Global budget of CO, 1988–1997: Source estimates and validation with a global model

Abstract

[1] We present a model study of carbon monoxide for 1988-1997 using the GEOS-Chem 3-D model driven by assimilated meteorological data, with time-varying emissions from biomass burning and from fossil fuel and industry, overhead ozone columns, and methane. The hydroxyl radical is calculated interactively using a chemical parameterization to capture chemical feedbacks. We document the inventory for fossil fuels/industry and discuss major uncertainties and the causes of differences with other inventories that give significantly lower emissions. We find that emissions hardly change from 1988 to 1997, as increases in Asia are offset by decreases elsewhere. The model reproduces the 20% decrease in CO at high northern latitudes and the 10% decrease in the North Pacific, caused primarily by the decrease in European emissions. The model compares well with observations at sites impacted by fossil fuel emissions from North America, Europe, and east Asia suggesting that the emissions from this source are reliable to 25%, and we argue that bottom-up emission estimates are likely to be too low rather than too high. The model is too low at the seasonal maximum in spring in the southern tropics, except for locations in the Atlantic Ocean. This problem may be caused by an overestimate of the frequency of tropical deep convection, a common problem in models that use assimilated meteorological data. We argue that the yield of CO from methane oxidation is near unity, contrary to some other studies, based on removal rates of intermediate species.

Carbon isotopic signatures of methanol and acetaldehyde emitted from biomass burning source

“…It can serve as an abundant source of HO X , particularly in the free and upper troposphere [Tie et al, 2003]. It is also an important source of important atmospheric constituents such as formaldehyde [e.g., Riemer et al, 1998] and carbon monoxide [e.g., Duncan et al, 2007]. These engender a critical effect on the oxidative capacity of the atmosphere and the radiative budget.…”

Atmospheric deposition of methanol over the Atlantic Ocean

“…Methanol is primarily released to air from terrestrial plants (during growth and decay); other identified sources include industrial emissions, biomass and biofuel burning, and atmospheric production (1)(2)(3)(4)(5). Methanol reacts with OH in the troposphere with a photochemical lifetime of ∼10 d, leading to formaldehyde (6) and carbon monoxide (7), among other products. Observations suggest that methanol can be further removed from air via deposition to land (8) and to the sea surface (9,10).…”

Methanol emissions from maize: Ontogenetic dependence to varying light conditions and guttation as an additional factor constraining the flux

“…Since it is an important precursor of carbon monoxide, formaldehyde and tropospheric ozone, it plays an important role in the global tropospheric chemistry (Tie et al, 2003;Millet et al, 2006;Duncan et al, 2007;Choi et al, 2010;Hu et al, 2011). Field and laboratory measurements have been carried out to characterize methanol sources and sinks.…”