Strengthening La Nina means more climate dangers for pacific countries

For countries surrounding the Pacific, the El Nino Southern Oscillation (ENSO) is closely watched each year, in order to predict the season’s predominant weather patterns. Over the last few weeks the oscillation has strengthened towards a La Nina event, similar to last year. La Nina events generally cause dry weather in the southern United States and stormy weather in the Pacific Northwest during winter and spring.

Sea surface height measurements from the pacific, which are used to indicate water temperature, are showing warm water in the west and cooler waters in the east. The temperature of the water helps to create and intensify certain weather patterns.

Bill Patzert of JPL says, "Conditions are ripe for a stormy, wet winter iStrengthening La Nina means more climate dangers for pacific countriesStrengthening La Nina means more climate dangers for pacific countriesn the Pacific Northwest and a dry, relatively rainless winter in Southern California, the Southwest and the southern tier of the United States." This is particularly a problem for the US as it has suffered a spate of dry weather in recent years, and along with abstraction from rivers has created a severe water shortage. There have also been widespread wildfires in the southwest as a result of the dry conditions.

La Nina’s can be positive events for other regions of the pacific however. On the South American coast the event is indicative of good fishing conditions, as the cool, nutrient rich deep Pacific waters well up close to the coast. Whilst elsewhere in the world, even beyond the Pacific Rim, the ENSO has been shown to have an effect on the climate.

The cause of ENSO is still not well understood and is the focus of many studies and satellite observations. It has been shown however, that a La Nina spell often follows a spell of El Nino conditions. Conditions in the pacific will now be closely monitored over the coming weeks by many weather satellites, as the changes in the sea can still intensify or dissipate the circulation.