Radiothermal radiation of the ice cover of the Arakhley lake as a geo-indicator of changes in a water body

Abstract

The object of this study was the ecosystem of a water body; the subject was the radio-thermal radiation of the ice cover as a geo-indicator of changes in the ecological state of the Lake Arakhley. On the basis of a systematic approach, the work assessed the contribution of the seasonal variability of the properties of the ice cover to the intensity of radio-thermal radiation as a geo-indicator of the ecological system. At present, the influence of the ice cover deformation during the crack formation period on the intensity of radio-thermal radiation has not been sufficiently studied, which determined the relevance of an experimental study for use in problems of assessing anthropogenic factors of influence. The aim of the study was to measure the seasonal variability of the intensity of radio-thermal radiation as a background geo-indicator of the temperature regime and deformation of the ice cover during the crack formation period in the absence of direct anthropogenic factors. In January-March 2020, remote radio-physical methods were used to study the intensity of radio-thermal radiation of the microwave range for the test area of the ice cover of the Lake Arakhley during synchronous contact measurements of deformation and temperature in a niche at a depth of 40 cm from the surface. According to the data obtained, the reaction of the deformation sensor signal to daily temperature variations with a time lag of 1…3 hours was recorded. According to the results of the study, the correlation coefficient of the data of the ice deformation channel and the intensity of radio-thermal radiation in the range of 8…14 mm exceeded ± 0.7 (with a window of 1000 s), with the data of the temperature sensor in most areas exceeded ± 0.9. This proves the relationship between the temperature and deformation of the ice surface with the intensity of radio-thermal radiation, as a seasonal geo-indicator in determining the ecological state of the lake. The increments in the brightness temperature during the period of increased crack formation in the 14 mm channel, with a significant correlation with the deformation data, were about 3…6 K, which can also serve as a geo-indicator of seasonal changes in the properties of the ice cover. The results of the study were obtained in the absence of direct anthropogenic factors and are background geoindicators of the seasonal state of the ice cover during the period of temperature and dynamic loads during deformation and cracking, and in the future will be used in practice for correction in assessing the impact of anthropogenic factors