Thunderstorms spread mercury pollution

August 31, 2016 by Kathleen Haughney, Florida State University
Credit: Florida State University

In the southern United States, an afternoon thunderstorm is part of a regular summer day. But new research shows those storms might be doing more than bringing some scary thunder and lightning.

In fact, these storms are moving significant amounts of to the ground.

In a new study published in the journal Environmental Science and Technology, Assistant Professor of Meteorology Christopher Holmes writes that thunderstorms have 50 percent higher concentrations of mercury than other rain events.

"The mercury is being transported into our region by winds, and tall thunderstorms are bringing it down to the earth," Holmes said.

Holmes and a team of researchers collected rain in a variety of locations in Florida, as well as Vermont, Georgia and Wisconsin. They then matched it to weather data that told them whether it was from a thunderstorm or just rain. They also used radar and satellite data to examine storm clouds.

In a regular rainstorm, clouds are only a few kilometers thick. In a thunderstorm, they reach about 15 kilometers thick. Researchers found that more mercury was in rain from the clouds that reached the highest altitudes.

"The highest concentrations occurred during thunderstorms and the lowest during a regular rainstorm," Holmes said.

For the last 20 years, the Mercury Deposition Network has recorded of precipitation across the United States. During this period, the states bordering the Gulf of Mexico have consistently seen the highest mercury deposition in the eastern U.S., typically double that of the northeast states.

Typically, the Southeast sees a high number of thunderstorms in the summer months. Holmes and his colleagues believe that this is the reason the Southeast has higher levels of mercury in rain.

Mercury is a naturally occurring chemical element that is used in several devices such as thermometers, barometers, fluorescent lamps and other devices. Exposure to high levels of mercury can be dangerous though.

Holmes said now that researchers know that the storms are spreading the mercury, they need to understand why there are high amounts of mercury at these higher altitudes and how it affects the Earth.

"We're trying to understand how mercury enters ecosystems in the U.S. and how it can affect people and wildlife," Holmes said.

Explore further: How mercury contamination affects reptiles in the Amazon basin

More information: Christopher D. Holmes et al. Thunderstorms Increase Mercury Wet Deposition, Environmental Science & Technology (2016). DOI: 10.1021/acs.est.6b02586

Related Stories

How mercury contamination affects reptiles in the Amazon basin

September 21, 2015

Mercury contamination in water and on land is of worldwide concern due to its toxic effects on ecosystems and human health. Mercury toxicity is of particular concern to reptiles because they are currently experiencing population ...

Alaska's shorebirds exposed to mercury

July 13, 2016

Shorebirds breeding in Alaska are being exposed to mercury at levels that could put their populations at risk, according to new research from The Condor: Ornithological Applications.

NASA image: Mercury solar transit

May 10, 2016

The planet Mercury is seen in silhouette, lower third of image, as it transits across the face of the sun Monday, May 9, 2016, as viewed from Boyertown, Pennsylvania.

Recommended for you

The powerful meteor that no one saw (except satellites)

March 19, 2019

At precisely 11:48 am on December 18, 2018, a large space rock heading straight for Earth at a speed of 19 miles per second exploded into a vast ball of fire as it entered the atmosphere, 15.9 miles above the Bering Sea.

OSIRIS-REx reveals asteroid Bennu has big surprises

March 19, 2019

A NASA spacecraft that will return a sample of a near-Earth asteroid named Bennu to Earth in 2023 made the first-ever close-up observations of particle plumes erupting from an asteroid's surface. Bennu also revealed itself ...

Nanoscale Lamb wave-driven motors in nonliquid environments

March 19, 2019

Light driven movement is challenging in nonliquid environments as micro-sized objects can experience strong dry adhesion to contact surfaces and resist movement. In a recent study, Jinsheng Lu and co-workers at the College ...

Revealing the rules behind virus scaffold construction

March 19, 2019

A team of researchers including Northwestern Engineering faculty has expanded the understanding of how virus shells self-assemble, an important step toward developing techniques that use viruses as vehicles to deliver targeted ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.