Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers to Scrutinize Megacity Pollution During Mexico City Field Campaign

06.03.2006


A team of researchers from the National Center for Atmospheric Research (NCAR) and other institutions is heading to Mexico City to participate in one of the most complex field campaigns ever undertaken in atmospheric chemistry. From March 1 to 29, the team will make multiple research flights in the NSF/NCAR C-130 aircraft and operate ground instruments to investigate the chemical and physical transformation of air pollution as it flows downwind from Mexico City.


The NSF/NCAR C-130 will fly out of Veracruz, Mexico to intercept Mexico City’s pollution plume downwind. A unique array of sensing instruments on board will sample the gases and aerosols in the plume. A four-engine turboprop, the NSF/NCAR C-130 was built for military transport and adapted for research missions in the mid-1990s. (©UCAR, photo by Carlye Calvin)


Mexico City, the world’s third largest urban area, has some of the worst air quality in the world. (Photo courtesy Nancy A. Marley.)



The team’s goal is to assess the pollution’s impact on regional and global air quality, climate, and ecosystems. The results are expected to be applicable to megacities (cities with 10 million or more inhabitants) in other locations around the world.

"Mexico City’s pollution probably doesn’t have a global impact, but all urban areas together do, and the world is urbanizing," explains NCAR scientist Sasha Madronich, one of the project’s principal investigators. "If we can understand the pollution impacts of Mexico City, we can apply this new knowledge to other urban areas across the globe."


The project, called MIRAGE (Megacity Impacts of Regional and Global Environments), is led by NCAR in partnership with several U.S. universities and other organizations.

MIRAGE is one component of a set of simultaneous field campaigns collectively called Megacity Initiative: Local and Global Research Observations (MILAGRO). This international effort will observe and quantify air pollution emitted by Mexico City from multiple perspectives. Other components of MILAGRO are led by the U.S. Department of Energy, the Molina Center on Energy and the Environment, and NASA. As part of the broader effort, researchers from more than 60 institutions in the United States, Mexico, and several other nations will convene in Mexico City to coordinate aircraft and ground-based measurements, satellite observations, and computer modeling. The cost of the MILAGRO campaign is estimated to be more than $20 million, with the National Science Foundation contributing about $10 million. NSF is also NCAR’s primary sponsor.

NCAR researchers hope that data from MIRAGE will shed light on four broad questions:

  • How far downwind does Mexico City’s pollution plume extend?
  • How are the pollutants transformed by chemical reactions occurring downwind of the city?
  • How do the pollutants affect visibility, as well as regional and global climate?
  • How do the urban pollutants interact with pollutants from other sources, such as agricultural and forest fires?

"We’re not looking so much at pollution inside the city because that’s already fairly well known," Madronich says. "We’re looking at the outflow. For the first time we’ll have an idea of how much pollution is outside the city and be able to understand its full life cycle."

Because air pollution is complicated, both chemically and physically, and evolves over time and distance, scientists have traditionally faced difficulty in quantifying its components. The MIRAGE team will use aircraft, ground stations, and satellite observations to gather data on how Mexico City’s air pollution ages as it disperses in the first hours and days after emission.

Aircraft and instruments

Researchers based in Veracruz, located east of the capital on the Gulf of Mexico, will crisscross Mexico City’s pollution plume in the C-130 aircraft. Using a complex package of instruments, they’ll make multiple flights to sample the gases and aerosols that comprise the plume, which usually spreads northeast from the city toward the gulf.

Others will set up ground-based instruments at the Technical University of Tecamac, about 25 miles (40 kilometers) northeast of Mexico City. From there, they will also launch GPS radiosondes, which are instrument packages attached to helium balloons that send atmospheric measurements to the ground via radio. The radiosondes will make vertical profiles of winds, temperatures, and humidity from the ground through the lower stratosphere.

Two kinds of pollutants

MIRAGE is especially significant because it focuses on both aerosols (airborne particles of dust, soot, and other pollutants) and gaseous pollutants (including ozone, nitrogen oxides, carbon monoxide, sulfur dioxide, and hydrocarbons and their oxidation products).

"In the past there have been air campaigns during which researchers have made lots of aerosol measurements, and other ones during which they’ve emphasized gas measurements," Madronich says. "The uniqueness of MIRAGE is that it brings them together, allowing us to study interactions between gases and aerosols."

Why Mexico City?

The researchers chose Mexico City for MIRAGE because it is the world’s third largest urban area, has some of the worst air quality in the world, and is situated in the tropics, as are most fast-growing megacities in developing nations.

Current computer models for studying air pollution were developed mainly for cities in industrialized nations, Madronich says. They don’t transfer well to megacities in the developing world, where people are more likely to burn coal and wood and drive vehicles that emit more harmful chemicals.

The field campaign will also gather information about aerosols, such as how long they endure in the atmosphere and how they affect clouds. These insights are useful to scientists who make computer models of global climate.

"The lifetime of organic aerosols may be longer than climate modelers have thought, and this could have a huge effect on climate," Madronich says.

Nicole Gordon | EurekAlert!
Further information:
http://www.ucar.edu

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Getting electrons to move in a semiconductor

25.04.2018 | Physics and Astronomy

Reconstructing what makes us tick

25.04.2018 | Physics and Astronomy

Cheap 3-D printer can produce self-folding materials

25.04.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>