No 4 (2023)

Studies of variations in the parameters of various geophysical fields were carried out using satellite data during the preparation of destructive earthquakes with magnitudes of 6 ≤ M ≤ 7.8 that occurred in Turkey in February 2023. It was found that the anomalies of these parameters manifested themselves from 34 to 25 days before the earthquakes as a sharp decrease in the values of relative humidity and outgoing longwave radiation, as well as in an increase in the density of local lineaments. An increase in surface skin temperature, surface air temperature, relative humidity, outgoing longwave radiation, as well as in the values of the aerosol optical depth and ionospheric total electron content was revealed 19–9 days before the analyzed seismic events. 5–2 days before these earthquakes, a decrease in the surface skin temperature, surface air temperature, the flux of outgoing longwave radiation, the ionospheric total electron content, as well as an increase in relative humidity and in the length of the secants of the rose diagrams of regional lineaments were recorded. Quantitative characteristics of these anomalies were identified.

The analysis of water exchange between the Bering (Pacific Ocean) and Chukchi (Arctic Ocean) seas in the summer period was carried out using satellite data on sea level, geostrophic currents, and measurement data of water discharge in the Bering Strait. It is shown that there is good agreement (r = 0.85, July–October 1997−2019) between the velocities of geostrophic currents (satellite data) and measurements of water transport (buoy station data) through the Bering Strait. It has been established that the temporal variability of water discharge through the Bering Strait is determined by sea level variations in the southern part of the Chukchi Sea (66°–68° N, 170°–172° W). Strengthening of the eastern (western) winds is accompanied by a decrease (increase) in the sea level in the southern part of the Chukchi Sea and, as a result, an increase (decrease) in the flow of water through the Bering Strait. Increase (decrease) in the flow of the Yukon River is accompanied by a rise (decrease) in sea level and changes in water circulation in the northern Bering Sea and the southern Chukchi Sea.

Determining the patterns of changes in the productivity of agricultural land in different areas used for growing agricultural land in the zone of influence of State Forest Strips (GZLP) is relevant due to the need to assess the future crop yield in fields with differences in geomorphological, soil and climatic conditions in the research area. An object. Sowing of winter grain crops in fields mixed within the influence of State forest strips. Materials and methods. The research methodology is based on the geoinformation analysis of the results of the decryption of actual satellite images, both to identify the distribution of cultivated fields located in the zone of influence of GZLP, and the state of crops on them. At the same time, the soil zonality of the research area was taken into account in view of the considerable length of forest strips. The assessment of the condition of winter grain crops as they move away from the planting was carried out using the NDVI vegetation index calculated from the high-resolution spectral channels of satellite images. Results and conclusions. Based on the results of the research, a database of spatial data of the processed fields has been compiled. The grouping of fields was carried out both according to the similarity of the conditions of the places of cultivation of crops and by agricultural crops. Their placement and geomorphological parameters have been established. With the use of geoinformation technologies for groups of fields using statistical processing tools, the average values of the width and area of the selected zones of influence, as well as terrain parameters, were determined. During geoinformation mapping, data on the state of crops at the end of May were obtained based on the change in the NDVI index by field groupings in the zone of GPLP impact. These data are the basis for the forecast of crop yields, taking into account the spatial location of fields.

The article considers the problem of increasing the accuracy of the classification of satellite image samples under the assumption that their samples are independent. The increase in accuracy was achieved by additional processing of the image as a spatially hierarchical quadtree, which is a type of random Markov field. A modification of this model was proposed – a spatially hierarchical quadtree with truncated branches. For the original and modified models, we compared the classification results of a real radar image characterized by a large amount of noise. The classification accuracy was estimated as the proportion of correctly classified pixels within the selected homogeneous areas. It has been established that within the framework of the modified model, homogeneous areas of images are more correctly classified by transferring the properties of accumulated images of the same region to them. The modified model makes it possible to obtain a classification result of higher accuracy than the original one when processing noisy images, while having less resource intensity.

The paper presents the results of a study of spatiotemporal variability of the characteristics of the wind field in the free atmosphere of the Northern Hemisphere in the SEVIRI radiometer field of view of European geostationary meteorological satellites of the second generation Meteosat 8–Meteosat 11 in the time interval 2007–2021. It is noted that the maximum wind speeds, as well as the maximum average monthly and seasonal anomalies of the wind speed module, are observed over the Atlantic. A feature of the temporal variability of the area-averaged wind speed modulus is revealed, which consists in a change in the sign of the trend at the turn of 2015–2017 from positive to negative. At the same time, positive linear trends in the time intervals from 2007 to the points of a change in the sign of the trend over the Atlantic, the entire region under consideration and Eurasia, including the European territory of the Russian Federation, are significantly different from zero with a probability of more than 95%. And the negative trend is significant only over the Atlantic. A high correlation was noted in the area of seasonal wind speed variations with the area of Arctic sea ice and temperature characteristics of the troposphere at levels of 500 and 200 hPa. Based on the analysis of the relationship between wind speed variability and the main climatic characteristics and large-scale atmospheric processes, a scheme is proposed for the effect of the accelerating reduction in the area of Arctic sea ice associated with global warming on wind speed in the free atmosphere.