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151.
Summary A couple of different techniques for implementing the variable resolution within numerical models of the atmosphere that use
quasi-uniform grids are estimated and compared based on their merit in the simple linear advection experiments. These techniques
are: grid stretching, Schmidt transforming and grid overlapping. The quasi-uniform grids are: a conformal cubic and an octagonal
grid. The techniques for the variable resolution are evaluated from the perspective of their effects on numerical solution
and the practicality of their application. Our analysis suggests that the grid stretching is for now the most optimal choice.
However, a special form of grid overlapping is presented that has potential to become a viable alternative in the future. 相似文献
152.
J. M. Popović Dr. S. Ničković M. B. Gavrilov 《Meteorology and Atmospheric Physics》1996,58(1-4):41-49
Summary Finite-difference analysis of Rossby modes has been performed for two staggered hexagonal grids. The solutions are compared with those obtained in analytical case and for rectangular grids. The result for one of the selected hexagonal grids better fits to the analytical solution then the results for the other considered grids. The obtained results may contribute to better understanding of the appropriateness of hexagonal grids in atmospheric and oceanographic modeling and numerical computations.With 6 Figures 相似文献
153.
au uu nu a¶rt;u a amma a nu¶rt; 1966–1981 naa, m ¶rt;, auu m m, u nu u ¶rt; uu n n¶rt;, ¶rt;num nu aa ¶rt; ¶rt;a n n¶rt;. m uu aa ¶rt;u u mu u. 相似文献
154.
au a u naam u a nu¶rt; 1963–1973
. naam, m aum mun ma m mm nam aum n (II) na¶rt;am m u a uu ¶rt; u u,¶rt; ua ma u¶rt;, u u¶rt;a ma mn muna. mu u m ¶rt;u mam nm nmum n¶rt;auma amu m m mm II u a¶rt; ¶rt; n. 相似文献
155.
Summary The total ozone response to strong major geomagnetic storms (Ap≥60) in winter along the 50° N latitudinal circle is studied. The results add to the recent results of Laštovička et al. (1992)
obtained for European middle latitudes (∼50°N) and to the results of Mlch (1994). A significant response of total ozone is
only observed in winter under high solar activity/E-phase of QBO conditions (E-max) and seems to be caused by geomagnetic
storm-induced changes of atmospheric dynamics. There are two sectors along latitude 50°N, which are sensitive to forcing by
geomagnetic storms both in total ozone and the troposphere — north-eastern Atlantic-European and eastern Siberia-Aleutian
sectors. The total ozone response under E-max conditions manifests itself mainly as a large decrease in the longitudinal variation
of ozone after the storm, which means an increase of ozone in Europe. The observed effects in total ozone consist in redistribution,
not production or loss of ozone. 相似文献
156.
The continuous increase in concentration of greenhouse gases in the atmosphere is expected to cool higher levels of the atmosphere. There is some direct and indirect experimental evidence of long-term trends in temperature and other parameters in the mesosphere and lower thermosphere (MLT). Here we look for long-term trends in the annual and semiannual variations of the radio wave absorption in the lower ionosphere, which corresponds to the MLT region heights. Data from central and southeastern Europe are used. A consistent tendency to a positive trend in the amplitude of the semiannual wave appears to be observed. The reality of a similar tendency in the amplitude of the annual wave is questionable in the sense that the trend in the amplitude of the annual wave is probably induced by the trend in the yearly average values of absorption. The phases of both the annual and semiannual waves display a forward tendency, i.e. shift to an earlier time in the year. A tentative interpretation of these results in terms of changes of the seasonal variation of temperature and wind at MLT heights does not contradict the trends observed in those parameters. 相似文献
157.
Summary Four fundamental forms of expansion of the double product of the gravity function into an infinite series are derived. Two isotropic parts are separated, one is expressed by Legendre polynomials and the other by invariants of Wigner's D-matrices.
¶rt; m n¶rt;mau ¶rt; au ¶rt; nu¶rt;uaumau uu ¶rt;. ¶rt; ¶rt; umn amu, na aam n nu a¶rt;a u ma n uauam amu ua.相似文献
158.
Summary On the basis of the 1966–73 data, the effect of the difference between pro- and anti-sectors of the IMF is found to be negligible in the winter midlatitude (Central Europe) ionosphere contrary to the dominant effect of this difference in the high-latitude ionosphere found earlier.
a ¶rt;a a 1966–73. u¶rt;m u m amu ¶rt; pro- u anti- mau . na a u ¶rt;um (¶rt; na) u, , a naa a, naum um u.相似文献
159.
The western part of the Bohemian Massif is characterized by repeated occurrences of intraplate earthquake swarms. To study surface deformations of this anomalous region, a network covering about 2000 square kilometres for repeated geodetic measurements was established in 1993 - 1994. The positions of the individual points of the network were carefully picked with respect to local tectonic structure and earthquake foci distribution. GPS and precise levelling measurements were performed 1-2 times a year. The GPS data were processed by Bernese GPS software.
No tendency to any displacement - either horizontal or vertical - of geological blocks was derived from the geodetic data for the period 1993 - 96. Only displacements of less than 5 mm/year in average could occur in the whole region in that period; larger displacements would have been revealed by our measurements. 相似文献
160.
Laštovička Jan Burešová Dalia Boška Josef Bremer Jurgen Märcz Ferenc 《Studia Geophysica et Geodaetica》1997,41(2):171-180
Data from four A3 radio wave circuits in central Europe are used to analyse the representativeness of the ionization and gravity wave activity pattern in the lower ionosphere (85 – 100 km) in the CRISTA experiment interval (3 – 12 November 1994) for the given conditions. It has been found that the CRISTA experiment interval was run under conditions, which are highly representative both of October – November 1994 and autumn, low-moderate solar activity, the descending phase of solar cycle conditions, i.e. CRISTA measurements may be considered to provide values identical with, or close to climatological values (at least for central Europe, h = 85 – 100 km). 相似文献