1324 



levels; consequently the deflux by antitrade will reach greater height 

 loo. The alleged figures for the oscillaiiou in height fits in closely 

 with this conception, only the range for tlie antitrade is much larger. 

 No doubt the relation is not so simple as presumed above. 



Upper trade-wind. Above the antitrade reappears a flowing of 

 air towards the equator, thus an uppertrade prevails there. 



Without doubt it is a consequence of the fact that the air in the 

 equatorial belt cools down over a higher column than in the 

 subtropics, the airpressure sinking therefore to a lower value, by 

 which a gradient towards the equator takes origin. 



I have compared Batavian airpressures for heights above 10 km. 

 with those Peppler ^) found for the N. -Atlantic and Europe and 

 obtained the following diiferences. 



According to these figures for the tropics and the subtropics the 

 reversal of pressure-difference, on which the transition from afflux 

 to deflux has to depend, occurs between 15 and 19 km. 



Peppler himself, comparing his pressures for 30° N (really 

 22è°— 37è°) with those for 2|°S— 224°N, ünds this reversal to occur 

 at a height of no less than 25 km., but his figures for the tropical 

 belt are uncertain. Howevei- they beai- on the same meridianal zone 

 as those for the subtropics, whereas Batavia is situated over a 

 quadrant more easterly. 



Consequently for Batavia the relation with the pressure-gradients 

 cannot yet be given with certainty ; however, it should be brought 

 forward that no doubt the sinking of the uppertrade to low levels 

 in June is closely connected with the quick falling of airpressure in 

 that month after the maximum in May. 



Where, however, does the air go which flows in? 



Deflux by an upper-antitrade is not probable. On the contrary in 

 higher layers the uppertrade turns into a strong westward current, 

 the Krakatoa-wind. Moreover, in the stratosphere, which is the home 

 of the uppertrade, we lack the heating by the sun, which causes 

 the strong convection in the troposphere. It must, however, be 



i> Beitrage z. Phy.s. d. fr. Alinosf. Bd. IV. 



