An investigation of the atmospheric sources and sinks of methyl bromide

Journal Article · Thu Jan 21 23:00:00 EST 1993 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/92GL02634· OSTI ID:6711112

Singh, H B ^[1]; Kanakidou, M ^[2]

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1. NASA Ames Research Center, Moffett Field, CA (United States)
2. CNRS, Gif-sur-Yvette (France)

Methyl Bromide (CH[sub 3]Br) is a ubiquitous component of the atmosphere and has been implicated as an important player in the depletion of stratospheric ozone. Atmospheric CH[sub 3]Br abundances, interhemispheric gradients, oceanic concentrations, man-made emissions, and removal processes have been analyzed and interpreted with the help of a simple box model and a 2-D global photochemical model. Its calculated atmospheric lifetime (T) of 1.7-1.9 years, based on reaction with OH radicals, is consistent with a global source of 90-110 Gg (10[sup 9] g)/year. Consequences of a much shorter lifetime of 1.2 years, due to possible deposition/hydrolysis losses, are also considered. Available data are used to estimate a CH[sub 3]Br source that is 35% (20-50%) man-made and 65% (80-50%) natural. Oceans are substantially supersaturated and provide the most important natural source of [approx]60 (40-80) Gg/year. Within the oceans 200-300 Gg/year of CH[sub 3]Br may be produced. Indirect emissions from automobile exhaust and biomass burning can not be well quantified (1-10 Gg/year). A global trend of 0.1-0.2 ppt/year is predicted. Model results show significant vertical and seasonal variations in the atmospheric abundances and interhemispheric gradients of CH[sub 3]Br. Substantial uncertainties in calibrations, source estimates, and deposition processes are present. 12 refs., 3 figs., 2 tabs.

• OSTI ID: 6711112
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 20:2; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020900 -- Petroleum-- Environmental Aspects
09 BIOMASS FUELS
095000 -- Biomass Fuels-- Environmental Aspects-- (1990-)
54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AIR POLLUTION
BIOMASS
BOX MODELS
BROMINATED ALIPHATIC HYDROCARBONS
DENSITY
DEPOSITION
EARTH ATMOSPHERE
ENERGY SOURCES
GLOBAL ANALYSIS
GLOBAL ASPECTS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROXYL RADICALS
LIFETIME
LOSSES
MATHEMATICAL MODELS
MATHEMATICS
METHYL BROMIDE
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OZONE
PHYSICAL PROPERTIES
POLLUTION
PRESSURE GRADIENTS
RADICALS
REMOVAL
RENEWABLE ENERGY SOURCES
SEASONAL VARIATIONS
SINKS
STRATOSPHERE
VARIATIONS