104 



OCEAN ATMOSPHERIC -ELECTRIC RESULTS 



it was necessary to compute the value of the other sign. 

 The formula used for this computation is X +/X . = 1.10. 

 Of these 645 values of computed air-earth current density 

 in the present table, 142 were obtained in the Atlantic 

 Ocean in seven series between July 30 and September 16, 

 1928. Three of the series, August 14-15, August 17-18, 

 and August 24-25, having a total of 58 values, have 34 

 values or 60 per cent of the total, lying between 3.5 and 

 5.0 X 10" ' esu. Such low values were not encountered on 

 any other part of the cruise; there are only eight other 

 scattered values as small as these in the entire table, 

 and several of them are associated with disturbed 

 weather conditions. That part of the Atlantic Ocean in 

 which the 34 low values were obtained, sustains a large 

 steamship traffic, and it may be that pollution from the 

 ships is a cause for low air-earth current density in the 

 region. Discussion of this possibility will be undertaken 

 in a later section of this volume. Except for the low At- 

 lantic values just mentioned, and omitting a few extreme 

 values, the range in the table is 5.0 to 15.0 x 10-7 esu. 



Meteorological Notes and Data. --Appropriate mete- 

 orological notes and measurements were made every 

 hour during a diurnal -variation series, but on most oc- 

 casions the variations throughout the twenty-four-hour 



period in any of the several meteorological elements, 

 except perhaps cloud types and cloud amount, appeared 

 to be too small to warrant detailed tabulation. Instead, 

 a summary of the meteorological data and notes has 

 been made below each series of atmospheric-electric 

 measurements, when such notes and data have been 

 available. The meteorological symbols and notations 

 used in section V, and defined in the explanatory note for 

 that section, have been used in the present section also. 

 Several of the series lack the meteorological notes 

 and data because the meteorological work was a part of 

 the program of nuclei observations, and when nuclei data 

 are lacking the meteorological data likewise are lacking. 

 Special note has been made of particularly disturbed 

 weather conditions under any series where one or more 

 of the atmospheric-electric elements obviously has been 

 disturbed by those conditions, and where specific note 

 was made by the observer of the disturbed meteorologi- 

 cal element. For more detailed meteorological informa- 

 tion reference may be made to Meteorology-I of this 

 series of publications of Carnegie results, which deals 

 with the meteorological data of cruise VII (Carnegie In- 

 stitution of Washington Publication 544, 1943). 



