Archives for category: Pollution

chesapeake_reference_map
Note: This is the first story of a multi-part series exploring the natural splendor and environmental issues of the Chesapeake Bay Watershed.
Read about the Bay headwaters here.

People who track water quality issues in the Chesapeake Bay are accustomed to bad news. But lately some glimmers of hope have begun to emerge amidst the polluted streams, dead zones, fish kills, and algae blooms.

In April 2016, the University of Maryland Center for Environmental Sciences published its annual Chesapeake Bay report card and found clearer water, lower levels of algae, and a resurgence of sea grasses. In the same month, the Maryland Department of Environment announced that it had mapped 53,000 acres of submerged aquatic vegetation—a record amount and a clear sign of the ecosystem’s improving health. In July 2016, the Maryland Department of Natural Resources reported that the size of the dead zone in the Bay in late June was the second smallest since 1985.

Other data sets also show progress. U.S. Geological Survey measurements of water quality in several rivers that flow into the Bay show improvements over the previous three decades. And the late-summer dead zone in the Bay seems to be shrinking, even as the early-summer dead zone remains stubbornly large.

“The big-picture trends are moving in the right direction,” said Mark Dubin, a University of Maryland Extension scientist who focuses on how agricultural practices affect water quality. “But this is a large and complex watershed. If you focus on certain areas and watersheds, we still see plenty of indicators going in the wrong direction, such as increasing urban growth and storm water runoff, and persistent areas of high soil phosphorus.”

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NASA Earth Observatory, August 2016

chesapeake_locator_map
Note: This is the first story of a multi-part series exploring the natural splendor and environmental issues of the Chesapeake Bay Watershed.
Read about farms and the Bay here.

In The Leatherstocking Tales, a series of historical novels set in the 18th century frontier of New York state, James Fenimore Cooper called Otsego Lake the Glimmerglass. He described “a bed of pure mountain atmosphere compressed into a setting of hills and woods.” It was a fitting description for the pristine, narrow lake which, despite some development around its shores, remains clean enough for swimming, for drinking, and for sheltering a wide array of fish. That’s not the case for every body of water in the Chesapeake Bay watershed.

After pooling in the Glimmerglass for a time, a droplet of rain that falls in upstate New York will eventually make its way into a small, winding stream that drains the southern end of the lake. These are the headwaters of the Susquehanna River and the beginning of an epic journey toward the sea. The Susquehanna flows across 464 miles (747 kilometers) and three states—New York, Pennsylvania, and Maryland—before emptying into the Chesapeake Bay and the Atlantic Ocean.

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NASA Earth Observatory, July 2016

As is often the case in the winter, a thick river of haze hovered over the Indo-Gangetic Plain in January 2013, casting a gray pall over northern India and Bangladesh. On January 10, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this image of haze hugging the Himalayas and spilling out into the Ganges delta and Bengal Sea.

The haze likely resulted from a combination of urban and industrial pollution, agricultural fires, and a regional meteorological phenomenon known as a temperature inversion. Usually the air higher in the atmosphere is cooler than the air near the surface, a situation that allows warm air to rise and disperse pollutants. However, cold air often settles over northern India in the winter, trapping warmer air—and pollution—close to the surface, where it has the greatest impact on human health.

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Earth Observatory, February 2013

A team of scientists have used the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite to confirm major reductions in the levels of a key air pollutant generated by coal power plants in the eastern United States. The pollutant, sulfur dioxide, contributes to the formation of acid rain and can cause serious health problems.

The scientists, led by an Environment Canada researcher, have shown that sulfur dioxide levels in the vicinity of major coal power plants have fallen by nearly half since 2005. The new findings, the first satellite observations of this type, confirm ground-based measurements of declining sulfur dioxide levels and demonstrate that scientists can potentially measure levels of harmful emissions throughout the world, even in places where ground monitoring is not extensive or does not exist. About two-thirds of sulfur dioxide pollution in American air comes from coal power plants. Geophysical Research Letters published details of the new research this month.

The scientists attribute the decline in sulfur dioxide to the Clean Air Interstate Rule, a rule passed by the U.S. Environmental Protection Agency in 2005 that called for deep cuts in sulfur dioxide emissions. In response to that rule, many power plants in the United States have installed desulfurization devices and taken other steps that limit the release of sulfur dioxide. The rule put a cap on emissions, but left it up to power companies to determine how to reduce emissions and allowed companies to trade pollution credits.

NASA, December 2011