PRECIPITATION ON MOUNTAIN SLOPES POCKELS 93 



For our present example we find G = 5100a grams per second 

 over a strip 1 meter wide and about 22 kilometers long. Hence, 

 there follows for the average precipitation for the whole mountain 

 slope 



W m ' = 0.833a millimeters per hour. 



Ill 



In the example Ave have just discussed the lower limit of the clouds 

 was higher than the summit of the mountain. If the reverse is the 

 case, then, for that portion of the mountain slope that is immersed 

 in the clouds we must take >j instead of y as the lower limit of the 

 integral in the formulas (14) to (16): therefore, the theoretical dis- 

 tribution of precipitation would no longer be symmetrical with 

 respect to the zero point on the axis of abscissas. As an example 

 of this case we will consider the flow of air above the ground profile 

 that is represented by the simple equation 



r) = C sin m x.e~ r1) 



As to the constants we will adopt the following: 



C =* 1000 meters, X = 24000 meters; 



hence m = 0.262 X 10" 3 , r = 0.269 X 10" 3 , 



and for the vertical coordinate rj we find from equation (5) 



tor x = — - — - — 0+ + - + - 



4 6 12 12 6 4 



7) = - 1495 - 1194 - 585 0+444 + 715 + 805 meters. 



The resulting curve is shown in fig. 2. The altitude of the sum- 

 mit of the mountain above the plain of the valley amounts to 2300 

 meters. The valley may be 100 meters above sea level; the atmos- 

 pheric pressure in the valley is assumed at 750 millimeters, the tem- 

 perature 23 , and the specific humidity 10 grams of water per kilo- 

 gram of air. From the Hertzian table we find the lower cloud limit 

 at the altitude of 1220 meters, that is to say at y = — 375. The 

 upper limit of the clouds is assumed at y' = 2400 and, therefore, at 

 4000 meters above sea level. Therefore, for that portion of the 

 clouds lying below the summit of the mountain, which is limited 

 to the negative values of the abscissas up to % = — 1.35 kilometers 

 approximately, since according to equation (7) 



v = Cam cos m x.e~ ny 



