J. Eric Klobas's Publications

Klobas, J. E. and Wilmouth, D. M.: UV spectroscopic determination of the chlorine monoxide (ClO) ∕ chlorine peroxide (ClOOCl) thermal equilibrium constant, Atmos. Chem. Phys., 19, 6205–6215, https://doi.org/10.5194/acp-19-6205-2019, 2019.

The thermal equilibrium constant between the chlorine monoxide radical (ClO) and its dimer, chlorine peroxide (ClOOCl), was determined as a function of temperature between 228–301K in a discharge flow apparatus using broadband UV absorption spectroscopy. A third law fit of the equilibrium values determined from the experimental data provides the expression: Keq = 2.16×10−27 e(8533±...

Klobas, J. Eric and David M. Wilmouth. 2019. Volcanogenic chlorofluorocarbons and the recent CFC anomalies. Harvard University, Cambridge, MA. https://dash.harvard.edu/handle/1/39913598.

This document is a white paper prepared at the request of the Scientific Assessment Panel (SAP) of the Montreal Protocol. We briefly review the literature regarding the volcanogenic production of chlorofluorocarbons within the context of the East Asian CFC-11 emissions anomaly first described in 2018. We conclude that volcanic emissions of CFC-11 cannot account for the observed emissions anomaly.

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...

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...