0000000000338527
AUTHOR
John M. C. Plane
showing 7 related works from this author
Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.
2020
8 pags., 5 figs., 2 tabs.
Modelling molecular iodine emissions in a coastal marine environment: The link to new particle formation
2006
International audience; A model of iodine chemistry in the marine boundary layer (MBL) has been used to investigate the impact of daytime coastal emissions of molecular iodine (I2). The model contains a full treatment of gas-phase iodine chemistry, combined with a description of the nucleation and growth, by condensation and coagulation, of iodine oxide nano-particles. In-situ measurements of coastal emissions of I2 made by the broadband cavity ring-down spectroscopy (BBCRDS) and inductively coupled plasma-mass spectrometry (ICP/MS) techniques are presented and compared to long path differential optical absorption spectroscopy (DOAS) observations of I2 at Mace Head, Ireland. Simultaneous me…
Stratospheric aerosol-Observations, processes, and impact on climate
2016
Interest in stratospheric aerosol and its role in climate have increased over the last decade due to the observed increase in stratospheric aerosol since 2000 and the potential for changes in the sulfur cycle induced by climate change. This review provides an overview about the advances in stratospheric aerosol research since the last comprehensive assessment of stratospheric aerosol was published in 2006. A crucial development since 2006 is the substantial improvement in the agreement between in situ and space-based inferences of stratospheric aerosol properties during volcanically quiescent periods. Furthermore, new measurement systems and techniques, both in situ and space based, have be…
Refractory metal nuggets in different types of cosmic spherules
2014
Abstract Out of the three basic cosmic spherule types collected from the seafloor, RMNs (refractory metal nuggets) have been reported from I-type spherules commonly, rarely from S-type spherules and never from the G-type spherules. Nuggets in the I-type cosmic spherules have formed by melting and complete oxidation during atmospheric entry, whereas no clear understanding emerged so far regarding the formation of the rare nuggets in S-type spherules. We collected cosmic spherules by raking the deep seafloor with magnets, and carried out systematic and sequential grinding, polishing and electron microscopic investigations on 992 cosmic spherules to identify RMNs. Fifty-four nuggets (RMNs) are…
Particle shapes and infrared extinction spectra of nitric acid dihydrate crystals: Optical constants of the β-NAD modification
2023
Satellite- and aircraft-based mid-infrared measurements of polar stratospheric clouds (PSCs) have provided spectroscopic evidence for the presence of β-NAT (nitric acid trihydrate) particles. Metastable nitric acid hydrate phases such as α-NAT and α-NAD (nitric acid dihydrate) have been frequently observed in laboratory experiments, but not yet detected as a constituent of PSCs in atmospheric measurements. As for the β-NAD modification, its formation was first observed in X-ray diffraction measurements when the low-temperature α-NAD phase was warmed to a temperature above 210 K. Its infrared spectrum has been reported, but so far no optical constants have been de…
O2(a1Δg) + Mg, Fe, and Ca: experimental kinetics and formulation of a weak collision, multiwell master equation with spin-hopping
2012
The first excited electronic state of molecular oxygen, O(2)(a(1)Δ(g)), is formed in the upper atmosphere by the photolysis of O(3). Its lifetime is over 70 min above 75 km, so that during the day its concentration is about 30 times greater than that of O(3). In order to explore its potential reactivity with atmospheric constituents produced by meteoric ablation, the reactions of Mg, Fe, and Ca with O(2)(a) were studied in a fast flow tube, where the metal atoms were produced either by thermal evaporation (Ca and Mg) or by pulsed laser ablation of a metal target (Fe), and detected by laser induced fluorescence spectroscopy. O(2)(a) was produced by bubbling a flow of Cl(2) through chilled al…
Photoreduction of gaseous oxidized mercury changes global atmospheric mercury speciation, transport and deposition
2018
9 pags, 8 figs. -- Correction autor: https://doi.org/10.1038/s41467-022-28455-w http://hdl.handle.net/10261/268181