AIRBORNE MEASUREMENTS OF ATMOSPHERIC METHANE OVER OIL-FIELDS IN WESTERN SIBERIA

Airborne measurements of atmospheric methane (CH4) over oil fields in western Siberia were carried out on August 1, 1994. Extremely sharp CH 4 peaks were observed in the horizontal distribution of CH4 at an alti tude of 150 m above the ground surface; the half widths of the peaks w ere 3 - 4 km and the concentration of the largest peak exceeded 2.9 pp mv. Since the CH4 distribution was considered to reflect the distribut ion of CH4 emission strength on the surface, there was strong CH4 emis sion al the peak positions. All of the observed CH4 peak positions wer e located at or near oil production sites and/or oil pipelines, sugges ting that natural gas was emitted from the facilities. Leakage or vent ing of natural gas are the probable CH4 sources.