91 



pressuTts, w/liich may themselves b-'-? more or less affected by suah 

 changes in the t-jmpero.tiir^. in fact, alterations in the best known 

 of these centers of atmospheric permanent high or low pressure, the 

 "A.zores high" and the ''ICL-landic low" have been explained on this 

 basis by some students. But here no general agreement has been 

 reached, this being one of the cases (common in geophysics) where 

 postulotion has been much e8Si._-r than demonstration. 



The Northeast Pacific semi-pcrmanent hieh is also known to 

 shift north in summ:-r, south in winter: and storms moving from the 

 Meution region toward California sometimes linger over th^ northeast 

 Pacific for five to ten days, during which time it is only reasonable 

 to suppose that their intensity is affected by evaporation from the 

 water, and by the accompanying surface temperature. But very little 

 is known as to the less regular shifts in position of this or of other 

 oceanic highs or lows, or to what extent these shifts are caused by 

 changes in sea temperatures if at all. 



Solution of the general relationship in this respect between 

 sea and air is an essential preliminary to any attem.pt to establish 

 whether or not oceanic variations are actually translated into 

 weather abnormalities, except, perhaps, for localities where the 

 climate is strictly oceanic (as on some islands), or where the wind 

 constantly blows inward from the sea over the land. 



To add to the difficulty that attends synthesis in this general 

 field, alterations in the atmospheric centers m^ay have climatic 

 effects quite the opposite of what the uninitiated might expec-^. 

 Thus it has been pointed out that in the colder months unusually 

 warm water off the southeastern United States may be expected to 

 favor oceanic low pressure and cold weather in the eastern states, 

 not warm. On the other side of the Atlantic, however, any intensifi- 

 cation of the Icelandic low m&y be expected to bring warm weather 

 along the land by strengthening the southerly component of the winds. 

 Nor is the tem.p-rature the only element of climate affected by such 

 alteroticns in the winds as raoy follow shifts in the highs and lows, 

 for effects on the rainfall may eoually be expected. Thus variations 

 in the mean air temperature and rainfall for India may hark back, in 

 part, to variations in the amount of ice melting from year to year 

 in the Antarctic Sea; variations in the rain that falls on the south- 

 central part of the United States may in part reflect variations in 

 the evaporation and air movement from the Caribbean Sea and Gulf of 

 Mexico; while evidence so far obtained suggests that the dampness and 

 temperature of winds blowing in from the sea (consequently the 

 temperature of the ocean surface for a considerable distance up wind) 

 has a part in governing the rainfall of Bouthern California. 



Sir Napier Shaw, in his book "Forecasting Weather" (1323, F. 160) 

 has recently remarked that actual analysis of^North Atlantic weather 

 "has been destructive of any hope of simple rules of weather sequence 

 or for the movement of high and lov; pressure areas. The atmosphere 

 over the North Atlantic is shown to be throughout the year in a state 

 of turmoil which defies simplicity of description, and it is clear 

 that something more than a process of classification is required be- 

 fore the sequences will become amenable to form:Ulated lav*'." This 

 statement by one of the m.ost eminent of living" meteorologists 

 sufficiently emphasizes the difficulty with which any institution - 

 far more any individual - is faced who undertakes serious investiga- 

 tion of the role that sea temperatures may play in the weather somplex. 



