"There is a connection between pollution in Mexico City and in Houston, Texas," says Dr. Anne M. Thompson, professor of meteorology, Penn State. "The spring, which is the end of the dry season, is the beginning of field burning. That is when the winds move toward the U.S. so that Houston gets an added boost of ozone into their cycle."
Thompson and a large team of researchers carries out a program launching ozonesondes in experiments that measure ozone and other variables in the atmosphere. The ozonesonde instrument packages are carried into the air by weather balloons. Recently, Thompson's team tested the air in the Mexico City area and Houston, Texas, and in Richland, Wash. Pollution in Mexico City affects U.S. Gulf Coast areas including Houston. Richland is affected by pollution coming across the Pacific Ocean from Asia.
The airborne instruments measure temperature, relative humidity, elevation, location -- if a geographic positioning system instrument is aboard – and ozone. The balloons reach an altitude of between 22 and 25 miles before they explode due to decreased pressure and the instrument package falls to Earth and shatters. Ozone is manufactured in the atmosphere by sunlight working on a combination of hydrocarbons, carbon monoxide and nitrogen oxides, all chemicals created by burning organic fuels. Ozone can be either a good chemical or a pollutant, depending on where it occurs in the atmosphere. In the upper atmosphere, ozone provides a shield against the suns ultra violet radiation, but in the lower atmosphere, it is a pollutant that causes health problems and can damage crops. "In August, over Mexico City, we recorded a level of 150 parts per billion of ozone," Thompson told attendees at the fall meeting of the American Geophysical Union in San Francisco, today (Dec. 11). "In the U.S., the standard is 80 parts per billion averaged over eight hours."
With the Mexican/Houston experiment, the researchers did find a link between ozone levels in the Mexico City area and levels a few days later in Houston on a number of occasions. The effect was strongest in March when Mexico City air was stagnant and the normal air flow is northeast toward Houston. The researchers have not completed analysis of the Richland experiment.
Tracking ozone transport and pollution are not as simple as finding a pollution source and tracking it. Natural factors play into the equation. "Summer rains are supposed to wash pollution out of the air," says Thompson. "But, because of lightning and pollution pumped up by thunderstorms, measurements over Mexico were still high in August."
Lightning occurs more frequently in the tropics than in other areas of the globe. The high amounts of energy released by a lightning strike or a cloud-to-cloud lightning flash produces nitric oxide, a chemical that leads to ozone formation. The amount of ozone produced can be significant and is related to the level of lightning activity.
Information from only a few locations will not supply sufficient data to understand global ozone production.
"Each time we send a balloon up, we lose the package," says the Penn State scientist. "Each package is $1,000."
A'ndrea Elyse Messer | EurekAlert!
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences