We present the chain of mechanisms linking free radical catalytic loss of stratospheric ozone, specifically over the central United States in summer, to increased climate forcing by CO2 and CH4 from fossil fuel use. This case directly engages detailed knowledge, emerging from in situ aircraft observations over the polar regions in winter, defining the temperature and water vapor dependence of the...
Publications
Anderson, J. G. & Clapp, C. E. (2018). Coupling free radical catalysis, climate change, and human health. Physical Chemistry Chemical Physics, 20 (16), 10569–10587. DOI: 10.1039/C7CP08331A.
Smith, J. P., J. A. Dykema, and D. W. Keith (2018), Production of Sulfates Onboard an Aircraft: Implications for the Cost and Feasibility of Stratospheric Solar Geoengineering, Earth Space Sci. 5, no. 4: 150-162, doi:10.1002/2018EA000370.
Injection of sulfate aerosols into the stratosphere, a form of solar geoengineering, has been proposed as a means to reduce some climatic changes by decreasing net anthropogenic radiative forcing. The cost and technical feasibility of forming aerosols with the appropriate size distribution are uncertain. We examine the possibility of producing the relevant sulfur species, SO2 or SO3, by in...
Cadoux A., Iacono-Marziano G., Scaillet B., Aiuppa S., Mather T.A., Pyle D.M., Deloule E., Gennaro E., Paonita A., 2018, The role of melt composition on aqueous fluid vs. silicate melt partitioning of bromine in magmas, Earth and Planetary Science Letters, 498, 450–463.
Volcanogenic halogens, in particular bromine, potentially play an important role in the ozone depletion of the atmosphere. Understanding bromine behaviour in magmas is therefore crucial to properly evaluate the contribution of volcanic eruptions to atmospheric chemistry and their environmental impact. To date, bromine partitioning between silicate melts and the gas phase is very poorly...
Anderson, J. G., D. K. Weisenstein, K. P. Bowman, C. R. Homeyer, J. B. Smith, D. M. Wilmouth, D. S. Sayres, J. E. Klobas, S. S. Leroy, J. A. Dykema, and S. C. Wofsy (2017), Stratospheric ozone over the United States in summer linked to observations of convection and temperature via chlorine and bromine catalysis, Proceedings of the National Academy of Sciences 114: E4905-E4913; doi: 10.1073/pnas.1619318114.
We present observations defining (i) the frequency and depth of convective penetration of water into the stratosphere over the United States in summer using the Next-Generation Radar system; (ii) the altitude-dependent distribution of inorganic chlorine established in the same coordinate system as the radar observations; (iii) the high resolution temperature structure in the stratosphere over the...
Sayres, D. S., R. Dobosy, C. Healy, E. Dumas, J. Kochendorfer, J. Munster, J. Wilkerson, B. Baker, and J. G. Anderson (2017), Arctic regional methane fluxes by ecotope as derived using eddy covariance from a low-flying aircraft, Atmos. Chem. Phys. 17(13): 8619-8633; doi: 10.5194/acp-17-8619-2017.
The Arctic terrestrial and sub-sea permafrost region contains approximately 30 % of the global carbon stock, and therefore understanding Arctic methane emissions and how they might change with a changing climate is important for quantifying the global methane budget and understanding its growth in the atmosphere. Here we present measurements from a new in situ flux observation system designed for...
Smith, J. B., D. M. Wilmouth, K. M. Bedka, K. P. Bowman, C. R. Homeyer, J. A. Dykema, M. R. Sargent, C. Clapp, S. S. Leroy, D. S. Sayres, J. M. Dean-Day, T. P. Bui, and J. G. Anderson (2017), A case-study of convectively sourced water vapor observed in the overworld stratosphere over the United States, J. Geophys. Res. Atmos. 122, doi:10.1002/2017JD026831.
On 27 August 2013, during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys field mission, NASA's ER‐2 research aircraft encountered a region of enhanced water vapor, extending over a depth of approximately 2 km and a minimum areal extent of 20,000 km2 in the stratosphere (375 K to 415 K potential temperature), south of...
Klobas, J. E., D. M. Wilmouth, D. K. Weisenstein, J. G. Anderson, and R. J. Salawitch (2017), Ozone depletion following future volcanic eruptions, Geophys. Res. Lett. 44, 7490-7499; doi: 10.1002/2017GL073972.
While explosive volcanic eruptions cause ozone loss in the current atmosphere due to an enhancement in the availability of reactive chlorine following the stratospheric injection of sulfur, future eruptions are expected to enhance total column ozone as halogen loading approaches pre-industrial levels. The timing of this shift in the impact of major volcanic eruptions on the thickness of the ozone...
Dobosy, R., D. Sayres, C. Healy, E. Dumas, M. Heuer, J. Kochendorfer, B. Baker, and J. Anderson (2017), Estimating random uncertainty in airborne flux measurements over Alaskan tundra: Update on the Flux Fragment Method, J. Atmos. Oceanic Technol., in press; doi: 10.1175/JTECH-D-16-0187.1.
Airborne turbulence measurement gives a spatial distribution of air-surface fluxes that networks of fixed surface sites typically can not capture. Much work has improved the accuracy of such measurements and the estimation of the uncertainty peculiar to streams of turbulence data measured from the air. A particularly significant challenge and opportunity is to distinguish fluxes from different...
Cadoux A., Iacono-Marziano G., Paonita. A., Deloule E., Aiuppa A., Eby N., Costa M., Brusca L., Berlo K., Geraki K., Mather T.A., Pyle D.M., Di Carlo I., 2017, A new set of standards for in-situ measurement of bromine abundances in natural silicate glasses: application to SR-XRF, LA-ICP-MS and SIMS techniques. Chemical Geology, 452, 60-70, doi: 10.1016/j.chemgeo.2017.01.012.
Measuring the low bromine abundances in Earth's materials remains an important challenge in order to constrain the geodynamical cycle of this element. Suitable standard materials are therefore required to establish reliable analytical methods to quantify Br abundances. In this study we characterise 21 Br-doped glasses synthesized from natural volcanic rocks of mafic to silicic compositions, in...
, , and (2016), The kinetics of the ClOOCl catalytic cycle, J. Geophys. Res. Atmos., 121, 13,768–13,783, doi:10.1002/2016JD025710.
We use simultaneous in situ observations of [ClO] and [ClOOCl] obtained in the Arctic polar vortex to evaluate the kinetics of the ClOOCl catalytic cycle. Available laboratory measurements of the ClOOCl absorption cross sections, the ClO + ClO + M reaction rate constant, and the ClO/ClOOCl equilibrium constant are considered, along with compendium evaluations of these...