Rethinking the Mesosphere’s Magnesium Ion Chemistry

Simon Petrie

doi:10.1071/EN04070

RESEARCH ARTICLE

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Rethinking the Mesosphere’s Magnesium Ion Chemistry

Simon Petrie

+ Author Affiliations

- Author Affiliations

Department of Chemistry, the Faculties, Australian National University, Canberra ACT 0200, Australia. Email: simon.petrie@anu.edu.au

Environmental Chemistry 2(1) 25-30 https://doi.org/10.1071/EN04070
Submitted: 24 September 2004 Accepted: 10 November 2004 Published: 21 March 2005

Environmental Context. Meteoric ablation profoundly influences the spectroscopic, chemical, and thermal properties of Earth’s upper atmosphere, yet much of the chemical processing of meteor-derived material remains a mystery. As the most abundant main-group metal in meteoric material, magnesium likely plays an important or dominant role but its mesospheric chemistry has received comparatively little study to date.

Abstract. High-level quantum chemical calculations address the structural and thermochemical properties of several novel magnesium-containing molecular ions which, we argue, are relevant to the Mg⁺ chemistry initiated by meteoric ablation in the mesosphere. A model for Mg⁺ chemistry is evaluated, with results indicating that most ionized magnesium at altitudes of 90 km and below is rapidly hydrated due to the association reactions of the pivotal HOMg⁺ ion. The implications of this new mechanism, apparently leading towards noctilucent cloud nucleation by Mg⁺, are briefly explored.

Keywords. : ab initio calculations — atmospheric chemistry — magnesium — mesosphere — noctilucent clouds

Acknowledgements

This work used the computational resources of the Australian Partnership for Advanced Computing (APAC), housed at the ANU Supercomputer Facility. The author thanks John Plane (University of East Anglia) for helpful discussions.

References

Rethinking the Mesosphere’s Magnesium Ion Chemistry

Acknowledgements

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