As the world braces for a third consecutive year of exceptional La Nia conditions, a new study reveals how our climate models might have missed this disaster.
It's the first time in a century that La Nia has stayed around for so long, and her wrath is being felt in southern Africa and South America, as well as in Australia and South-East Asia.
The Pacific Northwest will get a cool, wet winter and the Southwest will get a hot, dry one.
When it comes to our climate models, La Nia is not as well known as El Nio. When El Nio and La Nia conditions are present, the Pacific Ocean changes shape.
Strong trade winds push the surface layer of the Pacific Ocean west, dragging a layer of warm water like a finger. Near the Central American coast, deeper, cooler water rises to replace it.
The cool waters in the Pacific's east are trapped beneath a warm surface when El Nio occurs. There is less rain in Australia and more in the US Southeast. The trade winds expose more of the cool water. As a result, the jet stream high above gets pushed north, pushing rains that would normally fall in the south to the north.
Extreme events like El Nio and La Nia are expected to become more frequent due to global warming.
The show is being run by La Nia. Predicting the precise swing of the pendulum is taking some work while climate models accurately paint the big picture.
"The climate models are still getting reasonable answers for the average warming, but there's something about the regional variation, the spatial pattern of warming in the tropical oceans, that is off."
Researchers looked at El Nios and La Nias since 1979 and found a discrepancy between observations and models.
Reality could not be reproduced in the midlatitude oceans. One got very close.
The sea surface temperature appears to be on an incline. There is more cooling going on in the east Pacific and southern oceans.
The authors say that biased trends are a much more widespread problem in climate models.
Climate models can reproduce observed sea surface temperature trends, but there is something missing from the long-term picture.
The discrepancy can be explained by a ten-year swing in Pacific conditions. Two years ago, there were anomalies in the South Pacific.
It is possible that there is a natural variable in the southern ocean.
Maybe it's Climate change.
According to the researchers at the University of Washington, their findings have led them to conclude that the pattern of trend discrepancies is probably not caused by internal variability.
There are a number of reasons why the Southern Ocean might be cooling.
Sea ice melt and a shift in winds due to greenhouse gases are both options.
The changes will only last a short time. Researchers at the University of Washington argue that the east Pacific and southern oceans will warm eventually. They are more vulnerable to the effects of climate change than other areas.
Major changes in the Walker circulation and the associated large-scale circulation and precipitation patterns would be caused by a future shift toward a warming pattern.
We will be left with a huge source of uncertainty in multi-decadal projections of regional and global climate unless we can figure out why sea surface warming is so delayed in the east Pacific and Southern Ocean.
Scientists don't know when La Nia will end She could benefit from climate change for a long time.
There was a study published.
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