Environment

New research links rising global temperatures to more powerful summer storms, reduced air quality

New research links rising glob...
Rising global temperatures are causing energy shifts in Earth's atmosphere that are strengthening midlatitude storms and affecting air quality, according to new research
Rising global temperatures are causing energy shifts in Earth's atmosphere that are strengthening midlatitude storms and affecting air quality, according to new research
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Rising global temperatures are causing energy shifts in Earth's atmosphere that are strengthening midlatitude storms and affecting air quality, according to new research
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Rising global temperatures are causing energy shifts in Earth's atmosphere that are strengthening midlatitude storms and affecting air quality, according to new research

A new study out of MIT suggests rising global temperatures are causing energy shifts in Earth's atmosphere that are strengthening midlatitude storms, while weakening other important weather systems over North America, Europe and Asia.

Large storm systems called extratropical cyclones draw energy from processes related to Earth's horizontal temperature gradient – the difference in temperature between our planet's northern and southern latitudes. Larger differences in temperature normally result in stronger cyclones, while the reverse is true for slighter gradients.

These systems are created in regions poleward of Earth's tropical zones, and subsequently sweep over the midlatitude regions. While not as dramatic as tropical cyclones, they are responsible for swift changes in temperature and humidity, and are associated with a wide range of conditions, including rainfall and heavy gusts.

In recent decades, the Arctic has been warming faster than the rest of the Earth, which has effectively shortened the horizontal temperature gradient. The new study set out to discover what effect the Arctic warming might have had on atmospheric energy distribution and storm formation.

Using global temperature and humidity data collected by satellites and weather balloons starting from the 1970s, the researchers created a detailed grid showing these values at various atmospheric heights. They noted the average summertime temperature and humidity in regions between 20 degrees latitude and 80 degrees latitude for June, July and August in each year from 1979 – 2017. This information was then fed into an MIT developed algorithm capable of estimating the amount of energy at various points in the atmosphere that could be used for various weather events.

"We can see how this energy goes up and down over the years, and we can also separate how much energy is available for convection, which would manifest itself as thunderstorms for example, versus larger-scale circulations like extratropical cyclones," comments study co-author and Associate Professor Paul O'Gorman, of MIT's Department of Earth, Atmospheric and Planetary Sciences (EAPS).

The scientists discovered that the energy available to fuel large extratropical cyclones had diminished by as much as 6 percent since 1979. Conversely, the energy that drives more localized thunderstorms has risen by roughly 13 percent.

Alongside the destruction wreaked by powerful storms, the weakening of extratropical cyclones presents its own risks.

"Extratropical cyclones ventilate air and air pollution, so with weaker extratropical cyclones in the summer, you're looking at the potential for more poor air-quality days in urban areas," says graduate student at EAPS and study co-author, Charles Gertler. "Moving beyond air quality in cities, you have the potential for more destructive thunderstorms and more stagnant days with perhaps longer-lasting heat waves."

In future the researchers hope to fine tune the methodology so they can estimate how climate change could affect weather systems in specific regions.

The results of the study will be published this week in the Proceedings of the National Academy of Sciences.

Source: MIT

6 comments
Nobody
I'm not sure this article made any sense whatsoever.
aksdad
Not even the vaunted MIT can reasonably determine the energy to fuel extratropical cyclones nor the energy that drives localized thunderstorms with any precision whatsoever. It is not possible due to the extraordinarily chaotic nature of the constantly moving and changing air masses and ocean currents on earth. They also reveal a surprising lack of understanding of storm dynamics. But they're in good company. Virtually every climate scientist has assumed that heat alone determines the power of storms. What powers storms is the difference in temperature, not the total heat. Hot days under stable high pressure systems have no storms. Hot oceans alone don't produce cyclones. Only when there is a sharp temperature difference usually accompanied by a moisture difference do you get the instability that produces powerful storms.
ei3io
The polar arctic cap getting warmer causes the jet stream to wobble dropping lower in latitude at times from the lack of a deep cold pool that used to control contain it. This has jet streams stirring up the air currents that give us the temperature difference needed for more storms,,,
Cryptonoetic
Am I really supposed to believe that a global temperature increase (since 1979) of one-half a degree Celsius is causing a 13% increase in 'local' storm energy? Are tornadoes considered 'local' storms? If so, why were 2014 and 2018 the least active years for tornadoes? Then to argue that fewer strong hurricanes is a bad thing pretty much takes the cake.
Douglas Bennett Rogers
A "dry line", a boundary between low density, hot, humid air and high density cold, dense air is needed for strong storms. A dip in the jet stream promotes this but is not enough by itself. I suspect that intensive irrigation along the storm track promotes these storms.
Munoz-Nieves Jose
Subjectively I ca tell that something has changed. We don't have to take responsibility, we ca blame the God's, or what ever is needed so that we can begin to prepare. The unpreventabity of what is coming will eventually be a world emergency.