ATMOSPHERIC ELECTRICITY IN HIGH LATITUDES. 



79 



TABLE XIII. lonization and Relative Humidity. 



lonization and Temperature. From Table XIV. it will be seen that temperature 

 has a great effect on the ionization the ionization at temperatures lower than 

 20 C. being only a little greater than a third of those with temperatures between 

 10 and 15 C. No effect of temperature on the ratio r is apparent. 



TABLE XIV. lonization and Temperature. 



In discussing the effect of temperature on dissipation it was stated that the 

 absence of wind at low temperatures might account for the decreased dissipation ; 

 but we now see that the smallness of the dissipation is more likely caused by the low 

 ionization at low temperatures. 



Potential Gradient and Temperature. It has already been shown that the 

 potential gradient varies very greatly with the ionization and dissipation. As we 

 have also seen that the ionization and dissipation depend greatly on the temperature, 

 we should expect the temperature to have an effect on the potential gradient. That 

 such is the case can be seen from Table XV. The potential gradient is high with 

 low temperatures and low with high temperatures. This fact has often been noticed 

 and recorded before. 



