28G 



METEOROLOGY IN RUSSIA. 



a half higher than iu Iceland. In Siberia the mean minima are also 

 higher in January than in the other months, while generally in Europe 

 and North America the contrary is the case, indicating a greater inten- 

 sity of the storms in midwinter. In the annexed diagram the move- 

 ment of the minima is graphically represented. North America and 

 Western Europe have the same system of curves, the minima being 

 highest in summer, lowest iu winter. In Siberia and Eastern Asia the 

 contrary is the case ; this is especially marked at Pekiu. The stations 

 of Lugan, iu S. Eussia, and Catharinenburg, on the Ural, occupy an 

 intermediary position, having neither the oceanic nor the true continental 

 type. The greatest difference between the last two i^laces being that in 

 Lugan October has the highest minima in the year, and Catharinenburg 

 the lowest. This is not accidental. In October the conditions of the 

 temperature and moisture of the air on the Ural, and in Siberia, are 

 more favorable to the ^propagation of storms than in winter. In the 

 same season the Atlantic storms take a more northern course, causing 

 a great depression of the minima on the Ural. In Southern Enssia 

 the pressure is generally high in autumn, as also the minima. Octo- 

 ber is not a stormy month there, while November and December are. 



It is possible that in October Atlantic storms may reach as far as 

 Jakutsk. The sky is generally overcast there, it is the most cloudy 

 month of the year, and the number of west and southwest winds is great. 

 The temperature has not yet fallen so low, even in the northern inte- 

 rior of Siberia, as to i^revent the propagation of storms. 



We shall next consider the winds, which are in so intimate a connection 

 w ith the pressure of the air. I have said before that Wesselovsky had 

 proved the existence of a belt of eastern winds during autumn and winter 

 in Southern Eussia, while at the same time the southwest winds prevail 

 in the northern part of the country. The movements of the atmosphere 

 are better known at the present time as far as the Jenissei, and I have 

 been able to prove the existence of a belt of prevailing southwest winds 

 in Northern Siberia, and of eastern winds in the south of that country 

 and Central Asia. The division line runs about the parallel of 50° or 

 52° north in Siberia, and a little more south near the shores of the Black 

 Sea.*- 



This is illustrated by the following table, which shows the percentage of 

 ■winds iu winter in Western Siberia, Central Asia, and Southeastern 

 Eussia : 



South of 52°. 



Orenburg 



Semipalatinsk 



liaimsk, (Syo-Daria). 

 Astrachan 



'" Tswiistia " of the Kussiau Goograpbical Society, year 1871, No. 5.) 



