Satellite-based survey of extreme methane emissions in the Permian basin.

Industrial emissions play a major role in the global methane budget. The Permian basin is thought to be responsible for almost half of the methane emissions from all U.S. oil- and gas-producing regions, but little is known about individual contributors, a prerequisite for mitigation. We use a new class of satellite measurements acquired during several days in 2019 and 2020 to perform the first regional-scale and high-resolution survey of methane sources in the Permian. We find an unexpectedly large number of extreme point sources (37 plumes with emission rates >500 kg hour-1), which account for a range between 31 and 53% of the estimated emissions in the sampled area. Our analysis reveals that new facilities are major emitters in the area, often due to inefficient flaring operations (20% of detections). These results put current practices into question and are relevant to guide emission reduction efforts.

Measurement of internal stray radiation of a thermal infrared spectrometer based on temperature variation.

The level of internal stray radiation is an important criterion to evaluate the performance of a thermal infrared spectrometer. In this study, a novel method is proposed and evaluated to measure the internal stray radiation of a thermal infrared spectrometer based on temperature variation. The proposed method was used to measure the internal stray radiation values of an existing instrument. First, two output gray value curves were constructed for a single spectral channel in a cryogenic detector at two different spectrometer temperatures based on radiometric calibration measurements. Subsequently, the gray value and radiation flux of the internal stray radiation of the spectrometer were calculated. In addition, the internal stray radiation data measured at different spectral channels and different integration times were used to verify and evaluate the proposed method. Results show that the proposed method is valid, and the standard deviations of the various internal radiation values of the tested spectral channels and the various integration times are 3.47% and 1.46%, respectively. The proposed method is adaptable, flexible, and efficient.