Vol. 4] 



Holwmj.—Cold Water Belt. 



277 



paper. The marked fall in temperature on July 3 and 4 was 

 accompanied by a fall in the temperature of the air and by a 

 change in the color of the water from bine to a deep olive green. 

 As in this locality a cold polar current is an impossibility, unless 

 it persists directly across the equatorial region, we are forced 

 to the conclusion that the cold water rises from the ocean depths. 

 Captain Hoffmann reports a strong north flowing current that 

 makes a bend to seaward at this point where the fall in temper- 

 ature occurs. He states that the fall in temperature seems to 

 be related to the change in the direction of the current. Bu- 

 chanan attributes the cold water in this instance to the southwest 

 monsoon blowing off shore. Hann and Andrees do the same and 

 state that the cold water disappears with the coming of the north- 

 east monsoon. 



The authorities quoted, with the exception of Captain Hoff- 

 mann, seem to be in general agreement in accepting winds blowing 

 off shore as a sufficient explanation of cold coast water in these 

 areas. On our coast from San Francisco to Cape Flattery, the- 

 prevailing winds blow toward the shore, as shown in the Pilot 

 Charts. During the passage of an extratropieal cyclone. — the 

 "low" of the weather map — the winds may be temporarily re- 

 versed. As to trade winds on the California coast, the Pilot 

 Charts for 1903 show that the most northerly extension of the 

 trades — occurring in August — was to Lat. 37° 30'. This was 

 only in mid-ocean nearly 1,000 miles to the westward of San 

 Francisco. Nearer the coast the northern limit of the trades is 

 further to the south. At all seasons of the year the Pilot Charts 

 show a belt of northwest winds between the Southern California 

 Coast and the trade winds. Along Southern California where 

 the trades blowing off shore are the nearest to the coast is the 

 very locality that fails to show a definite belt of cold coast water. 



GENERAL TEMPERATURE CONDITIONS OP THE NORTH PACIFIC. 



For a brief summary of the temperature conditions of the 



North Pacific we may take a recent article by that eminent 



authority, Sir John Murray.* The charts which he gives afford 



* Murray, Sir John. On the Temperature of the Floor of the Ocean, etc. 

 ■Geog. Jour. 1899, XIV, p. 34. 



