The study was conducted in 2023 and comprised a comparative assessment of the state of Lake Markakol’s aquatic ecosystems in surface and bottom water strata. The analysis of bottom water temperatures showed correlation between this parameter and dissolved oxygen concentrations, indicating that pollution caused by organic impurities leads to lake eutrophication, in turn, pro-pelling the extinction of aquatic life. Although the main water physicochemical parameters of Markakol Lake correspond to the oligotrophic type, the shifts in dissolved oxygen and phos-phate content, as well as growth of aquatic vegetation indicate its transition to the mesotrophic type. Higher phosphate content in water is a consequence of pollution disturbing the biological balance, as well as stimulating the reservoir’s eutrophication and increased biological productivity, i.e. algal bloom. In addition, phosphate ions serve an informative indicator of Hazard Class 3 (organoleptically hazardous) anthropogenic pollution. Based on the correlation factor (r), two statistical models were considered for the target lake: 1) Water Pollution: nutri-ent concentrations depending on surface and bottom water temperatures (Model 1); and 2) changes in Water Pollution Indices (biogenic, heavy metals, mean) because of air temperature growth due to global warming of 0.25°C/decade (Model 2).

The spatial distributions of the potential ecological risk index (RI) and the geoaccumulation index (Igeo) in soils of the Zhetysu region (Kazakhstan) were examined. The enrichment factor ranged from 39.4 for cadmium to 21,481 for nickel. There are few non-ferrous metal enterprises and mineral deposits located in the region. Soil sampling was conducted at 54 locations across the region. The contamination indices were calculated based on the concentrations of four heavy metals in the soil in 2025: copper (Cu), lead (Pb), cadmium (Cd), and nickel (Ni). The RI index varied across the study area within range of 53–353, with an average value of 129. The main points of high environmental risk are the Balkhash Lake’s eastern coast (RI = 318) and industrial city Tekeli (RI = 353). The Igeo values were as follows: Cu −0.61–3.82 (mean: 2.07); Pb −0.58–3.35 (mean: 0.49); Cd −2.91–2.15 (mean: −0.11); and Ni −4.23–4.17 (mean: 0.43). The transport of contaminants occurs under the influence of the wind regime and water erosion processes. Lead, cadmium, and nickel have a variation coefficient greater than 50, indicating metal particle transport from adjacent areas. Wind patterns in certain areas of the region determine the distribution of foci of high heavy-metal concentrations in the soil.

This article contains the first obtained results of measuring the latitudinal variations of the very weak ammonia (NH3) absorption band at 552 nm along the central Jupiter meridian based on spectral observations in 2019. This study is preliminary in nature as the first attempt to clarify the possibility and advisability of further detailed study of this weak ammonia band behavior on the Jupiter disk. We obtained the latitude variations of the equivalent widths and equivalent absorption paths for the 552 nm NH3 band and, for comparison, the same characteristics for the more intense, but also weak NH3 645 nm band. The absorption maximum in both bands is observed in the equatorial zone, where in the center of the disk their equivalent widths are: W (552 nm) = 2.58 ± 0.29 A and W (645 nm) = 6.77 ± 0.25 A. A feature that distinguishes the behavior of the 552 nm NH3 band from the 645 nm NH3 band is a steeper decrease in absorption towards high latitudes, as well as small differences in the positions of absorption extrema in latitudes. The effect of latitudinal differences in the position of the extrema of the methane absorption bands was discovered by us as early as 1999 observations and was later noted also in the ammonia absorption bands. These features reflect structural differences in the Jupiter cloud layer and its troposphere and can serve as one of the means for its (troposphere) optical sounding.