Indo-Pacific Ocean warming is changing global rainfall patterns, say researchers

Posted: November 29, 2019 by oldbrew in climate, Clouds, Forecasting, modelling, Ocean dynamics, research, weather

It’s ‘according to a new study’ time again, as the Madden-Julian Oscillation (MJO) goes under the microscope. Another causes and effects puzzle.

New research by NOAA and a visiting scientist from India shows that warming of the Indo-Pacific Ocean is altering rainfall patterns from the tropics to the United States, contributing to declines in rainfall on the United States west and east coasts, reports

In a study published this week in the journal Nature, researchers report a doubling in the size of a warm pool of water spanning the western Pacific and eastern Indian Ocean in recent years.

This Indo-Pacific warm pool in what is already the warmest part of the global ocean is expanding each year by an area the size of California.

The expansion is changing a key weather and climate feature called the Madden-Julian Oscillation, which is characterized by a band of rain clouds that move over the tropical ocean from the Seychelles off Africa toward India and into the Pacific Ocean, influencing everything from monsoons in India to heat waves and flooding in the United States.

Warming ocean driving change in key climate pattern

The changes in the behavior of the MJO have brought a decline in rainfall to the central Pacific, the west and east coasts of the United States, north India, east Africa and the Yangtze basin in China.

These same changes are causing an increase in rainfall over northern Australia, the Amazon basin, southwest Africa and Southeast Asia, researchers conclude.

“NOAA is part of coordinated international efforts to extend the range of accurate weather forecasts out to lead times of two to four weeks and the MJO is one of the most important keys to the success of this enterprise,” said Michael McPhaden, a senior scientist at NOAA’s Pacific Marine Environmental Lab and co-author of the study.

“Our research provides a critical benchmark for determining which computer models to trust for extended range weather forecasting, based on their ability to simulate the observed behavior of the MJO in changing the climate.”

Though the entire Indo-Pacific Ocean has warmed, the warmest waters are over the west Pacific, creating a temperature contrast that drives moisture from the Indian Ocean to the west, enhancing cloud formation. This has changed the life cycle of the MJO. The length of time these clouds linger over the Indian Ocean has shrunk by four days from an average of 19 to 15 days.

Over the west Pacific, the clouds now reside five more days. It is this change in the residence of MJO-driven clouds that is altering weather patterns around the globe, researchers found.

Full article here.
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  1. oldbrew says:

    Our regular contributor and climate expert Ian Wilson has been looking closely at the MJO recently.

  2. […] über Indo-Pacific Ocean warming is changing global rainfall patterns, say researchers — Tallbloke&#8217… […]

  3. hunterson7 says:

    And if we worship St. Greta and give up our lives, it will have exactly how much influence in this weather driving system?

  4. Phoenix44 says:

    Once again, a nonsense paper that assumes the changes and thus effects start with warming caused by humans. Yet what this paper shows is that the MJO affects all sorts of stuff…which then MUST affect all sorts of other stuff…which affects yet more stuff…and ever-onwards, all the way back to the original pool of warm water. Hmm, so which is the “cause”?

    That’s the thing with complex, non-linear systems. A smallish change in the condition of one thing can have knock-on effects that change most or all of the system everywhere in a way that makes it impossible to determine the original cause – or even if there was one.

  5. As I said in a post a few down one should not believe anything BOM says. They push the climate scam and have adjusted past temperatures down and more recent ones up. They have dropped stations some of which had 100 years of data and have switched to stations at airports. The instruments are badly located and they allow one second temperature surges (as the exhaust of a jet) when they should be averaging of over several minutes as in USA.
    This site has posters of rainfall (annual), wet and dry periods and cyclone directions. In the posters it is evident that there are cyclical periods. There has been no change in rainfall pattern. I live in SE Qld, if anything there has been a slight increase in annual rainfall since the severe federation drought starting around 1900 although records are not available for rainfall prior to around 1895 when there were some records of cyclonic activity, heavy rainfall and flooding.
    While MJO may have some influence I feel that the long record of SOI and IPO shown in the posters is more useful. I have seen swings in daily SOI figures related to tides at Darwin and hence the position of the moon.I would think that position of the moon around the Earth, position of the Earth around the sun and the alignment of the planets particularly Jupiter as used by some long range forecasters would be more useful.

  6. Gamecock says:

    Climate is the generalized weather of an area or region.

    It is a result; it cannot be a cause.

  7. oldbrew says:

    Indeed. We’re told…

    ‘Warming ocean driving change in key climate pattern’ AND

    ‘This Indo-Pacific warm pool in what is already the warmest part of the global ocean is expanding each year by an area the size of California.

    The expansion is changing a key weather and climate feature called the Madden-Julian Oscillation’
    – – –
    Are they suggesting warming is causing warming – which leads to more warming?

    It still looks like the main warming was in the last two decades of the 20th Century.

  8. cognog2 says:

    I suspect the original warming of the pool could well be due to volcanic/tectonic activity. A pretty active area. But if it is not CO2 then these things get ignored and everything goes off at a tangent.

  9. ivan says:

    I doubt that any of the conclusions can be acceptable because it is all based on model simulations. Since we know they can’t model the atmosphere with any success, why should this be any different especially when they are trying to fit CO2 into it as the culprit.

  10. stpaulchuck says:

    “Super duper excessive heating will kill us all!!”
    “Now give me the money so I can save you.”


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