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Climate change and Antarctic meteorites

May 1, 2024 By EarthWise Leave a Comment

Researchers from Switzerland and Belgium have investigated the effects of the warming climate on access to meteorites in Antarctica. Meteorites are of great scientific interest because they provide unique information about the makeup of our solar system. Of all the meteorites that people have found, 62.6% of them were found in Antarctica.

Why is this? It is not because more meteorites land in Antarctica. Statistically, they can land anywhere on earth. Most end up in the ocean since the world’s oceans cover 70% of the planet.

Meteorites in Antarctica are more visible because environmental conditions are favorable for their preservation and their visibility. The arid and cold Antarctic environment helps to preserve meteorites and the lack of rocks and contrast with ice makes spotting meteorites much easier. The flow of ice sheets tends to concentrate meteorites in so-called meteorite stranding zones where the dark colored space rocks can be easily detected.

There are an estimated 300,000 to 800,000 meteorites in Antarctica. When meteorites warm up, they can transfer heat to the ice, which locally melts. Eventually, the meteorites sink beneath the surface. A recent study using satellite imagery, climate model projections, and AI predicts that for every tenth of a degree of increase in global air temperature, an average of 9,000 meteorites in Antarctica will disappear from the surface and will no longer be able to be found.

The study estimates that a quarter of Antarctic meteorites will be lost to glacial melt by 2050. If warming continues to accelerate, closer to three-quarters of the meteorites on the continent will be lost.

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Climate change threatens Antarctic meteorites

Photo, posted April 21, 2005, courtesy of Kevin Walsh via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Wildfires And Air Quality | Earth Wise

October 26, 2023 By EarthWise Leave a Comment

People in the Northeast have been dealing with unhealthy air quality in recent times because of smoke from hundreds of wildfires in Canada. Canada has experienced a much higher than average incidence of blazes this year with nearly 500 fires burning uncontrolled at times.

It turns out that states far away from Canada aren’t necessarily free from the impact of the fires. Early in October, smoke from a wildfire burning in Quebec made its way south all the way down to Florida and created unhealthy air quality and reduced visibility across much of the state. Smoke from the same fire had created hazy air in Boston, New York City, and parts of Connecticut before heading south.

It took a rather unusual set of atmospheric conditions to make this happen. The smoke drifted from Canada into the western Atlantic. From there, it got trapped behind a cold front and was then pushed south along the east coast until it finally moved inland across Florida.

Wildfires produce a variety of particles and gases from the burning of vegetation such as organic carbon, black carbon, nitrogen oxides, carbon monoxide and hazardous air pollutants. The mixture of particles and gases in wildfire smoke is associated with respiratory symptoms like shortness of breath and reduced lung function, as well as dangerous cardiovascular effects.

Smoke from increasingly frequent and increasingly large fires has started to undo decades of gains in air quality brought about by air pollution policies. According to researchers, wildfires in the United States in recent years have undone about 25% of past progress in cleaning up air pollution in states from coast to coast.

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Wildfire Smoke From Canada Creates Unhealthy Air Quality in Florida

Photo, posted June 8, 2023, courtesy of Anthony Quintano via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Lockdown Cleans Up Indian Air | Earth Wise

May 13, 2020 By EarthWise Leave a Comment

Our stories often discuss how human activities change the natural environment. With most of us confined to our homes, the lack of human activities is having profound effects on the environment. We are talking about some of these this week.

India suffers from some of the worst air pollution in the world. Of the most polluted cities in the world, 21 out of 30 were in India in 2019. According to World Health Organization standards, at least 140 million people in India breathe air containing 10 times or more greater levels than the safe limit for pollutants. Air pollution contributes to the premature death of 2 million Indians every year.

Half of India’s air pollution comes from industry, 27% from vehicles, and 17% from crop burning. Crop burning is prevalent because it is much cheaper than mechanical tilling after the harvest.

On March 25, the Indian government placed its 1.3 billion citizens under a strict lockdown to reduce the spread of COVID-19. The country-wide mandate decreased activity at factories and drastically reduced car, bus, truck, and airplane traffic.

Within one week, NASA satellite sensor observed aerosol levels at a 20-year low for this time of year in northern India. Aerosols are tiny solid and liquid particles suspended in the air that reduce visibility and can damage the human lungs and heart. Some aerosols have natural sources, such as dust storms, volcanic eruptions, and forest fires. But many come from human activities such as the burning of fossil fuels and croplands. Scientists expected to see changes in atmospheric conditions during the Indian lockdown, but the current changes are dramatic. They also present a unique opportunity to separate how natural and human sources of aerosols affect the atmosphere.

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Airborne Particle Levels Plummet in Northern India

Photo, posted April 29, 2020, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fish And Their Sense Of Smell

September 4, 2018 By EarthWise Leave a Comment

We use our sense of smell for all sorts of things, like locating food and habitat, avoiding danger, and so on. Fish do as well. But instead of smelling scent molecules in the air like humans do, fish use their nostrils to sense chemicals suspended in water.

The Delhi Air Pollution Crisis

December 12, 2017 By EarthWise Leave a Comment

Delhi, the capital city of India, has always been a city bursting at the seams. With over 19 million people, heavy industry, growing numbers of vehicles, and choking amounts of road dust, Delhi suffers from some of the worst air pollution in the world. It is a situation the country has been struggling with for years.