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Vol 61, No 4 (2025)
Articles
LAGRANGIAN (PHASE) STRUCTURES IN AN INCOMPRESSIBLE FLUID
Abstract
The paper considers a geometric approach to describing structures in barotropic flows of an incompressible fluid. This type of description has an analogy in geometric optics. The evolution of equilibrium flows is considered, in which the trajectories of Lagrangian invariants, expressed through the vorticity of the flow, change. The connection between vorticity and velocity is established through the asymptotic behavior of the solution to the Poisson equation. The limits of applicability of the proposed approach are discussed, as well as the possibility of its generalization for baroclinic flows.
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):423–429
423–429
THE STABILIZATION OF WAVE DISTURBANCES IN A GEOSTROPHIC HORIZONTAL SHEAR FLOW WITH ACCOUNT OF RELIEF AND BAROCLINICITY
Abstract
The stabilization mechanisms of unboundedly increasing wave numbers of transient modes for single-wave solutions of the atmospheric dynamics equations are considered, taking into account the relief and various forms of baroclinicity with preservation of the properties of the solutions as exact ones. Estimates of the wave numbers under the action of velocity shears and relief inclinations, baroclinicity, and also in the Ekman boundary layer in comparison with observations of periodic cloud structures have been made. Parameter values at which wave blocking is possible are noted. Bimodal solutions of the equations are also indicated. Estimates of the parameters of transient wave stationarity taking into account baroclinicity in protoplanetary disks (as an example, different from baroclinicity in geophysical hydrodynamics) show a multiband structure of velocity fields.
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):430-441
430-441
ASSESSMENT OF THE AREA OF APPLICABILITY OF THE SHALLOW-WATER APPROXIMATION FOR REPRODUCING DISPERSIVE TSUNAMI WAVES
Abstract
A practical method has been developed for determining the region of space in which the dispersionless shallow-water approximation is capable of reproducing dispersive tsunami waves with a given accuracy. We propose to evaluate the accuracy by the degree of delay of the dispersive wave packet relative to the front of long waves. The degree of delay is calculated along the wave rays emitted from the center of the source at different azimuth angles. The calculation of rays is implemented on a spherical surface taking into account the bottom relief, which is smoothed to meet the conditions of applicability of the ray theory. The dominant period of tsunami waves is calculated based on the shape of the initial elevation of the water surface in the source taking into account the distribution of ocean depths along each of the rays. The degree of delay of the dispersing wave packet is calculated based on the dominant period and the depth profile along the ray. The operation of the method is demonstrated using the example of two tsunami events on the Central Kuril Islands (Simushir tsunamis of 15.11.2006 and 13.01.2007).
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):442-456
442-456
OZONE PHOTOCHEMICAL PRODUCTION EFFICIENCY IN NEAR-SURFACE LAYER OVER BOREAL FORESTS OF CENTRAL AND SOUTHERN SIBERIA
Abstract
Quantitative assessments of photochemical ozone production (PO3), ozone production efficiency (ΔP) with respect to odd oxygen NOx (= NO + NO2), and NOx exponential lifetime (τN) are estimated from continuous measurements of near-surface mixing ratios of O3, NO and NO2 at the regional stations of ZOTTO (Central Siberia) and Fonovaya (Southern Siberia) in a photochemical active period from March–September. We obtain the general functional forms PO3 ≈ A·[NOx], ΔP = A/(1 + B[NOx]), τN = ΔP / A' uniformly valid for the range of the measured NOx mixing ratios (0.2–2 ppb), where A' is a proportionality constant in a NOx-limiting regime of ozone production, and coefficients A and B depend on the total OH reactivity and exact composition of the CO, CH4, and higher hydrocarbons (RH) mixture. We show that atmospheric oxidation of ozone precursors including those emitted from local biogenic sources, along with regional NOx emissions, provide an important regional source of O3 and sink for odd oxygen in the atmospheric boundary layer over boreal forests in the region of study.
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):457–473
457–473
AN IMPROVED VERSION OF THE ATMOSPHERIC SULFUR CYCLE SCHEME FOR EARTH SYSTEM MODEL OF INTERMEDIATE COMPLEXITY
Abstract
The scheme of the atmospheric sulfur cycle ChAP (Chemical and Aerosol Processes), which is developed for Earth system models of intermediate complexity, is extended by taking into account the dimethylsulfide (DMS) emissions into the atmosphere and the differences of the sulfates washout efficiency between different kinds of precipitation. In addition, the transport scheme is slightly revised. To keep the scheme computationally efficient, the new version of the scheme, ChAP–1.1, still employs the stationary approximations and the prescribed vertical profiles for sulfur compounds in the atmosphere (as it was used in ChAP–1.0 as well), which is related to relatively short lifetimes of the sulfur dioxide and sulfates in the troposphere. As a result, the horizontal distributions of the tropospheric sulfur dioxide and sulfates burdens agree better (relative to those for ChAP–1.0) with the reanalysis data CAMS (Copernicus Atmosphere Monitoring Service) and with the ACCMIP (Atmospheric Chemistry and Climate Model Intercomparison Project) data for the late 20th–early 21st centuries. According to the ChAP–1.1 simulations, the global sulfur dioxide burden in the atmosphere in 1990–2000 is 0.2 TgS, and the respective value for sulfates is 0.6–0.7 TgS with the corresponding lifetimes 1 day and 6 days.
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):474–486
474–486
SIMULATION OF AEROSOL DRY DEPOSITION UNDER CONDITIONS OF HETEROGENEITY LAND-USE CATEGORIES FOR THE ARCTIC REGIONS
Abstract
Modeling of dry deposition of aerosol particles is presented based on a model that takes into account the influence of particle size and density, land-use categories and dynamic friction velocity in the Arctic regions of the Far North with heterogeneous land-use categories. The influence of modeling the heterogeneity land-use categories on the pollution of the earth's surface due to dry deposition has been studied; the results obtained using the model used have been compared with models with averaged deposition parameters and corrections to the rate of dry deposition. Estimates of conditional contamination of the earth's surface by radioactive aerosols with particles of 0.1, 1 and 10 microns in the Arctic regions of the Far North with heterogeneous land-use categories under real meteorological conditions in summer and winter were obtained.
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):487–497
487–497
STUDY OF CHANGES IN THE CONCENTRATION OF GREENHOUSE GASES IN THE ATMOSPHERE IN THE URAL REGION BASED ON REANALYSIS AND SATELLITE MEASUREMENTS. PART 1. SPATIAL-TEMPORAL VARIATIONS IN THE CO2 AND CH4 CONCENTRATION
Abstract
The paper considers spatiotemporal variations in the atmospheric CO2 and CH4 concentrations near the surface based on the CAMS reanalysis data and GOSAT satellite measurements in the Ural Federal District (UFD) for the period 2010–2021. The uncertainty of the used data is estimated. The total uncertainty of CO2 and CH4 concentrations is primarily due to the uncertainty of ground-based measurements. The CAMS reanalysis data most accurately reflect the results of ground-based CO2 concentration measurements. On average, they overestimate these data by 0.59 ± 0.102 ppm. At the same time, the CH4 concentration values obtained on the basis of reanalysis are, on average, 71.57 ± 4.04 ppb lower compared to the results of ground-based measurements. In contrast, the results of GOSAT satellite measurements are in good agreement with the data of ground-based CH4 concentration measurements. On average, they show overestimated values by 4.68 ± 4.05 ppb, while for carbon dioxide CO2 there is an underestimation of 3.51 ± 0.104 ppm. An analysis of the spatial distribution of interannual changes showed that in the eastern and northeastern parts of the Urals Federal District, in some years, there is a significant annual increase in the concentration of CO2 and CH4, reaching values of 16 ppm and 90 ppb, respectively. Particularly high values are recorded in the hot season, when the air temperature exceeds 15 °C. According to the reanalysis, in the Tyumen Region, the Khanty-Mansi and Yamalo-Nenets Autonomous Okrugs, the maximum values of methane CH4 concentration during the year are observed in July-August and exceed the values in the winter period. A sharp increase in CO2 concentration was established for the entire territory of the Urals Federal District in 2012 and 2016. For CH4, a sharp increase in concentration occurred in 2012, 2016 and 2019.
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):498-518
498-518
RELATION OF CO2 CONCENTRATION TO METEOROLOGICAL CONDITIONS AND ATMOSPHERIC WAVE PROCESSES NEAR EAST ANTARCTICA
Abstract
The present study analyses the dependence of CO2 concentration on meteorological parameters and wave processes in the atmosphere. This analysis was based on data obtained during the 68-th Russian Antarctic Expedition on the Scientific expedition ship “Akademik Fedorov” (December 2022 — February 2023). Common spectral maxima in cross-spectra of temporal variations of meteorological parameters (atmospheric pressure, temperature and wind speed) and CO2 concentration in a wide range of periods (from ten minutes to a day) were analyzed. The oscillations with a discrete set of periods from ten minutes to a day were detected in the frequency spectra and cross-spectra of fluctuations of meteorological parameters and turbulent fluxes of momentum and heat, A possible mechanism of formation of the observed frequency spectra of variations of meteorological parameters and CO2 concentration is proposed. It is connected with the influence of the nonlinear process of advection of internal waves in the varying wind caused by solar tides (diurnal and semidiurnal) and the total field of internal waves from their regular sources (solar terminator) and irregular sources (meteorological fronts, orography, jet currents, convection and etc).
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):519-537
519-537
METHANE EMISSIONS FROM LAKES AND RESERVOIRS: UNCERTAINTIES DUE TO FORMATION AND BREAK-UP OF THE ICE COVER
Abstract
In terms of contribution to global warming, methane is the second most potent greenhouse gas after carbon dioxide in the Earth’s atmosphere. Freshwater bodies (lakes and reservoirs), being the most significant source of methane on a global scale, are distributed over the Earth’s surface in such a way that bulk of them is covered with ice for several months of the year. During the freeze-up, the water column is getting isolated from the atmosphere so that methane emissions cease or become restricted to open holes and cracks in the ice cover. Methane accumulated both under ice and within ice-trapped gas bubbles is released at spring ice melt. This review article examines in detail the ways of methane release from the bottom of seasonally ice-covered lakes and reservoirs, the mechanisms of methane accumulation in their water column and ice cover as well as under-ice processes facilitating and impeding such an accumulation. Factors controlling methane emissions at spring ice melt and current approaches for estimating the magnitude of these emissions are also discussed. The data systematized in the article can be used for: 1) planning field studies on seasonally ice-covered water bodies throughout winter/spring period; 2) development of process-oriented models that take into account the influence of ice cover on the spatiotemporal carbon dynamics of freshwater ecosystems and methane emissions from these ecosystems.
Izvestiya, Atmospheric and Oceanic Physics. 2025;61(4):538–552
538–552