Public Release: 27-Dec-2018
The Madden-Julian Oscillation’s precipitation variations are likely to increase in intensity under a warmer climate, while wind variations are likely to increase at a slower rate
Colorado State University
Every month or two, a massive pulse of clouds, rainfall and wind moves eastward around the Earth near the equator, providing the tropics their famous thunderstorms.
This band of recurring weather, first described by scientists in 1971, is called the Madden-Julian Oscillation. It has profound effects on weather in distant places, including the United States. Atmospheric scientists have long studied how the Madden-Julian Oscillation modulates extreme weather events across the globe, from hurricanes to floods to droughts.
As human activities cause the Earth’s temperature to increase, reliable, well-studied weather patterns like the Madden-Julian Oscillation will change too, say researchers at Colorado State University.
Eric Maloney, professor in the Department of Atmospheric Science, has led a new study published in Nature Climate Change that attributes future changes in the behavior of the Madden-Julian Oscillation to anthropogenic global warming. Maloney and co-authors used data from six existing climate models to synthesize current views of such changes projected for the years 2080-2100.
Their analysis reveals that while the Madden-Julian Oscillation’s precipitation variations are likely to increase in intensity under a warmer climate, wind variations are likely to increase at a slower rate, or even decrease. That’s in contrast to the conventional wisdom of a warming climate producing a more intense Madden-Julian Oscillation, and thus an across-the-board increase in extreme weather.
“In just looking at precipitation changes, the Madden-Julian Oscillation is supposed to increase in strength in a future climate,” Maloney said. “But one of the interesting things from our study is that we don’t think this can be generalized to wind as well.”
Atmospheric science relies on weather patterns like the Madden-Julian Oscillation to inform weather prediction in other areas of Earth. For example, atmospheric rivers, which are plumes of high atmospheric water vapor that can cause severe flooding on the U.S. west coast, are strongly modulated by certain phases of the Madden-Julian Oscillation.
According to Maloney’s work, the Madden-Julian Oscillation’s impact on remote areas may gradually decrease. Degradation in the oscillation’s wind signal may thus diminish meteorologists’ ability to predict extreme weather events. In particular, preferential warming of the upper troposphere in a future, warmer climate is expected to reduce the strength of the Madden-Julian Oscillation circulation.
Maloney and colleagues hope to continue studying the Madden-Julian Oscillation using a broader set of climate models to be used in the next Intergovernmental Panel on Climate Change assessment.
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Co-authors of the Nature Climate Change study are Ángel Adames of the University of Michigan and Hien Bui, a CSU atmospheric science postdoctoral researcher.
Link to paper: https://col.st/ine8t
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I am making real-time predictions about the lunar influence upon Madden Julian Oscillations (MJOs) right now at the astroclimateconnection blogspot web-site! So far, my predictions have been 100 % correct.
MJOs can be thought of as a complex atmospheric wave that moves from west-to-east along the equator. It is most evident when it couples with atmospheric convection/precipitation between East Africa and the Solomon Islands. It consists of an active region of enhanced precipitation/uplift followed by a region of suppressed precipitation
The slow-moving complex MJO wave can be thought of as a combination of an easterly moving Kelvin-wave and a westerly moving equatorial Rossby wave. The MJO wave complex moves with a group velocity of about 5 m/sec from west-to-east. Within the large MJO wave complex, Kelvin waves move from west-to-east with a phase velocity of 15 to 20 m/sec, and the equatorial Rossby Waves travel from east-to-west at roughly 5 m/sec.
I propose that the westward-moving Rossby-waves are generated in the active region of the MJO every time lunar-induced changes in the Earth’s rotation rate occur over the monthly cycle (i.e. roughly once every 6 – 7 days). These changes in the Earth’s rotation speed occur every time the Moon either crosses the equator or reaches lunar stand-still (i.e. when the Moon is at its maximum distance from the Equator). The westerly moving Rossby waves are visible as paired low-pressure cells that straddle the Equator.
In addition, I propose that the easterly moving Kelvin-waves that are embedded within the MJO wave complex are produced by the relative timing between the thunderstorm activity that peaks during the mid-afternoon (around 3:00 p.m.) in the MJO’s active region and the daily lunar tidal peak that arrives roughly 48 minutes later each afternoon. I think that the difference in timing between these two phenomena produces a disturbance that propagates towards the east at a speed of 15 to 20 m/sec – which just happens to match the speed of the Kelvin waves.
My collaborator and I are currently submitting a paper that shows that lunar influence upon the MJO leads to the initiation of moderate to strong El Nino events roughly once every 4 to 5 years.
To date, an increase in the frequency and severity of weather events as a function of global warming has not been detected. What has actually happened invalidates their theory.
The Madden-Julian Oscillation’s precipitation variations are likely to increase in intensity under a warmer climate
How does a variation change in intensity?!
What does that even mean, if anything?
Variations or oscillations have amplitude, and frequency and wavelength.
But not “intensity”.
Are they even trying to make sense?