TELECONNECTIONS BETWEEN NORTHEASTERN PACIFIC OCEAN AND 

 THE GULF OF MEXICO AND NORTHWESTERN ATLANTIC OCEAN 



James H. Johnson and Douglas R. McLain' 



ABSTRACT 



Anomalous large-scale air-sea interactions that took place over the Gulf of Mexico and the Atlantic 

 Ocean off the southeastern coast of the United States in the winter of 1957-58 caused a change of 

 sea-surface temperatures from near average values to cold anomalies of nearly 3.0°C in some regions. 

 Evidence suggests that the mechanism for the anomalous change in sea temperatures derived from 

 frequent outbreaks of cold, North American continental air flowing over the Gulf and ocean waters 

 with consequent anomalously high evaporation and sensible heat exchange. A contributing factor may 

 have been divergence of surface waters with associated upwelling in regions of high cyclonic activity. 

 These severe outbreaks of cold continental air over the eastern seaboard may be related to air-sea 

 interactions in the Pacific, thousands of miles distant. It is not clear what the full consequences of these 

 events are to fisheries. The evidence which is available suggests that they are significant and warrant 

 continued investigation. 



In recent years large-scale air-sea interactions 

 have captured the interest of a number of 

 oceanographers and meteorologists. Motivated by 

 the desire to develop and improve extended me- 

 teorological forecasts, Namias (1959, 1963, 1972, 

 and in numerous other articles) has been one of the 

 foremost investigators in studying these interac- 

 tions. Most of his work has centered in the 

 temperate latitudes of the northern hemisphere. 

 Bjerknes (1966a, b, 1969) has studied large-scale 

 interactions in the tropical Pacific Ocean, 

 especially, processes associated with the El Nino 

 phenomena. He has shown a relationship of fluc- 

 tuations in the atmospheric Hadley circulation to 

 large-scale anomalies of ocean temperatures. He 

 suggests that an anomalously high heat supply in 

 the equatorial Pacific, characterized by high equa- 

 torial ocean temperatures, intensifies the Hadley 

 circulation providing more than normal flux of 

 angular momentum to the mid-latitude belt of 

 westerly winds, thus affecting the weather over 

 the North American continent. He suggests that 

 regular monitoring of sea temperatures in the 

 eastern tropical Pacific is indispensable in long- 

 range weather forecasting for North America. 



Also motivated to develop improvements in 

 long-range weather forecasting, Quinn (1972) has 



'Pacific Environmental Group, c/o Fleet Numerical Weather 

 Central, National Marine Fisheries Service, NOAA, Monterey, 

 CA 93940. 



shown that large-scale interactions over the equa- 

 torial Pacific may affect the weather over the 

 continental United States. He suggests that ex- 

 tensive dry-zone developments in the equatorial 

 zone, which are associated with low sea-surface 

 temperatures, may contribute to ridge develop- 

 ment in the upper air circulation over the 

 Northeast Pacific and, conversely, wet-zone 

 developments (high equatorial sea temperatures) 

 are associated with trough formation. Further- 

 more, he describes the effects downstream over 

 the United States following development of these 

 troughs and ridges and implies that now it may be 

 possible, if these extreme developments are de- 

 tected early enough, to make long-range weather 

 predictions over North America. 



Rowntree (1972), recently carrying out com- 

 puter model studies, has confirmed that a sea 

 temperature maximum in the tropical eastern 

 Pacific leads to a persistent trough in the mid-lat- 

 itude flow to the north. 



Regions of the ocean particularly responsive to 

 the overlying atmosphere lie to the east of large 

 continental land masses. Jacobs (1951), Manabe 

 (1957), Wyrtki (1966), and Hishida and Nishiyama 

 (1969) have shown that in wintertime the 

 temperate western Pacific Ocean loses large 

 amounts of heat through evaporation and sensible 

 heat exchange because of the overflow of cold, dry 

 Siberian air masses. Parker (1968) pointed out a 

 similar effect in the winter of 1966 in the 

 northwestern Gulf of Mexico. 



Manuscript accepted June 1974. 



FISHERY BULLETIN: VOL. 73, NO. 2, 1975. 



806 



