1.
Volarić,
B., K. Kempni and
ABSTRACT:
This
paper is the first detailed presentation of S. Škreb’s
complete work, due to various circumstances, is still not adequately known,
although essential for the progress in science and especially for the progress
of the Geophysical Institute in
The
description of his life and work gives an insight into his specific work, which
attracted attention at a rather early stage. The description of Škreb’s activity as Director of the Institute brings
to light numerous difficulties he was confronted with, and which were due first
to the situation after the First World War, then to the poor concern of the
authorities for the development of science in this region, and finally to the
outbreak of the Second World War. Nevertheless, under Škreb’s
leadership the Institute was noted for the quality of its results and their
significance, which consequently produced a fruitful co-operation with numerous
institutions at home and abroad.
The
paper gives a description of S. Škreb’s
activity as Professor of Geophysics at the
The
enclosed bibliography is the most comprehensive list of Škreb’s
scientific papers and studies or discussions so far, including the papers
written about him. It is preceded by the presentation of his main papers. Škreb’s scientific work deals with problems of
theoretical meteorology, meteorological statistics and climatology, and
comprises critical treatises from different fields of geophysics in a broader
sense.
Škreb’s first paper dates from 1910 and treats the
influence of the Earth’s rotation on the atmospheric circulation. His
mathematical and numerical results belong to the basic material for further
development in the study of atmospheric circulation.
His
study of the climate and climatic elements in
Škreb’s papers on climatiological
statistics are distinguished by a critical approach to statistical methods when
applied to meteorological data. Furthermore, he dealt with specific properties
of meteorological time series, as well as with the necessity of specifications
of the least square method when applied in climatology. He pointed on the
existence of symmetrical and asymmetrical frequency distributions in
climatology, which resulted in other ways of statistical analyses. With these
studies he tried to abolish the formal application of statistical methods in
climatology.
The
topics of Škreb’s scientific debates are
many-sided. The most significant ones comprise: by accepting Kepler’s idea of explaining gravitation by the
radiation theory he stressed the role of “movement quantity”, and
introduced its elementary quantity by the name of “kormo”;
he also discussed the cause of the celestial body rotation existence; moreover,
he made a detailed analysis of the meaning and significance of basic terms of
Newton’s mechanics.
This
paper includes written memories of his students and collaborations, describing
S. Škreb in his everyday work and life, thus completing
this presentation of the efforts of a man who dedicated all his life to the
development of science and to the existence and development of the Geophysical
Institute in
2.
Mann,
M. and N. Šinik (1990): Some properties of
hydrodynamic instability in a quasi-geostrophic atmosphere.
Geofizika,
7, 55-70.
ABSTRACT:
The baroclinic
hydrodynamic instability of zonal flow has been studied by a two-level model
which takes into account the influence of a barotropic,
nonlinear shear in a quasigeostrophic atmosphere.
There are regions where a horizontal wind shear supports the baroclinic amplification of an unstable wave. It can be
found near the inflexional part of the zonal flow meridional profile.
[PDF]
3.
Juras, J. (1990): On the stochastic model for the temporal
persistence of cloud cover. Geofizika, 7, 71-81. (in Croatian)
ABSTRACT:
The considered stochastic model is based
on the assumption that the series of observations of cloud cover can be
represented by the series of normal variates which
have properties of the Markov process. This assumption made possible the
estimation of the joint probabilities for 1331 (=113) possible
combinations of observations on the basis of frequency distribution of cloud
cover at 7, 14, and 21 local time. The theoretical frequency distribution of mean
daily cloud amount is obtained by adding the joint probabilities which
contribute to the corresponding class (nearest tenth). The
autocorrelation coefficient, which is the only free model parameter, has been
determined in the way that the theoretical
distribution fits the observed distribution in the best way. The
differences between these two distributions
could be partly explained by the contributions of mesoscale
processes (convective storm, radiation fog) which have a much lower persistence
than the prevailing large scale processes. Finally, there is a brief survey of
possible applications of the results on the data control, the evolution of
weather modification and the verification of forecast.
[PDF]
4.
Negi, J. G. and R. K. Tiwari
(1990): Walsh spectral resolution of earth’s rotation and atmospheric
circulation: a non sinusoidal perspective. Geofizika, 7, 83-93.
ABSTRACT:
Lambeck and Hopgood (1981, 1982) have made a comparative study of
spectral characteristics of the angular momentum of atmospheric circulation and
fluctuations in the Length-of-Day (LOD) data. The
Fourier analysis of these data reveals a good correlation between the two
processes, including a large spread of power in the range of a 20- to 70-month
period. We re-examine here the above two time series by using the Walsh
spectral analysis, which seems to be more appropriate for series with sharp
peaks and reversals. The comparative study shows that in addition to 12-, 6-
and 3-month seasonal terms, the present work discovers statistically
significant (90% confidence interval) periods of (i)
26 months (hitherto weakly resolved) associated with a quasibiennial
term, and (ii) 40 ± 4 months in both the data. The resolution of the spread
components removes meteorological noise uncertainity
from astronomical observations of LOD in the study of
the excitation mechanism of solid earth.
[PDF]
5.
Grubišić, V.
(1990): Atmospheric ozone, polar ozone holes and photochemical smog. Geofizika, 7,
95-106. (in Croatian)
ABSTRACT:
The role of ozone in the atmosphere, the
characteristics of its spatial distribution and annual variation are analyzed.
Two important ozone related problems,
polar ozone holes and photochemical smog, are considered.
[PDF]
6.
Beg, G.
and M. Orlić (1990): Topographic Rossby
waves in the
ABSTRACT:
In the paper two models of topographic Rossby waves are reviewed. The first one reproduces the
propagation of waves along the straight coast, and is based on the paper
published by V. T. Buchwald and J. K. Adams in 1968. The second model simulates
the propagation of waves in a circular basin, and is described in some detail
on the basis of derivation sketched by H. Lamb and his Hydrodynamics (1932).
Both models have been applied on the
[PDF]
7.
Markušić,
S.,
ABSTRACT:
Based on the catalogue of all located
earthquakes in
[PDF]