Aircraft measurements of the concentrations of CO2, CH4, N2O, and CO and the carbon and oxygen isotopic ratios of CO2 in the troposphere over Russia

Nakazawa, Takakiyo; Sugawara, Satoshi; Inoue, Gen; Machida, Toshinobu; Makshyutov, Shamil; Mukai, Hitoshi

doi:10.1029/96jd03131

Cited by 86 publications

(60 citation statements)

References 79 publications

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“…In spite of the fact that measurements were conducted during different years, the higher mixing ratios in summer compared to spring indicate the presence of a seasonal varying source with a maximum in summer. This source is strong enough to compensate the influence of the seasonally varying large-scale destruction of CH 4 in reaction with OH, which causes a summer minimum in the CH 4 mixing ratio at background sites (Houweling et al 2000; similar effect was reported for Siberia by Nakazawa et al 1997). For the spring campaign of 2004 (T8) the zone averaged CH 4M are in the range 1.88-1.90 ppm, which is close to the background as measured at Mace Head.…”

Section: Results For Western Siberiasupporting

confidence: 53%

Application of stable isotope analysis for improved understanding of the methane budget: comparison of TROICA measurements with TM3 model simulations

et al. 2009

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Presented is a detailed comparison of CH 4 and δ 13 C-CH 4 measurements with simulations of the global transport model TM3. Experimental data were obtained during campaigns along the Trans-Siberian railroad in the framework of the TROICA project. Two summer (1999 and 2001) and one spring (2003) expeditions are evaluated. Model simulations include sensitivity tests to further investigate the isotopic composition of natural gas and emissions from Siberian wetlands. Comparison of the average mixing ratio of methane and its isotopic composition (δ 13 C) has been performed for different geographic zones, including the European part of Russia, Western Siberia and Central Siberia. Simulations are in reasonable agreement with the measurements for the European part of Russia and confirm a high contribution of natural gas to the observed methane levels. An increase of emission from bogs shifts the simulated methane isotopic composition closer to the observations. The relative importance of the Western Siberia emissions in current inventories is underestimated in comparison with other wetland regions in the former USSR. Simulated average mixing ratios are in a good agreement with the observations in Central Siberia, while 13 C(CH 4 ) values tend to be higher than measured in all considered scenarios. These results point to a bias in the modeled source mixture over Russia, which could be repaired by shifting emissions from isotopically heavy methane sources (e.g. coal,

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Section: Results For Western Siberiasupporting

confidence: 53%

Application of stable isotope analysis for improved understanding of the methane budget: comparison of TROICA measurements with TM3 model simulations

et al. 2009

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“…3 and listed in Table l No appreciable vertical gradient of the N20 concentration was also found in the troposphere over Russia [Nakazawa et al, 1997b]. An average value of the tropospheric N20 concentration over Japan for the period January 1992-December 1998 was 312.46 ppbv.…”

Section: Resultsmentioning

confidence: 99%

Concentration variations of tropospheric nitrous oxide over Japan

Ishijima

Nakazawa

Sugawara

et al. 2001

Geophysical Research Letters

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“…However, more detailed inspection of the latitudinal distributions indicates that CH4 emissions are somewhat different, especially in northern middle latitudes from 30N to 50N where strong CH4 sources exist. Longitudinal variation of the CH4 concentration was also pointed out based on observations (e. g., Sugawara et al, 1996;Nakazawa et al, 1997c) and model studies (Fung et al, 1991;Hemn et al, 1997). For example, Sugawara et al (1996) and Nakazawa et al (1997c) found from their aircraft measurements over Russia that the lower tropospheric CH4 concentration over Siberia is considerably high even in the summer season, due to the release of a substantial amount of CH4 from natural wetlands and the leakage of natural gas.…”

Section: Sensitivity Tests Of the Model Resultsmentioning

confidence: 99%

Methane Emissions Deduced from a Two-Dimensional Atmospheric Transport Model and Surface Measurements

Saeki

Nakazawa

Tanaka

et al. 1998

Journal of the Meteorological Society of Japan

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Latitudinal and temporal distributions of CH4 emission were estimated by an iterative inverse method using a two-dimensional atmospheric transport model and the 1983-1994 CH4 concentration data from the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory Global Sampling Network. The atmospheric transport of the model was validated by simulating the concentrations of 85Kr, CFC-11, CFC-12 and CO2 observed at various locations world wide. A zonally averaged OH field for the destruction of CH4 in the atmosphere, originally derived from a three-dimensional photochemical transport model, was adjusted to simulate the observed concentration of atmospheric CH3CC13. A. calculated average latitudinal distribution of CH4 emission showed a large north-south difference, with about 75% of the total global emission residing in the northern hemisphere. The CH4 emission varied seasonally in high latitudes of the northern hemisphere, with a maximum in the summer season, while no seasonality of the CH4 release was found in the southern hemisphere. Averaged global emission of the natural and anthropogenic CL for the period 1984-1994 was estimated to be 559+9Tg/yr, with chemical loss of 528+10Tg/yr and the atmospheric increase of 31Tg/yr. In sensitivity experiments of the model results, the global emission of CH4 was found to be sensitive to the OH concentration and the atmospheric temperature but less to the atmospheric transport coefficients and the CH4 concentration data used. The latitudinal CH4 emission distribution was dependent largely on the specification of the horizontal transport coefficients. It was also found that the 613C value of a bacterial source associated with a large amount of CH4 emission, as well as the soil absorption process of CH4 with a large kinetic isotopic fractionation, significantly impacts the determination of S13C in atmospheric CH4.

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Aircraft measurements of the concentrations of CO₂, CH₄, N₂O, and CO and the carbon and oxygen isotopic ratios of CO₂ in the troposphere over Russia

Cited by 86 publications

References 79 publications

Application of stable isotope analysis for improved understanding of the methane budget: comparison of TROICA measurements with TM3 model simulations

Application of stable isotope analysis for improved understanding of the methane budget: comparison of TROICA measurements with TM3 model simulations

Concentration variations of tropospheric nitrous oxide over Japan

Methane Emissions Deduced from a Two-Dimensional Atmospheric Transport Model and Surface Measurements

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