scholarly journals Potential impact of iodinated replacement compounds CF<sub>3</sub>I and CH<sub>3</sub>I on atmospheric ozone: a three-dimensional modeling study

2010 ◽  
Vol 10 (7) ◽  
pp. 16659-16690
Author(s):  
◽  
K. O. Patten ◽  
D. J. Wuebbles ◽  
◽  
Keyword(s):  
Transport Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Atmospheric Ozone ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Model Calculations ◽  
Three Dimensional Modeling ◽  
Land Surfaces ◽  
The Tropics

Abstract. The concept of Ozone Depletion Potentials (ODPs) is extensively used in policy considerations related to concerns about the effects of various halocarbons and other gases on stratospheric ozone. Many of the recent candidate replacement compounds have atmospheric lifetimes shorter than one year in order to limit their environmental effects, especially on stratospheric ozone. Using a three-dimensional global chemistry-transport model (CTM) of the troposphere and the stratosphere, the purpose of this study is to evaluate the potential effects of several very short-lived iodinated substances, namely iodotrifluoromethane (CF3I) and methyl iodide (CH3I), on atmospheric ozone. Like other chemicals with extremely short lifetimes, the stratospheric halogen loading and resulting ozone effects from these compounds are strongly dependent on the location of emissions. For CF3I, a possible replacement candidate for bromotrifluoromethane (CF3Br), ODPs derived by the three-dimensional model are 0.008 with chemical lifetime of 5.03 days and 0.016 with a lifetime of 1.13 days for emissions assumed to be evenly distributed over land surfaces at mid-latitudes and the tropics, respectively. While this is the first time the ODPs have been evaluated with a three-dimensional model, these values are in good agreement with those derived previously. The model calculations suggest that tropical convection could deliver a larger portion of the gas and their breakdown products to the upper troposphere and lower stratosphere if emission source is located in the tropics. The resulting ODP for CH3I, emitted from mid-latitudes, is 0.017 with lifetime of 13.59 days. The validity of our model iodine chemistry to evaluate ODPs of the iodine species is guaranteed with good qualitative agreement between the model derived distribution of background CH3I, based on global source emission fluxes from previous studies, and available observations especially in vertical profiles.

scholarly journals Potential impact of iodinated replacement compounds CF<sub>3</sub>I and CH<sub>3</sub>I on atmospheric ozone: a three-dimensional modeling study

2010 ◽  
Vol 10 (20) ◽  
pp. 10129-10144 ◽  
Author(s):  
D. Youn ◽  
K. O. Patten ◽  
D. J. Wuebbles ◽  
H. Lee ◽  
C.-W. So
Keyword(s):  
Transport Model ◽  
Stratospheric Ozone ◽  
Vertical Mixing ◽  
Three Dimensional ◽  
Convective Transport ◽  
Atmospheric Ozone ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Model Calculations ◽  
The Tropics

Abstract. The concept of Ozone Depletion Potentials (ODPs) is extensively used in policy considerations related to concerns about the effects of various halocarbons and other gases on stratospheric ozone. Many of the recent candidate replacement compounds have atmospheric lifetimes shorter than one year in order to limit their environmental effects, especially on stratospheric ozone. Using a three-dimensional global chemistry-transport model (CTM) of the troposphere and the stratosphere, the purpose of this study is to evaluate the potential effects of several very short-lived iodinated substances, namely iodotrifluoromethane (CF3I) and methyl iodide (CH3I), on atmospheric ozone. Like other chemicals with extremely short lifetimes, the stratospheric halogen loading and resulting ozone effects from these compounds are strongly dependent on the location of emissions. For CF3I, a possible replacement candidate for bromotrifluoromethane (CF3Br), ODPs derived by the three-dimensional model are 0.008 with chemical lifetime of 5.03 days and 0.016 with a lifetime of 1.13 days for emissions assumed to be evenly distributed over land surfaces at mid-latitudes and the tropics, respectively. While this is the first time the ODPs have been evaluated with a three-dimensional model, these values are in good agreement with those derived previously. The model calculations suggest that tropical convection could deliver a larger portion of the gas and their breakdown products to the upper troposphere and lower stratosphere if emission source is located in the tropics. The resulting ODP for CH3I, emitted from mid-latitudes, is 0.017 with lifetime of 13.59 days. Valid simulations of convective transport, vertical mixing and degradation chemistry of CH3I are shown that have good qualitative agreement between the model derived distribution of background CH3I, based on global source emission fluxes from previous studies, and available observations especially in vertical profiles.

scholarly journals Three-dimensional model evaluation of the Ozone Depletion Potentials for n-propyl bromide, trichloroethylene and perchloroethylene

2011 ◽  
Vol 11 (5) ◽  
pp. 2371-2380 ◽  
Author(s):  
D. J. Wuebbles ◽  
K. O. Patten ◽  
D. Wang ◽  
D. Youn ◽  
M. Martínez-Avilés ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Ozone Depletion ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Past Study ◽  
Three Dimensional Model ◽  
Chemistry Transport Model ◽  
Land Surfaces ◽  
Simplified Modeling

Abstract. The existing solvents trichloroethylene (TCE) and perchloroethylene (PCE) and proposed solvent n-propyl bromide (nPB) have atmospheric lifetimes from days to a few months, but contain chlorine or bromine that could affect stratospheric ozone. Several previous studies estimated the Ozone Depletion Potentials (ODPs) for various assumptions of nPB emissions location, but these studies used simplified modeling treatments. The primary purpose of this study is to reevaluate the ODP for n-propyl bromide (nPB) using a current-generation chemistry-transport model of the troposphere and stratosphere. For the first time, ODPs for TCE and PCE are also evaluated in a three-dimensional, global atmospheric chemistry-transport model. Emissions representing industrial use of each compound are incorporated on land surfaces from 30° N to 60° N. The atmospheric chemical lifetime obtained for nPB is 24.7 days, similar to past literature, but the ODP is 0.0049, lower than in our past study of nPB. The derived atmospheric lifetime for TCE is 13.0 days and for PCE is 111 days. The corresponding ODPs are 0.00037 and 0.0050, respectively.

scholarly journals Atmospheric lifetimes and Ozone Depletion Potentials of trans-1-chloro-3,3,3-trifluoropropylene and trans-1,2-dichloroethylene in a three-dimensional model

2010 ◽  
Vol 10 (22) ◽  
pp. 10867-10874 ◽  
Author(s):  
K. O. Patten ◽  
D. J. Wuebbles
Keyword(s):  
Environmental Effects ◽  
Atmospheric Chemistry ◽  
Ozone Depletion ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Atmospheric Lifetime ◽  
Ozone Loss ◽  
Land Surfaces

Abstract. The chloroalkenes trans-1-chloro-3,3,3-trifluoropropylene (tCFP) and trans-1,2-dichloroethylene (tDCE) have been proposed as candidate replacements for other compounds in current use that cause concerns regarding potential environmental effects including destruction of stratospheric ozone. Because tCFP and tDCE contain chlorine atoms, the effects of these short-lived compounds on stratospheric ozone must be established. In this study, we derive the atmospheric lifetimes and Ozone Depletion Potentials (ODPs) for tCFP and for tDCE assuming emissions from land surfaces at latitudes 30° N to 60° N using the MOZART 3 three-dimensional model of atmospheric chemistry and physics. 53% of the ozone loss due to tCFP and 98% of the ozone loss due to tDCE take place in the troposphere, rather than in the stratosphere as generally expected from longer-lived chlorocarbons. The atmospheric lifetime of tCFP against chemical reaction is 40.4 days, and its ODP is quite small at 0.00034. The tDCE atmospheric lifetime is 12.7 days, and its ODP is 0.00024, which is the lowest ODP found for any chlorocarbon we have studied. Our study suggests that chlorine from tCFP and tDCE are unlikely to affect ozone at quantities likely to be emitted to the atmosphere.

scholarly journals Three-dimensional model evaluation of the Ozone Depletion Potentials for n-propyl bromide, trichloroethylene and perchloroethylene

2010 ◽  
Vol 10 (7) ◽  
pp. 17889-17910 ◽  
Author(s):  
D. J. Wuebbles ◽  
K. O. Patten ◽  
D. Wang ◽  
D. Youn ◽  
M. Martínez-Avilés ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Chemistry Transport Model ◽  
Atmospheric Lifetime ◽  
Land Surfaces ◽  
Simplified Modeling ◽  
First Time

Abstract. The existing solvents trichloroethylene (TCE) and perchloroethylene (PCE) and proposed solvent n-propyl bromide (nPB) have atmospheric lifetimes from days to a few months, but contain chlorine or bromine that could affect stratospheric ozone. Several previous studies estimated the Ozone Depletion Potentials (ODPs) for various assumptions for location of nPB emissions, but these studies used simplified modeling treatments. The primary purpose of this study is to reevaluate the ODP for nPB using a current-generation chemistry-transport model of the troposphere and stratosphere. For the first time, ODPs for TCE and PCE are also evaluated. Emissions representing industrial use of each compound are incorporated on land surfaces from 30° N to 60° N. The atmospheric chemical lifetime obtained for nPB is 24.7 days, similar to past literature, but the ODP is 0.0049, lower than in past studies. The derived atmospheric lifetime for TCE is 13.0 days and for PCE is 111 days. The corresponding ODPs are 0.00035 and 0.0060, respectively.

scholarly journals Atmospheric lifetimes and ozone depletion potentials of trans-1-chloro-3,3,3-trifluoropropylene and trans-1,2-dichloroethylene in a three-dimensional model

2010 ◽  
Vol 10 (7) ◽  
pp. 16637-16657 ◽  
Author(s):  
K. O. Patten ◽  
D. J. Wuebbles
Keyword(s):  
Chemical Reaction ◽  
Environmental Effects ◽  
Atmospheric Chemistry ◽  
Ozone Depletion ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Atmospheric Lifetime ◽  
Land Surfaces

Abstract. The chloroalkenes trans-1-chloro-3,3,3-trifluoropropylene (tCFP) and trans-1,2-dichloroethylene (tDCE) have been proposed as candidate replacements for other compounds in current use that cause concerns regarding potential environmental effects including destruction of stratospheric ozone. Because tCFP and tDCE contain chlorine atoms, the effects of these short-lived compounds on stratospheric ozone must be established. In this study, we derive the atmospheric lifetimes and Ozone Depletion Potentials (ODPs) for tCFP and for tDCE assuming emissions from land surfaces at latitudes 30° N to 60° N using the MOZART 3 three-dimensional model of atmospheric chemistry and physics. Both tCFP and tDCE are shown to primarily affect ozone in the troposphere, rather than in the stratosphere as generally expected from longer-lived chlorocarbons. The atmospheric lifetime of tCFP against chemical reaction is 40.4 days, and its ODP is quite small at 0.00034. The tDCE atmospheric lifetime is 12.7 days, and its ODP is 0.00024, which is the lowest ODP found for any chlorocarbon we have studied. Our study suggests that chlorine from tCFP and tDCE are unlikely to significantly affect ozone at quantities likely to be emitted to the atmosphere.

A comparison of one-, two- and three-dimensional model representations of stratospheric gases

1979 ◽  
Vol 290 (1376) ◽  
pp. 477-494 ◽  
Keyword(s):  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Jet Streams ◽  
Model Calculations ◽  
One Dimensional ◽  
Dimensional Models ◽  
Molecular Number

Three- and two-dimensional model results have been averaged to investigate conceptual errors in two- and one-dimensional models. Average dynamical quantities show inter-hemispheric asymmetries in both mean and eddy vertical motions, with anomalous behaviour of tracers near effective source and sink regions. Zonal, hemispheric and global means of the rates of gas reactions show large deviations between terms like k : [A] [B] and k : [A] [B], causing significant errors in two- and one-dimensional model calculations. These errors are often associated with dynamical features such as jet streams or the tropopause, and affect the entire model atmospheres except in the summer mid-stratosphere. It is concluded that correlated measurements of atmospheric molecular number densities are urgently required to understand the deficiencies in models, which have been widely used to make perturbation calculations of the effects of aircraft and chloro-fluoromethanes on stratospheric ozone. The sources of error described in this work arise from inadequacies in the formulation of one- and two-dimensional models, rather than from uncertainties in the input data, and have not been included in published error analyses.

scholarly journals Analysis of a rapid increase of stratospheric ozone during late austral summer 2008 over Kerguelen (49.4° S, 70.3° E)

2011 ◽  
Vol 11 (1) ◽  
pp. 363-373 ◽  
Author(s):  
H. Bencherif ◽  
L. El Amraoui ◽  
G. Kirgis ◽  
J. Leclair De Bellevue ◽  
A. Hauchecorne ◽  
...  
Keyword(s):  
Potential Vorticity ◽  
Large Scale ◽  
Lower Stratosphere ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Austral Summer ◽  
Air Masses ◽  
Global Mapping ◽  
The Tropics

Abstract. This paper reports on an increase of ozone event observed over Kerguelen (49.4° S, 70.3° E) in relationship with large-scale isentropic transport. This is evidenced by ground-based observations (co-localised radiosonde and SAOZ experiments) together with satellite global observations (Aura/MLS) assimilated into MOCAGE, a Méteo-France model. The study is based on the analyses of the first ozonesonde experiment never recorded at the Kerguelen site within the framework of a French campaign called ROCK that took place from April to August 2008. Comparisons and interpretations of the observed event are supported by co-localised SAOZ observations, by global mapping of tracers (O3, N2O and columns of O3) from Aura/MLS and Aura/OMI experiments, and by model simulations of Ertel Potential Vorticity initialised by the ECMWF (European Centre for Medium-Range Weather Forecasts) data reanalyses. Satellite and ground-based observational data revealed a consistent increase of ozone in the local stratosphere by mid-April 2008. Additionally, Ozone (O3) and nitrous oxide (N2O) profiles obtained during January–May 2008 using the Microwave Limb Sounder (MLS) aboard the Aura satellite are assimilated into MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle), a global three-dimensional chemistry transport model of Météo-France. The assimilated total O3 values are consistent with SAOZ ground observations (within ±5%), and isentropic distributions of O3 match well with maps of advected potential vorticity (APV) derived from the MIMOSA model, a high-resolution advection transport model, and from the ECMWF reanalysis. The event studied seems to be related to the isentropic transport of air masses that took place simultaneously in the lower- and middle-stratosphere, respectively from the polar region and from the tropics to the mid-latitudes. In fact, the ozone increase observed by mid April 2008 resulted simultaneously: (1) from an equator-ward departure of polar air masses characterised with a high-ozone layer in the lower stratosphere (near the 475 K isentropic level), and (2) from a reverse isentropic transport from the tropics to mid- and high-latitudes in the upper stratosphere (nearby the 700 K level). The increase of ozone observed over Kerguelen from the 16-April ozonesonde profile is thus attributed to a concomitant isentropic transport of ozone in two stratospheric layers: the tropical air moving southward and reaching over Kerguelen in the upper stratosphere, and the polar air passing over the same area but in the lower stratosphere.

scholarly journals DESIGNING A THREE-DIMENSIONAL MODEL OF THE CLASS SAFETY FOR THE RAILWAYS IN THE PROGRAM ASCON KOMPAS

2019 ◽  
Vol 7 ◽  
pp. 62-66
Author(s):  
Alexandra Zhuravleva
Keyword(s):  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Training Class ◽  
A Company ◽  
Safety Rules

This article demonstrates the possibility of a graphical program Kompas ASCON in the sphere of three-dimensional modeling of engineering and building objects. The created three-dimensional model of the training class for employees of JSC "Russian Railways" to study safety rules can have a real embodiment – all components are built according to catalogs and statements. In the course of work on this project various tools of the program are mastered: models of the room of a class of furniture are created. The basic operations of three-dimensional modeling and methods of creating assembly units are studied. All components of the class are paired. The resulting project has a high visibility and can be used as a presentation as a company that performs class projects, and the customer.

Modelling the global sources and sinks of radiatively active gases

1995 ◽  
Vol 351 (1696) ◽  
pp. 397-411 ◽  
Keyword(s):  
Numerical Models ◽  
Stratospheric Ozone ◽  
Trace Gases ◽  
Three Dimensional ◽  
Relative Importance ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Sources And Sinks ◽  
Two Dimensional Model

The use of numerical models in understanding the budgets of atmospheric trace gases is discussed. The budget of methane is calculated in a two-dimensional model. The contrasting behaviour of the Northern and Southern Hemisphere reflects changes in the relative importance of emissions, transport and chemistry. Models can also be used to test hypotheses. An example of such a study is presented in which it is shown that changes in stratospheric ozone could have played a significant role in the dramatic change in methane trend observed in the early 1990s. Finally, use of a three-dimensional model to study tropospheric trace gases is introduced.

Three-Dimensional Computational Hydrodynamics Modeling for Algae Transport and Growth

2017 ◽  
Author(s):  
Haidong Liu ◽  
Zhongquan Charlie Zheng ◽  
Bryan Young
Keyword(s):  
Green Algae ◽  
Hydrodynamic Model ◽  
Algal Blooms ◽  
Stokes Equations ◽  
Transport Model ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Fractional Step Method ◽  
Blue Green Algae

In this study, a three-dimensional model coupling hydrodynamics with algae transport dynamics is investigated. The hydrodynamic model solves the three-dimensional Navier-Stokes equations by a semi-implicit, fractional step method, where the hydrostatic components are determined first and the non-hydrostatic pressure and other components are determined in a subsequent step. Wind velocity on the water surface is accounted for the effect of wind stress on the flow velocities in the hydrodynamic model. Then, the model is coupled with an algae transport model, which enables simulation of algae transport and algal blooms. As an example, the model is implemented to analyze the transition of blue-green algae in Milford Lake, which is the largest man-made lake in Kansas suffering from blue-green algae blooms. The three-dimensional model provides a robust and efficient way for hydrodynamic and algae modeling and can be implemented to studies on different types of rivers and reservoirs easily. The simulated results can be very useful for algae control and prediction in both short and long terms.

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