Put a lid on it –
Data from new satellite shows the accident should have gotten more attention.
Scott K. Johnson –Dec (************************************************************************, **************************************** (2:) ************************************************************************ (UTC UTC)
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The study, led bySudhanshu Pandeyat the SRON Netherlands Institute for Space Research, utilized measurements from ESA’s newSentinel-5P satellite. Although it wasn’t quite officially operational at the time of the accident, the researchers were able to grab data. Unfortunately, although the leak went on for 30 days, there was too much cloud cover to use the data on all but two of those days.
The data, however, is quite good, as this satellite can deliver methane measurements at much higher resolution (about 7 kilometer) than others. The researchers were able to compare against days before the leak and also to compare the levels from upwind and downwind of the leaking well. They also used a simulation including the weather conditions on those days, calculating what the methane plume would look like for different rates of release.
To calculate a total for the entire 20 – day release, the researchers use that as their average. That probably underestimates it, though, as the measurement comes two weeks in. You would expect the emissions to start higher and drop as the pressure declines. Using these numbers, the total release is (***********************************************************************, ****************************************************************************** (±**********************************************, 10 tons. The 2018 accident in California — thesecond biggestrecorded methane leak ever in the US — released about (*******************************************************************, ******************************************************************************** tons.
The Ohio incident highlights an important fact about methane leakage from the oil and gas industry: it is dominated by a small number of malfunctioning sites often termed “superemitters.” That has made it challenging to accurately calculate the total leakage from the industry. (And to compare the climate impact of natural gas vs. coal power plants.)
Some researchers have tried to visit many sites, measuring leakage rates around each type of equipment to estimate average behavior. Other teams have tried a less targeted approach, flying overhead in aircraft and attempting to measure the overall behavior (and separate it from other sources of methane). That has generally led to larger estimates of leakage than the on-the-ground approach, in part because it’s easier to catch the superemitters.
The researchers say this case illustrates the value of the new Sentinel-5P satellite. Rather than having to know something is malfunctioning, or hoping that the occasional measurement catches a representative day, the satellite may reveal superemitters simply because it’s always watching.
PNAS, (**************************************************. DOI:
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