Methane and carbon monoxide emissions from asphalt pavement: Measurements and estimates of their importance to global budgets

We measured emissions of methane from asphalt surfaces used in pavement for roadways. Maximum emissions were 22 mg/m2/hr for 1- to 4-week-old pavement during maximum sunlight intensity. Emissions were much smaller at low sunlight intensity and dropped off to negligible amounts at night. Smaller emissions were observed for asphalt pavement of 2.5 to 3 years approximate age under similar conditions. Companion measurements of carbon monoxide emissions resulted in maximum emissions of about 2.6 mg/m2/hr for 1-week-old pavement. These findings indicate that emissions of CH4 and CO are a function of both sunlight and temperature. Based on our results, methane emissions from asphalt pavement cannot be a significant source of atmospheric methane as compared to other identified methane sources. Therefore, although asphalt methane emissions are a form of fossil fuel methane, they cannot explain the relatively high fraction of 14C-depleted methane in the atmosphere.

[1]  Steven C. Wofsy,et al.  Interactions of CH4 and Co in the Earth's Atmosphere , 1976 .

[2]  R. Cicerone,et al.  Biogeochemical aspects of atmospheric methane , 1988 .

[3]  D. Blake,et al.  Continuing Worldwide Increase in Tropospheric Methane, 1978 to 1987 , 1988, Science.

[4]  The use of radiocarbon measurements in atmospheric studies. , 1990 .

[5]  D. Etheridge,et al.  Evidence of changing concentrations of atmospheric CO2, N2O and CH4 from air bubbles in Antarctic ice , 1986, Nature.

[6]  C. M. Stevens,et al.  Stable carbon isotopic composition of methane from some natural and anthropogenic sources , 1988 .

[7]  Veerabhadran Ramanathan,et al.  Trace gas trends and their potential role in climate change , 1985 .

[8]  V P Puzinauskas,et al.  DIFFERENCES BETWEEN PETROLEUM ASPHALT, COAL-TAR PITCH AND ROAD TAR , 1978 .

[9]  W. Seiler,et al.  Methane emission from rice paddies , 1983 .

[10]  D. Ehhalt,et al.  Sources and sinks of atmospheric methane , 1978 .

[11]  D. Blake,et al.  Methane: Interhemispheric concentration gradient and atmospheric residence time. , 1982, Proceedings of the National Academy of Sciences of the United States of America.

[12]  D. Ehhalt.  The atmospheric cycle of methane , 1974 .

[13]  D. I. Sebacher,et al.  Methane flux in forested freshwater swamps of the southeastern United States , 1981 .

[14]  Paul J. Crutzen,et al.  A two‐dimensional photochemical model of the atmosphere: 2. The tropospheric budgets of the anthropogenic chlorocarbons CO, CH4, CH3Cl and the effect of various NO x sources on tropospheric ozone , 1983 .

[15]  M. Manning,et al.  Radiocarbon determination of atmospheric methane at Baring Head, New Zealand , 1988, Nature.

[16]  H. Craig,et al.  Methane: The record in polar ice cores , 1982 .

[17]  W. Broecker,et al.  Carbon-14 in Methane Sources and in Atmospheric Methane: The Contribution from Fossil Carbon , 1989, Science.

[18]  Ralph J. Cicerone,et al.  Seasonal variation of methane flux from a California rice paddy , 1983 .

[19]  M. Khalil,et al.  Atmospheric methane /CH4/ - Trends and seasonal cycles , 1981 .

[20]  Ralph J. Cicerone,et al.  Sources of atmospheric methane: Measurements in rice paddies and a discussion , 1981 .

[21]  M. Khalil,et al.  Atmospheric methane in the recent and ancient atmospheres Concentrations, trends, and interhemispheric gradient , 1984 .

[22]  S. Wofsy,et al.  Tropospheric chemistry: A global perspective , 1981 .

[23]  T. Barber,et al.  Fossil carbon sources of atmospheric methane , 1988, Nature.

[24]  John M. Melack,et al.  Methane flux from the central Amazonian floodplain , 1988 .

[25]  A. J. Crawford,et al.  The global distribution of methane in the troposphere , 1987 .

[26]  D. I. Sebacher,et al.  Atmospheric methane sources: Alaskan tundra bogs, an alpine fen, and a subarctic boreal marsh , 1986 .

[27]  V. Ramanathan,et al.  Methane and Nitrous Oxide: Their Effects on the Terrestrial Climate , 1980 .

[28]  Inez Y. Fung,et al.  Methane emission from natural wetlands: Global distribution, area, and environmental characteristics of sources , 1987 .

[29]  S. Tyler.  13C/12C Ratios in Atmospheric Methane and Some of Its Sources , 1989 .

[30]  Luiz Antonio Martinelli,et al.  Methane emissions to the troposphere from the Amazon floodplain , 1988 .