Seasonal Variations In Air Temperature Research Articles

VARIATIONS OF δ18О AND δ2H VALUES OF PRECIPITATION IN MOSCOW FROM 2017 TO 2019

To reveal variations in the iso topic composition of O and H in the atmospheric precipitation in Moscow and the processes influencing the isotope composition, all events of precipitation in 2017-2019 were sampled at the Meteorological Observatory of the Moscow State University: 158 samples in 2017, 119 samples in 2018 and 143 samples in 2019. The study is a prolongation of continuous measurements of the isotope composition of precipitation, started by authors in 2014. The study of the isotope composition of precipitation at the MSU Meteorological Observatory was supported by the IAEA and became a part of the Global Network of Isotopes in Precipitation (GNIP) database. It has been found that the intra-annual variability of the isotop e composition of precipitation has a pronounced seasonality. The most isotopically heavy precipitation falls from May to August, and the most isotop ically light precipitation at December-February, mainly due to seasonal air temperature variations. The ratio of the average monthly δ18O values in precipitation and air temperature for the study period varied from 0.34 to 0.39‰/°C, which is consistent with the previously obtained data for precipitation in Moscow. The δ2H-δ18O ratio in precipitation was clos e to that of the Global Meteoric Water Line, pointing to the equilibrium conditions during precipitation formation. It was established that in the summer months isotopic composition is significantly influenced by undercloud evaporation. The deuterium excess va lues in precipitation are not markedly seasonal; however, lower dexc values (below the 3-year average of 11‰) are typical for the summer months (July-August). It is most likely due to undercloud evaporation in conditions of low relative humidity and high air temperatures. Higher dexc values (above 11‰) prevailed from October to April.

Global photosynthetic capacity of C3 biomes retrieved from solar-induced chlorophyll fluorescence and leaf chlorophyll content

The maximum Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (Vcmax) has been widely used to help determine the photosynthetic capacity for carbon cycle modelling. Field measurements of Vcmax are very limited, so fixed Vcmax values over growing seasons are often used, causing considerable uncertainties in modelled results. Also, the lack of a global Vcmax dataset with seasonal variations limits our understanding of the spatial and temporal patterns of Vcmax, and hence photosynthesis. This study proposes a refined data assimilation scheme to retrieve daily Vcmax using remotely sensed solar-induced chlorophyll fluorescence (SIF) and leaf chlorophyll content (LCC) data. Using the refined method, we produced a global Vcmax dataset with daily 0.1° × 0.1° resolutions. The seasonal variations in Vcmax have been successfully retrieved. Vcmax retrieved in this study was compared with field-measured Vcmax from past literature. Good agreements were achieved in relation to Vcmax measured at 201 sites (R2 is 0.78, and relative RMSE is 34%) and the seasonal variation in Vcmax measured at 9 sites (R2 ranges from 0.57 to 0.99, and the relative RMSE ranged from 6% to 28%). Our method effectively utilizes the information from both SIF and LCC, showing advantages over previous approaches that estimate Vcmax based solely on using SIF or LCC. Our results suggest that the spatial distribution of Vcmax depends on the spatial distribution of biomes, along with air temperature and absorbed photosynthetically active radiation (APAR). Higher seasonal mean air temperature and APAR tend to lead to higher seasonal mean Vcmax. The seasonal variation in Vcmax is driven by the seasonal variations in air temperature and APAR, rather than their seasonal means. We also derived and analyzed Vcmax25, which is Vcmax normalized to 25 °C (Vcmax25) and has been found to be more closely related to the Rubisco content. Vcmax25 also has considerable spatiotemporal variations, and the variations differ to that in Vcmax. Different biomes have different ratios of Vcmax25 to LCC. Air temperature and APAR exert weak but positive effects on the seasonal variation in Vcmax25. Vcmax retrieved in this study enhances our understanding of the spatiotemporal pattern of leaf photosynthetic capacity on the global scale and is potentially useful to terrestrial carbon cycle modelling.

Evaluating the Influence of Different Layouts of Residential Buildings on the Urban Thermal Environment

Urban residential building layouts have an impact on air temperature and thermal comfort. Research has shown that poorly designed building layouts can lead to thermal discomfort. Thus, it is crucial to analyze the relationship between residential building layouts and air temperature. We used the ENVI-met 3D microclimate model to simulate six typical residential building layouts and explore the diurnal and seasonal variations in air temperature. In addition, we used the physiological equivalent temperature (PET) as the evaluation index for the thermal comfort of different building layouts. The diurnal results showed that the air temperature of the parallel layout rose faster and fell faster, and these changes were more significant in summer. The results of the air temperature classifications indicated that the frequency of low-air-temperature areas in the parallel layout is approximately 12% smaller than that of the enclosed and semi-enclosed layouts, and the high-air-temperature area frequency is 11% higher than that of the enclosed and semi-enclosed layouts in summer. In winter, the frequency of low-air-temperature areas in the parallel layout is approximately 7% smaller than that of the enclosed and semi-enclosed layouts, and the high-air-temperature area frequency is 5% higher than that of the enclosed and semi-enclosed layouts. In combination with the PET results, we found that the enclosed layout is the optimal configuration. Moreover, in some cases, increased building height and vegetation lead to a reduction in air temperature.

Assessment of Quality of Fresh Concrete Delivered at Varying Temperatures

Concrete is increasingly utilized in the construction field in Southern Nevada. This area has an arid and hot summer and freezing cold winter conditions. These extreme conditions affect the properties of fresh concrete, which can cause cracking. Hot weather conditions may adversely affect both fresh and hardened concrete properties. Even though practices can minimize the detrimental effects, good quality control of fresh concrete, from mixing to finishing, is crucial under hot weather conditions. The objective of the present study is to evaluate the seasonal consistency of concrete quality, considering strength and slump properties. Another objective of this research is to determine the relationship between the seasonal air temperature variations and those of freshly batched concrete. Results indicate that strength and slump remain constant with varying air and concrete temperatures during pour. Additionally, during the hot season (air temperature above 27 °C (80 °F)), fresh concrete’s temperature is lower than the air’s temperature, in contrast during the cold season (air temperature below 16 °C (60 °F)), fresh concrete’s temperature is higher than the air’s temperature. Fresh concrete temperature and air temperature are similar in the range of 60 to 80 °F. Therefore, to limit the use of additional water or admixtures it is recommended to pour concrete when the air temperature is in the range of 16° and 27 °C (60 to 80 °F).

Data Analysis of Seasonal Air Temperature Variations in East Asia Using the Meteorological Datasets

Data Analysis of Seasonal Air Temperature Variations in East Asia Using the Meteorological Datasets

Subglacial discharge controls seasonal variations in the thermal structure of a glacial lake in Patagonia

Water temperature in glacial lakes affects underwater melting and calving of glaciers terminating in lakes. Despite its importance, seasonal lake temperature variations are poorly understood because taking long-term measurements near the front of calving glaciers is challenging. To investigate the thermal structure and its seasonal variations, we performed year-around temperature and current measurement at depths of 58–392 m in Lago Grey, a 410-m-deep glacial lake in Patagonia. The measurement revealed critical impacts of subglacial discharge on the lake thermal condition. Water below a depth of ~100 m showed the coldest temperature in mid-summer, under the influence of glacial discharge, whereas temperature in the upper layer followed a seasonal variation of air temperature. The boundary of the lower and upper layers was controlled by the depth of a sill which blocks outflow of dense and cold glacial meltwater. Our data implies that subglacial discharge and bathymetry dictate mass loss and the retreat of lake-terminating glaciers. The cold lakewater hinders underwater melting and facilitates formation of a floating terminus.

Assessment of the performance of CORDEX regional climate models in simulating rainfall and air temperature over southwest Ethiopia

This study analyzed the performance of four (REgional MOdel (REMO2009), High-Resolution Hamburg Climate Model 5 (HIRAM5), Climate Limited-Area Modeling Community (CCLM4-8) and Rossby Centre Regional Atmospheric Model (RCA4)) Regional Climate Models (RCMs) simulations from Coordinated Regional Climate Downscaling Experiment (CORDEX) Africa program. The simulation period of 1985–2005 was evaluated considering how each RCM simulated the observed rainfall and air temperature over southwest Ethiopia. It was found that all the RCMs simulated the seasonal rainfall, but not the peak rainfall, with all models including their ensemble underestimating the peak rainfall. However, the ensemble was better than the individual RCMs in simulating both rainfall and air temperature. All models were slightly biased around a warm climate zone in simulating maximum air temperature when compared to the simulation of air minimum temperature. Of the four RCMs, REMO2009 performed well in simulating the maximum and minimum air temperatures. The interseasonal variation in rainfall was greater than the seasonal variation in air temperature. In terms of cumulative distribution, the HIRAM5 captured more extreme rainfall events and overestimated the return period. Overall, the differences in performance among the RCMs provided strong evidence for the use of regional-scale data at the local scale in climate impact assessments being controversial. In relation to the spatial pattern of the rainfall, most of the models simulated the observed minimum rainfall in the north and northeast, medium rainfall in the central region, and maximum rainfall in the south and southwest of the study area. The overall results indicate that choosing a reliable RCM is fundamentally necessary to delivering a strong basis for any climate-change impact study.

Eco-engineering of coastal environment through saltmarsh restoration towards climate change impact mitigation and community adaptation in Bangladesh

A field research was undertaken to investigate the effects of saltmarsh restoration and some eco-engineering activities on the climate change impact mitigation and community adaptation in the coastal environment of Sonadia Island, Cox’s Bazar, Bangladesh. Two research sites viz., saltmarsh restoration site (SMRS) and impacted site (IP) were selected for this study. Amount of carbon assimilation by saltmarsh plant Porteresia coarctata at SMRS was increased from 165.17 ± 68.35 to 198.18 ± 41.32 g/m2 during the study. The highest carbon assimilation (198.18 ± 41.32 g/m2) was noticed during winter, while the highest biomass (10.47 ± 0.25 kg/m2) was measured from SMRS. Soil compactness, organic matter, organic carbon, field water capacity, plant height, plant biomass and shoot density were found to be significantly (p < 0.05 to 0.01) higher in the SMRS than that of the IS. Seasonal variations of air temperature, water temperature, water pH, water salinity, water transparency, tidal height, inundation period, wave velocity, soil temperature, soil pH, pore water salinity, sedimentation, soil texture particle density, plant height, biomass and shoot density at different significance levels (p < 0.05 to p < 0.01) were noticed throughout the study. Correlation matrix showed that the plant height, biomass and shoot density were positively correlated with sedimentation, and negatively correlated with wave velocity at different significant levels (p < 0.05 to p < 0.01). From the present study, it is evident that SMRS, which was controlled and managed with some artificial inputs not only showed the elevated levels of plant height, biomass, shoot density, sedimentation and carbon assimilation but also exhibited remarkable changes in some of the factors studied rather than impacted site (IS), the findings of which could be helpful for the protection of coastal environment as well as mitigation of climate change impact that will ultimately save the local community from natural calamities in the long run.

Seasonal variation in air temperature drives reproductive phenology of entomophilous plants in a cool-temperate mire community

Phenological responses of plants to temperature dynamics are receiving attention due to the ongoing challenge with climate change. Most previous phenological studies have focused on flowering phenology rather than fruiting phenology. However, at mid-latitudes, the air temperature periodically changes during the growing period of plants. Hence, cool temperatures early and late in the growing period may affect reproductive success through pollination and fruit-development processes. To evaluate the linkages between reproductive phenology and success, we compared the phenologies, photosynthetic capacities, and fruit-set rates among 25 species within a cool-temperate community in northern Japan. The ambient temperature during the flowering periods of individual species increased with delays in flowering-onset time, whereas the ambient temperature during fruit-development periods was highest for species which bloomed in July. Fruit-set success among species was positively correlated with the ambient temperatures during the reproductive periods and with the photosynthetic capacity. Fruit production of early blooming species was limited by cool temperatures during the flowering period, presumably because of low pollinator activity, whereas that of late-blooming species was limited by cool temperatures during the fruit-development period because of slow fruit-development (i.e., sink limitation). Thus, limiting factors of fruit production varied depending on the flowering phenology of individual species within a community.

Evaluation of High-Resolution Crop Model Meteorological Forcing Datasets at Regional Scale: Air Temperature and Precipitation over Major Land Areas of China

Air temperature and precipitation are two important meteorological factors affecting the earth’s energy exchange and hydrological process. High quality temperature and precipitation forcing datasets are of great significance to agro-meteorology and disaster monitoring. In this study, the accuracy of air temperature and precipitation of the fifth generation of atmospheric reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ERA5) and High-Resolution China Meteorological Administration Land Data Assimilation System (HRCLDAS) datasets are compared and evaluated from multiple spatial–temporal perspectives based on the ground meteorological station observations over major land areas of China in 2018. Concurrently, the applicability to the monitoring of high temperatures and rainstorms is also distinguished. The results show that (1) although both forcing datasets can capture the broad features of spatial distribution and seasonal variation in air temperature and precipitation, HRCLDAS shows more detailed features, especially in areas with complex underlying surfaces; (2) compared with the ground observations, it can be found that the air temperature and precipitation of HRCLDAS perform better than ERA5. The root-mean-square error (RMSE) of mean air temperature are 1.3 °C for HRCLDAS and 2.3 °C for ERA5, and the RMSE of precipitation are 2.4 mm for HRCLDAS and 5.4 mm for ERA5; (3) in the monitoring of important weather processes, the two forcing datasets can well reproduce the high temperature, rainstorm and heavy rainstorm events from June to August in 2018. HRCLDAS is more accurate in the area and magnitude of high temperature and rainstorm due to its high spatial and temporal resolution. The evaluation results can help researchers to understand the superiority and drawbacks of these two forcing datasets and select datasets reasonably in the study of climate change, agro-meteorological modeling, extreme weather research, hydrological processes and sustainable development.

Air temperature lapse rates and cloud cover in a hyper-oceanic climate

AbstractAir temperature lapse rates vary geographically and temporally. Sub-Antarctic Macquarie Island provides an opportunity to compare lapse rates between windward and leeward slopes in a hyper-oceanic climate. Lapse rates were steep by global standards, typically close to the dry adiabatic lapse rate despite the near-constant high humidity. Limited diurnal and seasonal variation occurs in lapse rates on Macquarie Island. High variability of lapse rates on the eastern (lee) slope in summer months and in the midday hours appears to be driven by solar radiation. No diurnal or seasonal pattern was evident on the western slope. Development of orographic cloud is expected to modify lapse rates, given the theoretical shift between dry and saturated adiabatic lapse rates that occurs with condensation of water vapour. Cloud cover was frequent, with higher elevations being under cloud 50% of the time, with no seasonal variation. However, cloud base level did not explain variation in lapse rates. Low cloud is likely to be of ecological importance because it influences fog precipitation, solar radiation and evapotranspiration. Year-round dominance of westerly airflows and limited seasonal variation in air temperature and humidity explain the limited seasonal variation in cloud cover and lapse rates on Macquarie Island.

Seasonal Variation in Air Temperature and Relative Humidity on Building Areas and in Green Spaces in Beijing, China

The cooling and humidifying effects of urban parks are an essential component of city ecosystems in terms of regulating microclimates or mitigating urban heat islands (UHIs). Air temperature and relative humidity are two main factors of thermal environmental comfort and have a critical impact on the urban environmental quality of human settlements. We measured the 2-m height air temperature and relative humidity at the Beijing Olympic Park and a nearby building roof for more than 1 year to elucidate seasonal variations in air temperature and relative humidity, as well as to investigate the outdoor thermal comfort. The results showed that the lawn of the park could, on average, reduce the air temperature by (0.80±0.19)°C, and increase the relative humidity by (5.24±2.91)% relative to the values measured at the building roof during daytime. During the nighttime, the lawn of the park reduced the air temperature by (2.64±0.64)°C and increased the relative humidity by (10.77±5.20)%. The park was cooler and more humid than surrounding building area, especially in night period (more pronounced cooling with 1.84 °C). Additionally, the lawn of the park could improve outdoor thermal comfort through its cooling and humidifying effects. The level of thermal comfort in the park was higher than that around the building roof for a total of 11 days annually in which it was above one or more thermal comfort levels (average reduced human comfort index of 0.92) except during the winter.

Radon concentration in groundwater sources of the Baikal region (East Siberia, Russia)

In this study, we conduct a systematic study of groundwater radioactivity in the territories around Lake Baikal in Siberia, including Pribaikalie and Transbaikalia. The database includes more than 200 measurements of 222Rn from monitored water sources in the study region. We classify the groundwater sources in the Baikal region into seven groups (I–VII) that differ in radon concentration in space and time. The spatial distribution of water sources belonging to certain groups depend on geochemical and structural factors. In Transbaikalia, intrusive rocks with elevated contents of uranium are abundant. In Pribaikalie, many water sources are classified into Groups I and II (Q < 100 Bq/L). Group I includes groundwater with background concentrations, and Group II includes groundwater with anomalous concentrations of radon. Water sources belonging to elevated radon concentration Groups III to VI are considered as anomalies. Faulting is one of the main causes of radon anomalies as groundwater in the fault zones is enriched with 222Rn due to the increased permeability of rocks and rock crushing resulting from displacements of the fault walls.Monitoring of water sources in Pribaikalie shows that 222Rn concentrations vary also in time mainly within the range of values corresponding to a particular group. The oscillatory pattern of the temporal variations is clearly revealed by radon measurements conducted every two weeks and depends mainly on meteorological factors. Seasonal variations in air temperature and atmospheric pressure lead to changes in groundwater temperature, dilution of groundwater due to precipitation, freezing the top layer of soil, and other phenomena. As a result, the concentration regularly increases in winter and decreases in summer. In this study, seismic activity has not been revealed as significant factor of impact on the concentration of radon in groundwater, since strong earthquakes did not occur during the monitoring period.

Experimental analysis on temperature field variations of heterogeneous surrounding rock under the condition of periodically changing mine ventilation

ABSTRACT Seasonal variations of air temperature cause seasonal heat-transfer between tunnel airflow and surrounding rocks of coalmine tunnels. This study analyzed the distribution and evolution law of temperature in inhomogeneous surrounding rocks under varying ventilation cycle and airflow amplitude using a self-developed experimental simulation system of inhomogeneous surrounding rocks. The results show that under the periodically changing ventilation, the functional relationship between the temperature of the surrounding rock and ventilation time met the cosine function. The amplitude attenuation and fluctuation delay of temperature waves in surrounding rocks differ across various depths under the condition of periodic ventilation.

Effects of seasonal air temperature variation on airflow and surrounding rock temperature of mines

In underground mines, high air temperatures in the summer months lead to an increase in inlet airflow temperatures. This leads to seasonal thermal pollution in the mines. This paper examines the dynamics and effects of seasonal variation in surface air temperatures and surrounding rock temperatures in deep coal mines. It also examines temperature variations in the main ventilation circuit, working face, and surrounding rock. The study results revealed that airflow temperatures were significantly affected by seasonal air temperature variations. The greater the distance was between the inlet and the wellhead of the ventilation shaft, the less the effect was on temperature. Moreover, slight temperature variations (1.0–3.0 °C) were observed between various points on the return route during the summer months. Airflow temperatures along the airflow inlet to the return route of the working face first decreased, but then increased. The temperature field of the surrounding rock increased gradually with increased distance between the mine roadway and inlet, with recorded rock temperatures as high as 40.53 °C. The radius of the heat-adjusting layer was between 28 and 33 m.

Diurnal and intra-season variation of warm-season temperature in coastal zone of Qinghai Lake

The Qinghai Lake is the largest saltwater lake in the Tibetan Plateau and in mainland China. Effects of the lake on surface climate of the coastal areas, however, are not well understood. This article utilizes hourly observation data of warm season from 17 automatic weather stations to analyze the diurnal and seasonal variations in air temperature in different coastal zones of the Qinghai Lake. The EOS/MODIS data was also used to analyze the surface temperature differences between the lake and its surrounding areas. The results show a few unique characteristics of the plateau lake: (1) based on the satellite data, lake surface temperature is lower than its surrounding areas (4.9~25.1 °C and 12.2~35.6 °C respectively) in the daytime, while it is obviously higher than that in the surrounding areas (1.9~10.5 °C and − 13.1~6.3 °C respectively) at the nighttime. Daily mean water surface temperature is higher than that in the surrounding areas, which is 7.8~17.9 °C and − 2.6~17.9 °C respectively; (2) based on data of meteorological stations, coastal zones closer to the shoreline have a higher air temperature during the warm season largely due to the much warmer nighttime near the shoreline than those in deep inland zones. For the on-shore, near-shore, and far-shore zones, mean daytime air temperature is 8.7~9.6 °C, 9.5~11.1 °C, and 10.0~10.7 °C, respectively, and the mean nighttime air temperature is 2.9~4.1 °C, 1.3~12.3 °C, and − 0.2~0.4 °C respectively. The hourly mean diurnal temperature range (DTR) increases with distance to the shoreline, which is 8.6 °C, 10.9 °C, and 12.3 °C in the on-shore, near-shore, and far-shore zones respectively; (3) differences between maximum and minimum 5-day mean daily maximum (minimum) air temperature during the warm season are 20.3 °C (23.3 °C), 21.7 °C (25.6 °C), and 22.6 °C (26.7 °C) for the on-shore, near-shore, and far-shore zones, respectively, indicating an asymmetrical effect on daytime and nighttime air temperature in the on-shore zone; (4) daily maximum air temperature of the on-shore zone is lower before early October, but it is slightly higher afterward and occurs later; (5) daily minimum air temperature of the on-shore zone is on average higher than that of the far-shore zone, especially after the mid-September, and it also appears later in autumn than in summer.

The dependence of сircannual dynamics of blood pressure on seasonal fluctuations of meteorological and heliophysical factors. Meta-analysis

Many clinical studies have shown seasonal dynamics of blood pressure (BP), which most authors attribute to seasonal variations in air temperature. However, the fact that in the conditions of modern urban society the influence on the person of air temperature on the street is minimized, as well as the fact that the seasonal dynamics of BP is observed and in a tropical climate contradict this statement. It is known, that the length of the day, the atmospheric pressure, the relative humidity, geomagnetic activity are subject to seasonal dynamics. Studies have shown that fluctuations in these meteorological factors can cause change in blood pressure.Aim.To use meta-analysis of the results of studies, conducted in different climatic zones (from subarctic to tropical) and devoted to seasonal dynamics of BP, to determine which meteorological conditions most often corresponded to the annual maximum of BP and which to the annual minimum of BP.Material and methods. We selected 15 publications about seasonal dynamics of BP and seasonal exacerbations of arterial hypertension in 21 regions of the Northern Hemisphere of the Earth.Results.We confirmed that, in addition to air temperature, other factors are also subject to seasonal dynamics (atmospheric pressure, relative humidity, partial oxygen density in the air). No correlation was found between the amplitude of seasonal fluctuations in air temperature and the amplitude of seasonal fluctuations in BP. In addition, the amplitude of drcannual blood pressure fluctuations was greater in regions with a clear seasonal dynamics of the average monthly atmospheric pressure, compared with regions in which the this parameter does not have a clear seasonal dynamics. Also, in some regions, the seasonal maximum of BP coincided with high geomagnetic activity.Conclusion. According to the results, we concluded that seasonal fluctuations of BP are not a reaction of the cardiovascular system to seasonal dynamics of air temperature only. Most likely, seasonal fluctuations of BP are caused by changes in all meteorological factors that have seasonal dynamics.

Seasonal physico-chemical characterization of water of sacred lake Nachiketa Tal, Garhwal Himalaya

The management of natural surface water resources needs the understanding of water quality. The present study on the physico-chemical parameters of water quality of sacred lake Nachiketa Tal of Garhwal Himalaya was undertaken. During the period from May 2015 to April 2016 at four sampling stations, seasonal variations in air temperature, water temperature, electrical conductivity, turbidity, salinity, TDS, dissolved oxygen, free CO2, hardness, alkalinity, nitrates, phosphates, chlorides, calcium and magnesium were recorded. The statistical correlation and cluster analysis between the various physico-chemical parameters of Nachiketa Tal were computed. The results of this study revealed that the concentration of the nutrients, turbidity, electrical conductivity, TDS increased with a decreasing trend of dissolved oxygen in all the sampling stations during the monsoon season. Thus, degradation in the water quality of the lake was resulted in the monsoon season.

Effect of buoyancy-driven natural convection in a rock-pit mine air preconditioning system acting as a large-scale thermal energy storage mass

Underground mining is among the most energy-intensive industries and ventilation comprises a significant portion of the energy demands of this important industry. Using the vast volume of broken rock, left in a decommissioned mine pit, as a thermal energy storage mass has enormous potential to lower ventilation-related energy costs in deep underground mines. This approach facilitates moderating seasonal air temperature variations. Seasonal thermal energy storage is a cost-effective solution to improve cooling and heating process efficiencies, thereby reducing associated costs. Temperature gradients observed in the proposed storage system suggest the presence of a natural convection heat transfer mechanism that is buoyancy-driven. The effect of natural convection and a variety of heat transfer mechanisms were modeled and simulation results and field-data measurements were compared. The conjugate heat transfer and fluid flow model that was developed considers the porous rock mass in the rock-pit along with the air (i.e. fluid) blanketing the top surface. The effects of rock size, permeability and porosity were studied. It was observed that, for the range of porosities (from 0.45 to 0.20), these parameters have a small effect on the outlet air temperature and the performance of thermal storage phenomenon. The novel model compares forced (from ventilation fan) and natural (result of buoyancy) convection. Further, it incorporates the effect of design factors, such as air trench positions and flow rate of ventilated air, on energy savings.

Parameter Variations in the Subsoil Radon Field at the Paratunka Station of the Petropavlovsk-Kamchatsky Geodynamic Test Site in 2011–2016

A network of stations for subsoil radon monitoring is in operation at the Petropavlovsk-Kamchatsky geodynamic testing area and is aimed at detection of strong earthquake precursors. At all stations, measurements are carried out using gas-discharge counters located at different depths within aeration zones of soft sediments. The volume activity of radon (VA Rn) is monitored at the most equipped station Paratunka (PRT) at three measurement sites located across the regional fault. The radon flux density (RFD) is measured from the surface. The article reviews responses in the dynamics of VA Rn and RFD from the surface at the PRT station prior to the Kamchatka earthquakes with magnitudes М W > 5 that occurred over the period of 2011–2016. The revealed RFD seasonal cycle is likely related to the seasonal variations in air temperature. The postseismic effect caused by the strongest deep Okhotsk earthquake (May 24, 2013, М W = 8.3) is detected in the RFD data. The behavior of VA Rn dynamics during time periods of the strong earthquakes is different. The results confirm the existing opinion on the formation of narrowly localized zones of Rn runoff to the atmosphere owing to both vertical and horizontal irregularities in the top layer of soil, which can react differently to changes in the geoenvironment stress–strain. On the basis of the real-time radon monitoring data, the authors have issued partially successful short-term prediction for several earthquakes. The results of this work confirm the opinion of many researchers that radon monitoring can be used in the short-term prediction of strong earthquakes.