You must log in to edit PetroWiki. Help with editing
Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. SPE disclaims any and all liability for your use of such content. More information
Message: PetroWiki content is moving to OnePetro! Please note that all projects need to be complete by November 1, 2024, to ensure a smooth transition. Online editing will be turned off on this date.
Glossary:Top-down emission approach
Estimate made using different remote sensing based techniques, e.g. satellite and airborne, to measure ambient air concentrations of methane, calculate methane flux based on atmospheric and meteorological conditions, and then attribute the emission to different activities. Each measurement technique has different resolution capabilities, strengths and weaknesses.[1]
(Note - Methane emissions are allocated to the natural gas industry by: (a) using a ratio of methane to ethane or propane (longer chain aliphatic which do not occur from biogenic sources); (b) isotopic ratio analysis, using a co-located tracer (such as SF6 or C2H2); or (c) subtracting estimates of other sources of methane emissions such as, livestock, wetlands, agriculture, waste management, etc. together with background methane concentrations.)