scholarly journals Seasonal Regional Differentiation of Human Thermal Comfort Conditions in Algeria

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Salah Sahabi Abed ◽  
Andreas Matzarakis

The thermal conditions of the bioclimate of Algeria are investigated applying especially the physiologically equivalent temperature (PET) seasonal variability of five main Algerian cities representing different climate and geographical conditions: coastal region, highland region, and Sahara zone. The physiologically equivalent temperature (PET) calculated for this study at 12.00 UTC (13.00 local time) is used to emphasize the impacts of climate on human heat stress in different seasonal and regional regimes. This study is important since it is performed for the first time in Algeria using a deterministic approach through the calculation of PET based on the body-atmosphere energy balance using the Munich Energy-Balance Model for Individuals (MEMI). Applying PET is a new feature in assessing the bioclimate of Algeria and serves the touristic and the health sector in particular. For touristic purposes, it is part of the new internationally introduced climate touristic/transfer information scheme (CTIS) enabling the Algerian results to be paled in comparison to other countries. Considering climate change, the study shows as a new feature a significant increase in the number of days with strong and extreme heat stress within the last three decades and discusses the risks and advantages for future tourism in Algeria.

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 444
Author(s):  
Yuting Wu ◽  
Kathrin Graw ◽  
Andreas Matzarakis

Weather and climate conditions can be decisive regarding travel plans or outdoor events, especially for sport events. The Olympic Games 2020, postponed to 2021, will take place in Tokyo at a time which is considered to be the hottest and most humid time of the year. However, a part of the athletic competitions is relocated to the northern city Sapporo. Therefore, it is important to quantify thermal comfort for different occasions and destinations and make the results accessible to visitors and sport attendees. The following analysis will quantify and compare thermal comfort and heat stress between Sapporo and Tokyo using thermal indices like the Physiologically Equivalent Temperature and the modified Physiologically Equivalent Temperature (PET and mPET). The results reveal different precipitation patterns for the cities. While a higher precipitation rate appears in Sapporo during winter, the precipitation rate is higher in Tokyo during summer. PET and mPET exhibit a greater probability of heat stress conditions in Tokyo during the Olympic Games, whereas Sapporo has more moderate values for the same period. The Climate-Tourism/Transfer-Information-Scheme (CTIS) integrates and simplifies climate information and makes them comprehensible for non-specialists. The CTIS of Tokyo illustrates lower suitable conditions for “Heat stress”, “Sunny days” and “Sultriness”. Transferring parts of the athletics competition to a northern city is thus more convenient for athletes, staff members and spectators. Hence, heat stress can be avoided and an acceptable outdoor stay is ensured. Overall, this quantification and comparison of the thermal conditions in Sapporo and Tokyo reveal limitations but also possibilities for the organizers of the Olympic Games. Furthermore it can be used to raise awareness for promoting or arranging countermeasures and heat mitigation at specific events and destinations, if necessary.


Author(s):  
Atsumasa Yoshida ◽  
Yasuhiro Shimazaki ◽  
Shinichi Kinoshita ◽  
Ryota Suzuki

There is an increased world attention on environmental issues with the global trend of environmental degradation. Especially thermal environment was highly concerned as human safety. We have been focused on creation of amenity environment with energy-saving way. This study is uncommonly dealing with human feeling for human thermal comfort, that is to say quantification of environment has been done. The feeling of comfort is mixed sense and can be totally easier to improve compared with straightforward way, and this may lead to energy and cost saving way of improvement. Moreover, this is human-oriented and can reflect humans’ wishes. Since thermal comfort index is useful tool for understanding the present state and evaluating the impact of countermeasures, effectiveness of human thermal load which is thermal comfort index based on energy balance of human body was examined. The human thermal comfort around the human body in outdoor is influenced by six dominant factors; air temperature, humidity, solar radiation, wind speed, metabolism and clothing. The difference between indoor and outdoor is expressed mainly as non-uniform and unsteady. Therefore, the unsteady responses of each dominant factors were examined and clarified human thermal load is quite good estimation of human thermal comfort. In steady state and even in unsteady state, thermal comfort can be obtained by using human thermal load on the whole. The reason is human thermal load consider the amount of physiology and also weather parameters. In the process of creating energy balance model of human, clothing material was deeply considered. For establishing better thermal environment, clothing material is of great use, because clothing material has an impact on thermal exchange between exterior environment and human body and more easy way to improve in 6 factors. The traditional treatment of clothing in human science was only resistance of heat transfer and this was not enough for all clothing effects. In daily life, effect of humidity exists and moisture property is required. Moreover color of material has impact on energy balance in clothing material. In order to show a way of better thermal environment, the heat and the moisture transfer coefficients on clothing material, radiative properties, and additional properties such as convection heat transfer coefficient were measured, and energy flow of clothing material was totally investigated. Finally, the effects of clothing material for human thermal comfort were predicted and this energy balance human model has become much better model.


Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 580 ◽  
Author(s):  
Ioannis Charalampopoulos ◽  
Andre Santos Nouri

This paper aims to analyse and conclude about the behaviour of the most commonly used human thermal comfort indices under a variety of atmospheric conditions in order to provide further information about their appropriateness. Utilising Generalized Additive Models (GAMs), this article examines the indices’ sensitivity when exposed to diverse classified atmospheric conditions. Concentrated upon analysing commonly used human thermal indices, two Statistical/Algebraic indices (Thermohygrometric Index (THI) and HUMIDEX (HUM)), and four Energy Balance Model indices (Physiologically Equivalent Temperature (PET), modified PET (mPET), Universal Thermal Climate Index (UTCI), and Perceived Temperature (PT)) were selected. The results of the study are twofold, the identification of (1) index sensitivity to parameters’ variation, and change rates, resultant of different atmospheric conditions; and, (2) the overall pertinence of each of the indices for local thermal comfort evaluation. The results indicate that the thermohygrometric indices cannot follow and present the thermal conditions’ variations. On the other hand, UTCI is very sensitive under low radiation condition, and PET/mPET present higher sensitivity when the weather is dominated by high radiation and air temperature. PT index provides the lower sensitive among the human energy balance indices, but this is adequately sensitive to describe the thermal comfort environment.


Author(s):  
Gandhi M. ◽  
Swaminathan S.

Ghrelin as human natural hormones is involved in fundamental regulatory process of eating and energy balance. It is a stomach derived hormone that acts as at the ghrelin receptor in multiple tissues throughout to the body. Its properties includes increasing appetite, decreasing systemic inflammation, decreasing vascular resistance ,increasing cardiac output, increasing glucose and IGF-1 levels, Hence it may play a significant role in Diabetes mellitus. Many studies have linked ghrelin to obesity and this paper is an attempt to bring out recent findings on the role of ghrelin in Diabetes Mellitus, particularly type2 Diabetes mellitus.


1990 ◽  
Vol 36 (123) ◽  
pp. 217-221 ◽  
Author(s):  
Roger J. Braithwaite ◽  
Ole B. Olesen

AbstractDaily ice ablation on two outlet glaciers from the Greenland ice sheet, Nordbogletscher (1979–83) and Qamanârssûp sermia (1980–86), is related to air temperature by a linear regression equation. Analysis of this ablation-temperature equation with the help of a simple energy-balance model shows that sensible-heat flux has the greatest temperature response and accounts for about one-half of the temperature response of ablation. Net radiation accounts for about one-quarter of the temperature response of ablation, and latent-heat flux and errors account for the remainder. The temperature response of sensible-heat flux at QQamanârssûp sermia is greater than at Nordbogletscher mainly due to higher average wind speeds. The association of high winds with high temperatures during Föhn events further increases sensible-heat flux. The energy-balance model shows that ablation from a snow surface is only about half that from an ice surface at the same air temperature.


2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Akansha Patel ◽  
Ajanta Goswami ◽  
Jaydeo K. Dharpure ◽  
Meloth Thamban ◽  
Parmanand Sharma ◽  
...  

2021 ◽  
pp. 1-19
Author(s):  
Rebecca L. Stewart ◽  
Matthew Westoby ◽  
Francesca Pellicciotti ◽  
Ann Rowan ◽  
Darrel Swift ◽  
...  

Abstract Surface energy-balance models are commonly used in conjunction with satellite thermal imagery to estimate supraglacial debris thickness. Removing the need for local meteorological data in the debris thickness estimation workflow could improve the versatility and spatiotemporal application of debris thickness estimation. We evaluate the use of regional reanalysis data to derive debris thickness for two mountain glaciers using a surface energy-balance model. Results forced using ERA-5 agree with AWS-derived estimates to within 0.01 ± 0.05 m for Miage Glacier, Italy, and 0.01 ± 0.02 m for Khumbu Glacier, Nepal. ERA-5 data were then used to estimate spatiotemporal changes in debris thickness over a ~20-year period for Miage Glacier, Khumbu Glacier and Haut Glacier d'Arolla, Switzerland. We observe significant increases in debris thickness at the terminus for Haut Glacier d'Arolla and at the margins of the expanding debris cover at all glaciers. While simulated debris thickness was underestimated compared to point measurements in areas of thick debris, our approach can reconstruct glacier-scale debris thickness distribution and its temporal evolution over multiple decades. We find significant changes in debris thickness over areas of thin debris, areas susceptible to high ablation rates, where current knowledge of debris evolution is limited.


2020 ◽  
pp. 1-16
Author(s):  
Tim Hill ◽  
Christine F. Dow ◽  
Eleanor A. Bash ◽  
Luke Copland

Abstract Glacier surficial melt rates are commonly modelled using surface energy balance (SEB) models, with outputs applied to extend point-based mass-balance measurements to regional scales, assess water resource availability, examine supraglacial hydrology and to investigate the relationship between surface melt and ice dynamics. We present an improved SEB model that addresses the primary limitations of existing models by: (1) deriving high-resolution (30 m) surface albedo from Landsat 8 imagery, (2) calculating shadows cast onto the glacier surface by high-relief topography to model incident shortwave radiation, (3) developing an algorithm to map debris sufficiently thick to insulate the glacier surface and (4) presenting a formulation of the SEB model coupled to a subsurface heat conduction model. We drive the model with 6 years of in situ meteorological data from Kaskawulsh Glacier and Nàłùdäy (Lowell) Glacier in the St. Elias Mountains, Yukon, Canada, and validate outputs against in situ measurements. Modelled seasonal melt agrees with observations within 9% across a range of elevations on both glaciers in years with high-quality in situ observations. We recommend applying the model to investigate the impacts of surface melt for individual glaciers when sufficient input data are available.


2021 ◽  
Vol 13 (5) ◽  
pp. 2836
Author(s):  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Muhammad Bilal ◽  
Hadeed Ashraf ◽  
Muhammad Farooq ◽  
...  

Poultry are one of the most vulnerable species of its kind once the temperature-humidity nexus is explored. This is so because the broilers lack sweat glands as compared to humans and undergo panting process to mitigate their latent heat (moisture produced in the body) in the air. As a result, moisture production inside poultry house needs to be maintained to avoid any serious health and welfare complications. Several strategies such as compressor-based air-conditioning systems have been implemented worldwide to attenuate the heat stress in poultry, but these are not economical. Therefore, this study focuses on the development of low-cost and environmentally friendly improved evaporative cooling systems (DEC, IEC, MEC) from the viewpoint of heat stress in poultry houses. Thermodynamic analysis of these systems was carried out for the climatic conditions of Multan, Pakistan. The results appreciably controlled the environmental conditions which showed that for the months of April, May, and June, the decrease in temperature by direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and Maisotsenko-Cycle evaporative cooling (MEC) systems is 7–10 °C, 5–6.5 °C, and 9.5–12 °C, respectively. In case of July, August, and September, the decrease in temperature by DEC, IEC, and MEC systems is 5.5–7 °C, 3.5–4.5 °C, and 7–7.5 °C, respectively. In addition, drop in temperature-humidity index (THI) values by DEC, IEC, and MEC is 3.5–9 °C, 3–7 °C, and 5.5–10 °C, respectively for all months. Optimum temperature and relative humidity conditions are determined for poultry birds and thereby, systems’ performance is thermodynamically evaluated for poultry farms from the viewpoint of THI, temperature-humidity-velocity index (THVI), and thermal exposure time (ET). From the analysis, it is concluded that MEC system performed relatively better than others due to its ability of dew-point cooling and achieved THI threshold limit with reasonable temperature and humidity indexes.


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