|
| |
|
| |
|
| |
|
| |
|
| |
|
|
Precipitation totals and rich precipitations in Klementinum in Prague between 1805 and 2007
Střeštík, Jaroslav
In the university campus Klementinum in Prague daily precipitation totals have been observed since 1805 without interruption. This seris, in contrast to the temperature series, does not display any long-term change similar to the global warming, only a little drier period 1850-1880 and perhaps a weak decrease after 1980 can be observed. Numbers of days without precipitations in the individual years do not show any long-term change or periodicity. The incidence of rich precipitations can be described by two methods. When it is expressed by the number of days in a year when daily precipitation totals exceeded 5 or 10 mm, its long-term trend is similar to the long-term change of precipitation totals. When it is expressed by the number of days in a year when daily precipitation totals exceeded 1 or 2 per cent of the annual precipitation total, no long-term trend or periodicity is observed.
|
|
|
Tree stem diameter and the Moon: a detailed analysis of periodic relationships
Mikulecký, M. ; Střeštík, Jaroslav
Zürcher and Cantiani (Nature, 1998) reported "a strong correlation" between rhythmic fluctuations of diameter of spruce stem on one side and gravimetric lunisolar tides on the ohter. The relationship between stem diameter D and tidal force G has been tested by more exact biometrical means. The 75 diameter and gravity hourly values have been processed by the Halberg cosinor regression and by Bartlett cross-"correlation". The higher peaks of the stem curve are located at 0,7-2,8 hours later than the peaks of the inverted tides. The cross-"correlation" between D and G as the function of time lag shows a 24-hour periodicity with its maximal significant deviation from zero for G delayed after D by 4 hours.
|
|
| |
|
|
The influence of geomagnetic activity on the course of stratospheric warming
Davídkovová, Hana ; Bochníček, Josef ; Hejda, Pavel ; Huth, Radan
The temperature of the winter polar lower stratosphere is affected except the solar activity and atmospheric circulation by the geomagnetic activity as well. Plausible physical mechanism for its effect was described by Arnold and Robinson. According to this paper, warming in the lower thermosphere caused by geomagnetic activity produces the reduction of blending mid and high latitude air masses. In consequence of this reduction the temperature of solar insulated region (polar lower stratosphere)decreases. The aim of this work is to verify functionality of such mechanism.
|
|
|
Processes which control the Earth’s Temperature
Oupický, Pavel
There are discussed in this paper some of natural processes which control the temperature of Earth and they are explained and confronted with climate models Daisyworld, Greenhouseworld and Moses. There are presented also the results from the measuring of plant reflectivity with spectroradiometer
|
guest ::
