Seasonal Variations In Air Temperature Research Articles

Seasonal thermal insulation to mitigate climate change impacts on foundations in permafrost regions

Climate change impact on existing infrastructure built on permafrost is of concern to many engineers and scientists. Some studies predict widespread collapse of the existing infrastructure. Adapting structures in the permafrost region to climate change is an important contemporary issue. In this paper, we analyze impacts of permanent and seasonal thermal insulation on permafrost temperature. An analysis of the available data shows that permanent thermal insulation increases the permafrost temperature when the soil surface is exposed to seasonal air temperature variations and when the mean annual soil surface temperature is below 0°C (32°F).We study the thermal impact of seasonal insulation applied in the spring and removed in the autumn to restrict summer heat flow into the ground. The absence of thermal insulation in winter permits soil cooling. We present the results from two-dimensional thermal analyses of a building in the discontinuous permafrost zone. These results show the effectiveness of seasonal thermal insulation. Summer seasonal thermal insulation on the soil surface in a ventilated crawl space decreases permafrost temperature and can be valuable for increasing foundation integrity in a warming climate. The impact of seasonally installed thermal insulation on permafrost increases as the thawing index increases. Seasonal thermal insulation is especially valuable in the discontinuous permafrost zone, where bearing capacity of shallow foundations and adfreeze strength of frozen soil with piles are sensitive to minor soil temperature changes.The method is adaptive and flexible, and the initial cost is low, all of which are important considerations given the uncertainties of climate warming. Using seasonal insulation permits an incremental response to future climate warming conditions as they occur.

Factors influencing collection performance of near surface interseasonal ground energy collection and storage systems

The influence of surface boundary conditions, varying climatic conditions and engineering material parameters on the collection performance of near surface interseasonal ground energy collection and storage systems are investigated. In particular, the performance of a proposed design of an interseasonal heat storage system which has also been investigated by others as part of a full scale demonstration project is considered. A numerical model is developed and validated against field data. It is then applied to undertake a series of simulations with varying system parameters. It is found that (i) higher values of thermal conductivity of the storage layer result in increased storage of thermal energy and lower peak temperatures, (ii) system heat losses are strongly influenced by the performance of insulation layers, (iii) warmer climatic conditions provide more thermal energy available to be stored; however, changes in the amplitude of seasonal air temperature variations have an effect on the rate of collection of thermal energy and (iv) the use of correct surface boundary conditions is critical in modelling the dynamics of these systems.

Diagnostics of the anti-seepage screen of a protective dam in permafrost on using an inverse problem with piezometric measurement data

Using the finite elementmethod we designed and implemented a nonlinear geomechanical model of the rock mass in the vicinity of the protective dam of tailing facilities in the permafrost of the Kumtor mine (the Kyrgyz Republic). The model takes into account the information on the structure of the object, the data on the strain-strength, thermophysical and filtration properties of frozen and thawed soil, as well as on the seasonal variations in air temperature. Numerical experiments showed that, under constant external conditions, the invariant properties of the rock mass, and the position of the neutral layer, the zero isotherm separating frozen and thawed rocks reaches a stationary position in 12–15 years after filling the storage; minor damage to the antiseepage screen can lead to a vast destruction area in the body of the dam. Using synthetic data, we demonstrated the solvability of the inverse boundary-value problem of determining the timing and location of damage in the anti-seepage screen from the data of piezometric measurements at several observation wells.

Delineation of soil body area exposed to thermal effect of subway stations and tunnels

The mathematical model is developed for describing temperature variation in soil body surrounding subway stations and tunnels, considering seasonal variation of air temperature, soil freezing–thawing and induced heat flow from the subway. Using the finite element method, the authors calculate temperature field in soil body surrounding subway stations and tunnels at various depths. Based on the numerical experiments, the thermal effect of shallow subway stations and tunnels on the surrounding soil body is estimated. The article offers the estimation procedure for delineation of influence zone of subway structures on temperature of surrounding soil. It is found that the zone of thermal effect of a subway structure grows with the depth of the subway structure occurrence. The dimension of the mentioned zone is conditioned by amount of heat produced in the underground structures of subway.

Factors Affecting Process Temperature and Biogas Production in Small-scale Rural Biogas Digesters in Winter in Northern Vietnam.

This study investigated the main factors influencing digester temperature and methods to reduce heat losses during the cold season in the subtropics. Four composite digesters (two insulated and two uninsulated) were buried underground to measure their internal temperature (°C) at a depth of 140 cm and 180 cm, biogas production and methane (CH4) concentration in biogas from August to February. In parallel the temperature of the air (100 cm above ground), in the slurry mixing tank and in the soil (10, 100, 140, and 180 cm depth) was measured by thermocouple. The influent amount was measured daily and the influent chemical composition was measured monthly during the whole experimental period. Seasonal variations in air temperature significantly affected the temperature in the soil, mixing tank and digester. Consequently, biogas production, which is temperature dependent, was influenced by the season. The main factors determining the internal temperature in the digesters were insulation with Styrofoam, air temperature and temperature of slurry in the mixing tank. Biogas production is low due to the cold climate conditions in winter in Northern Vietnam, but the study proved that storing slurry in the mixing tank until its temperature peak at around 14:00 h will increase the temperature in the digester and thus increase potential biogas production. Algorithms are provided linking digester temperature to the temperature of slurry in the mixing tank.

Development and Role of Flux Coupler in a Coupled Atmosphere - Ocean Modeling System

ABSTRACT The exchange of momentum and radiation fluxes plays a vital role at the interface of atmosphere and ocean. In the present study an attempt has been made to develop a flux coupling algorithm for coupling atmosphere and ocean models as a single model system. The developed coupler has been used for the Kalpakkam region located in the east coast of India as a case study to understand the coastal processes and effect of thermal water pollution on coastal processes due to the establishment of nuclear power plants. The annual and seasonal variation of air temperature, wind speed, sea surface temperature and radiation fluxes; latent and sensible heat fluxes over the Kalpakkam region for a period of five years (2007 - July 2011) has been observed with available OAFlux data. During this period increasing trend of dynamical and thermodynamical variables has been observed. The Weather Research and Forecast (WRF) model has been configured and used to simulate atmospheric parameters over the Kalpakkam region. Thereafter the developed coupler has been used to extract the wind components and radiation parameters from the WRF model output, wherein the wind and radiation stresses were computed using bulk aerodynamic formulations. The heat fluxes show a positive correlation with the temperature gradient and wind speed. The robustness of developed algorithm was assessed through numerical experiments and statistical methods. The model simulated output and coupler estimated variable of wind speed and radiation fluxes have been validated with the available observations. The model results showed the overestimation of radiation fluxes than the observational data. The overestimated fluxes have been added as a correction factor in the coupler to maintain the constant variation in the fluxes. The comparison ascertains the fact that model and coupler performance is satisfactory in comparison with observational data.

Variations in the content of stress proteins in the needles of common pine (Pinus sylvestris L.) within an annual cycle

This investigation has focused on the content of heat shock proteins (Hsps) and dehydrins (dhn) in the needles of Pinus sylvestris L. (common pine) depending on environmental conditions and on adaptation of photosynthetic activity. Unlike the case of photosynthetic activity, no relationships have been revealed between variations in environmental conditions over 2 years of observations and variations in Hsps content. It has been discovered that constitutive and stress forms of Hsp70, Hsp60 and dhn are accumulated in the cold season of the year, whereas for Hsp17.6 and Hsp101 this accumulation occurs in the warm season. Seasonal air temperature variations influenced the content of Hsps; variations of temperature and moisture conditions influenced the content of dhn. The supposition is made that accumulation of Hsp70, Hsp60 and dhn in the needles may be the factor and/or the marker of the autumn and spring adaptation of the photosynthetic apparatus, while accumulation of Hsp17.6 and Hsp101 is the marker of summer “heat” adaptation.

COMPLEX TETRAPOD BURROWS FROM MIDDLE TRIASSIC RED BEDS OF THE ARGANA BASIN (WESTERN HIGH ATLAS, MOROCCO)

Although burrowing ability has been widespread in tetrapods for more than 300 million years, subsurface dwelling structures that indicate communal behavior are poorly evidenced from pre-Cenozoic strata. Here we present recently discovered tetrapod burrows from Middle Triassic red beds of the Argana Basin in central Morocco, whose complexity suggests an origin by gregarious animals. The well-preserved burrows occur in interbedded mudstones and sandstones interpreted as channel and overbank deposits of ephemeral, braided streams. All burrows originate from the top of thick-bedded sandstones and descend as moderately inclined (10°–30°), partially spiral tunnels to laterally extended, branched chambers in underlying mudstones. Tunnel segments are biconvex to planoconvex in cross section, up to 20 cm wide and 12 cm in maximum height and exhibit transverse scratch marks along the ceilings and sidewalls. Distinctive burrow characteristics include a laterally sinuous geometry (wavelength λ = 38–45 cm; amplitude A = 5–10 cm) of the tubelike passages and the presence of grouped alcoves in terminal chambers. We attribute the burrows to procolophonids or therapsids based on closely associated tetrapod tracks and the limited diameter of the excavations. Our findings represent the second oldest record of communal fossorial behavior by tetrapods and the oldest example from low-latitude areas. Beyond providing refuge from predators, these elaborate underground structures probably functioned as a buffer against diurnal or seasonal variations of air temperature and humidity in a semiarid habitat that was situated just north of the paleoequator.

Integration of satellite‐measured LST data into cokriging for temperature estimation on tropical and temperate islands

AbstractCokriging, a multivariate geostatistical interpolation method, uses elevation information as a secondary variable to improve the prediction accuracy of air temperature in mountainous areas. Although the secondary variable plays an important role in cokriging, the performance of interpolation largely depends on the amount of input data. The purpose of this study was to improve air temperature estimation by merging hypertemporal Moderate Resolution Imaging Spectroradiometer land surface temperature (LST) data and ground observations as interpolation data. Two significantly different island environments, tropical Hawaii Island (USA) and temperate Jeju Island (Korea), were selected for interpolation experiments. Spatiotemporal characteristics of air temperature prediction were compared between three cokriging methods and the conventional inverse‐distance weighted interpolation. Due to the year‐round trade winds, there was significant difference in prediction errors between windward and leeward slopes of Hawaii Island. LST‐derived temperature was not regularly sampled from cloud‐prone, windward slopes. As a result, prediction reliability was lower on windward slopes than leeward slopes, and overall prediction accuracy decreased in the wet season. Jeju Island is a mid‐latitude volcanic island heavily influenced by the Asian monsoons. This climatic setting creates the seasonal variations of air temperature that is far greater than its spatial variations. The environmental lapse rate (ELR) of Jeju Island became much steeper in winter, and prediction accuracy and reliability were reduced due to an increase in the spatial variations of air temperature. With the addition of satellite‐derived air temperature data, the root mean square errors of cokriging decreased by 27.3–52.9% for Hawaii Island and 34.6–37.6% for Jeju Island depending on cokriging models. Copyright © 2010 Royal Meteorological Society

Spatial and seasonal characterization of net primary productivity and climate variables in southeastern China using MODIS data

We developed a sophisticated method to depict the spatial and seasonal characterization of net primary productivity (NPP) and climate variables. The role of climate variability in the seasonal variation of NPP exerts delayed and continuous effects. This study expands on this by mapping the seasonal characterization of NPP and climate variables from space using geographic information system (GIS) technology at the pixel level. Our approach was developed in southeastern China using moderate-resolution imaging spectroradiometer (MODIS) data. The results showed that air temperature, precipitation and sunshine percentage contributed significantly to seasonal variation of NPP. In the northern portion of the study area, a significant positive 32-d lagged correlation was observed between seasonal variation of NPP and climate (P<0.01), and the influences of changing climate on NPP lasted for 48 d or 64 d. In central southeastern China, NPP showed 16-d, 48-d, and 96-d lagged correlation with air temperature, precipitation, and sunshine percentage, respectively (P<0.01); the influences of air temperature and precipitation on NPP lasted for 48 d or 64 d, while sunshine influence on NPP only persisted for 16 d. Due to complex topography and vegetation distribution in the southern part of the study region, the spatial patterns of vegetation-climate relationship became complicated and diversiform, especially for precipitation influences on NPP. In the northern part of the study area, all vegetation NPP had an almost similar response to seasonal variation of air temperature except for broad crops. The impacts of seasonal variation of precipitation and sunshine on broad and cereal crop NPP were slightly different from other vegetation NPP.

Dual nitrate isotopes in dry deposition: Utility for partitioning NOx source contributions to landscape nitrogen deposition

Dry deposition is a major component of total atmospheric nitrogen deposition and thus an important source of bioavailable nitrogen to ecosystems. However, relative to wet deposition, less is known regarding the sources and spatial variability of dry deposition. This is in part due to difficulty in measuring dry deposition and associated deposition velocities. Passive sampling techniques offer potential for improving our understanding of the spatial distribution and sources of gaseous and aerosol N species, referred to here as dry deposition. We report dual nitrate isotopic composition (δ15N and δ18O) in actively collected dry and wet deposition across the high‐deposition region of Ohio, New York, and Pennsylvania. We also present results from initial tests to examine the efficacy of using passive nitric acid collectors as a collection medium for isotopic analysis at a site in New York. Isotopic values in actively collected dry deposition, including particulate nitrate and gaseous nitric acid, are compared with those in wet nitrate deposition and surrounding NOx emission sources. δ15N values in dry and wet fractions are highest at the westernmost sites and lowest at the easternmost sites, and stationary source NOx emissions (e.g., power plants and incinerators) appear to be the primary control on δ15N spatial variability. In contrast, δ18O values show a less consistent spatial pattern in dry deposition. Both δ15N and δ18O show strong seasonality, with higher values in winter than summer. Seasonal variations in stationary source NOx emissions appear to be the most likely explanation for seasonal variations in δ15N, whereas seasonal variations in air temperature and solar radiation indicate variable chemical oxidation pathways control δ18O patterns. Additionally, we demonstrate the utility of passive samplers for collecting the nitric acid (HNO3) component of dry deposition suitable for isotopic analysis. We observe slight differences in δ15N‐HNO3 values between simultaneous samples collected actively and passively (0.6‰). However, we observe a larger offset in δ18O values between actively and passively collected samples; the causes for this offset warrant further investigation. Nonetheless, passive sample collection represents a significant cost savings over active sampling techniques and could allow a more extensive understanding of patterns of dry deposition and associated insights to nitrogen sources across landscapes.

Heating and cooling degree day prediction within the London urban heat island area

This paper describes the London Site Specific Air Temperature prediction model, which comprises of a suite of artificial neural network (ANN) models to predict site-specific hourly air temperature within the Greater London Area (GLA). The model was developed using a back-propagation ANN model based on hourly air temperature measurements at 77 fixed temperature stations (FTS) and hourly meteorological data (off-site variables) from Heathrow; it also includes six on-site variables calculated for each FTS. The temporal and spatial validity of the model was tested using data measured 7 years later from the original dataset, which include new FTS locations. It was found that site-specific hourly air temperature prediction is within accepted range and improves considerably for average daily and monthly values. Therefore, the model can be used with confidence to predict daily and seasonal variations of air temperature within the GLA and in particular for the calculation of monthly and annual heating degree days (HDD) and cooling degree hours (CDH). It was found that as expected HDD increase and CDH decrease with distance from the urban heat island centre point; however, all variations cannot be explained with distance and six key on-site variables namely aspect ratio, surface albedo, plan density ratio, green density ratio, fabric density ratio and thermal mass have been identified to explain the remaining variation. Practical applications: Research studies have confirmed the extent of Urban Heat Island (UHI) within many cities in Europe. Studies have also confirmed the impact of the UHI on energy demand by buildings. There is therefore need to consider this in the design of building by using site-specific external temperatures in the energy calculations for urban buildings. This paper describes the development of a model, which can generate site-specific air temperature in a large number of locations in London. The model's predictions can be used for the calculation of HDD and CDH for any base temperature across London using any Heathrow weather file for a specific year, design years or future climate years; such values can be used for the calculation of site specific building heating and cooling loads.

Catch me in winter! Seasonal variation in air temperature severely enhances physiological stress and mortality of species subjected to sorting operations and discarded during annual fishing activities

Several studies have considered the direct and indirect effects of demersal trawling on discarded species in terms of sublethal damages, survival, and stress due to the fishing processes. Nevertheless the effects of air temperature on the physiological stress and the survival of species during sorting operations were only marginally explored. This factor could be particularly important in the context of sustainable fisheries at temperate latitudes where the seasonal variation of air temperature can be particularly pronounced. In this study the seasonal effects of rapido trawling on the non-target species Liocarcinus depurator (Portunidae) in the Northern Adriatic Sea (Mediterranean Sea) have been compared by applying survival tests and considering the unbalance in metabolites’ concentration as indicators of physiological stress. Results showed consistently higher mortalities during exposure to air in summer (temperature: 28°C), which reached about 96% in 20 min, compared to winter (temperature: 9°C) when only 2% of individuals died. Furthermore trawled and emersed crabs showed significant increase of hemolymph ammonia, lactate, and glucose concentrations as effects of extreme exercise and suffocation, which was more prominent during summer, suggesting that air temperature can play an important role in determining non-target species survival.

Seasonal air temperature variations retrieved from a Geladaindong ice core, Tibetan Plateau

A 70-year history of precipitation δ18O record has been retrieved using an ice core drilled from a plat portion of the firn area in the Guoqu Glacier (33°34′37.8″ N, 91°10′35.3″ E, 5720 m a.s.l.) on Mt. Geladaindong (the source region of Yangtze River) during October and November, 2005. Based on the seasonality of δ18O records and the significant positive relationships between monsoon/non-monsoon δ18O values and summer/spring air temperature from the nearby meteorological stations, the history of summer and spring air temperature have been reconstructed for the last 70 years. The results show that both summer and spring air temperature variations present similar trends during the last 70 years. Regression analysis indicates that the slope of the temperature-δ18O relationship is 1.3°C/‰ for non-monsoon δ18O values and spring air temperature, and 0.4°C/‰ for monsoon δ18O values and summer air temperature. Variation of air temperature recorded in the ice core is consistent with that in the Northern Hemisphere (NH), however, the warming trend in the Geladaindong region is more intense than that in the NH, reflecting a higher sensitivity to global warming in the high elevation regions. In addition, warming trend is greater in spring than in summer.

Seasonal groundwater turnover

Seasonal air temperature variations and corresponding changes in groundwater temperature cause convective movements in groundwater similar to the seasonal turnover in lakes. Numerical simulations were performed to investigate the natural conditions for thermally driven groundwater convection to take place. Thermally driven convection could be triggered by a horizontal groundwater flow. Convection then starts at a considerably lower Rayleigh number (Ra) than the general critical Rayleigh number (Rac) assuming that 10°C groundwater is cooled to 4°C, i.e. heated from below convection in porous media. This study supports the hypothesis that seasonal temperature variations, under certain conditions, initiate and drive thermal convection.

Seasonal Productivity of Colonies of Honeybees, Apis mellitera adansonii (Hymenoptera: Apidae) under Natural Environmental Conditions in Lagos, Nigeria

Natural environmental conditions such as temperatures, relative humidity and hive temperatures were monitored in relation to colonies productivity. Hive temperatures (28.0 – 40.3 °C) of colonized hives were generally higher than the air temperatures (26.0-33.3 °C) in both dry and wet seasons. However, temperatures of uncolonized hives (25.3 – 31.7 °C) were lower than the air temperatures. In the wet season, when the average air temperature was 26.0 – 29.3 °c and the average relative humidity (R.H) was 59.7 % – 74.7 %, the yield of honey and beeswax from each of the hives ranged between 0.5 and 1.0 kg. The yield of honey and beeswax in the dry season was comparatively higher (4.0 – 13.5 kg) at air temperatures ranging from 28.0 to 33.3 °c and 53.3 %, 69.7 % relative humidity. The honey flow period of colonies of Apis mellifera adansonii was February to May while the peak period of honey and beeswax production was April. The results of this study revealed that seasonal variations in air temperature and humidity influenced the productivity of colonies of A. mellifera adansonii.

Diurnal and intraseasonal variations observed on the West Coast of India

As part of the Arabian Sea Monsoon Experiment (ARMEX), several automatic weather stations (AWSs) were installed on the west coast of India, and some among them have been recording weather data for more than one year. Here temporal variations observed at three coastal stations, namely Honnavar, Karwar and Vijaydurg during July 2002 to December 2003 are presented. The seasonal variations in air temperature, humidity, wind speed, etc., are along the expected lines. A strong diurnal variation in rainfall pattern is observed, but the dependence on local time is different at Honnavar and Vijaydurg which are not more than 250 kilometres apart. It is shown that the surface pressure exhibits strong variations on different time scales throughout the year, and the dominant time scales shift with the seasons.

Net CO2 Uptake for Agave tequilana in a Warm and a Temperate Environment1

The main objective was to evaluate the effects of seasonal variations in air temperature, soil water content, and irradiation on the net rate of CO2 uptake for Agave tequilana growing in a warm subtropical environment (Amatitan, Jalisco, Mexico) and in a temperate subtropical environment (Arandas, Jalisco, Mexico). At Amatitan, the lowest value of positive daily net CO2 uptake (141 mmol/m2/d) occurred at the end of the summer rainy season and the highest values during the winter (578 and 921 mmol/m2/d); at Arandas, the lowest value (188 mmol/m2/d) occurred at midsummer and the highest values at the end of the summer (763 mmol/m2/d) and in late winter (572 mmol/m2/d). The highest values of daily net CO2 uptake in both localities reflected prolonged daily periods of net CO2 uptake that included both daytime and nighttime assimilation accompanied by high rates of nocturnal net CO2 uptake due to moderate nighttime air temperatures. High temperatures in the summer reduced daily net CO2 uptake at both localities but in late summer, the nighttime temperatures at Arandas were moderate, which lead to high daily net CO2 uptake. Leaf succulence allowed substantial daily net CO2 uptake when the soil water content was relatively low during the winter and the spring (January–March). Indeed, appreciable daily net CO2 uptake occurred throughout the year for A. tequilana at both localities, indicating that this CAM plant species can sequester carbon even during prolonged dry periods.

A pilot study on the design of an underground food storage cavern in Korea

This paper reports the background information and the initial results obtained from the pilot underground food storage cavern in Korea, where the seasonal variation of air temperature makes the running of on-ground food storage tanks uneconomical. A pilot cavern has been driven into a granite rock mass which is the typical massive rock in Korea. Basic mechanical properties, including the thermal properties, were measured. The change of rock strengths and the behavior of joints upon the change of temperature, were also identified. A series of monitoring systems have been setup to measure the temperature of the ground, the behavior of the rock mass during excavation and running (i.e. cooling) of the cavern. The results of this paper can provide useful information for the design of future commercial underground food storage caverns in Korea.

Seasonal and spatial trends of certain chlorobenzene isomers in the Michigan atmosphere

Four isomers of chlorobenzenes (1,2,3,4-tetra-, 1,2,4,5-tetra- (TeCB), penta- (PeCB) and hexa-(HCB)) were analyzed in atmospheric gases collected over 24 h as often as every six days from Pellston, Deckerville, South Haven and Dexter, Michigan during one year. HCB sampling also included 10 earlier months. Sites were located to give broad coverage to Michigan and, in three cases, to measure variations in concentration near one of the Great Lakes where chlorobenzenes are compounds of concern. The TeCB isomers show high concentrations at every site at various times. The ratio between 1,2,3,4- and 1,2,4,5-TeCB isomers is approximately 2 for most sampling dates, including both high and background concentrations. One significant variation occurs statewide because of a higher concentration of 1,2,4,5-TeCB. At the South Haven site PeCB concentrations are much higher than other sites during June and July. One date of extreme PeCB concentration at South Haven corresponds to high levels of both TeCB isomers, suggesting a similar source. HCB concentrations have a greater range of values during warmer seasons, suggesting that there are a variety of sources to Michigan, some of which are affected by seasonal air temperature variations.