70 H. I. JENSEN. 



In years of minimum sunspot intensity Queensland 

 experiences scorchingly hot summers, and every part has 

 very cold winters for its latitude. In New South Wales 

 (Sydney for example) the summers are hot with frequent 

 north-west winds, relieved at times by southerly bursters ; 

 the winters are cold and rather protracted, but as the 

 atmosphere is dry the cold is not felt as much as in the wet 

 winters accompanying a sunspot maximum, and the nights 

 are not rendered unpleasant by rain, fog or snow. In years 

 of minimum sunspot intensity the Central Australian 

 cyclonic area in summer is of comparatively small dimen- 

 sions, and consequently, the outwardly blowing hot winds 

 reach the surface of the earth in the coastal districts, 

 giving us in Sydney frequent north-west winds. In winter 

 this area is covered by a vast permanent anticyclone, from 

 which the cold, dry, westerly winds originate. The anti- 

 cyclone belt is greatly widened, and the rainbringing mon- 

 soonal and antarctic V disturbances are consequently not 

 frequent. 



The deductions which, I would suggest, to be drawn 

 from the work of Koppen, Nordmann, and McDowall, are 

 that the curve representing the annual variations in 

 temperature does in tropical regions agree ivith the 

 inverted sunspot curve, and in temperate regions ivith 

 the actual sunspot curve. The importance and explan- 

 ation of this apparent anomaly I shall now proceed to 

 discuss. 



(b) For well known reasons, depending on the sun's 

 apparent motion to the north or south of the Equator, 

 the tropical regions of the earth have their greatest 

 rainfall in summer, whereas the temperate regions have 

 theirs in winter. Assuming that sunspot maxima induce 

 strong atmospheric circulation and great evaporation, we 

 find that in such periods the earth's atmosphere is very 



