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Editorial
The main objective of atmospheric dynamics is to study of those processes of the atmosphere
that are associated with weather and climate, in order to understand and simulate with
numerical models the different motion systems ranging from the micro-scale to the global
circulation. In atmospheric dynamics the fluid is regarded as a continuous medium, and the
fundamental laws of fluid mechanics and thermodynamics are expressed in terms of partial
differential equations involving the fluid velocity, pressure, density, and temperature. The
integration of the governing hydro-thermodynamic equations by numerical methods offers an
opportunity to investigate basic theoretical problems (such as the interactions and energy
transport processes among the motion systems of different spatial and temporal scales), it
paves the way for objective and reliable weather and air-pollution dispersion forecasts, and it
constitutes the single possibility to describe the forced and free changes of the climate system.
Successful modeling work requires a close co-operation between the meteorologist and
physicist, who are experienced in fluid dynamics and nonlinear processes, mathematics and
computer sciences, data assimilation, model initialization, and numerical methods.
Development of different scale dispersion models demands the collaboration with air
chemistry researchers. In addition, parameterization techniques of the soil–vegetation–
atmosphere exchange processes call for solving problems of soil science, biology, and
ecology. For a productive scientific co-operation, it is inevitable to clearly define the
objective of the common research, assure continuous communication among the different
teams, and demand regular publications of high quality.
The principal mission of the Working Group on Atmospheric Dynamics, belonging to
the Scientific Committee for Meteorology of the Hungarian Academy of Sciences, is to create
the conditions mentioned above. The tasks of the members of the Working Group include
provision of a scientific forum for the different research teams and for the Hungarian
investigators working in foreign institutes in order to exchange results related to geophysical
fluid dynamics, assisting scientific co-operations and team work. Programs of the Working
Group contribute to these goals by organizing joint lectures, conferences, and presentations
of the following scientific groups:
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Numerical Weather Prediction and Climate Dynamics Division of the Hungarian
Meteorological Service (HMS),
Department of Meteorology, Department of Applied Analysis and Computational
Mathematics, and von Kármán Laboratory of Environmental Flows of the Eötvös
Loránd University (ELTE, Budapest), and
Department of Fluid Mechanics, Budapest University of Technology and Economics.
One of the most important events of the Hungarian meteorological community is the
Scientific Days of Meteorology, organized every year at the headquarters of the Hungarian
Academy of Sciences. Recent topics of these conferences, arranged by our Working Group,
included numerical modeling (in 2003), climate dynamics research (in 2004), and cloud
physics and micrometeorology (in 2006).
The present thematic issue of IDŐJÁRÁS, with 14 scientific papers, is also the results
of our activity. The leading paper is dedicated to recall the first steps of numerical weather
prediction in Hungary. The following papers describe the present status of numerical models,
as ALADIN or MM5, for the Carpathian Basin. Meso-scale processes, ensemble forecasts and
dynamic downscaling methods represent the main fields of this research work at the HMS.
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Fluid mechanics laboratory experiments offer a powerful tool for the analysis of
atmospheric dynamics. This type of experimental work can successfully illustrate the structure
of mountain waves.
Investigations of model initialization and data assimilation methods are examples of the
most fruitful research activities at the Numerical Weather Prediction and Climate Dynamics
Division of the HMS. Development of a variational data assimilation system for a limited
area model and the application of high-resolution satellite observations in the ALADIN/HU
model are presented.
Elaborating a new meso-scale transport model for the Carpathian Basin at ELTE and
HMS (methodology and applications) illustrates the research activity in the field of air
pollution.
Up-to-date mathematical background in the theory of partial differential equation
systems and numerical methods is an indispensable knowledge. Four papers are dedicated to
these questions from the Mathematical Institute of ELTE. Theoretical and applied results of
splitting methods, main attributes and applications of semi-groups, and possible application
of discontinuous Galerkin methods are demonstrated.
The 30 authors of the 14 papers represent different generations, from the pioneers of
numerical modeling activity in Hungary, “the elderly generation”, through present-day
researchers successfully continuing the numerical modeling work, up to the new generation
consisting of PhD students and young scientists.
The editors and invited authors dedicate this thematic issue of IDŐJÁRÁS to the
illustration of the status and main results of atmospheric dynamics and numerical weather
prediction research in Hungary at the beginning of the 21st century for the enrichment of the
knowledge of the readers.
Gusztáv Götz and Tamás Weidinger
Guest editors
Working Group on Atmospheric Dynamics
Scientific Committee for Meteorology
Hungarian Academy of Sciences
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