Temporal Temperature Distribution Research Articles

Distribution Characteristics and Prediction of Temperature and Relative Humidity in a South China Greenhouse

South China has a climate characteristic of high temperature and high humidity, and the temperature and relative humidity inside a Venlo greenhouse are higher than those in the atmosphere. This paper studied the effect of ventilation conditions on the spatial and temporal distribution of temperature and relative humidity in a Venlo greenhouse. Two ventilation conditions, with and without a fan-pad system, were studied. A GA + BP neural network was applied to predict the temperature and relative humidity in fan-pad ventilation in the greenhouse. The results show that the temperature in the Venlo greenhouse ranged from 15.8 °C to 48.5 °C, and the relative humidity ranged from 24.9% to 100% during the tomato-planting cycle. The percentage of days when the temperature exceeded 35 °C was 67.3%, and the percentage of days when the average relative humidity exceeded 70% was 83.7%. The maximum temperature differences between the three heights under NV (Natural Ventilation) and FPV (Fan-pad Ventilation) conditions were 3.4 °C and 4.5 °C, respectively. The maximum relative humidity differences between the three heights under NV and FPV conditions were 8.4% and 21.7%, respectively. The maximum temperature difference in the longitudinal section under the FPV conditions was 3.2 °C, while the relative humidity was 11.4%. The cooling efficiency of the fan-pad system ranged from 16.6% to 70.2%. The non-uniform coefficients of the temperature under the FPV conditions were higher than those under the NV conditions, while the nonuniform coefficients of the relative humidity were the highest during the day. The R2, MAE, MAPE and RMSE of the temperature-testing model were 0.91, 0.94, 0.11, and 1.33, respectively, while those of relative humidity model were 0.93, 2.83, 0.10, and 3.86, respectively. The results provide a reference for the design and management of Venlo greenhouses in South China.

Evaluation of weather generator tools to estimate climate conditions in different agro ecological zones of North Shewa, Ethiopia

The information on climatic condition is difficult to obtain, expensive, and time-consuming so as to make timely decision on agricultural activities. As a scientific effort, this study was conducted to assess the temporal changes and trends of rainfall and temperature, to know the performance of weather generator (WG) tools in capturing the temporal and spatial distribution of rainfall, maximum temperature (Tmax) and minimum temperature (Tmin) and to evaluate the performance of WG in simulating the observed rainfall, Tmax and Tmin by using statistical methods. Mann–Kendall's trend analysis revealed that rainfall had non-significant (P < 0.05) decreasing trends, while Tmax and Tmin had an increasing significant (P < 0.05) trends at all stations. NASA POWER data followed by NewlocClim exactly capture the temporal changes of rainfall, Tmax, and Tmin in all stations except Debre Birhan and Mehal Meda. NewlocClim well captures rainfall at Alem ketema, while NASA well simulates rainfall at Debre Birhan and Majete stations. However Had-GEM2-ES, MRI-CGCM3, and CSIRO-Mk3.6.0 were not handling the spatial variability of observed rainfall at all stations. Similarly, some WGs showed moderate to good performance in capturing the spatial distributions of Tmax and Tmin. The smallest RMSE and CV, the highest R and d values were observed in NASA POWER and NewlocClim for rainfall, Tmax and Tmin. Therefore, NASA and NewlocClim are more accurate with goodness of fit to estimate rainfall, Tmax and Tmin in most of the stations to access weather data for ungagged stations for timely and reasonable decision-making on agriculture.

A case study on early-age cracking of high-strength concrete construction by coupled thermal-mechanical analysis and field monitoring

The use of high-strength concrete (HSC) in constructing high-rise reinforced concrete buildings and their deep foundations is becoming more popular because of the significant reduction in member size and, thus, self-weight in structural members. However, the higher cement content in HSC may result in increased heat of hydration and autogenous shrinkage, growing concerns about forming early-age cracks in HSC structural members. This case study assessed the early-age cracking of HSC in bored pile construction of high-rise buildings. A nonlinear transient coupled thermal-mechanical response analysis was performed to evaluate the potential of early-age cracking caused by the heat of hydration generated in the HSC using ABAQUS and two subprograms, USDFLD and UEXPAN. A 3-D finite element model was developed considering thermal effects, time-dependent evolution of early-age strength and stiffness of HSC, crack strain development, autogenous shrinkage, and stress-relaxation in the analysis. Field measurements were carried out on a 3-m diameter bored pile constructed using Grade C50/60 HSC (fck,cube = 60 MPa) for a high-rise building project in Hong Kong to evaluate the validity of the numerical model. Optical fiber sensors were used to monitor the temperature changes of the pile for approximately 380 hours after casting. The temporal and spatial temperature distributions measured in the field measurements agree well with the simulations. Large thermal gradients and high tensile stress zones were observed across the horizontal cross-sections of the pile, resulting in the formation of vertical annular cracks. Based on the results of the analysis, the maximum crack widths were predicted and compared with the durability crack width limits.

An experimental‐based thermal prediction model for butt fusion welding of polymer pipes

AbstractHigh‐density polyethylene (HDPE) is one of the most used thermoplastic materials for piping applications, due to its significant advantages. The butt‐fusion process is the most used joining processes for HDPE welding. During the process, the behavior of the material changes. This behavioral change depends on the applied welding process and on the used parameters. Thermal analysis can be used as a tool to reveal and evaluate the modifications of the physical and mechanical properties. In this study, an experimental program was applied to HDPE to assess the effects of different parameters on the welding process including heating temperature, heating duration and the applied strength. Tests are performed according to a full factorial design of experiment (DOE). Mathematical models derived from experimental data are used to establish relationships between the input parameters, such as force and heating duration and the corresponding outputs such as temperature distribution during the different welding phases and the thickness of the molten polymer. The empirical models can be used to implement a control strategy for the temperature and hence quantify the thickness of the molten zone to improve the quality of the weld joint by selecting the appropriate welding conditions for the molten zone.Highlights High‐density polyethylene piping butt‐fusion joint examination using Infrared imaging. Spatial–temporal distribution of temperature for different phases of the welding process. Mathematical Regression techniques are performed. Thickness of molten polymer is assessed. Results are useful for saving material and improvement of the process.

Influence of extraction and injection conditions on the performance of thermal-enhanced soil vapor extraction

Thermal-enhanced soil vapor extraction (T-SVE) is an in-situ remedial technique that can address the limitations of contaminant mass transfer and soil permeability. The relative humidity of the injected air, heating temperature of the thermal well, extraction pressure, and extraction mode are important design parameters of a T-SVE system that determine the temporal and spatial distributions of soil temperature and removal rate. Using a thermal–hydraulic–chemical coupled model with the interphase mass transfer of contaminants and water evaporation/condensation, this study investigated the effects of relative humidity, heating temperature, extraction pressure, and extraction mode on T-SVE performance. The results showed that with an increase in relative humidity, the heating temperature of the contaminated soil significantly improved; however, the removal rate of contaminants decreased, particularly in the late stage of remediation. Considering the heating temperature of the thermal well, a critical air relative humidity value that significantly affects the removal rate of contaminants was observed. The heating temperature of the thermal well must be considered in engineering design; however, the evaluation of the relative humidity of the air cannot be ignored.

Time-dependent model of temperature distribution in continuous flow pulsed electric field treatment chambers

A key component of a continuous flow pulsed electric field (PEF) system is the treatment chamber, where the product is exposed to electric pulses. Determination of the temperature distribution in the chamber during PEF treatment is important since high local increases in temperatures can affect the quality of the product. Coupled simulations of electric field, fluid flow, and heating in the existing literature do not model each individual electric pulse, but rather employ a “duty cycle” approach, which does not account for transient variations in treatment intensity and temperature changes in the medium. We present a time-dependent approach to modelling PEF treatment in continuous flow treatment chambers, which can model each pulse separately, and thus enables a more accurate study of temporal and spatial distributions of electric field and temperature. The model has been validated on laboratory scale treatment chambers of parallel plate or colinear design and using realistic protocols. Industrial relevance textThe paper is relevant to all pulsed electric field (PEF) applications either on laboratory or industrial scale that implement a continuous flow treatment chamber. It presents an improved modelling approach which allows for an analysis of the electrical current, electric field, and temperature distribution in the chamber during, at the end, and in between application of electrical pulses. The model can be used to predict the peak temperature at the end of each pulse in the hot spots, which if large enough could potentially lead to thermal damage of the product or in extreme cases even potential local boiling of the medium, resulting not only in degradation of the treated product, but also in accelerated electrode fouling, oxidation, and dissolution (etching), as well as arcing. This would not only affect the quality of the treated product but would also affect the wear and lifetime of electrodes/chambers, and of the pulse generator. The model can also be used to avoid expensive trial-and-error optimization of the PEF protocols and chamber geometries in situ.

Effect of natural fracture on the heat mining of enhanced geothermal system based on the thermo-hydro-mechanical coupling model

ABSTRACT Hydraulic fracture, natural fracture and fracture networks play a vital role for heat mining of Enhanced Geothermal System (EGS). In this work, a two-dimensional thermo-hydro-mechanical (THM) EGS model was proposed to investigate the effect of natural fracture on heat extraction performance. Based on the local thermal non-equilibrium theory and discrete natural fracture network, the spatial and temporal distribution of temperature, pore pressure, effective stress, rock matrix porosity and permeability are investigated. The results show that the natural fracture has a significant negative effect on the production temperature. After the 40-year prediction, the production temperature of the base model is 45.5°C lower than that of the without natural fracture model. In the initial operation stage, the low-temperature region is mainly distributed in the region of artificial fracture and injection well, then it expands significantly to the natural fracture due to the stress redistribution. The key parameters of quantity and orientation of natural fracture can lead to a decline in production temperature and earlier thermal breakthroughs within the thermal reservoir.

Study on Radiofrequency Ablation of Lung and Kidney Tumors With and Without Nanoparticles Using Multi-Tined Electrode

Abstract Radio frequency ablation (RFA) is an alternative method for the cure of malign tumors in the liver, lung, and kidney. In the present work, finite element method (FEM) analysis is conducted to study the effect of nanoparticles on the temporal and spatial temperature distribution during RFA. Three-dimensional thermoelectrically FEM model consisting of a multitined radio frequency electrode (nine-tine, deployed up to 2 cm) and a cubical tumor of size 50 mm3 is developed. Numerical simulation is carried out under the temperature-controlled mode (95 °C) with 10 min ablation time. A study using multitined electrodes is carried out on different tissues, i.e., lung and kidney, with and without nanoparticles. Results show that the nanoparticles increase the heat conduction rate and decrease the ablation time up to 13% for the inclusion of 6% nanoparticles. It has been found that the spatial temperature distribution becomes uniform with nanoparticle assistance.

Predicting spatio-temporal radiofrequency ablation temperature using deep neural networks

Radiofrequency ablation (RFA) of the medial branch nerve is a widely used therapeutic intervention for facet joint pain. However, denervation of the multifidus muscle is an inevitable consequence of RFA. New ablation techniques with the potential to prevent muscle denervation can be designed using computational simulations. However, depending on the complexity of the model, they could be computationally expensive. As an alternative approach, deep neural networks (DNNs) can be used to predict tissue temperature during RFA procedure. The objective of this paper is to predict the tissue spatial and temporal temperature distributions during RFA using DNNs. First, finite element (FE) models with a range of distances between the probes were run to obtain the temperature readings. The measured temperatures were then used to train the DNNs that predict the spatio-temporal temperature distribution within the tissue. Finally, a separate data obtained from FE simulations were used to test the efficacy of the network. The results presented in this paper demonstrate that the network can achieve an error rate as low as 0.05%, accompanied by a 92% reduction in time compared to FE simulations. The approach proposed in this study will play a major role in the design of new RFA treatments for facet joint pain.

Diagnosing Mechanisms of Hydrologic Change under Global Warming in the CESM1 Large Ensemble

Abstract Global warming is expected to cause significant changes in the pattern of precipitation minus evaporation (P − E), which represents the net flux of water from the atmosphere to the surface or, equivalently, the convergence of moisture transport within the atmosphere. In most global climate model simulations, the pattern of P − E change resembles an amplification of the historical pattern—a tendency known as “wet gets wetter, dry gets drier.” However, models also predict significant departures from this approximation that are not well understood. Here, we introduce a new method of decomposing the pattern of P − E change into contributions from various dynamic and thermodynamic mechanisms and use it to investigate the response of P − E to global warming within the CESM1 Large Ensemble. In contrast to previous decompositions of P − E change, ours incorporates changes not only in the monthly means of atmospheric winds and moisture, but also in their temporal variability, allowing us to isolate the hydrologic impacts of changes in the mean circulation, transient eddies, relative humidity, and the spatial and temporal distributions of temperature. In general, we find that changes in the mean circulation primarily control the P − E response in the tropics, while temperature changes dominate at higher latitudes. Although the relative importance of specific mechanisms varies by region, at the global scale departures from the wet-gets-wetter approximation over land are primarily due to changes in the temperature lapse rate, while changes in the mean circulation, relative humidity, and horizontal temperature gradients play a secondary role.

Investigation of hydro-thermal variations and mechanical properties in cold region tunnels under long-term freeze–thaw cycles

Long-term freeze–thaw cycles have a significant impact on the safety and durability of tunnels located in cold regions. In this study, a hydro-thermal–mechanical coupling model and calculation method were developed based on the Guanjiaoshan Tunnel. The model's precision and rationality underwent comprehensive validation. The study aimed to discuss the temporal and spatial distributions of temperature, water, and mechanical fields under long-term freeze–thaw cycles. The findings revealed that the water migration influence zones can be classified into three distinct zones. The ice-water phase change and stress exhibit periodic fluctuations following an annual cycle. Significantly, the lining's stress, or danger level, exhibited two peaks during the autumn and spring seasons. The magnitude of the autumn peak exceeded that of the spring peak. Throughout the initial 12-year period, the tunnel's danger level consistently remained below the threshold value of 1.0, affirming its adherence to safety standards during its early service period. Furthermore, the construction of tunnels has the potential to contribute to frozen soils expansion in specific zones due to prolonged freeze–thaw cycles. These study results not only enhance our understanding of hydro-thermal variations but also provide valuable insights for predicting the long-term security performance of tunnels in cold regions.

Geothermal gradients in a high-organic content landfill

Geothermal gradients in a high-organic content landfill

Three-Dimensional Thermal Modeling of In Situ Heating Tests for High-Level Radioactive Nuclear Waste Repository

This study aims to model the temperature evolution near the heater of an in situ heating test for a nuclear waste repository. Based on the governing equation of heat conduction, a mathematical model is established to obtain temporal and spatial temperature distributions in the in situ heating test. Then, semi-analytical solutions are derived using the Laplace and Fourier transforms and their inverse transforms. The corresponding results in the time domain are obtained by conducting the Crump method. The semi-analytical solution is applied to predict temperature change near the heater in two in situ heating tests. Finally, a parametric study is conducted to explore the impacts of some parameters on the temperature evolution of the buffer layer for one prototype repository in situ heating test. The results show that the semi-analytical solution of the proposed model can well predict the temperature change near the heater in the two in situ heating tests. The thermal conductivities of the buffer layer and the rock layer and the thickness of the buffer layer have significant effects on the temperature evolution of the buffer layer in the prototype repository in situ heating test.

Soybean phenological changes in response to climate warming in three northeastern provinces of China

ContextSoybean plays an important role in agricultural production in three northeastern provinces of China; furthermore, climate change, particularly temperature and rainfall changes, can significantly regulate soybean phenological periods. Research QuestionCurrent research on the spatial and temporal characteristics of soybean phenology and its relationship with climate change in the three northeastern provinces of China is still inadequate. MethodsIn this study, phenological and meteorological data from 26 agrometeorological stations in northeastern China were used to evaluate temporal and spatial changes and their correlations with soybean temperature, rainfall, phenological stage, and growth duration over the long term in three northeastern provinces. ResultsOn average, 22 of the 26 stations showed increases in temperature, and 15 stations showed increases in rainfall during the survey stage. All of soybean growth nodes were delayed, except R8, which advanced by 0.28 days, and all soybean growth durations were shortened except for during the V3-R1 period. In addition, temperature was negatively correlated with growth duration, while rainfall was positively correlated with growth duration. Further, the spatial and temporal distribution of temperature and rainfall showed that an increase in temperature led to an increase in thermal conditions and a significant northward and eastward expansion of the cumulative temperature zone, with the most significant increase in temperature occurring in most areas of Heilongjiang, followed by Liaoning. ConclusionsSoybean planting practices in the three eastern provinces should be adjusted to medium- and late-maturing varieties, which can adapt to climate change and mitigate its effects during the phenological period, due their tolerance to high heat. SignificanceThese findings fill a knowledge gap for understanding the relationship between soybean phenological changes and climate change in the three northeastern provinces.

Melting numerical simulation of hydrated salt phase change material in thermal management of cylindrical battery cells using enthalpy-porosity model

Battery thermal management using different cooling techniques is rapidly growing. Understanding the proper cooling and melting process when phase change materials (PCM) are used is of prime importance in this area. Hence, a transient thermal-fluid and melting process of hydrated salt PCM enclosed in a battery module with six cylindrical cells is numerically investigated to understand the melting process of the PCM. Four structural models S1, S2, S3, and S4 are constructed for the present numerical simulation. The battery cell wall is kept at a constant temperature of 35℃, while the rectangular enclosure walls are assumed to be insulated. A finite volume scheme-based CFD (computational fluid dynamics) software is used to simulate the melting process of hydrated salt PCM. In order to capture the phase change phenomenon from solid to liquid, an enthalpy-porosity equation is solved. The temporal temperature distribution, liquid fraction, velocity and enthalpy are analyzed. The results obtained by the numerical computation suggest that the battery cell arrangement used in S1 and S2 model at the initial time step gives better space for temperature distribution and liquid fraction up to the time step of 420 s, while S3 and S4 model after a time interval of 420 s provide better scope for temperature distribution and complete melting of hydrated PCM.

Application of MODIS land surface temperature data on ENSO-based analysis in Kalimantan

El Nino Southern Oscillation as climate anomaly has been impacted Land Surface Temperature (LST) in Indonesia. Higher temperature during El Nino has been considered to give more risk in fire hazards in Kalimantan, thus, analysis of spatial and temporal distribution of LST became crucial. This study aims to analyze the spatial and temporal distribution of land surface temperature in Kalimantan based on the ENSO phases from 2014 to 2020. MODIS MOD11A1 images and ONI index were used as analysis materials. Image processing was conducted by selecting pixels using the QC band and then processing the LST values using a scale using RStudio software. The result shows the distribution of higher LST values on the southern side of Kalimantan, influenced by low elevation, peat soil, and land use change. The temporal distribution shows a tendency for higher temperatures in the dry months of August to October, with an increase of 4.5 percent during El Nino and a decrease of 0.9 percent during La Nina from 2014 to 2020. This study could contribute to management and mitigation for fire risk in certain area and period as ENSO occurred in Kalimantan.

Soft Sensors for Property-Controlled Multi-Stage Press Hardening of 22MnB5

In multi-stage press hardening, the product properties are determined by the thermo-mechanical history during the sequence of heat treatment and forming steps. To measure these properties and finally to control them by feedback, two soft sensors are developed in this work. The press hardening of 22MnB5 sheet material in a progressive die, where the material is first rapidly austenitized, then pre-cooled, stretch-formed, and finally die bent, serves as the framework for the development of these sensors. To provide feedback on the temporal and spatial temperature distribution, a soft sensor based on a model derived from the Dynamic mode decomposition (DMD) is presented. The model is extended to a parametric DMD and combined with a Kalman filter to estimate the temperature (-distribution) as a function of all process-relevant control variables. The soft sensor can estimate the temperature distribution based on local thermocouple measurements with an error of less than 10 °C during the process-relevant time steps. For the online prediction of the final microstructure, an artificial neural network (ANN)-based microstructure soft sensor is developed. As part of this, a transferable framework for deriving input parameters for the ANN based on the process route in multi-stage press hardening is presented, along with a method for developing a training database using a 1-element model implemented with LS-Dyna and utilizing the material model Mat248 (PHS_BMW). The developed ANN-based microstructure soft sensor can predict the final microstructure for specific regions of the formed and hardened sheet in a time span of far less than 1 s with a maximum deviation of a phase fraction of 1.8 % to a reference simulation.

Vulnerability Identification and Analysis of Contributors to Desertification in Inner Mongolia

Desertification vulnerability and contributing factors are of global concern. This study analyzed the spatial and temporal distribution of net primary productivity (NPP), precipitation, and temperature from 1985 to 2015. The rain use efficiency (RUE) of vegetation was selected as an indicator; and desertification vulnerability and contributors were evaluated with the Mann−Kendall test (M−K test) and the Thornthwaite−Memorial model. The results showed that NPP was lower in that years that had lower precipitation and higher temperatures, and vice versa. NPP was spatially consistent with precipitation distribution and roughly opposite to the spatial distribution of the annual change rate of temperature. The desertification vulnerability decreased from west to east, among which both the western sub−region (WSR) and the central sub−region (CSR) had the largest proportion of regions with high desertification vulnerability. On the other hand, the eastern sub−region (ESR) mostly comprises areas with extremely low or low desertification vulnerability. The vulnerability contributors for desertification differed among each sub−region. The desertified regions in WSR and ESR were mainly influenced by human activity (HA), but primarily driven by the combined impact of Precipitation−Temperature (PT) and HA in CSR. The south−east part of the CSR was only affected by HA, whereas the lesser affected regions in the study area were affected by PT and HA simultaneously. The study provides recommendations for the improvement of regional ecological environments to prevent future disasters.

Experimental Study of the Thermal Performance of a Sensitive Solar Energy Storage System on a Rock Bed (Granite) for a Drying Application

The use of solar energy is hampered by the intermittency of the resource and the constraints of storing the thermal form of this energy. The processes using this resource are therefore faced with problems of continuity of the process. To remedy this, this work proposes to develop a device for the accumulation of solar thermal energy by a sensitive storage system on a rock bed. A solar thermal energy storage system has been developed and experimentally studied with a view to coupling it to a solar dryer. The thermal performance of the system was evaluated in terms of temporal distribution of bed temperature, total energy stored, total energy discharged, charging efficiency, discharging efficiency. The results obtained indicate that the stratification in the storage system decreases in the afternoon due to the reduction of solar radiation and the output temperature of the solar collector. This contributes to a decrease in the thermal performance of the storage system. The charging efficiency obtained is 76.8%, the discharging efficiency 44.4%. The results also indicate that out of 4.7 MJ of total stored energy almost 89% or 4.17% was recovered during the discharge phase which is interesting for solar dryers.

Physical meaning of temperature and evaluation of distribution laws (in the area of the Lake Sevan basin)

Formulation of the problem. In the work, the most general definition of temperature was discussed and presented, the temporal probability distribution of air temperature was analyzed and evaluated. Temperature has no specific definition. Thus it will be difficult to study the nature of any geophysical phenomena, including the characteristics of temperature distribution, without understanding the modern scientific definition and adjustment of temperature. The aim of the work is to give the most modern reasonable definition of temperature or what the thermometer measures, the answer to which requires a more specific scientific justification, as well as to evaluate the patterns of possible spatiotemporal distribution of air temperature in the territory of Armenia and in the area of the Lake Sevan basin. Methods. To solve the set tasks, the authors used corresponding research and published works as a theoretical basis in the work. In the work, the average monthly data of actual observations of the temperature of the ground surface air layer and the amount of precipitation of the «Center for Hydrometeorology and Monitoring» SNCO of the Ministry of Environment of the Republic of Armenia were used. It was found that temperature is a quantity characterizing the thermal state and radiation of the terrestrial and celestial bodies and, in general, the environment, which is strongly related to the entropy change of the system; temperature is the main thermodynamic characteristic of thermal equilibrium; the thermodynamic and microscopic concepts of temperature coincide; the temperature-heat (energy) difference becomes known in the sense that a system can have high energy but low temperature. The authors applied the following research methods in the article: mathematical and statistical, extrapolation, analysis, analogy, correlation, cartographic. Results. Energy depends on the geometry (dimensions) of the system, but temperature does not. A trend of increasing air temperature is observed in the RA territory, which is also a result of the entropy change of the system. It can change very quickly, depending on the environmental factors in the given area (the growth rate of greenhouse farms, the artificial filling of valleys, which are wave carriers of air flow, the relentless use of green spaces for the purpose of public buildings, and other factors) in the process of disrupting the excessively permissible norms, which are currently separate needs serious research and prevention. The long-term variability of surface air temperature in the area of the Lake Sevan basin is analyzed. The analysis carried out made it possible to give a quantitative assessment characterizing the climate change in this region over the past 98 years. An analysis of the observational data showed that the trend of climate warming is confirmed by an increase in air temperature both in winter and over a long period of time. The change in surface air temperature occurs at a rate of 0.002 ºС/year to 0.012 ºС/year and is generally 0.008 ºС/year (or 0.08 ºС/10 years) for all analyzed stations. The results obtained confirm the presence of two periods of warming observed in 1927–1970 and 1971–2021. All the results obtained in the course of the work testify to the trend of climate mitigation in the area of the Lake Sevan basin at the end of the 20th - beginning of the 21st century.