Synchrotron radiation and long path cryogenic cells: New tools and results for modelling chlorinated compounds absorption in the 8-12µm atmospheric window

2020 ◽  
Author(s):  
Laurent Manceron
Keyword(s):  
High Resolution ◽  
Atmospheric Chemistry ◽  
Broad Band ◽  
Spectroscopic Studies ◽  
Heterogeneous Reactions ◽  
Chlorine Nitrate ◽  
Synchrotron Source ◽  
Fourier Transform Spectrometry ◽  
Vibrational Levels ◽  
Stratospheric Clouds

<p> </p><p><strong>Anusanth Anantharajah<sup>a</sup>, Fridolin Kwabia Tchana<sup>a</sup>, Jean-Marie Flaud<sup>a</sup> , Pascale Roy<sup>b</sup> and Laurent Manceron<sup>b,c</sup></strong></p><ul><li>a- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, <br>Université de Paris et Université Paris-Est Créteil, Institut Pierre Simon Laplace, <br>61 Avenue du Général de Gaulle, 94010 Créteil Cedex, France.</li> <li>b- Synchrotron SOLEIL, AILES Beamline, L’Orme des Merisiers, Saint-Aubin F-91192, France.</li> <li>c-  Sorbonne Université, CNRS, MONARIS, UMR 8233, 4 place Jussieu, F-75005 Paris, France. </li> </ul><p> </p><p>Nitryl chloride (ClNO<sub>2</sub>) and Chlorine Nitrate are molecules of great interest for atmospheric chemistry since these are produced by heterogeneous reactions, in the marine troposphere, between NaCl sea-salt aerosols or ClO and gaseous N<sub>2</sub>O<sub>5</sub> [1,2], and on polar stratospheric clouds, between N<sub>2</sub>O<sub>5</sub> and solid HCl [3,4].</p><p> </p><p>Many high-resolution spectroscopic studies in the microwave and mid-infrared regions are available. However, these molecules present low-lying vibrational levels and thus numerous hot bands in the regions of the NOx stretching and bending mode absorptions in the 8-12 µm atmospheric transparency window which could serve for remote sensing and quantification of these species.</p><p>Fourier Transform Spectrometry is a useful technique to observe broad band high resolution spectra (0.001 cm<sup>-1</sup>) of these molecules and a significant advantage is gained by combining interferometry with the high brightness of a synchrotron source [5]. At SOLEIL we have developed specific instrumentation to study such reactive molecules and a few results concerning chlorine-containing compounds will be presented.</p><ol><li>B. J. Finlayson-Pitts, M. J. Ezell, and J. N. Pitts Jr, Nature <strong>337</strong>, 241-244 (1989).</li> <li>W. Behnke, V. Scheer, and C. Zetzsch, J. Aerosol Sci. <strong>24</strong>, 115-116 (1993).</li> <li>. M. A. Tolbert, M. J. Rossi, and D. M. Golden, Science <strong>240</strong>, 1018-1021 (1988).</li> <li>M. T. Leu, Geophys. Res. Lett. <strong>15</strong>, 851-854 (1988).</li> <li> J-M. Flaud, A. Anantharajah, F. Kwabia Tchana, L. Manceron, J. Orphal, G. Wagner, and M. Birk, J Quant Spectrosc Radiat Transf <strong>224</strong>, 217-221 (2019).</li> </ol><p> </p>

The high-resolution spectroscopy of dissociating molecules

1990 ◽  
Vol 332 (1625) ◽  
pp. 297-307 ◽  
Keyword(s):  
High Resolution ◽  
Energy Flow ◽  
Energy State ◽  
Reaction Dynamics ◽  
Theoretical Models ◽  
Spectroscopic Studies ◽  
High Resolution Spectroscopy ◽  
Bond Breaking ◽  
Vibrational Levels ◽  
Dynamical Constraints

Results from spectroscopic studies of the vibrational levels of dissociating molecules and from state-selected, state-resolved photofragmentation spectroscopy are presented. The extent of energy flow among the modes of a molecule is explored through the couplings, or lack thereof, revealed by high-resolution spectroscopy. The dynamics of energy flow during bond breaking are revealed by photofragment excitation spectroscopy and by product energy state distributions. These completely resolved data provide sensitive tests of dynamical constraints such as vibrational or rotational adiabaticity and thus of theoretical models for unimolecular reaction dynamics.

scholarly journals Contribution of liquid, NAT and ice particles to chlorine activation and ozone depletion in Antarctic winter and spring

2015 ◽  
Vol 15 (4) ◽  
pp. 2019-2030 ◽  
Author(s):  
O. Kirner ◽  
R. Müller ◽  
R. Ruhnke ◽  
H. Fischer
Keyword(s):  
Atmospheric Chemistry ◽  
Ozone Depletion ◽  
Climate Model ◽  
Heterogeneous Reactions ◽  
Heterogeneous Chemistry ◽  
Ice Particles ◽  
Synoptic Conditions ◽  
Almost All ◽  
Stratospheric Clouds ◽  
The Impact

Abstract. Heterogeneous reactions in the Antarctic stratosphere are the cause of chlorine activation and ozone depletion, but the relative roles of different types of polar stratospheric clouds (PSCs) in chlorine activation is an open question. We use multi-year simulations of the chemistry-climate model ECHAM5/MESSy for Atmospheric Chemistry (EMAC) to investigate the impact that the various types of PSCs have on Antarctic chlorine activation and ozone loss. One standard and three sensitivity EMAC simulations have been performed. In all simulations a Newtonian relaxation technique using the ERA-Interim reanalysis was applied to simulate realistic synoptic conditions. In the three sensitivity simulations, we only changed the heterogeneous chemistry on PSC particles by switching the chemistry on liquid, nitric acid trihydrate (NAT) and ice particles on and off. The results of these simulations show that the significance of heterogeneous reactions on NAT and ice particles for chlorine activation and ozone depletion in Antarctic winter and spring is small in comparison to the significance of heterogeneous reactions on liquid particles. Liquid particles alone are sufficient to activate almost all of the available chlorine, with the exception of the upper PSC regions between 10 and 30 hPa, where temporarily ice particles show a relevant contribution. Shortly after the first PSC occurrence, NAT particles contribute a small fraction to chlorine activation. Heterogeneous chemistry on liquid particles is responsible for more than 90% of the ozone depletion in Antarctic spring in the model simulations. In high southern latitudes, heterogeneous chemistry on ice particles causes only up to 5 DU of additional ozone depletion in the column and heterogeneous chemistry on NAT particles less than 0.5 DU. The simulated HNO3, ClO and O3 results agree closely with observations from the Microwave Limb Sounder (MLS) onboard NASA's Aura satellite.

Investigation of the rovibrational levels of the B3Πg state of 14N2 molecule above the dissociation limit N(4S) + N(4S) by Fourier transform spectrometry

1990 ◽  
Vol 68 (11) ◽  
pp. 1257-1261 ◽  
Author(s):  
F. Roux ◽  
F. Michaud
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Emission Spectrum ◽  
Dissociation Limit ◽  
Fourier Transform Spectrometry ◽  
Strong Intensity ◽  
Vibrational Levels ◽  
Dissociation Threshold

Rotational analyses of vibrational levels of the B3Πg state, located above the dissociation threshold N(4S) + N(4S) were performed from a high-resolution emission spectrum recorded by Fourier transform spectrometry. Strong intensity perturbations were observed in the B3Πg vibrational levels ν′ = 13, 14, and 15.

scholarly journals Spatial and seasonal variability of PM<sub>2.5</sub> acidity at two Chinese megacities: insights into the formation of secondary inorganic aerosols

2012 ◽  
Vol 12 (3) ◽  
pp. 1377-1395 ◽  
Author(s):  
K. He ◽  
Q. Zhao ◽  
Y. Ma ◽  
F. Duan ◽  
F. Yang ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Temporal Variations ◽  
Early Summer ◽  
Heterogeneous Reactions ◽  
Rural Site ◽  
Urban Site ◽  
Simultaneous Increase ◽  
Northwestern Pacific ◽  
Inorganic Aerosols ◽  
Aerosol Acidity

Abstract. Aerosol acidity is one of the most important parameters influencing atmospheric chemistry and physics. Based on continuous field observations from January 2005 to May 2006 and thermodynamic modeling, we investigated the spatial and seasonal variations in PM2.5 acidity in two megacities in China, Beijing and Chongqing. Spatially, PM2.5 was generally more acidic in Chongqing than in Beijing, but a reverse spatial pattern was found within the two cities, with more acidic PM2.5 at the urban site in Beijing whereas the rural site in Chongqing. Ionic compositions of PM2.5 revealed that it was the higher concentrations of NO3− at the urban site in Beijing and the lower concentrations of Ca2+ within the rural site in Chongqing that made their PM2.5 more acidic. Temporally, PM2.5 was more acidic in summer and fall than in winter, while in the spring of 2006, the acidity of PM2.5 was higher in Beijing but lower in Chongqing than that in 2005. These were attributed to the more efficient formation of nitrate relative to sulfate as a result of the influence of Asian desert dust in 2006 in Beijing and the greater wet deposition of ammonium compared to sulfate and nitrate in 2005 in Chongqing. Furthermore, simultaneous increase of PM2.5 acidity was observed from spring to early summer of 2005 in both cities. This synoptic-scale evolution of PM2.5 acidity was accompanied by the changes in air masses origins, which were influenced by the movements of a subtropical high over the northwestern Pacific in early summer. Finally, the correlations between [NO3−]/[SO42−] and [NH4+]/[SO42−] suggests that under conditions of high aerosol acidity, heterogeneous reactions became one of the major pathways for the formation of nitrate at both cities. These findings provided new insights in our understanding of the spatial and temporal variations in aerosol acidity in Beijing and Chongqing, as well as those reported in other cities in China.

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