Study of the Wildfire Effect on Local Atmospheric Parameters using Remote Sensing Techniques

Abstract

This paper presents the results of an experiment on remote sensing of a smoke plume over a model fire with the use of a specialized lidar for detecting optical turbulence, which is based on the backscatter enhancement effect. Burning was 1600 m away, and the area of the model fire varied from 1, 9, and 25 m². During combustion, a lidar echo signal in the main receiving channel, which records aerosol scattering and the turbulent component, increased relative to an echo signal in the additional receiving channel, which records only the aerosol. The width of the smoke plume did not exceed 20 m; an increase in the main echo signal was observed immediately after the plume at distances of up to 600 m. In this experiment, a plume of warm smoke acted as a phase screen which changed the coherent structure of a laser beam. After the completion of intensive combustion, the temperature inside the plume rapidly decreased and the lidar recorded only the aerosol content. Appearance of two indicators in an echo signal, an increase in the aerosol concentration and strengthening of turbulence, clearly points out to a burning source. The lidar estimate of the structure characteristic of the refractive index \(C_{n}^{2}\) at an altitude of 10 m above the combustion focus was compared with data of AMK-03 ultrasonic meteorological station at an altitude of 3 m and results of simulation of a grass-roots fire published earlier.