Abstract
The impact of smoke from forest fires in western Siberia on meteorological, atmospheric electric, and aerological variables has been analyzed. The anomalous distribution of water vapor in the atmosphere associated with the peculiarities of the evaporation regime and the absence of advective moisture transfer over the southern regions of Western Siberia during the fires. With an increase in the height of the homogeneous surface smoke layer with an unchanged aerosol optical thickness, the cooling of the earth's surface and heating of the atmosphere was weakened. The smoke plume spreads predominantly in the middle of the troposphere, creating aerosol layers elevated above the ground, the lower part of which had a negative volume charge. The effect of diurnal variations in the electrical field in the near-surface layer, differs from the known similar effects.
TopIntroduction
This chapter presents the effects of forest fires on the meteorological variables and electric field variations of the atmosphere. The electric state of the surface layer of the atmosphere with intense smoke is the least studied among other meteorological variables, so the most attention has been paid to the study of this factor.
The complex interrelation between the temporal variations in this field on the one hand and the physical, chemical, and biological processes that form the environmental state on the other hand determines the interest in monitoring atmospheric electricity as both an affecting factor and an indicator of the observed environmental changes. Among the found regularities of temporal variations of electric field strength (E), the most well-known ones belong to the “fair weather”. These regularities are the following (Chalmers, 1967; Sedunov, 1991; Kupovykh, Morozov, & Shvarts, 1998; Anisimov & Mareev, 2008; Donchenko, Kabanov, Kaul, Nagorskiy & Samokhvalov, 2015; Mareev et al. 2016): diurnal unitary variations caused by change in the Earth’s charge as a whole; the electrode effect related to accumulation of voluminous positive charges near the Earth’s surface; electrooptical correlation in the optical hazes expressed as the dependence of field intensity on aerosol particle concentration; and some others.
Yet the least known are processes of electrical charge accumulation and the E variations under disturbed “fair weather” (thunderstorm, volcanic eruptions and dust storm, natural and technogenic smoke, etc.). Since these atmospheric phenomena are episodic and hardly predictable in time, they complicate field studies in the sense of interpretation of their results. Nevertheless, some of the recently discovered effects related to the dynamics of atmospheric electricity indicate the necessity of taking these effects into account during complex monitoring and simulation of natural climatic processes (Ippolitov, Kabanov, & Smirnov, 2011; Ippolitov, Kabanov, Nagorskiy, Pkhalagov, & Smirnov, 2013; Donchenko et al., 2015). For example, low-frequency oscillations in electric field have been detected in the atmosphere prior to thunderstorms; records of these phenomena can provide control over development of mesoscale convection systems and dynamics of acoustical and gravity waves emerging during such a development (Ippolitov, Kabanov, Nagorskiy, & Smirnov, 2012). The studied effects of selective electrical charge accumulation of aerosol particles depending on their size and composition in the cases of cloud formation (Smirnov, 2010; Mareev et al., 2016), volcanic eruptions (Leblanc et al., 2008; Adushkin, Soloviev, & Spivak, 2018; Firstov et al., 2019) and dust storms (Sow et al., 2011; Gorchakova, Mokhov, & Rublev, 2015; Adushkin et al., 2018; Katz et al., 2018) also indicate the essential differences of variations in electrical field under these conditions compared to “clear weather” ones.
Key Terms in this Chapter
Temperature Inversion: A phenomenon observed when the temperature in the troposphere increases with height instead of its decreasing.
Electric Field of the Atmosphere: Constantly exists in the atmosphere, it is caused by charges of the Earth and the ionosphere. The field strength is 130 V / m on average and decreases exponentially with height.
Global Electrical Circuit: A distributed current circuit that formed by highly conductive layers of the earth’s surface and ionosphere, separated by atmosphere, whose conductivity is negligible in the boundary layer, but exponentially increases with height.
Insolation: Irradiation of the earth's surface with solar radiation of all types, which has light, heat and bactericidal effects.
Electrode Effect: The formation of a space charge near the earth's surface, since the vertical conduction current in this layer is caused by the upward movement of positive ions at closed to zero negative ion conduction currents.
Light Ions: Atmospheric ions consisting of a complex (up to a dozen or more) of molecules carrying one elementary charge. They have the greatest mobility and therefore play a major role in the electrical conductivity of air.
Meteorological Range of Visibility: It characterizes the transparency of the atmosphere and the ability to distinguish distant objects visually.
Optical Thickness: A dimensionless quantity that characterizes the attenuation of light in atmosphere due to its absorption and scattering.
Aerological Sounding: Measuring of the atmospheric air characteristics with height based on devices raised by pilot balls, radiosondes, aerostats, airplanes, rockets and satellites.
Troposphere: The lowest part of the Earth’s atmosphere, which contains about 80% of the mass of the atmosphere and 99% of its water vapor. The upper boundary of the troposphere is located in the polar latitudes at heights of ~ 8-10 km, in the middle latitudes - at heights of ~ 10-12 km, in the equatorial latitudes - at heights of ~ 16-18 km.
Cloud Types: Cb - Cumulonimbus; Cu - Cumulus; Ns – Nimbostratus, Frnb - Fractonimbus; St - Stratus; As - Altostratus; Ac - Altocumulus; Cs - Cirrostratus; Cc — Cirrocumulus; Ci - Cirrus.