Nav: Home

How severe drought influences ozone pollution

April 10, 2019

From 2011 to 2015, California experienced its worst drought on record, with a parching combination of high temperatures and low precipitation. Drought conditions can have complicated effects on ozone air quality, so to better understand the process, researchers have analyzed data from two ozone-polluted cities before, during and after the California drought. They report their results in ACS' journal Environmental Science & Technology.

Although ozone in the stratosphere protects the earth from ultraviolet radiation, at ground level the molecule is a harmful air pollutant to humans, animals and plants. Ground-level ozone forms when nitrogen oxide compounds, primarily from motor vehicle emissions, react with volatile organic compounds (VOCs) from natural and anthropomorphic sources. Isoprene, a VOC emitted by plants, is a significant contributor to ozone production during summer months in many locations around the world. However, plants also decrease air ozone levels by taking the gas up through pores in their leaves. Because drought conditions affect both of these plant-related processes, Angelique Demetillo, Sally Pusede and colleagues wanted to examine air concentrations of isoprene and ozone -- as well as leaf area index, nitrogen dioxide and meteorology -- before, during and after the California drought.

For their study, the researchers analyzed publicly available data collected from the ground and satellites in Fresno, an ozone-polluted city close to an oak savanna, and Bakersfield, California. They found that isoprene concentrations did not change significantly during the early drought, but they dropped by more than 50 percent during the most severe drought conditions. The effects of drought on isoprene were also dependent on atmospheric temperature. The researchers found that drought altered ozone production such that the process became chemically more sensitive to the decrease in isoprene and other drought-affected VOCs. These factors led to an estimated overall decrease in ozone production of approximately 20 percent during the severe drought. However, this decrease was offset by a comparable reduction in ozone uptake by plants, leading to only a 6 percent reduction in ozone levels overall during the severe drought period. These results suggest that drought influences on ozone pollution are complex and depend on drought severity and duration, the researchers say.
-end-
The authors acknowledge funding from NASA, the NASA Student Airborne Research Program, the National Suborbital Research Center and the NASA Airborne Science Program.

The paper's abstract will be available on April 10 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.est.8b04852

The American Chemical Society, the world's largest scientific society, is a not-for-profit organization chartered by the U.S. Congress. ACS is a global leader in providing access to chemistry-related information and research through its multiple databases, peer-reviewed journals and scientific conferences. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies. Its main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Follow us: Twitter | Facebook

American Chemical Society

Related Drought Articles:

An evapotranspiration deficit drought index to detect drought impacts on ecosystems
The difference between actual and potential evapotranspiration, technically termed a standardized evapotranspiration deficit drought index (SEDI), can more sensitively capture the biological changes of ecosystems in response to the dynamics of drought intensity, compared with indices based on precipitation and temperature.
Sesame yields stable in drought conditions
Research shows adding sesame to cotton-sorghum crop rotations is possible in west Texas
Mapping the effects of drought on vulnerable populations
The greater frequency of droughts, combined with underlying economic, social, and environmental risks means that dry spells have an increasingly destructive impact on vulnerable populations, and particularly on children in the developing world.
Asia's glaciers provide buffer against drought
A new study to assess the contribution that Asia's high mountain glaciers make to relieving water stress in the region is published this week (May 29, 2019) in the journal Nature.
How severe drought influences ozone pollution
From 2011 to 2015, California experienced its worst drought on record, with a parching combination of high temperatures and low precipitation.
A faster, more accurate way to monitor drought
A new drought monitoring method developed at Duke University allows scientists to identify the onset of drought sooner, meaning conservation or remediation measures could be put into place sooner.
How does the Amazon rain forest cope with drought?
The Amazon rain forest isn't necessarily a place that many would associate with a drought, yet prolonged dry spells are projected to become more prevalent and severe because of climate change.
Trees change inside as drought persists
James Cook University scientists in Australia have found that trees change their anatomy in response to prolonged drought.
Climate changes require better adaptation to drought
Europe's future climate will be characterised by more frequent heat waves and more widespread drought.
New research identifies two types of drought across China and how they evolve
Dr. Linying WANG and Professor Xing YUAN, from the Institute of Atmospheric Physics, Chinese Academy of Sciences, used in-situ observations and reanalysis datasets to explore the long-term variability and trends of two types of flash drought.
More Drought News and Drought Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#541 Wayfinding
These days when we want to know where we are or how to get where we want to go, most of us will pull out a smart phone with a built-in GPS and map app. Some of us old timers might still use an old school paper map from time to time. But we didn't always used to lean so heavily on maps and technology, and in some remote places of the world some people still navigate and wayfind their way without the aid of these tools... and in some cases do better without them. This week, host Rachelle Saunders...
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.