Károly Tar

COMPOSITION AND SOURCES OF URBAN AND RURAL ATMOSPHERIC AEROSOL IN EASTERN HUNGARY

Abstract In an eastern Hungarian region urban and rural aerosol samples have been collected regularly over several years. Concentrations have been determined for 19 elements by the protoninduced X-ray emission method. The examined concentrations have been compared with other data representative for source areas influencing Hungarian atmosphere as well as for typical conditions in Western Europe. Seasonal variations, correlations with the amount of precipitation and wind sector distributions were observed for separate elements. Absolute principal component analysis revealed four typical factors contributing to the aerosol burden. Trajectory sector analysis has been used for studying the influence of long-range transport from the heavily industrialized “Black triangle” area in Central/Eastern Europe on the one hand and Saharan area on the other. Our data offer further basis to investigate the existence and nature of differences between air qualities in Western and Eastern Europe caused by structural and technological differences in the energy sector and industry of the regions mentioned.

Some statistical characteristics of the wind energy over the Great Hungarian Plain

SYNOPSIS In this study changes in the surface pressure field over Europe are analysed to see if they are reflected in the statistical structure of the wind field over the Great Hungarian Plain. The data bais consists of hourly wind speed data of three meteorological stations (Debrecen, Békéscsaba and Szeged) at the Great Hungarian Plain, coming from the periods between 1968–72 and 1991–95, respectively. A new statistical test is also shown in the paper, in order to apply it for determining significance of statistical differences between expected values of non-independent time series. Decrease of wind energy might be expected at the Great Hungarian Plain, however no definite results were obtained on the data base considered.

Temporal Change of some Statistical Characteristics of Daily Average Wind Speed in Hungary

In this study it is analysed whether or not changes in the surface pressure field over Europe are reflected in the statistical structure of the wind field over Hungary. The data consists of hourly wind speed data of 9 meteorological stations from the periods between 1968–72 and 1991–95. It is shown that the distribution of daily average wind speeds, except for one station, differ significantly from each other in the two examined periods, which appears in the decrease of wind speeds in the second five-year period. It is established, by the help of Fourier polinoms, that times of extremities also change in the latter period, which involve transformation of the summer wind field, as well.

The mathematical model of shading buildings

SYNOPSIS In any passive solar energy application the orientation of the building is highly significant. An optimum orientation is easy to achieve when the buildings are located relatively far from one another. However, this freedom does not apply in the urban environment. Here, the problem can be reduced to a study of the shading of a vertically positioned rectangle. This paper introduces mathematical formulae to determine the width of the shadow of rectangles with a given exposure and height, at a given distance from one another, during bright periods of sunshine.

A mathematical model of shading rows of plants

SYNOPSIS This paper reviews a previous analysis on the shading of buildings [1] and applies the same principles to applications in agriculture, e.g. the shading of rows of plants. The new model is applicable to vertical parallel rows of plants, such as the cordon-trained grapevine, aligned in any direction and on either horizontal or inclined slopes. At any particular plantation, information for optimal planting procedures could be determined. The plants could make a much greater use of solar energy compared with conventional procedures, with enhanced quality and quantity.

The concept, velocity and energy-distribution of characteristic and non-characteristic wind directions

SYNOPSIS The concepts of the characteristic and non-characteristic wind directions were defined by a statistical test. It was established from the wind data of 13 meteorological observatories in Hungary that the wind speed of characteristic wind directions is greater than that of all and the non-characteristic directions. Further, one characteristic wind direction transports about four times as much wind power as one non-characteristic direction.