Search

Your search keyword '"Dutton, G. S"' showing total 3 results
Start Over Author "Dutton, G. S" Publisher american geophysical union
3 results on '"Dutton, G. S"'

1. Interannual variability in tropospheric nitrous oxide

Author

Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Thompson, R. L., Dlugokencky, E., Chevallier, F., Ciais, P., Dutton, G. S., Elkins, J. W., Langenfelds, R. L., Weiss, R. F., Tohjima, Y., O'Doherty, Simon, Krummel, P. B., Fraser, P. J., Steele, L. P., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Thompson, R. L., Dlugokencky, E., Chevallier, F., Ciais, P., Dutton, G. S., Elkins, J. W., Langenfelds, R. L., Weiss, R. F., Tohjima, Y., O'Doherty, Simon, Krummel, P. B., Fraser, P. J., and Steele, L. P.

Abstract

Observations of tropospheric N2O mixing ratio show significant variability on interannual timescales (0.2 ppb, 1 standard deviation). We found that interannual variability in N2O is weakly correlated with that in CFC-12 and SF6 for the northern extratropics and more strongly correlated for the southern extratropics, suggesting that interannual variability in all these species is influenced by large-scale atmospheric circulation changes and, for SF6 in particular, interhemispheric transport. N2O interannual variability was not, however, correlated with polar lower stratospheric temperature, which is used as a proxy for stratosphere-to-troposphere transport in the extratropics. This suggests that stratosphere-to-troposphere transport is not a dominant factor in year-to-year variations in N2O growth rate. Instead, we found strong correlations of N2O interannual variability with the Multivariate ENSO Index. The climate variables, precipitation, soil moisture, and temperature were also found to be significantly correlated with N2O interannual variability, suggesting that climate-driven changes in soil N2O flux may be important for variations in N2O growth rate., European Research Council (EU Seventh Research Framework Programme (grant agreement 283576, MACC-II)), Research Council of Norway (contract 193774, SOGG-EA)

Published
2014

2. The diurnal variation of hydrogen, nitrogen, and chlorine radicals: implications for the heterogeneous production of HNO_2

Author

Salawitch, R. J., Wofsy, S. C., Wennberg, P. O., Cohen, R. C., Anderson, J. G., Fahey, D. W., Gao, R. S., Keim, E. R., Woodbridge, E. L., Stimpfle, R. M., Koplow, J. P., Kohn, D. W., Webster, C. R., May, R. D., Pfister, L., Gottlieb, E. W., Michelsen, H. A., Yue, G. K., Prather, M. J., Wilson, J. C., Brock, C. A., Jonsson, H. H., Dye, J. E., Baumgardner, D., Proffitt, M. H., Loewenstein, M., Podolske, J. R., Elkins, J. W., Dutton, G. S., Hintsa, E. J., Dessler, A. E., Weinstock, E. M., Kelly, K. K., Boering, K. A., Daube, B. C., Chan, K. R., and Bowen, S. W.

Abstract

In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained through sunrise and sunset in the lower stratosphere during SPADE are compared to results from a photochemical model constrained by observed concentrations of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N_(2)O_(5) on sulfate aerosols agree with measured concentrations of NO, NO_(2), and ClO throughout the day, but fail to account for high concentrations of OH and HO_(2) observed near sunrise and sunset. The morning burst of [OH] and [HO_(2)] coincides with the rise of [NO] from photolysis of NO_(2), suggesting a new source of HO_(x) that photolyzes in the near UV (350 to 400 nm) spectral region. A model that allows for the heterogeneous production of HNO_(2) results in an excellent simulation of the diurnal variations of [OH] and [HO_(2)].

Published
1994

3. The distribution of hydrogen, nitrogen, and chlorine radicals in the lower stratosphere: Implications for changes in O_3 due to emission of NO_y from supersonic aircraft

Author

Salawitch, R. J., Wofsy, S. C., Wennberg, P. O., Cohen, R. C., Anderson, J. G., Fahey, D. W., Gao, R. S., Keim, E. R., Woodbridge, E. L., Stimpfle, R. M., Koplow, J. P., Kohn, D. W., Webster, C. R., May, R. D., Pfister, L., Gottlieb, E. W., Michelsen, H. A., Yue, G. K., Wilson, J. C., Brock, C. A., Jonsson, H. H., Dye, J. E., Baumgardner, D., Proffitt, M. H., Loewenstein, M., Podolske, J. R., Elkins, J. W., Dutton, G. S., Hintsa, E. J., Dessler, A. E., Weinstock, E. M., Kelly, K. K., Boering, K. A., Daube, B. C., Chan, K. R., and Bowen, S. W.

Abstract

In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained in the lower stratosphere during SPADE are compared to results from a photochemical model that assimilates measurements of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N_2O_5 agree well with measured concentrations of NO and ClO, but concentrations of HO_2 and OH are underestimated by 10 to 25%, concentrations of NO_2 are overestimated by 10 to 30%, and concentrations of HCl are overestimated by a factor of 2. Discrepancies for [OH] and [HO_2] are reduced if we allow for higher yields of O(^1D) from O_3 photolysis and for heterogeneous production of HNO_2. The data suggest more efficient catalytic removal of O_3 by hydrogen and halogen radicals relative to nitrogen oxide radicals than predicted by models using recommended rates and cross sections. Increases in [O_3] in the lower stratosphere may be larger in response to inputs of NO_y from supersonic aircraft than estimated by current assessment models.

Published
1994

Catalog

Books, media, physical & digital resources
See catalog results