# Atmospheric Electricity Measurements in the Pacific Northwest, Russia
## 3 Observed Effects and Main Results  
Precipitation influences the AEF measurements the most. To isolate other signals, we need to know how precipitation affects the electrical characteristics of the surface air. Figure 5 shows an example of rain for 8 August 2009. Figure 5a shows the PG curve. On Figure 5b shows the unipolarity curve: air conductivity caused by positive ions divided by air conductivity caused by negative ions. Figure 5c shows the level of precipitation. The rain effect is manifested in a large negative PG bay and unipolarity. The effect of rain from thunderclouds in PG is represented by a high-amplitude alternating signal. Figure 6 shows the effect of snow in the electrical characteristics of the surface air for 26 February 2010. Figure 6a shows the PG curve. Figure 6b shows the unipolarity curve. The snow effect manifests itself in a large positive bay PG and unipolar electrical conductivity. The rain gauge could not register snow correctly. Therefore, the snow phenomenon was determined from the observation log. The next meteorological phenomenon that affects PG is fog (Figure 7). It was determined visually by the researcher and recorded in the observation log. Figure 4: Snow level in winter 2008–2009. Figure 5: Rain effect for 8 August 2009: **(a)** PG values; **(b)** the value of unipolarity; **(c)** the precipitation level. Figure 6: Snow effect for 26 February 2010: **(a)** PG values; **(b)** the value of unipolarity. During fog, the average levels of PG (Figure 7a) and air humidity (Figure 7c) increase. The average electrical conductivity of the air decreases during fog (Figure 7b). The electrical conductivity in this case is calculated as the sum of the electrical conductivity caused by positive ions and the electrical conductivity caused by negative ions \(\lambda=\lambda_{+}+\lambda_{-}\). The explanation for this behavior of PG during fog can be as follows. The electrical conductivity depending on the mobility of ions can be represented by the formula  
\[\lambda=e\Sigma(n_{i}u_{i}), \tag{3}\]  
where \(n\) is the concentration of particles and \(u\) is their mobility. The mobility of ions is the speed of their movement in an electric field of intensity equal to unity. It is determined in a simplified form by the [PERSON] formula:  
\[u_{i}=a\frac{e_{i}}{m_{i}}\frac{l_{i}}{v_{i}}, \tag{4}\]  
where \(a\) is a certain numerical coefficient, \(e/m\) is the ratio of the charge to the mass of the ion, \(l\) is the mean free path of the ion, and \(v\) is the average speed of its random motion. The mechanism of behavior of the electrical conductivity of air during fog is as follows. Water molecules attach to the charged ions of aerosols, which sharply reduces their mobility. A decrease in mobility leads to a decrease in electrical conductivity. With a relative constancy of the conduction current, in the case of a decrease in the electrical conductivity of the air, the value of PG increases (Figure 7a). When studying the effect of wind in atmospheric electricity, one should take into account the season, the state of the earth's surface, and cloud cover. An example of the  
Figure 7: Fog effect for 31 May 2010: (**a**) PG values; (**b**) electrical conductivity of air; (**c**) air humidity. wind effect in the AEF at the Paratunka observatory in winter for 14 December 2021 is shown in Figure 8. At 2:00 UTC, the wind speed increased (Figure 8b). The flow of dry cold air reduced the humidity of the ground air (Figure 8c). A decrease in air humidity according to Formula (3) leads to an increase in electrical conductivity. An increase in the level of electrical conductivity leads to a decrease in the PG level. After 16h UTC, the wind strength increased (Figure 8b) and the snow begins to blow. Snow particles broke off from the surface of the snow cover, charged, and created large PG fluctuations at the sensor (Figure 8a). Extensive literature is devoted to the effect of the sunrise in an electric field. A review of early publications was given by [PERSON] [10].