heating up

Cold spells and global warming

February 10, 2025 By EarthWise Leave a Comment

January saw some major bouts of subfreezing temperatures across much of North America and significant snowfall in places like Pensacola, Florida and New Orleans. This spate of frigid weather undoubtedly prompted many people to question whether global warming is really happening. But such cold spells quite likely are not happening in spite of global warming, but actually as a result of it.

The polar jet stream is a slim band of westerly winds that circles the Arctic. It is formed where cold air from the north meets warmer air to the south. As the planet warms, the Arctic has been heating up nearly four times faster than the rest of the planet, which narrows the difference in temperature between the northern air and southern air. The result is that the jet stream is weaker and more meandering, which allows frigid air to reach further south.

The polar vortex is a whirling mass of cold air that extends across the Arctic. It is stronger in the winter when the Northern Hemisphere leans away from the sun. The polar jet stream normally holds on to the vortex and keeps it far to the north. But when the jet stream gets wobbly, this mass of cold air can break out and travel south, even to places like Florida, Louisiana, and Texas.

The planet as a whole is warming, and the Arctic is warming even faster. But there will still be plenty of ice, snow, and frigid air in the Arctic winter for decades to come. As the behavior of the polar jet stream gets increasingly erratic, there may well be more frequent episodes of plunging temperatures in areas unaccustomed to them.

**********

Web Links

Severe Cold Spells May Persist Because of Warming, Not in Spite of It

Photo, posted January 5, 2025, courtesy of Dermot O’Halloran via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Rivers And Climate Change | Earth Wise

October 11, 2023 By EarthWise Leave a Comment

Our planet is heating up. Scientists have concluded that the changing climate is primarily the result of increased greenhouse gas emissions from human activities. Some of the effects of global climate change include thawing permafrost, rising seas, intensifying storms and wildfires, and warming oceans.

According to a new study led by researchers from Penn State University, rivers are warming and losing oxygen even faster than oceans. The study, which was recently published in the journal Nature Climate Change, found that warming occurred in 87% and oxygen loss occurred in 70% of the nearly 800 rivers studied.

The research team projects that within the next 70 years some river systems, especially those in the American South, will experience such low oxygen levels that the rivers could “induce acute death” for some fish species and threaten the aquatic diversity of river ecosystems.

The research team used artificial intelligence and deep learning to analyze water quality data from nearly 800 rivers across the U.S. and central Europe. The researchers found that rivers are warming up and deoxygenating faster than oceans, which could have serious implications for both aquatic life and humans.

While climate change has led to warming and oxygen loss in oceans and lakes around the world, the researchers did not expect to find warming and deoxygenation in shallower, flowing rivers. Since life in water depends on temperature and dissolved oxygen, the researchers hope this study serves as a wake up call. Warming and deoxygenating rivers have significant implications for water quality and the health of aquatic ecosystems worldwide.

**********

Web Links

Rivers are rapidly warming, losing oxygen; aquatic life at risk

Photo, posted June 2, 2017, courtesy of Francisco Anzola via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Even The Deep Sea Is Warming | Earth Wise

November 17, 2020 By EarthWise Leave a Comment

Approximately 75% of the area covered by ocean is deep, dark, and cold. This is known as the deep sea. But even in these remote regions of the planet things are heating up.

According to a new study published in the journal Geophysical Research Letters, researchers analyzed a decade of hourly temperature readings at four depths in the Atlantic Ocean’s Argentine Basin, off the coast of Uruguay. The research team selected recording depths that would best represent the average depth of the ocean, which is just over 12,000 feet.

The researchers found that deep sea temperatures fluctuate more than was previously known. They also detected a warming trend at the bottom of the ocean. In fact, all recordings indicated a warming trend of 0.02 to 0.04 degrees Celsius per decade between 2009 and 2019. This is a significant warming trend in the deep sea because temperature fluctuations are typically measured in thousandths of a degree.

Researchers say this increase is consistent with warming trends in the shallow ocean associated with anthropogenic climate change. However, they say more research is needed to better understand what is driving the warming temperatures in the deep sea.

A better understanding of what is driving these changes could have far-reaching implications. Since oceans absorb a significant amount of the world’s heat, learning about the oceans’ temperature trends could help researchers better understand temperature fluctuations in the atmosphere as well.

The researchers hope their findings will demonstrate the need to survey deep ocean temperatures annually in order to better identify the long-term trends.

**********

Web Links

The deep sea is slowly warming

Photo, posted July 1, 2018, courtesy of NOAA Ocean Exploration and Research via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Alien Waters Invade The Arctic

June 18, 2018 By EarthWise Leave a Comment

The Arctic is heating up faster than any other region of the planet. As a result, once-distinct boundaries between the frigid polar ocean and the warmer, neighboring Atlantic and Pacific Oceans are blurring, opening the way for the southern waters to enter the polar regions. The volume of Pacific Ocean water flowing into the Arctic Ocean through the Bering Strait has increased by 70% over the past decade. The Arctic Ocean’s cold layering system that blocks Atlantic inflows is breaking down.

2017 Was Hot

March 1, 2018 By EarthWise Leave a Comment

There’s no argument to be made about whether 2017 was hot or not. The only uncertainty is whether it was the second or third warmest year ever recorded.

[Read more…] about 2017 Was Hot