The reduction of methane emissions, especially in the oil and gas (O&G) industry, serves as a cost-effective method to decrease greenhouse gases (GHGs), increase energy security, enhance economic growth, and improve air quality and worker safety. Large-scale patterns of natural and anthropogenic methane emissions have been detected with public, low-resolution satellites [1]. Another approach is to perform measurements and quantification using aircraft [2]; [3]; [4]. However, methane emissions associated with anthropogenic activities tend to derive from many relatively small point sources [5]. For this, GHGSat, a private company headquartered in Canada, pioneered the use of high-resolution satellites to monitor methane emissions directly from different sectors worldwide, including the O&G assets. In addition, the company mounted the instrument in a light aircraft flying 150 times closer to the ground than the satellites. The primary instrument is a spectrometer operating in the short-wave infrared (SWIR), based on a Wide-Angle Fixed-cavity Fabry-Pérot (WAF-P) interferometer. This instrument provides imagery – from either space or the air - along with spectroscopic information on gas abundances of targets on the ground. The analysis of these data revolves around the amount of light absorbed by methane gas, which has been found to occur at specific wavelengths of the SWIR spectral range of 1600-1700 nanometers. The objective of this paper is to review results from these instruments deployed at approximately 500 kilometers (310 miles) and 2 kilometers (1.25 miles) in altitude. In addition, a discussion related to the unique advantages offered by using the same instrument at two different altitudes is presented.
Methane, the simplest alkane and main constituent of natural gas, is a potent greenhouse gas that contributes to about one-third of today's anthropogenic greenhouse gas (GHG) warming [6]. However, methane has a short residence time in the atmosphere when compared to the residence time of carbon dioxide (CO2). Therefore, a reduction in methane emissions can efficiently have an impact in the shorter-term warming rate [7].
