Janusz Pudykiewicz - Academia.edu (original) (raw)

Uploads

Papers by Janusz Pudykiewicz

Journal of Computational Physics, 2022

ICAO journal, Dec 1, 1992

Journal of the Meteorological Society of Japan, 1990

The global scale predictive tracer model designed to simulate atmospheric transport processes as ... more The global scale predictive tracer model designed to simulate atmospheric transport processes as well as a tropospheric and stratospheric chemistry is described. The model consists of a global spectral model and a set of the mass conservation equations coupled through the chemistry terms. The model was tested in both diagnostic and fully predictive mode simulating the hemispheric scale dispersion of radionuclides from the Chernobyl accident. The analysis of the predictive run results indicate that the model is able to predict the large scale mass distribution for periods up to six days when started from a sufficiently accurate initial condition. An extended prediction of the hemispheric tracer distribution was performed up to 24 days; the tracer field in these experiments was updated every 6 days using an initial condition provided by a parallel run of the diagnostic model.

Journal of Climate, Mar 1, 1995

The Canadian Aerosol Module [CAM] is being incorporated into a new, multipollutant, multi-issue E... more The Canadian Aerosol Module [CAM] is being incorporated into a new, multipollutant, multi-issue Eulerian regional air quality modelling system AURAMS [AES Unified Regional Air-Quality Modelling System] whose first application will be to simulate paniculate matter [PM] emissions, transport, chemistry, and removal in eastern North America. CAM employs a sizedistributed multi-component aerosol algorithm and has been used in Canadian climate models to assess the climatic impact of atmospheric aerosols. In addition to CAM, AURAMS will contain an emissions pre-processor, a meteorological driver, and a chemical transport model, including gasand aqueous-phase chemistry and removal processes for gaseous species.

Air Pollution Modeling and Its Application VIII, 1991

The numerical simulation of atmospheric dispersion is used increasingly to assess the state of th... more The numerical simulation of atmospheric dispersion is used increasingly to assess the state of the environment. A well known example is the use of numerical dispersion models with complex chemistry schemes for studies of atmospheric oxidants and acid rain phenomenon. The other important application of tracer models is the simulation of accidental releases of toxic and radioactive materials. The Atmospheric Environment Service (AES) of Canada recently used such a tracer model to simulate the dispersion of nuclear debris from the Chernobyl reactor accident. This research was the beginning of the development of a sophisticated Environmental Emergency Response (EER) system which is currently operational at the Canadian Meteorological Center (CMC). Similar efforts were also undertaken by the meteorological services of other countries. The objective of this paper is to present a general description of the Canadian Nuclear Emergency Response Model (CANERM) and compare it to similar models which are being used in other meteorological centers around the world.

Journal of Geophysical Research: Atmospheres, 2007

During July and August, 2004, balloon‐borne ozonesondes were released daily at 12 sites in the ea... more During July and August, 2004, balloon‐borne ozonesondes were released daily at 12 sites in the eastern USA and Canada, producing the largest single set of free tropospheric ozone measurements ever compiled for this region. At the same time, a number of air quality forecast models were run daily as part of a larger field experiment. In this paper, we compare these ozonesonde profiles with predicted ozone profiles from several versions of two of these forecast models, the Environment Canada CHRONOS and AURAMS models. We find that the models show considerable skill at predicting ozone in the planetary boundary layer and immediately above. Individual station biases are variable, but often small. Standard deviations of observation‐forecast differences are large, however. Ozone variability in the models is somewhat higher than observed. Most strikingly, none of the model versions is able to reproduce the typical tropospheric ozone profile of increasing mixing ratio with altitude. Results ...

Bulletin of the American Meteorological Society, Jun 1, 2004

... LI Shibei MENG Fan (Chinese Research Academy of Environmental Sciences, Beijing 100012). Air ... more ... LI Shibei MENG Fan (Chinese Research Academy of Environmental Sciences, Beijing 100012). Air Quality Prediction System consists of air ... 1, WANG Zu-lu et al (Fujian Institute of Meteorological Science,Fuzhou,Fujian 350001);Observation Results and Characteristic Analysis of ...

Recent advances in chemistry and meteorology models and computational efficiency have allowed the... more Recent advances in chemistry and meteorology models and computational efficiency have allowed the operational use of coupled chemistry-transport models (CTMs) by local air quality forecasters. The

However my specific comment is about Figure 9. It seems to me that it is a bit misleading because... more However my specific comment is about Figure 9. It seems to me that it is a bit misleading because the results in it cannot be compared directly with the results in Figures 3 and other. This is because Gaussian distribution of the source term (corresponding to the Fig. 9) has mean value of the source term equal to zero. Thus the regularisation term in functional 10 tends the estimated source term closer to zero value. While the

Recent advances in chemistry and meteorology models and computational efficiency have allowed the... more Recent advances in chemistry and meteorology models and computational efficiency have allowed the operational use of coupled chemistry-transport models (CTMs) by local air quality forecasters. The adoption of numerical model guidance by operational forecasters, the number of whom has been increasing rapidly in the past several years, depends on the reliability of numerical model guidance in critical high ozone (O3) cases. In turn, routine use of these models by forecasters can result in a positive feedback of information to model developers to further improve model performance.

Geoscientific Model Development Discussions

This study presents a methodology for the optimization of a monitoring network of sensors measuri... more This study presents a methodology for the optimization of a monitoring network of sensors measuring the polluting substances in an urban environment with a view to estimate an unknown emission source. The methodology was presented by coupling the Simulated Annealing algorithm with the renormalization inversion technique and the Computational Fluid Dynamics (CFD) modeling approach. Performance of a network was analyzed by reconstructing the unknown continuous point emissions using the concentration measurements from the sensors in that optimized network. This approach was successfully applied and validated with 20 trials of the Mock Urban Setting Test (MUST) tracer field experiment in an urban-like environment. The optimal networks in the MUST urban region enabled to reduce the size of original network (40-sensors) to ~ 1/3^rd (13-sensors) and to 1/4^th (10-sensors). The 10 and 13 sensors optimal networks have estimated the averaged ...

Journal of Computational Physics

In this paper, we investigate the use of higher-order exponential Rosenbrock time integration met... more In this paper, we investigate the use of higher-order exponential Rosenbrock time integration methods for the shallow water equations on the sphere. This stiff, nonlinear model provides a 'testing ground' for accurate and stable time integration methods in weather modeling, serving as the focus for exploration of novel methods for many years. We therefore identify a candidate set of three recent exponential Rosenbrock methods of orders four and five (exprb42, pexprb43 and exprb53) for use in this model. Based on their multi-stage structure, we propose a set of modifications to the phipm/IOM2 algorithm for efficiently calculating the matrix functions ϕ k. We then investigate the performance of these methods on a suite of four challenging test problems, comparing them against the epi3 method investigated previously in [1, 2] on these problems. In all cases, the proposed methods enable accurate solutions at much longer time-steps than epi3, proving considerably more efficient as either the desired solution error decreases, or as the test problem nonlinearity increases.

Journal of Computational Physics, 2022

ICAO journal, Dec 1, 1992

Journal of the Meteorological Society of Japan, 1990

The global scale predictive tracer model designed to simulate atmospheric transport processes as ... more The global scale predictive tracer model designed to simulate atmospheric transport processes as well as a tropospheric and stratospheric chemistry is described. The model consists of a global spectral model and a set of the mass conservation equations coupled through the chemistry terms. The model was tested in both diagnostic and fully predictive mode simulating the hemispheric scale dispersion of radionuclides from the Chernobyl accident. The analysis of the predictive run results indicate that the model is able to predict the large scale mass distribution for periods up to six days when started from a sufficiently accurate initial condition. An extended prediction of the hemispheric tracer distribution was performed up to 24 days; the tracer field in these experiments was updated every 6 days using an initial condition provided by a parallel run of the diagnostic model.

Journal of Climate, Mar 1, 1995

The Canadian Aerosol Module [CAM] is being incorporated into a new, multipollutant, multi-issue E... more The Canadian Aerosol Module [CAM] is being incorporated into a new, multipollutant, multi-issue Eulerian regional air quality modelling system AURAMS [AES Unified Regional Air-Quality Modelling System] whose first application will be to simulate paniculate matter [PM] emissions, transport, chemistry, and removal in eastern North America. CAM employs a sizedistributed multi-component aerosol algorithm and has been used in Canadian climate models to assess the climatic impact of atmospheric aerosols. In addition to CAM, AURAMS will contain an emissions pre-processor, a meteorological driver, and a chemical transport model, including gasand aqueous-phase chemistry and removal processes for gaseous species.

Air Pollution Modeling and Its Application VIII, 1991

The numerical simulation of atmospheric dispersion is used increasingly to assess the state of th... more The numerical simulation of atmospheric dispersion is used increasingly to assess the state of the environment. A well known example is the use of numerical dispersion models with complex chemistry schemes for studies of atmospheric oxidants and acid rain phenomenon. The other important application of tracer models is the simulation of accidental releases of toxic and radioactive materials. The Atmospheric Environment Service (AES) of Canada recently used such a tracer model to simulate the dispersion of nuclear debris from the Chernobyl reactor accident. This research was the beginning of the development of a sophisticated Environmental Emergency Response (EER) system which is currently operational at the Canadian Meteorological Center (CMC). Similar efforts were also undertaken by the meteorological services of other countries. The objective of this paper is to present a general description of the Canadian Nuclear Emergency Response Model (CANERM) and compare it to similar models which are being used in other meteorological centers around the world.

Journal of Geophysical Research: Atmospheres, 2007

During July and August, 2004, balloon‐borne ozonesondes were released daily at 12 sites in the ea... more During July and August, 2004, balloon‐borne ozonesondes were released daily at 12 sites in the eastern USA and Canada, producing the largest single set of free tropospheric ozone measurements ever compiled for this region. At the same time, a number of air quality forecast models were run daily as part of a larger field experiment. In this paper, we compare these ozonesonde profiles with predicted ozone profiles from several versions of two of these forecast models, the Environment Canada CHRONOS and AURAMS models. We find that the models show considerable skill at predicting ozone in the planetary boundary layer and immediately above. Individual station biases are variable, but often small. Standard deviations of observation‐forecast differences are large, however. Ozone variability in the models is somewhat higher than observed. Most strikingly, none of the model versions is able to reproduce the typical tropospheric ozone profile of increasing mixing ratio with altitude. Results ...

Bulletin of the American Meteorological Society, Jun 1, 2004

... LI Shibei MENG Fan (Chinese Research Academy of Environmental Sciences, Beijing 100012). Air ... more ... LI Shibei MENG Fan (Chinese Research Academy of Environmental Sciences, Beijing 100012). Air Quality Prediction System consists of air ... 1, WANG Zu-lu et al (Fujian Institute of Meteorological Science,Fuzhou,Fujian 350001);Observation Results and Characteristic Analysis of ...

Recent advances in chemistry and meteorology models and computational efficiency have allowed the... more Recent advances in chemistry and meteorology models and computational efficiency have allowed the operational use of coupled chemistry-transport models (CTMs) by local air quality forecasters. The

However my specific comment is about Figure 9. It seems to me that it is a bit misleading because... more However my specific comment is about Figure 9. It seems to me that it is a bit misleading because the results in it cannot be compared directly with the results in Figures 3 and other. This is because Gaussian distribution of the source term (corresponding to the Fig. 9) has mean value of the source term equal to zero. Thus the regularisation term in functional 10 tends the estimated source term closer to zero value. While the

Recent advances in chemistry and meteorology models and computational efficiency have allowed the... more Recent advances in chemistry and meteorology models and computational efficiency have allowed the operational use of coupled chemistry-transport models (CTMs) by local air quality forecasters. The adoption of numerical model guidance by operational forecasters, the number of whom has been increasing rapidly in the past several years, depends on the reliability of numerical model guidance in critical high ozone (O3) cases. In turn, routine use of these models by forecasters can result in a positive feedback of information to model developers to further improve model performance.

Geoscientific Model Development Discussions

This study presents a methodology for the optimization of a monitoring network of sensors measuri... more This study presents a methodology for the optimization of a monitoring network of sensors measuring the polluting substances in an urban environment with a view to estimate an unknown emission source. The methodology was presented by coupling the Simulated Annealing algorithm with the renormalization inversion technique and the Computational Fluid Dynamics (CFD) modeling approach. Performance of a network was analyzed by reconstructing the unknown continuous point emissions using the concentration measurements from the sensors in that optimized network. This approach was successfully applied and validated with 20 trials of the Mock Urban Setting Test (MUST) tracer field experiment in an urban-like environment. The optimal networks in the MUST urban region enabled to reduce the size of original network (40-sensors) to ~ 1/3^rd (13-sensors) and to 1/4^th (10-sensors). The 10 and 13 sensors optimal networks have estimated the averaged ...

Journal of Computational Physics

In this paper, we investigate the use of higher-order exponential Rosenbrock time integration met... more In this paper, we investigate the use of higher-order exponential Rosenbrock time integration methods for the shallow water equations on the sphere. This stiff, nonlinear model provides a 'testing ground' for accurate and stable time integration methods in weather modeling, serving as the focus for exploration of novel methods for many years. We therefore identify a candidate set of three recent exponential Rosenbrock methods of orders four and five (exprb42, pexprb43 and exprb53) for use in this model. Based on their multi-stage structure, we propose a set of modifications to the phipm/IOM2 algorithm for efficiently calculating the matrix functions ϕ k. We then investigate the performance of these methods on a suite of four challenging test problems, comparing them against the epi3 method investigated previously in [1, 2] on these problems. In all cases, the proposed methods enable accurate solutions at much longer time-steps than epi3, proving considerably more efficient as either the desired solution error decreases, or as the test problem nonlinearity increases.