Science & Technology

Researchers focus on methane released from reservoirs

sauce: Journal of Geophysical Research: Biogeosciences

methane Is a powerful greenhouse gas that accounts for about one-fifth of global warming today. In addition to methane emitted from livestock and other agricultural practices, gas is also emitted from fossil fuel production, transportation, combustion, and decomposition of organic matter. Methane is continuously released into the atmosphere. Accurate measurement and emission modeling systems are important because scientists track these emissions and use them for climate modeling and greenhouse gas budgeting.

Inland waters such as wetlands and reservoirs bring significant amounts of methane to the atmosphere, but previous estimates are limited and highly variable. Previous estimates of reservoir emissions ranged from 18 to 70 teragrams of methane per year.

Now by new research Johnson et al... Use a grid approach to estimate daily methane emissions from the reservoir. Their approach provides detailed estimates of methane flux, both geographically and temporally.

The authors note that the amount of methane released from the reservoir may vary depending on the area of ​​the reservoir, the climate of the area, the time or year when flux measurements are taken, and the freeze-thaw cycle. .. To better capture these fluctuations, researchers have set 0.25 ° x 0.25 ° (latitude and longitude) grid patterns in reservoirs around the world. They used the available methane measurements reported for the reservoir to compensate for the differences caused by making measurements at specific times or seasons. They used satellite observations to define ice-free emissions periods and model total global emissions.

Researchers used the average methane flux estimates for each grid and the duration of the emission period to calculate global daily emissions over the entire annual cycle. They found that the global surface area of ​​the reservoir is nearly 300,000 square kilometers and that the reservoir is concentrated in temperate and tropical regions. Temperate and tropical reservoirs emit more methane (121.4-140.9 milligrams per square meter per day) and more in warm months compared to northern reservoirs (39.1 milligrams per square meter per day). Produced emissions.

Globally, researchers have estimated that 10.1 teragrams of methane are released from reservoirs a year. This is a lower value than previously estimated. The authors focus on different surface areas, the processing of seasonal / daily emission measurements, and shorter emission periods to account for the differences. They say their new method will help reduce the uncertainty of the world’s methane balance, and their estimates will help estimate bottom-up biogeochemical and top-down atmospheric methane emissions. Stated. (((Journal of Geophysical Research: Biogeosciences,, 2021)

— Sarah Derouin, Science Writer

Quote: Derouin, S. (2021), researchers focused on the methane released from the reservoir, Eos, 102, Published on October 19, 2021.
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Researchers focus on methane released from reservoirs Researchers focus on methane released from reservoirs

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