A team of 15 scientists headed by Gary Morris of Valparaiso University in Indiana analyzed data from a variety of sources, including weather balloons launched from the campus of Rice University in Houston, NASA satellite instruments, aircraft, and computer models. Their findings will be published on 26 September in the Journal of Geophysical Research (Atmospheres).
Houston frequently fails to meet federal standards for ground-level ozone. Besides posing a health risk for people with respiratory problems, ground-level ozone has also been linked to increased rates of asthma among children, and it can destroy plants and reduce crop yields.
In the new study, Morris and colleagues tracked an air mass from the region of Alaskan-Canadian forest fires as it traveled across Canada, through the mid-western United States and down the Mississippi valley into the Houston area. "We found that with the arrival of the pollutants associated with these forest fires, ozone levels increased between 50-100 percent in the first five kilometers [three miles] over Houston," Morris said.
Morris, Scott Hersey from Rice, Anne Thompson from Pennsylvania State University, and the other researchers employed imagery from NASA's Moderate Resolution Imaging Spectroradiometer on the Terra satellite, aerosol (fine particle) data from the Total Ozone Mapping Spectrometer satellite, and carbon monoxide data from the Atmospheric Infrared Sounder on the Aqua spacecraft. The weather balloons in the study were launched as part of the Tropospheric Ozone Pollution Project, to measure ozone levels from the ground up to more than 30,000 meters [100,000 feet]. Fortuitously, the project coincided with the arrival of pollution from the northern fires.
Normal summer meteorological conditions, smoke from the distant forest fires, and the typical urban pollution generated in the Houston area combined to greatly increase local ozone concentrations during this two-day event in July 2004. The scientists believe that such pollution episodes will continue. Understanding the transport and transformation of gases and aerosols over long distances is needed for improved air quality forecasting, they say.
"This event highlights the critical role imported sources can have on local air quality," said Morris. "Environmental managers at the state level need to take into consideration the impact of such sources as they develop their comprehensive plans to come into compliance with federal regulations. Continuous operation of a network that provides data on ozone concentrations above the surface would be helpful in accurately identifying the sources of pollutants and improving air quality forecasts."
Harvey Leifert | EurekAlert!
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Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
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Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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