TheConversation

Weather forecasters talk about wind shear a lot during hurricane season, but what exactly is it? I teach meteorology at Georgia Tech, in a part of the country that pays close attention to the Atlantic hurricane season. Here’s a quick look at one of the key forces that can determine whether a storm will become a destructive hurricane. What is wind shear? Wind shear is defined as the change in wind speed, wind direction, or both, over some distance. You may have heard airplane pilots talk about turbulence and warn passengers that they’re in for a bumpy ride. They’re typically seeing signs of sudden changes in wind speed or wind direction directly ahead, and wind shear can sometimes cause this. With hurricanes, the focus is usually on vertical wind shear, or how wind changes in speed and direction with height. The effects of wind shear when wind speed increases with height (left) or changes direction (right)....

One of the big contributors to the record-breaking global temperatures over the past year – El Niño – is now gone, and its opposite, La Niña, is on the way. Whether that’s a relief or not depends in part on where you live. Above-normal temperatures are still forecast across the U.S. in summer 2024. And if you live along the U.S. Atlantic or Gulf coasts, La Niña can contribute to the worst possible combination of climate conditions for fueling hurricanes. Pedro DiNezio, an atmosphere and ocean scientist at the University of Colorado who studies El Niño and La Niña, explains why and what’s ahead. What is La Niña? La Niña and El Niño are the two extremes of a recurring climate pattern that can affect weather around the world. Forecasters know La Niña has arrived when temperatures in the eastern Pacific Ocean along the equator west of South America cool by at least half a degree Celsius (0.9 Fahrenheit) below no...

In June 2019, then-presidential candidate Joe Biden tweeted: “Trump doesn’t get the basics. He thinks his tariffs are being paid by China. Any freshman econ student could tell you that the American people are paying his tariffs.” Fast-forward five years to May 2024, and President Biden has announced a hike in tariffs on a variety of Chinese imports, including a 100% tariff that would significantly increase the price of Chinese-made electric vehicles. For a nation committed to reducing greenhouse gas emissions, efforts by the U.S. to block low-cost EVs might seem counterproductive. At a price of around US$12,000, Chinese automaker BYD’s Seagull electric car could quickly expand EV sales if it landed at that price in the U.S., where the cheapest new electric cars cost nearly three times more. As an expert in global supply chains, however, I believe the Biden tariffs can succeed in giving the U.S. EV industry room to grow. Without the tariffs, U.S. auto sa...

Bat populations in Colorado may be headed for a decline that could cause ecological disruptions across the state. Two bats discovered in Boulder County in late February 2024 were confirmed to have white-nose syndrome, a deadly fungal disease. Additional bats in Larimer County also tested positive for white-nose syndrome early this spring. The first North American bats with white fungus on their faces, ears and wings were discovered in 2006 in caves where they hibernated near Albany, New York. The fungus causes bats to lose nutrients and moisture through their skin and to wake early from hibernation in search of food and water. The disease spread west quickly, reaching Washington state in 2015 and California four years later. It was confirmed in Montana and New Mexico by 2021. Evidence of the fungus was first reported in Colorado in the summer of 2022. I’m a bat biologist, and most of my research has focused on the genetics of Myotis bats. Knowing which bat populations a...

It’s become common to read that microplastics – little bits of plastic, smaller than a pencil eraser – are turning up everywhere and in everything, including the ocean, farmland, food and human bodies. Now a new term is gaining attention: nanoplastics. These particles are even tinier than microplastics – so small that they’re invisible to the naked eye. Nanoplastics are a type of microplastic, distinguished by their extremely small size. Microplastics are usually less than 5 millimeters across; nanoplastics are between 1 and 1,000 nanometers across. For comparison, an average human hair is roughly 80,000-100,000 nanometers wide. Nanoplastics are attracting growing concern thanks to recent technological advances that have made researchers more able to detect and analyze them. Their smaller size means that they are more easily transported over long distances and into more diverse environments than microplastics. They can more easily penetrate cells a...