Radical loss in the atmosphere from Cu-Fe redox coupling in aerosols
Author:
Mao J.,Fan S.,Jacob D. J.,Travis K. R.
Abstract
Abstract. The hydroperoxyl radical (HO2) is a major precursor of OH and tropospheric ozone. OH is the main atmospheric oxidant, while tropospheric ozone is an important surface pollutant and greenhouse gas. Standard gas-phase models for atmospheric chemistry tend to overestimate observed HO2 concentrations, and this has been tentatively attributed to heterogeneous uptake by aerosol particles. It is generally assumed that HO2 uptake by aerosol involve conversion to H2O2, but this is of limited efficacy as an HO2 sink because H2O2 can photolyze to regenerate OH and from there HO2. Joint atmospheric observations of HO2 and H2O2 suggest that HO2 uptake by aerosols may in fact not produce H2O2. Here we propose a catalytic mechanism involving coupling of the transition metal ions (TMI) Cu(I)/Cu(II) and Fe(II)/Fe(III) to rapidly convert HO2 to H2O in aerosols. The implied HO2 uptake significantly affects global model predictions of tropospheric OH, ozone, and other species, improving comparisons to observations, and may have a major and previously unrecognized impact on atmospheric oxidant chemistry.
Publisher
Copernicus GmbH
Reference51 articles.
1. Alvarado, M. J., Logan, J. A., Mao, J., Apel, E., Riemer, D., Blake, D., Cohen, R. C., Min, K. E., Perring, A. E., Browne, E. C., Wooldridge, P. J., Diskin, G. S., Sachse, G. W., Fuelberg, H., Sessions, W. R., Harrigan, D. L., Huey, G., Liao, J., Case-Hanks, A., Jimenez, J. L., Cubison, M. J., Vay, S. A., Weinheimer, A. J., Knapp, D. J., Montzka, D. D., Flocke, F. M., Pollack, I. B., Wennberg, P. O., Kurten, A., Crounse, J., Clair, J. M. S., Wisthaler, A., Mikoviny, T., Yantosca, R. M., Carouge, C. C., and Le Sager, P.: Nitrogen oxides and PAN in plumes from boreal fires during ARCTAS-B and their impact on ozone: an integrated analysis of aircraft and satellite observations, Atmos. Chem. Phys., 10, 9739–9760, https://doi.org/10.5194/acp-10-9739-2010, 2010. 2. Bjergbakke, E., Sehested, K., and Rasmussen, O. L.: The reaction mechanism and rate constants in the radiolysis of \\chem{Fe^{2+}}-\\chem{Cu^{2+}} solutions, Radiat. Res., 66, 433–442, 1976. 3. Cantrell, C. A., Shetter, R. E., Gilpin, T. M., and Calvert, J. G.: Peroxy radicals measured during Mauna Loa observatory photochemistry experiment 2: the data and first analysis, J. Geophys. Res.-Atmos., 101, 14643–14652, 1996. 4. Cantrell, C. A., Edwards, G. D., Stephens, S., Mauldin, R. L., Zondlo, M. A., Kosciuch, E., Eisele, F. L., Shetter, R. E., Lefer, B. L., Hall, S., Flocke, F., Weinheimer, A., Fried, A., Apel, E., Kondo, Y., Blake, D. R., Blake, N. J., Simpson, I. J., Bandy, A. R., Thornton, D. C., Heikes, B. G., Singh, H. B., Brune, W. H., Harder, H., Martinez, M., Jacob, D. J., Avery, M. A., Barrick, J. D., Sachse, G. W., Olson, J. R., Crawford, J. H., and Clarke, A. D.: Peroxy radical behavior during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign as measured aboard the NASA P-3B aircraft, J. Geophys. Res., 108, 8797, https://doi.org/10.1029/2003jd003674, 2003a. 5. Cantrell, C. A., Mauldin, L., Zondlo, M., Eisele, F., Kosciuch, E., Shetter, R., Lefer, B., Hall, S., Campos, T., Ridley, B., Walega, J., Fried, A., Wert, B., Flocke, F., Weinheimer, A., Hannigan, J., Coffey, M., Atlas, E., Stephens, S., Heikes, B., Snow, J., Blake, D., Blake, N., Katzenstein, A., Lopez, J., Browell, E. V., Dibb, J., Scheuer, E., Seid, G., and Talbot, R.: Steady state free radical budgets and ozone photochemistry during TOPSE, J. Geophys. Res.-Atmos., 108, 8361, https://doi.org/10.1029/2002jd002198, 2003b.
Cited by
8 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献
|
|