May 15, 2013 — After taking a rented camper outfitted with special equipment to measure methane on a cross-continent drive, a UC Santa Barbara scientist has found that methane emissions across large parts of the U.S. are higher than currently known, confirming what other more local studies have found. Their research is published in the journal Atmospheric Environment.
Methane is a potent greenhouse gas, stronger than carbon dioxide on a 20-year timescale, according to the Intergovernmental Panel on Climate Change, though on a century timescale, carbon dioxide is far stronger. “This research suggests significant benefits to slowing climate change could result from reducing industrial methane emissions in parallel with efforts on carbon dioxide,” said Ira Leifer, a researcher with UCSB’s Marine Science Institute.
Leifer was joined by two UCSB undergraduate students on the road trip from Los Angeles to Florida, taking a primarily southern route through Arizona, New Mexico, Texas, Louisiana, and along the Gulf of Mexico. They used specialized instrumentation, a gas chromatograph, to measure methane. The device was mounted in the RV, with an air ram on the roof that collected air samples from in front of the vehicle.
“We tried to pass through urban areas during nighttime hours, to avoid being stuck in traffic and sampling mostly exhaust fumes,” Leifer said. “Someone was always monitoring the chromatograph, and when we would see a strong signal, we would look to see what potential sources were in the area, and modify the survey to investigate and, if possible, circumnavigate potential sources.”
The researchers meandered slowly through areas of fossil fuel activity, such as petroleum and natural gas production, refining, and distribution areas, and other areas of interest. The wide range of sources studied included a coal-loading terminal, a wildfire, and wetlands.
The team analyzed the data in conjunction with researchers at the University of Bremen, Germany, who analyzed inventories and satellite data from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument onboard the European Space Agency’s (ESA) ENVISAT satellite to confirm the finding of strong methane sources in regions of fossil fuel activity. The surface measurements found methane levels increased as the researchers moved toward Houston, and then decreased as they continued westward — the same trend observed in satellite data spanning the continent.
Previous methane studies have focused primarily on large-scale airborne data, which were challenging to separate from local sources, according to Leifer. In fact, clear identification of individual sources often could not be conducted, requiring computer models and other surface measurements.…
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Em 2005 foi declarado pela UNESCO como Ano Internacional da Física, em homenagem aos 100 anos das publicações dos artigos revolucionários de Albert Einstein. Em 1905 Einstein publicou o artigo que explicou o efeito fotoelétrico e introduz o conceito do fóton (o quantum de luz), explicou a origem do movimento Browniano (movimento de partículas em suspensão em um líquido), reforçando a hipótese da existência dos átomos, que naquele momento não estava bem estabelecida ainda. Contudo, os mais famosos foram os artigos que ele apresentou a Teoria da Relatividade Restrita e a equivalência entre massa e energia, a famosa equação E=mc2
