2l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 70 



THE TEMPERATURE VARIATIONS IN DIFFERENT MONTHS 

 OF THE YEAR IN BATAVIA 



We have already shown that earlier investigators found a differ- 

 ence between summer and winter as to the eleven-year periodical 

 variations of the meteorolo'gical elements. For example, Blanford's 

 curves for air pressure in Siberia and Russia indicate that these go 

 directly with the sun spots during winter and oppositely to the air 

 pressure variations in India, while in summer they agree with the 

 latter and go oppositely with the sun spots. The two Lockyers 

 found also for different stations that the air pressure goes differently 

 in relation to the prominences in summer and winter. 



It would be therefore of great interest to study the eleven-year 

 variations in the meteorological elements for each month of the 

 year at different stations. Figure 78 gives curves of variations 

 of the temperature (t) and the air pressure (P) in Batavia for 

 each month of the year (curves I to XII). They are smoothed first 

 by consecutive two-year and then three-year means, that is to say, 

 according to the formula t = l(a + 2b-\-2c + d). The curves A indi- 

 cate the corresponding values for temperature and air pressure 

 for the whole year and the lowest curve S is the curve of relative 

 sun spot numbers. It may be seen that in all these curves there is 

 a great similarity, and that the variations on the whole for all the 

 months go in the same direction, and show agreement with the 

 inverted sun spot curve, although with some irregularities. The 

 variations are generally more marked in the winter months and least 

 marked in the summer months (VI to VIII). The air pressure 

 curves run on the whole in pretty good agreement with the curves for 

 the temperature, but as earlier mentioned with a displacement of 

 phase ; that is to say, the variations of the air pressure come earlier 

 than the variations of temperature. At special times there occurred 

 great differences, so that the air pressure curve may even go op- 

 positely to the temperature curve, as for example in December 

 and January and partly also February for the years 1883 to 1886, 

 for February and March, 1895 to 1906, and at other times, but a 

 fixed rule can hardly be laid down in this respect. It appears for 

 example, that the air pressure in December has a tendency to go 

 oppositely to the temperature variations, but the result for the year 

 in spite of this is as curve A shows a quite good agreement between 

 variations in air pressure and variations in teniperature, and these 

 curves show further, as already said, a quite good agreement with 

 the sun spot curve. 



