Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas

17.03.2017

Fertilizers, animal waste, changes to atmospheric chemistry and warming soils all tied to increased ammonia over US, Europe, China and India

The first global, long-term satellite study of airborne ammonia gas has revealed "hotspots" of the pollutant over four of the world's most productive agricultural regions. Using data from NASA's Atmospheric Infrared Sounder (AIRS) satellite instrument, the University of Maryland-led research team discovered steadily increasing ammonia concentrations from 2002 to 2016 over agricultural centers in the United States, Europe, China and India. Increased atmospheric ammonia is linked to poor air and water quality.


This map shows global trends in atmospheric ammonia (NH3) as measured from space from 2002 to 2016. Hot colors represent increases due to a combination of increased fertilizer application, reduced scavenging by acid aerosols and climate warming. Cool colors represent decreases due to reduced agricultural burning or fewer wildfires.

Credit: Juying Warner/GRL

The study, published March 16, 2017 in the journal Geophysical Research Letters, also describes the probable causes for increased airborne ammonia in each region. Although the specifics vary between areas, the increases in ammonia are broadly tied to crop fertilizers, livestock animal wastes, changes to atmospheric chemistry and warming soils that retain less ammonia. The results could help illuminate strategies to control pollution from ammonia and ammonia byproducts near agricultural areas.

"Our study reports the first global, long-term trends of atmospheric ammonia from space," said Juying Warner, as associate research scientist in atmospheric and oceanic science at UMD. "Measuring ammonia from the ground is difficult, but the satellite-based method we have developed allows us to track ammonia efficiently and accurately. We hope that our results will help guide better management of ammonia emissions."

Gaseous ammonia is a natural part of Earth's nitrogen cycle, but excess ammonia is harmful to plants and reduces air and water quality. In the troposphere--the lowest, densest part of the atmosphere where all weather takes place and where people live -- ammonia gas reacts with nitric and sulfuric acids to form nitrate-containing particles that contribute to aerosol pollution that is damaging to human health.

Ammonia gas can also fall back to Earth and enter lakes, streams and oceans, where it contributes to harmful algal blooms and "dead zones" with dangerously low oxygen levels.

"Little ammonia comes from tailpipes or smokestacks. It's mainly agricultural, from fertilizer and animal husbandry," said Russell Dickerson, a professor of atmospheric and oceanic science at UMD. "It has a profound effect on air and water quality -- and ecosystems. Here in Maryland, ammonia from the atmosphere contributes as much as a quarter of the nitrogen pollution in the Chesapeake Bay, causing eutrophication and leading to dead zones that make life very difficult for oysters, blue crabs and other wildlife."

Each major agricultural region highlighted in the study experienced a slightly different combination of factors that correlate with increased ammonia in the air from 2002 to 2016.

The United States, for example, has not experienced a dramatic increase in fertilizer use or major changes in fertilizer application practices. But Warner, Dickerson and their colleagues found that successful legislation to reduce acid rain in the early 1990s most likely had the unintended effect of increasing gaseous ammonia. The acids that cause acid rain also scrub ammonia gas from the atmosphere, and so the sharp decrease in these acids in the atmosphere is the most plausible explanation for the increase in ammonia over the same time frame.

Europe experienced the least dramatic increase in atmospheric ammonia of the four major agricultural areas highlighted by the study. The researchers suggest this is due in part to successful limits on ammonia-rich fertilizers and improved practices for treating animal waste. Much like the United States, a major potential cause for increased ammonia traces back to reductions in atmospheric acids that would normally remove ammonia from the atmosphere.

"The decrease in acid rain is a good thing. Aerosol loading has plummeted--a substantial benefit to us all," Dickerson said. "But it has also increased gaseous ammonia loading, which we can see from space."

In China, a complex interaction of factors is tied to increased atmospheric ammonia. The study authors suggest that efforts to limit sulfur dioxide--a key precursor of sulfuric acid, one of the acids that scrubs ammonia from the atmosphere--could be partially responsible. But China has also greatly expanded agricultural activities since 2002, widening its use of ammonia-containing fertilizers and increasing ammonia emissions from animal waste. Warming of agricultural soils, due at least in part to global climate change, could also contribute.

"The increase in ammonia has spiked aerosol loading in China. This is a major contributor to the thick haze seen in Beijing during the winter, for example," Warner said. "Also, meat is becoming a more popular component of the Chinese diet. As people shift from a vegetarian to a meat-based diet, ammonia emissions will continue to go up."

In India, a broad increase in fertilizer use coupled with large contributions from livestock waste have resulted in the world's highest concentrations of atmospheric ammonia. But the researchers note that ammonia concentrations have not increased nearly as quickly as over other regions. The study authors suggest that this is most likely due to increased emissions of acid rain precursors and, consequently, some increased scrubbing of ammonia from the atmosphere. This leads to increased levels of haze, a dangerous trend confirmed by other NASA satellite instruments, Dickerson said.

In all regions, the researchers attributed some of the increase in atmospheric ammonia to climate change, reflected in warmer air and soil temperatures. Ammonia vaporizes more readily from warmer soil, so as the soils in each region have warmed year by year, their contributions to atmospheric ammonia have also increased since 2002.

The study also ascribes some fluctuations in ammonia to wildfires, but these events are sporadic and unpredictable. As such, the researchers excluded wildfires in their current analysis.

"This analysis has provided the first evidence for some processes we suspected were happening in the atmosphere for some time," Warner said. "We would like to incorporate data from other sources, such as the Joint Polar Satellite System, in future studies to build a clearer picture."

Warner, Dickerson and their colleagues hope that a better understanding of atmospheric ammonia will help policy makers craft approaches that better balance the high demand for agriculture with the need for environmental protection.

"As the world's population grows, so does the demand for food--especially meat," Dickerson said. "This means farmers and ranchers need more fertilizer, which makes it harder to maintain clean air and water. Wise agricultural practices and reduced greenhouse gas emissions can help avoid adverse effects."

###

The research paper, "Increased atmospheric ammonia over the world's major agricultural areas detected from space," Juying Warner, Russell Dickerson, Zigang Wei, Larrabee Strow, Yuxuan Wang, and Qing Liang, was published March 16, 2017 in the journal Geophysical Research Letters.

This work was supported by NASA (Award Nos. NNX11AG39G and NNX12AJ05G.) The content of this article does not necessarily reflect the views of this organization.

Media Relations Contact:

Matthew Wright
301-405-9267
mewright@umd.edu


University of Maryland
College of Computer, Mathematical, and Natural Sciences
2300 Symons Hall
College Park, MD 20742
http://www.cmns.umd.edu
@UMDscience

About the College of Computer, Mathematical, and Natural Sciences

The College of Computer, Mathematical, and Natural Sciences at the University of Maryland educates more than 7,000 future scientific leaders in its undergraduate and graduate programs each year. The college's 10 departments and more than a dozen interdisciplinary research centers foster scientific discovery with annual sponsored research funding exceeding $150 million.

Media Contact

Matthew Wright
mewright@umd.edu
301-405-9267

 @UMDRightNow

http://www.umdrightnow.umd.edu/ 

Matthew Wright | EurekAlert!

More articles from Studies and Analyses:

nachricht Antarctic Ice Sheet mass loss has increased
14.06.2018 | Technische Universität Dresden

nachricht WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>