ChemInform Abstract: Reaction of Chlorine Nitrate with Protonated Water Clusters: A Model for Heterogeneous Reactions on Polar Stratospheric Clouds.

ChemInform ◽  
2010 ◽  
Vol 23 (42) ◽  
pp. no-no
Author(s):  
C. M. NELSON ◽  
M. OKUMURA
Keyword(s):  
Water Clusters ◽  
Heterogeneous Reactions ◽  
Polar Stratospheric Clouds ◽  
Chlorine Nitrate ◽  
Stratospheric Clouds

scholarly journals Development of a chemistry module for GCMs: first results of a multiannual integration

1998 ◽  
Vol 16 (2) ◽  
pp. 205-228 ◽  
Author(s):  
B. Steil ◽  
M. Dameris ◽  
C. Brühl ◽  
P. J. Crutzen ◽  
V. Grewe ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
General Circulation ◽  
Lower Stratosphere ◽  
Photochemical Reactions ◽  
Heterogeneous Reactions ◽  
Atmospheric Composition ◽  
Polar Stratospheric Clouds ◽  
First Results ◽  
Stratospheric Clouds ◽  
Chemistry Module

Abstract. The comprehensive chemistry module CHEM has been developed for application in general circulation models (GCMs) describing tropospheric and stratospheric chemistry, including photochemical reactions and heterogeneous reactions on sulphate aerosols and polar stratospheric clouds. It has been coupled to the spectral atmospheric GCM ECHAM3. The model configuration used in the current study has been run in an "off-line" mode, i.e. the calculated chemical species do not affect the radiative forcing of the dynamic fields. First results of a 15-year model integration indicate that the model ECHAM3/CHEM runs are numerically efficient and stable, i.e. that no model drift can be detected in dynamic and chemical parameters. The model reproduces the main features regarding ozone, in particular intra- and interannual variability. The ozone columns are somewhat higher than observed (approximately 10%), while the amplitude of the annual cycle is in agreement with observations. A comparison with HALOE data reveals, however, a serious model deficiency regarding lower-stratosphere dynamics at high latitudes. Contrary to what is concluded by observations, the lower stratosphere is characterized by slight upward motions in the polar regions, so that some of the mentioned good agreements must be considered as fortuitous. Nevertheless, ECHAM3/CHEM well describes the chemical processes leading to ozone reduction. It has been shown that the mean fraction of the northern hemisphere, which is covered by polar stratospheric clouds (PSCs) as well as the temporal appearance of PSCs in the model, is in fair agreement with observations. The model results show an activation of chlorine inside the polar vortex which is stronger in the southern than in the northern winter hemisphere, yielding an ozone hole over the Antarctic; this hole, however, is also caused to a substantial degree by the dynamics. Interhemispheric differences concerning reformation of chlorine reservoir species HCl and ClONO2 in spring have also been well reproduced by the model.Key words. Atmospheric composition and structure · Middle atmosphere · Meteorology and atmospheric dynamics · Climatology · General circulation

scholarly journals Mountain-wave induced polar stratospheric clouds and their representation in the global chemistry model ICON-ART

2020 ◽  
Author(s):  
Michael Weimer ◽  
Jennifer Buchmüller ◽  
Lars Hoffmann ◽  
Ole Kirner ◽  
Beiping Luo ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Climate Models ◽  
Hot Spot ◽  
Heterogeneous Reactions ◽  
Polar Stratospheric Clouds ◽  
Mountain Wave ◽  
Mountain Waves ◽  
Stratospheric Clouds ◽  
Wave Induced ◽  
The Antarctic

Abstract. Polar stratospheric clouds (PSCs) are a driver for ozone depletion in the lower polar stratosphere. They provide surfaces for heterogeneous reactions activating chlorine and bromine reservoir species during the polar night. PSCs are represented in current global chemistry-climate models, but one process is still a challenge: the representation of PSCs formed locally in conjunction with unresolved mountain waves. In this study, we present simulations with the ICOsahedral Nonhydrostatic modelling framework (ICON) with its extension for Aerosols and Reactive Trace gases (ART) that include local grid refinements (nesting) with two-way interaction. Here, the nesting is set up around the Antarctic Peninsula which is a well-known hot spot for the generation of mountain waves in the southern hemisphere. We compare our model results with satellite measurements from the Cloud-Aerosol LIdar with Orthogonal Polarisation (CALIOP) and the Atmospheric InfraRed Sounder (AIRS). We study a mountain wave event that took place from 19 to 29 July 2008 and find similar structures of PSCs as well as a fairly realistic development of the mountain wave in the Antarctic Peninsula nest. We compare a global simulation without nesting with the nested configuration to show the benefit. Although the mountain waves cannot be resolved adequately in the used global resolution (about 160 km), their effect from the nested regions (about 80 and 40 km) on the global domain is represented. Thus, we show in this study that by using the two-way nesting technique the gap between directly resolved mountain-wave induced PSCs and their representation and effect on chemistry in coarse global resolutions can be bridged by the ICON-ART model.

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>

scholarly journals A closer look at Arctic ozone loss and polar stratospheric clouds

2010 ◽  
Vol 10 (3) ◽  
pp. 6681-6712 ◽  
Author(s):  
N. R. P. Harris ◽  
R. Lehmann ◽  
M. Rex ◽  
P. von der Gathen
Keyword(s):  
Nitric Acid ◽  
Climate Models ◽  
Empirical Relationship ◽  
Early Spring ◽  
Polar Stratospheric Clouds ◽  
Chlorine Nitrate ◽  
Ozone Loss ◽  
Near Ultraviolet ◽  
Chlorine Monoxide ◽  
Stratospheric Clouds

Abstract. The empirical relationship found between column-integrated Arctic ozone loss and the volume of polar stratospheric clouds inferred from meteorological analyses is updated and examined in more detail. The relationship is found to hold at different altitudes as well as in the column. Analysis of the photochemistry leading to the ozone loss shows that the early winter activation is limited by the photolysis of nitric acid. This step produces nitrogen dioxide which is converted to chlorine nitrate which in turn reacts with hydrogen chloride on any polar stratospheric clouds to form active chlorine. The rate-limiting step is the photolysis of nitric acid: this occurs at the same rate every year and so the interannual variation in the ozone loss is caused by the extent and persistence of the polar stratospheric clouds. In early spring the ozone loss rate increases as the solar insolation increases the photolysis of the chlorine monoxide dimer. However the length of the ozone loss period is determined by the photolysis of nitric acid which also occurs in the near ultraviolet. As a result of these compensating effects, the amount of the ozone loss is principally limited by the extent of original activation rather than its timing. In addition a number of factors, including the vertical changes in pressure and total inorganic chlorine as well as denitrification and renitrification, offset each other. As a result the extent of original activation is the most important factor influencing ozone loss. These results indicate that relatively simple parameterisations of Arctic ozone loss could be developed for use in coupled chemistry climate models.

scholarly journals On the linkage between tropospheric and Polar Stratospheric clouds in the Arctic as observed by space–borne lidar

2012 ◽  
Vol 12 (8) ◽  
pp. 3791-3798 ◽  
Author(s):  
P. Achtert ◽  
M. Karlsson Andersson ◽  
F. Khosrawi ◽  
J. Gumbel
Keyword(s):  
Lower Stratosphere ◽  
Satellite Observation ◽  
Heterogeneous Reactions ◽  
The Arctic ◽  
Polar Stratospheric Clouds ◽  
Cloud Systems ◽  
Lidar Measurements ◽  
Polar Stratosphere ◽  
Temporal And Spatial ◽  
Stratospheric Clouds

Abstract. The type of Polar stratospheric clouds (PSCs) as well as their temporal and spatial extent are important for the occurrence of heterogeneous reactions in the polar stratosphere. The formation of PSCs depends strongly on temperature. However, the mechanisms of the formation of solid PSCs are still poorly understood. Recent satellite studies of Antarctic PSCs have shown that their formation can be associated with deep-tropospheric clouds which have the ability to cool the lower stratosphere radiatively and/or adiabatically. In the present study, lidar measurements aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite were used to investigate whether the formation of Arctic PSCs can be associated with deep-tropospheric clouds as well. Deep-tropospheric cloud systems have a vertical extent of more than 6.5 km with a cloud top height above 7 km altitude. PSCs observed by CALIPSO during the Arctic winter 2007/2008 were classified according to their type (STS, NAT, or ice) and to the kind of underlying tropospheric clouds. Our analysis reveals that 172 out of 211 observed PSCs occurred in connection with tropospheric clouds. 72% of these 172 observed PSCs occurred above deep-tropospheric clouds. We also find that the type of PSC seems to be connected to the characteristics of the underlying tropospheric cloud system. During the Arctic winter 2007/2008 PSCs consisting of ice were mainly observed in connection with deep-tropospheric cloud systems while no ice PSC was detected above cirrus. Furthermore, we find no correlation between the occurrence of PSCs and the top temperature of tropospheric clouds. Thus, our findings suggest that Arctic PSC formation is connected to adiabatice cooling, i.e. dynamic effects rather than radiative cooling.

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