Air Temperature Fluctuations Research Articles

Effect of phase change material using in building thermal comfort applications through several climate conditions.

Nowadays, buildings sector contributes to climate change by consuming a considerable amount of energy to afford thermal comfort for occupants. Passive cooling techniques are a promising solution to increase the thermal inertia of building envelopes, and reduce temperature fluctuations. The phase change materials, known as PCM, can be efficiently employed to this purpose, because of their high energy storage density. Among the various existing solutions, the present study is dedicated to solid-liquid phase change materials. Temperature evolution (according to their defined temperature range) induces the chemical change of the material and its state. For building applications, the chemical transition can be accomplished from liquid to solid (solidification) and from solid to liquid (melting). In fact, this paper presents a comparative thermal analysis of several test rooms with and without phase change materials embedded in a composite wallboard in different climates. The used PCM consist in a flexible sheet of 5 mm thickness (Energain, manufactured by the company DuPont de Nemours). The main properties of such a commercial solution have been delivered by the manufacturer and from analyses. The room model was validated using laboratory instrumentations and measurements of a test room in four cities: Lyon; Reading and Casablanca. Results indicate that this phase change material board can absorb heat gains and also reduce the indoor air temperature fluctuations during daytime. The aim of the study is to show the benefits of this layer with phase change material and compare it in different climatic zones.

Long-period changes of the air temperature in Tatarstan and their forecast till the end of the 21st century

Long-term changes in air temperature on the territory of the Republic of Tatarstan in the 20th–21st centuries are considered. The periods of unambiguous changes in the surface air temperature are determined. It is established that the average winter temperature from the 1970s to 2017, increased in the Kazan region by more than 3 °C and the average summer temperature increased by about 2 °C over the same period. The contribution of global scale processes to the variability of the temperature of the Kazan region is shown: it was 37 % in winter, 23 % in summer. The correlation analysis of the anomalies of average annual air temperature in Kazan and the series of air temperature anomalies in each node over the continents, as well as the ocean surface temperature in each coordinate node on Earth for 1880 –2017, was performed. Long-distance communications were detected in the temperature field between Kazan and remote regions of the Earth. It is noted that long-period climate fluctuations in Kazan occur synchronously with fluctuations in the high latitudes of Asia and North America, with fluctuations in ocean surface temperature in the Arctic ocean, with fluctuations in air temperature in the Far East, and with fluctuations in ocean surface temperature in the Southern hemisphere in the Indian and Pacific oceans, as well as air temperature in southern Australia. It is suggested that there is a global mechanism that regulates long-term climate fluctuations throughout the Earth in the considered interval of 200 years of observations. According to the CMIP5 project, climatic scenarios were built for Kazan until the end of the 21st century.

Impact of Heat Resources on Rice Productivity in the Sarpinsky Lowland

The possibility of rice cultivation in the northern areas of rice sowing is determined by the sum of effective air temperatures (Σt ≥ 15 ∘C) over the growing season and its distribution over the vegetation phases of the plants. A long-term statistical and correlation analysis of rice productivity depending on the thermal resources of the Sarpinsky lowland at the Maliye Derbeta meteorological station for the period from 1964 to 2018 (correlation coefficient r = 0.68) is given. It is established that the sum of effective air temperatures varies from 3140.2 to 3999.7 ∘C, while the average annual value is 2820 ∘C. The highest yield (more than 5 t/ha) of rice grains is formed in years with the sum of effective temperatures over 3000 ∘C. The fluctuations of air temperature and their influence on the production process, and the yield of rice grains are analyzed, the results of which can be used as source data in modeling climate change scenarios and predicting rice grain production. The optimal amounts of effective air temperatures for the period April-September, ensuring the realization of the potential productivity of rice in the Sarpinsky lowland conditions, are determined.

Quantifying the cooling effect of urban vegetation by mobile traverse method: A local-scale urban heat island study in a subtropical megacity

Increasing vegetation is considered one of the most efficient ways to mitigate the urban heat island (UHI) effect due to the cooling effect of evapotranspiration. Considering the adverse consequences of the UHI effect on sustainable development and health problems among city dwellers, the effectiveness of urban vegetation on regulation of the UHI effect should be quantitatively evaluated and analyzed to satisfy the needs of urban planning and policy making. Therefore, in this study we analyzed an one-year field experiment data along an 8-km-long belt transect with various land use types and measured the air temperature at 2-h intervals in Shenzhen, a subtropical megacity in China. The results showed that (1) a higher UHI intensity (UHII) was found during the nighttime throughout the year, with a maximum UHII of 4.02 °C during a heat wave night. (2) Both UHI intensity and the Discomfort Index showed a significant negative linear relationship to vegetated area ratio, especially during nighttime with a strong UHI effect. (3) The UHII decreases by 0.16–0.55 °C during nighttime and 0.05–0.15 °C during daytime, when the vegetated area ratio increases by 10%. (4) Increasing vegetation coverage could significantly reduce air temperature fluctuations and areas with vegetation coverage greater than 55% could maintain a relative stable thermal environment for the dwellers. These results could be useful for urban thermal environmental management and urban planning.

Cold-related Florida manatee mortality in relation to air and water temperatures.

Many tropical and subtropical species are sensitive to sudden temperature changes, especially drops in temperature. During winters 2009–2010 and 2010–2011, unusually cold temperatures occurred in many parts of Florida, USA, resulting in increased mortality of Florida manatees, sea turtles, fish, corals, and other species. The Florida manatee, in particular, is highly susceptible to cold stress and death when water temperatures drop below 20°C. We sought to characterize the magnitude and timing of reports of cold-related manatee carcasses in relation to fluctuations in water and air temperatures in central-east and central-west Florida during the six winters from 2008 to 2014. We used a generalized linear model to predict counts of manatee carcasses with a cold-related cause of death reported over 7-day bins in relation to various short-term (two weeks or less) and cumulative (incrementally summed from the start of the winter) heating-degree-day effects (HDD; < 20°C) and a categorical winter variable. Using water temperature data, the top-ranked model in both regions included a short-term temperature effect (14-day HDD sum) that preceded increases in reports of cold-related manatee carcasses by 7 days. Cumulative exposure to cold weather over the winter amplified effects on mortality in the central-east region. Quantifying the relationship between cold events and manatee mortality helps us prepare for rescue and salvage operations when extremely cold weather is forecast. This is especially important because anticipated loss or degradation of warm-water refuges due to human activities and sea level rise could potentially impact the manatee population in the future. These methods could also be applied to other species susceptible to cold-related mortality.

Experimental thermal performance of wallboard with hybrid microencapsulated phase change materials for building application

Combining phase-change materials (PCM) into building envelopes can improve indoor environmental comfort and reduce energy consumption. To adapt to seasonal changes (e.g., hot summer and cold winter), a novel type of hybrid PCM-containing wallboard (including three different PCMs) was fabricated. The hybrid PCM wallboard has a wide phase-change temperature range and can work under different climates for indoor thermal comfort and energy saving. Reduce-scale test cells, two hybrid PCM wallboard integrated test boxes (including Mode 1 PCM wallboard and Mode 2 PCM wallboard) and another equipped with gypsum wallboards, were compared to study the thermal performance of the PCM contained wallboard in both passive and active systems. The results indicate that the hybrid PCM system can narrow indoor air temperature fluctuations and maintain indoor thermal comfort at any time of the entire year. Mode 2 PCM wallboards were found to be more suitable for regulating the indoor thermal environment, as they exhibited more heat release to the indoors during the daytime and less heat loss at nighttime during winter. Under stimulations of different temperature fluctuations, three different layers of the PCMs worked to respond to the temperature fluctuations. Two indices (I and E) were put forward to evaluate the thermal performance of the PCM wallboards. The I index showed that Mode 1 PCM wallboard is suitable for reducing fluctuations of indoor temperature in winter and transition season scenarios. According to the E index, throughout one year, Mode 2 PCM wallboard has higher utilization efficiency than that of Mode 1. Finally, a comparative test was performed with the active system to evaluate the energy saving potential of the two hybrid PCM wallboards. The results show that energy consumption in the hybrid PCM wallboard box is nearly 30% less than that of gypsum wallboard.

Present climate development in Southern Siberia: a 55-year weather observations record

Siberia is a key region for study of the climate development in north-central Eurasia in terms of global climatic change. The relief creates a major orographic barrier for atmospheric streams influencing the regional altitudinal weather zonality. Systematic 55-year (1963-2017) weather observations along the 700 km N-S latitudinal transect across the southern Siberian plains and the adjoining ranges of the Altai-Sayan Mountains document progressing seasonal temperature and humidity shifts. Standard meteorological data from twenty meteorological stations in different topographical and natural settings with specific weather conditions document a rise of a regional atmospheric humidity balance reflected by the increased bulk annual precipitation rates in the mountain areas accompanied by pronounced seasonal air-temperature fluctuations. This regionally trend provides evidence speaking in favor of the strengthening climate continentality over Siberia, which is also manifested by the pronounced seasonal temperature regime with increased thermally positive and negative air temperature anomalies. A landscape response to a climate warming is particularly evident in the high mountain zone. The present thermal conditions with raised MAT contribute to the progressing melting of mountain glaciers and degradation of permafrost in the alpine zone, as well as aridization of the parkland-steppe areas that are being partly transformed into continental semi-arid to deserted steppes. The associated environmental transformations trigger shifts in the local biotopes and ecosystems, with an altitudinal expansion of taiga-forest into the alpine tundra belt and xerothermic grassland invasions in the foothills. The modern climate changes have a major bearing to the Altai-Sayans socio-economic development.

Numerical study on the cooling performance of a novel passive system: Cylindrical phase change material-assisted earth-air heat exchanger

Abstract The application of renewable energy technologies, such as the earth-air heat exchanger (EAHE), is quite conducive to reducing the energy consumption of buildings. However, the heat transfer process of traditional EAHE may greatly change the soil temperature, which hinders the system from fully exerting its thermal performance. Based on the features of high energy density and stable output temperature in the phase change heat storage process, this paper proposes a cylindrical phase change material-assisted EAHE (CPCM-EAHE) to improve the performance of such systems. An equivalent heat capacity method based 3-D numerical model for this novel system was established on the ANSYS Fluent platform. And its calculation result was verified by an indoor experimental set-up. Under summer high-temperature meteorological conditions of Chongqing, the cooling performance of CPCM-EAHE and traditional EAHE is comparatively studied through this numerical model. The results tell that PCM does enhance the heat transfer of EAHE most of the time, as well as delay its transition from the heating mode to cooling mode but advance its transition from the cooling mode to heating mode. These changes finally make the CPCM-EAHE achieve excellent cooling performance. Specifically, compared to traditional EAHE, the daily maximum cooling capacity of CPCM-EAHE is increased by 28.55%–39.74%. Even from the whole 20-day investigation period, its total cooling output is increased by 20.05% as well. Finally, this CPCM-EAHE can damp the temperature fluctuation of fresh air to approximately 1 °C.

Permutation Entropy-Based Analysis of Temperature Complexity Spatial-Temporal Variation and Its Driving Factors in China

Air temperature fluctuation complexity (TFC) describes the uncertainty of temperature changes. The analysis of its spatial and temporal variation is of great significance to evaluate prediction uncertainty of the regional temperature trends and the climate change. In this study, annual-TFC from 1979–2017 and seasonal-TFC from 1983–2017 in China were calculated by permutation entropy (PE). Their temporal trend is described by the Mann-Kendall method. Driving factors of their spatial variations are explored through GeoDetector. The results show that: (1). TFC shows a downward trend generally, with obvious time variation. (2). The spatial variation of TFC is mainly manifested in the differences among the five sub-regions in China. There is low uncertainty in the short-term temperature trends in the northwest and southeast. The northeastern and southwestern regions show high uncertainties. TFC in the central region is moderate. (3). The vegetation is the main factor of spatial variation, followed by the climate and altitude, and the latitude and terrain display the lowest impact. The interactions of vegetation-altitude, vegetation-climate and altitude-latitude can interpret more than 50% of the spatial variations. These results provide insights into causes and mechanisms of the complexity of the climate system. They can help to determine the influencing process of various factors.

INFLUENCE OF CLIMATIC AND ANTHROPOGENIC FACTORS ON THE WHITE SEA – CATCHMENT SYSTEM

Variability of the regional climate is investigated, and its impact on river runoff and some economic processes in the catchment, including fisheries – one of the main livelihoods of the local population – is evaluated. Warming of the regional climate over the past 60 years has not led to any tangible change in mean annual river runoff (no significant trend observed), but was evident in the increase of the water temperature in rivers and the White Sea. The greatest temperature increase is typical for winter months, especially January (mean values over 1991–2017 exceed the climatic norms by 1.7–2.5 °С). The change in flow over the past decades (since 1997) as compared to the preceding period is multidirectional and not significant. During the maximal climate warming in the catchment in 1987–2015, total river runoff varied within 200–310 km3/yr, the average over this period being ca. 230 km3/yr. The water temperature in rivers in the catchment has increased since the mid-1980’s by an average of 1 °С; these variations are coherent to air temperature fluctuations over the catchments of the respective rivers. The observed excessive summer heating of the White Sea under climate warming unfavorably affects the productivity of herring and navaga, fish of the Arctic origin. Since the 1990’s, ecological parameters such as atmospheric emissions and effluent discharges have changed for the better because of the regional economy decline, and since the 2000’s – owing to changes in the structure of the economy and investments in technological upgrade and nature conservation measures.

Heat transfer characteristics of a composite radiant wall under cooling/heating conditions

The radiant wall composited with capillary tubes has been widely applied in heating or cooling systems due to its large heat transfer area, low-temperature heating and high-temperature cooling. In this study, a ratio model of heat transfer in steady-state condition was established, which explores heat transfer capacity from the capillary layer (active layer) towards the indoor and outdoor sides. The experimental data including the radiant surface temperature, the capillary layer temperature and the heat flux distribution were collected in cooling and heating conditions. The proposed ratio model was validated. The results show that the fluctuation of indoor air temperature is relatively small, suggesting that the radiant system possesses higher stability. Results showed that thermal resistances of the composite radiant wall in summer and winter conditions vary greatly due to different moisture contents. With the continuation of the system operation, the calculated values from the ratio model under the steady-state condition were more consistent with average values obtained from experiments under unsteady-state conditions, indicating that the overall heat transfer performance of the composite radiant wall could be properly evaluated by the proposed model in engineering applications.

Testing A Methodology to Assess Fluctuations of Coastal Rocks Surface Temperature

The aim of this work is testing a cheap and user-friendly methodology suitable for studying temperature fluctuations of coastal rocks’ surfaces. An infrared thermometer was used, that permits a contactless measurement of the average surface temperature of a patch around a measuring point. Temperature was measured in an array of selected plots every 45 min from dawn to sunset in a 20 m2 study area along the rocky coast of Calafuria (NW Italy). During the experiment daily temperature in all plots was minimum at dawn and quickly reached its peak value shortly after sun culmination; subsequently, it underwent a small-gradient decrease until sunset. In connection with temporary sun-shading and wind gusts relevant short-term rock surface temperature fluctuations were recorded. Considering mean daily temperature in each plot, it proved to be positively correlated with distance from the shoreline. As regards daily temperature range, its amplitude progressively increased moving farther from the shoreline. The measuring points located where the rock is extensively covered by barnacles experience a temperature magnification effect, possibly due to a micro-greenhouse effect triggered by the production of carbon dioxide by this biota. The entity of measured daily temperature fluctuations is ca. one order of magnitude greater than air temperature fluctuations measured at the same elevation in the closest meteorological station. The results of this work highlight that the infrared thermometer is an effective tool to measure rock surface temperature along rocky coasts, capable of detecting temperature fluctuations more effectively than traditionally employed data loggers. Moreover, this work emphasizes the relevance of temporary sun-shading and wind gusts in triggering short-term rock surface temperature fluctuations, potentially capable of enhancing thermal fatigue and foster surface rock breakdown.

Review on performance assessment of phase change materials in buildings for thermal management through passive approach

Abstract Latent heat energy storage (LHES) systems using phase change materials (PCMs) are well known for its excellent thermal energy storage and release during melting and solidifications respectively. PCMs can be efficiently deployed in applications where significant temperature difference exists in the system for intermittent thermal energy storage. Several research contributions has been made on integrating PCMs in buildings for thermal management, as it enhances building thermal inertia, reduces maximum heat flux, shifts peak energy demand, reduces temperature fluctuations of air, etc., owing to its isothermal behavior and high energy storage density during phase change. Results of several research articles reveal that incorporation of PCM in buildings could significantly improve indoor comfort conditions and reduce energy demand of Heating ventilation and air conditioning (HVAC) systems, provided appropriate PCM selection, encapsulation methods, location deployed etc. This review paper is devoted to elucidate various facts attributing PCM integration in buildings for thermal management through passive approach. The facts includes performance of PCMs in buildings in terms of heat gain reduction, temperature attenuation, peak energy demand shifting and energy saving potential, encapsulation deployed, are discussed and presented in order to expedite the interpretation for future researchers, who took their research work in the field of building thermal energy management.

Performance evaluation of flat rectangular earth-to-air heat exchangers in harmonically fluctuating thermal environments

An earth-to-air heat exchanger (EAHE) is an excellent passive technology that uses shallow geothermal energy directly to generate cooled or heated air for thermal regulation of buildings. Previous studies have focused on circular EAHEs, paying insufficient attention to the effect of cross-sectional shape. In this paper, we propose an EAHE having a flat rectangular cross section, develop a mathematical model to calculate its thermal performance in a harmonic thermal environment, and validate the theoretical results using a three-dimensional numerical model. Our results indicate that compared with a circular EAHE shape of the same cross-sectional area, the outlet air temperature fluctuation of the flat rectangular EAHE is 24.7% lesser and its phase shift is 22.67 days longer, and the soil's thermal disturbance range is shorter, resulting in a temperature wave in the soil around the buried pipe that decays faster and creates a more stable pipe wall temperature. The cooling/heating capacity of the flat rectangular EAHE is greater than that of the circular EAHE. The pressure drop and fan power consumption of the flat rectangular EAHE is greater than that of circular EAHE, and thus the coefficient of performance (COP) value of the flat rectangular EAHE is less than that of the circular EAHE.

Investigation of the performance of a cylindrical PCM-to-air heat exchanger (PAHE) for free ventilation cooling in fluctuating ambient environments

This paper proposes the use of a cylindrical annulus composed of phase change material (PCM), referred to as a PCM–air heat exchanger (PAHE), to regulate the supplied air temperature in ventilated buildings exposed to fluctuating thermal environments. The forced convection inside the PAHE tube enhances the heat transfer between the air and PCM, and thus both the sensible and latent heat transfer contribute to reducing the air temperature fluctuations and peak cooling/heating loads. Both experiments and numerical simulations are performed to investigate the performance of a PAHE exposed to fluctuating ambient temperatures. The effects of three PAHE parameters, i.e., the flow rate through the PAHE tube, melting temperature of the PCM, external diameter of the PAHE, and the tube length on the PAHE performance were investigated numerically. Maintaining a stable inner surface temperature in the PAHE is crucial for maximizing its ability to reduce air temperature fluctuation amplitude. For this purpose, these key parameters should be appropriately selected. The cooling performance of the PAHE in a region with hot summers and cold winters region was evaluated. The simulation incorporated real meteorological data of two transitional seasons and a summer, and demonstrated a maximum reduction in air temperature of 5.4 °C.

ТРЕЩИНОСТОЙКОСТЬ МАССИВНЫХ БЕТОННЫХ КОНСТРУКЦИЙ В СТРОИТЕЛЬНЫЙ ПЕРИОД С УЧЕТОМ ТЕМПЕРАТУРНЫХ ВОЗДЕЙСТВИЙ

Concrete is a fundamental material of modern construction due to its reliability, the ability to harden in air and under water, the ability to build structures of any shape and sizes. In particular, it is used in the construction of advanced structures and their parts: nuclear power plants, large hydraulic struc-tures, bridges, massive foundations of multi-storey buildings, etc. This paper is devoted to relevant objective in the field of construction of buildings and structures with a high level of responsibility, the study of thermal crack resistance of massive concrete structures, taking into account the temperature effects during the building period. The calculations are given of the thermal crack resistance of the foundation plate of the reactor department of Leningrad NPP-2 under continuous concreting with one block at full height. It is highlighted that the use of the simplest calculation model, which does not con-sider fluctuations in air temperature during the building period, leads to a significant error of the sur-face insulation thickness that is optimal from the point of view of providing the thermal crack re-sistance of a massive concrete structure.

Glacier runoff and regime of rivers with glacial power (a case of study: Naryn river, Kyrgyzstan)

In this paper, we considered the glacial runoff of the Bolshoi and Kichi Naryn rivers, as well as their large tributaries which are main sources of the Toktogul water reservoir. Taking into account that rivers with glacier melting feeding form their water flow mostly during summer months, it would be interesting to analyse their water regime during warm seasons. All tributaries of the Naryn River demonstrate the runoff decrease from June to August; while the main channels of the Chon and Kichi Naryn themselves have another dynamic. In July, the seasonal snow cover already melted and the runoff formation occurs as a result of glacier melting that depend on monthly average temperatures. In August, the monthly amounts of precipitation and temperatures have decreasing trends that lead to immediate decline of the runoff volumes. Interestingly those fluctuations of precipitation and air temperatures and their impact on the glacier runoff forming have little impact on the total runoff volume of rivers. So, the glacial component in the run-off forming has exceptional value for the Naryn River during the summer period.

Enhancing a vertical earth-to-air heat exchanger system using tubular phase change material

Abstract: In this study, a new vertical earth-to-air heat exchanger (VEAHE) system coupled with tubular phase change material (PCM) components was proposed. The proposed system has smaller occupied areas and higher geothermal energy use efficiency than traditional EAHE systems. Moreover, the tubular PCM component enables the system's air temperature at the outlet to be more stable, thereby enhancing the system's thermal performance. In particular, the tubular components' simple geometry, easy fabrication, convenient assembling-disassembling and low-cost facilitate their usage in practical applications. To explore the system's thermal performance, an experimental set-up was established and its numerical model was developed. Then the model was verified through a comparison between the system's simulated and monitored air temperatures at the outlet. The verification produced acceptable results with the maximum absolute relative error of 1.33%. Based on this model, the influences of the tubular PCM component, tube depth, PCM conductivity and container length on the proposed system's thermal performance were investigated. Results indicated that the tubular PCM components can effectively reduce the VEAHE system's air temperature peak and fluctuation at the outlet, and increase its average cooling capacity. For the proposed system, as the tube depths increase from 12 to 24 m, the air temperature peak and fluctuation at the outlet decrease from 25.74 °C and 3.59 °C to 21.01 °C and 0.62 °C, respectively. Different thermal conductivity of PCM has almost same influences on the system's air temperature at the outlet as the container diameter is 50 mm. Such influences, however, become apparent and require to be considered as the container diameter increases to 150 mm. The air temperature fluctuation at the outlet decreases as the container lengths increase, and 12 m can be considered as an appropriate length for the proposed system. Additionally, the system's static payback period was calculated as 18.03 years.

Dynamic heat transfer modeling of a closed refrigerated display cabinet

This study proposes a simplified heat transfer model of a closed refrigerated display cabinet using a zonal approach. The dynamic model was developed and solved with a spectral method to predict the temperature fluctuations occurring with “on/off” compressor regulation. The equivalent load thickness in which the temperature fluctuations were of the same order as those at the load surface was estimated as a function of “on/off” compressor operating frequency. The air temperature fluctuations are dampened whenever the air exchanges heat with solid surfaces (e.g. walls, loads) and with the ambient air (e.g. through the doors). Despite exposure to large air temperature fluctuations (up to 5 °C), the load surface temperature showed only small fluctuations (ΔTl ≤ 0.5 °C). Good agreement was found between the predicted and the measured temperature fluctuations. The model can also be applied in order to predict air and load temperature increases during defrost operation.

Влияние современных температурных колебаний на хозяйственную деятельность населения в Байкальском регионе

&lt;span&gt;В работе рассмотрена динамика ряда характеристик отопительного периода в многолетнем и межгодовом режиме на юге Байкальского региона. Выявлено сокращение продолжительности отопительного периода последних десятилетий (с 1991 по 2017 гг.) относительно многолетних данных до 1960 г. на 6–10 дней. Показан значительный рост температуры наружного воздуха в течение отопительного сезона на 3,9 °C в Чите, 4,1&lt;/span&gt;&lt;span class="myHorizontalScaleForEmDashSpaceBefore"&gt; &lt;/span&gt;&lt;span&gt;–&lt;/span&gt;&lt;span class="myHorizontalScaleForEmDashSpaceAfter"&gt; &lt;/span&gt;&lt;span&gt;в Иркутске и 5,0 °C&lt;/span&gt;&lt;span class="myHorizontalScaleForEmDashSpaceBefore"&gt; &lt;/span&gt;&lt;span&gt;–&lt;/span&gt;&lt;span class="myHorizontalScaleForEmDashSpaceAfter"&gt; &lt;/span&gt;&lt;span&gt;в Улан-Удэ. Совокупное изменение этих показателей повлияло на снижение индекса потребления топлива на 15–19%. Анализ межгодовых колебаний характеристик отопительного периода с 1991 г. по 2017 г. выявил, что аномально низкие температуры выше по модулю и отмечаются чаще по сравнению с аномально теплыми зимами. Изменение межгодовых колебаний индекса потребления топлива составило от 14–20%, что сопоставимо с многолетними колебаниями (до 1960 г.). Показано, что резкие межгодовые колебания температуры воздуха на фоне современного потепления демонстрируют неоднозначность их влияния на хозяйственную деятельность в Байкальском регионе.&lt;/span&gt;