Scientists with the National Oceanic and Atmospheric Administration today confirmed what many had pretty much surmised: El Nino is back.

Officially the El Nino Southern Oscillation (ENSO), the cyclical pattern of ocean conditions has broad implications for weather and the Pacific food chain.

According to the NOAA news release:

“NOAA expects this El Niño to continue developing during the next several months, with further strengthening possible. The event is expected to last through winter 2009-10.”

NOAA’s Climate Prediction Center suggested about a month ago that conditions were right for the return of El Nino.

More recently, the high incidence of underweight sea lion pups turning up along the California coast was taken by some as a harbinger of ENSO. During El Nino cycles, normal upwelling of deep, cold water slows down, essentially shutting down the “food elevator” for many species.

Of course, there can be an upside. According to NOAA:

“El Niño’s impacts depend on a variety of factors, such as intensity and extent of ocean warming, and the time of year. Contrary to popular belief, not all effects are negative. On the positive side, El Niño can help to suppress Atlantic hurricane activity. In the United States, it typically brings beneficial winter precipitation to the arid Southwest, less wintry weather across the North, and a reduced risk of Florida wildfires.”

Links to climate change are less clear. Some scientists have suggested that warming air and sea temperatures might bring about more and longer El Nino events.