and Atmospheric Administration (NOAA),
Earth System Research Laboratory (ESRL)
What does this program measure?
The Mauna Loa Observatory CATS (Chromatograph for Atmospheric Trace Species) CATS program measures the following, where 'ppt' is parts-per-trillion, and 'ppb' is parts-per-billion.
|Methyl Halides||Methyl Bromide||CH3Br||ppt|
|Chlorinated Solvents||Carbon Tetrachloride||CCl4||ppt|
|Chlorinated Solvents||Methyl Chloride||CH3Cl||ppt|
|Other Measurements||Nitrous Oxide||N2O||ppb|
|Other Measurements||Methyl Chloroform||CH3CCl3||ppt|
|Other Measurements||Carbonyl Sulfide||COS||ppt|
How does this program work?
Electron Capture Detection-Gas Chromatography is done continuously at MLO.
Why is this research important?
All of these gases are greenhouse gases. Chlorofluorocarbons (CFCs), Hydrochlorofluorocarbons (HCFCs), methyl halides (CH3Br and CH3Cl), and N2O deplete stratospheric ozone. Chlorinated solvents are involved in regional air quality.
Are there any trends in the data?
CFCs, CH3CCl3, CH3Br, and CCl4 are decreasing because of the Montreal Protocol. N2O, HCFCs, and HFCs are increasing.
How does this program fit into the big picture?
What is it's role in global climate change?
All of these gases are greenhouse gases to a certain degree.
Comments and References
- Butler , J.H., J.W. Elkins, B.D. Hall, S.O. Cummings, and S.A. Montzka, A decrease in the growth rates of atmospheric halon concentrations, Nature, 359, 403-405, 1992.
- Butler, J.H., J.W. Elkins, T.M. Thompson, and K.B. Egan, Tropospheric and dissolved N 2O of the west Pacific and east Indian Oceans during the El Niño-Southern Oscillation event of 1987, J. Geophys. Res. , 94 (D12), 14865-14877, 1989.
- Dlugokencky, E.J., T. J. Conway, P. P. Tans, S. A. Montzka, and J. W. Elkins, Recent trends in greenhouse gases, in Sixth Symposium on Global Change Studies, pp. 202-204, 1995.
- Elkins, J.W., T.M. Thompson, T.H. Swanson, J.H. Butler, B.D. Hall, S.O. Cummings, D.A. Fisher, and A.G. Raffo, Decrease in the growth rates of atmospheric chlorofluorocarbons 11 and 12, Nature, 364 (August 26, 1993), 780-783, 1993.
- Montzka, S.A., J.H. Butler, R.C. Myers, T.M. Thompson, T.H. Swanson, A.D. Clarke, L.T. Lock, J.W. Elkins, Decline in the tropospheric abundance of halogen from halocarbons: Implications for stratospheric ozone depletion., Science, 272, 1318-1322, 1996.