"Current and recent trends," it said, "favor the continued development of a weak-to-moderate strength El Niño into the Northern Hemisphere in Fall 2009, with further strengthening possible thereafter."
The warming episode means that July-September precipitation is expected to be above average over the central and west-central Pacific, with drier conditions over Indonesia.
Closer to home, NOAA expects little change in U.S. precipitation and temperature levels during the summer and early fall, but more precipitation and warmer weather is expected for late fall and the coming winter.
A NOAA press release pointed out that El Niño impacts may include positives like reducing hurricane activity in the Atlantic and providing more rain to the arid Southwest.
But an El Niño also increases the probability of strong winter storms in California and across the southern U.S., and warming of the Pacific Ocean, which hurts salmon productivity.
Off the West Coast, the extra-cold ocean water of the past couple of years that has boosted salmon survival has subsided. Now, much of the near ocean is showing average sea surface temperatures for this time of year.
NOAA Fisheries ocean researcher Bill Petersen, who is based in Newport, Ore., said it is difficult to know just what effects the new El Niño will have in the North Pacific.
"It's a little scary," he said.
But so far, relatively good conditions for salmon still exist offshore, even though the lack of northerly winds in June led to little upwelling. Upwelling conditions help boost biological productivity by bringing up nutrients from deep waters that trigger plankton blooms and start the food chain rattling every spring.
Petersen said the kinds of plankton normally found in northern waters, the best chow for young salmon, are still showing up off the Pacific coast.
"Things are holding together," Petersen told NW Fishletter, though the June survey cruise by NOAA scientists turned up only average to above-average numbers of young salmonids in nearby waters. In May, they saw higher numbers than ever before.
Petersen said ocean conditions are definitely less productive than last year, but with the North Pacific in a strongly negative PDO [Pacific Decadal Oscillation] phase, El Niños tend to be a lot less powerful. He said it may only amount to a "little downturn" in the good conditions of the past several years.
"We still expect a big chinook run next year," Petersen said.
The region should get used to fairly sudden changes in ocean regimes, Petersen said, because they are happening more often, and it's likely a result of climate change.
NOAA scientist Ed Casillas said the latest trawl survey also turned up high numbers of juvenile coho and sockeye. He said the NMFS system for describing ocean indicators has been downgraded a little, from mostly green last year, to between yellow and green.
NOAA's El Niño forecast was seconded by Australia's Bureau of Meteorology, which said conditions had reached such a point in the equatorial Pacific, that should they persist for the next four months, they would consider 2009 an El Niño year.
The Aussies said climate models showed little chance that the warming would stall or reverse, noting some sub-surface sea water temperatures were up to 4 degrees C above average, with a large volume of warmer-than-normal subsurface water evident across the equatorial Pacific. -B. R.
The following links were mentioned in this story:
July 9, 2009, Climate Prediction Center, NOAA
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