scholarly journals What is the most threatening for citizens of a mid-latitude city: cold stress or heat stress?

2021 ◽  
Author(s):  
Sara Top ◽  
Dragan Milošević ◽  
Steven Caluwaerts ◽  
Stevan Savić
Keyword(s):  
Heat Stress ◽  
Cold Stress ◽  
Thermal Comfort ◽  
Heat Wave ◽  
Outdoor Thermal Comfort ◽  
Belgian Society ◽  
Human Thermal Comfort ◽  
Summer Heat ◽  
Heat And Cold Stress ◽  
The City

<p>Both heat and cold waves cause extreme human thermal discomfort and a clear excess in mortality. This shows the importance of knowing the prevailing thermal comfort conditions and how thermal comfort conditions vary in various environments so measures can be taken. Microclimatic and outdoor human thermal comfort conditions are investigated in various built-up and green areas in the city of Ghent (Belgium) using meteorological measurements of six weather stations of the MOCCA (Monitoring the Cities Climate and Atmosphere) network in combination with calculations done by RayMan.</p><p>Normal to extreme summer heat wave periods show that dangerous strong heat stress prevails during the daytime periods at all locations. Comparison of thermal comfort during normal and extreme summer heat wave periods showed that heat stress is more extreme when a heat wave is more intense. Overall the urban park in Ghent was the most comfortable location during heat waves since it effectively mitigates heat stress in the city. These results should be taken into account in urban planning and design to keep mid-latitude cities livable.</p><p>Further, a one year data series revealed that outdoor cold stress was more apparent during 2017 in the mid-latitude city of Ghent that experiences a mild maritime climate. During spring and summer, both heat stress and cold stress occurred due to the larger diurnal temperature range compared to the other seasons. Even though high Physiological Equivalent Temperatures (PET) were obtained during a heat wave in summer, heat stress did not occur as intensely and as frequently compared to cold stress on annual level. It could thus be stated that outdoors, cold stress is a bigger threat than heat stress. However, one should keep in mind that the study was executed for outdoor thermal heat comfort and that people will take shelter or take measures when feeling uncomfortable. The question is thus rather, how are citizens protected against heat and cold stress? Currently, the Belgian society is better adapted to cold stress since most buildings contain central heating, while air conditioning is not standard. Future projections predict an increase in temperature, causing more occurrence of extreme heat stress, while extreme cold stress will be reduced. Additionally, the urban heat island effect currently has mainly a positive effect on the average annual outdoor thermal comfort conditions, while it will become a negative effect in the warmer future. Measures should thus be taken to reduce the threat of future heat stress.</p>

scholarly journals Impact of climate change on outdoor thermal comfort in cities in united states

2020 ◽  
Vol 158 ◽  
pp. 01002
Author(s):  
Yuqiao Huang ◽  
Dayi Lai ◽  
Yiqing Liu ◽  
Huang Xuan
Keyword(s):  
Climate Change ◽  
United States ◽  
Heat Stress ◽  
Cold Stress ◽  
Thermal Comfort ◽  
The United States ◽  
Stress Rate ◽  
Outdoor Thermal Comfort ◽  
Open Spaces ◽  
Impact Of Climate Change

Since urban open spaces provide various benefits to the citizens, it is necessary to improve the outdoor thermal comfort in urban open spaces. However, global warming increases heat stress and at the same time decrease cold stress of outdoor spaces. The final impact of climate change on outdoor thermal comfort is not evident, and depends on the climate characteristics. This study investigated the influence of climate change on outdoor thermal comfort conditions of five selected cities (Minneapolis, New York City, San Francisco, Miami, and Las Vegas) with distinctive climate patterns in the United States. It is found that all cities suffered from deterioration in thermal comfort. This is because the increases in the heat stress rate were greater than the decreases in cold stress rate. In the 2080s, the greatest reduction in acceptable thermal stress rate happened in Miami from 44.7% to 21.3% under high emission scenario.

scholarly journals A New Method to Assess Fine-Scale Outdoor Thermal Comfort for Urban Agglomerations

Climate ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Dirk Lauwaet ◽  
Bino Maiheu ◽  
Koen De Ridder ◽  
Wesley Boënne ◽  
Hans Hooyberghs ◽  
...  
Keyword(s):  
Heat Stress ◽  
Thermal Comfort ◽  
Rural Areas ◽  
Urban Areas ◽  
Urban Heat Islands ◽  
Outdoor Thermal Comfort ◽  
Urban Agglomerations ◽  
Human Thermal Comfort ◽  
Air Temperatures ◽  
Water Surfaces

In urban areas, high air temperatures and heat stress levels greatly affect human thermal comfort and public health, with climate change further increasing the mortality risks. This study presents a high resolution (100 m) modelling method, including detailed offline radiation calculations, that is able to efficiently calculate outdoor heat stress for entire urban agglomerations for a time period spanning several months. A dedicated measurement campaign was set up to evaluate model performance, yielding satisfactory results. As an example, the modelling tool was used to assess the effectiveness of green areas and water surfaces to cool air temperatures and wet bulb globe temperatures during a typical hot day in the city of Ghent (Belgium), since the use of vegetation and water bodies are shown to be promising in mitigating the adverse effects of urban heat islands and improving thermal comfort. The results show that air temperature reduction is most profound over water surfaces during the afternoon, while open rural areas are coolest during the night. Radiation shading from trees, and to a lesser extent, from buildings, is found to be most effective in reducing wet bulb globe temperatures and improving thermal comfort during the warmest moments of the day.

scholarly journals Analysis of human thermal comfort in Central European City during summer of 2015: A case of Novi Sad (Serbia)

2020 ◽  
Vol 100 (1) ◽  
pp. 31-39
Author(s):  
Dragan Milosevic ◽  
Stevan Savic ◽  
Danijela Arsenovic ◽  
Zorana Luzanin ◽  
Jelena Dunjic
Keyword(s):  
Heat Stress ◽  
Thermal Comfort ◽  
Extreme Heat ◽  
Outdoor Thermal Comfort ◽  
European City ◽  
Central European ◽  
Human Thermal Comfort ◽  
Local Climate Zones ◽  
Novi Sad ◽  
Extreme Heat Stress

Urban meteorological network (UMN) was established in the Central European City of Novi Sad (Serbia) based on "local climate zones" (LCZs) system. Physiologically Equivalent Temperature (PET) index was used for the assessment of outdoor thermal comfort in the "built" and "land cover" LCZ classes of Novi Sad. The index was calculated in the RayMan software based on the meteorological, physiological as well as building and vegetation data. Temporal analysis was performed for extreme heat stress days (PETmax ? 41 ?C), extreme heat stress hours (PETav ? 41 ?C) and days with occurrence of "tropical nights" (Tmin > 20 ?C) during exceptionally hot summer of 2015. Our results show that extreme heat stress hours are the least frequent in compact midrise LCZ 2, followed by dense trees LCZ A. On the contrary, countryside (low plants - LCZ D) showed to be the most uncomfortable area during daytime followed by compact low-rise areas (LCZ 3). Tropical nights are the most frequent in midrise LCZs 5 and 2 (40-46 nights) and decreasing towards open, sparsely built and natural LCZs (6-8 tropical nights in LCZs A and D). This is almost 800% decrease and it has implications for health and recreation of urban population and emphasizes the need for UMN development based on LCZ system.

scholarly journals Parametric Design Structures in Low Rise Buildings in Relation to the Urban Context in UAE

2021 ◽  
Vol 13 (15) ◽  
pp. 8595
Author(s):  
Lindita Bande ◽  
Abeer Alshamsi ◽  
Anoud Alhefeiti ◽  
Sarah Alderei ◽  
Sebah Shaban ◽  
...  
Keyword(s):  
Heat Stress ◽  
Parametric Design ◽  
Residential Buildings ◽  
Cost Evaluation ◽  
Outdoor Thermal Comfort ◽  
Climate Index ◽  
Cooling Load ◽  
Design Structure ◽  
Al Ain ◽  
The City

The city of Al Ain (Abu Dhabi, UAE) has a mainly low rise residential buildings. Villas as part of a compound or separate units represent the majority of the residential areas in the city. Due to the harsh hot arid climate of Al Ain, the energy demand for the cooling load is quite high. Therefore, it is relevant finding new retrofit strategies that are efficient in reducing the cooling load of the villas. The aim of this study is to analyze one particular strategy (parametric shading structure) in terms of design, construction, cost, energy impact on the selected villa. The main data for this study is taken from the local sources. There are six steps followed in this analysis: case study analysis; climate analysis; parametric structure and PV panels; building energy consumption and outdoor thermal comfort; modelling, simulation, and validation; materials, construction, and cost evaluation. The model of the villa was validated for the full year 2020 based on the electricity bills obtained. After adding the parametric design structure, the reduction after shading is approximately 10%. Meanwhile the UTCI (Universal Thermal Climate Index) dropped from extreme heat stress to strong heat stress (average for the month of March and September). These findings are promising in the retrofit industry due to the advanced calculations used to optimize the parametric design structure.

scholarly journals Empirical Model of Human Thermal Comfort in Subtropical Climates: A First Approach to the Brazilian Subtropical Index (BSI)

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 391 ◽  
Author(s):  
João Gobo ◽  
Marlon Faria ◽  
Emerson Galvani ◽  
Fabio Goncalves ◽  
Leonardo Monteiro
Keyword(s):  
Thermal Comfort ◽  
Empirical Model ◽  
Thermal Sensation ◽  
Meteorological Data ◽  
Well Being ◽  
Global Solar Radiation ◽  
Coefficient Of Determination ◽  
Subtropical Climate ◽  
Human Thermal Comfort ◽  
The City

The bioclimatic well-being of individuals is associated with the environmental characteristics of where they live. Knowing the relationships between local and regional climatic variables as well as the physical characteristics of a given region and their implications on thermal comfort is important for identifying aspects of thermal sensation in the population. The aim of this study is to develop an empirical model of human thermal comfort based on subjective and individual environmental patterns observed in the city of Santa Maria, located in the state of Rio Grande do Sul, Brazil (Subtropical climate). Meteorological data were collected by means of an automatic meteorological station installed in the city center, which contained sensors measuring global solar radiation, air temperature, globe temperature (via a grey globe thermometer), relative humidity and wind speed and direction. A total of 1720 people were also interviewed using a questionnaire adapted from the model recommended by ISO 10551. Linear regressions were performed to obtain the predictive model. The observed results proposed a new empirical model for subtropical climate, the Brazilian Subtropical Index (BSI), which was verified to be more than 79% accurate, with a coefficient of determination of 0.926 and an adjusted R2 value of 0.924.

scholarly journals Future Changes in Human-Biometeorological Index Classes in Three Regions of Luxembourg, Western-Central Europe

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hanna Leona Lokys ◽  
Jürgen Junk ◽  
Andreas Krein
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Thermal Stress ◽  
Thermal Comfort ◽  
Central Europe ◽  
Spatial Resolution ◽  
Climate Index ◽  
Human Thermal Comfort ◽  
Air Temperatures ◽  
The Impact

Projected climate change will cause increasing air temperatures affecting human thermal comfort. In the highly populated areas of Western-Central Europe a large population will be exposed to these changes. In particular Luxembourg—with its dense population and the large cross-border commuter flows—is vulnerable to changing thermal stress. Based on climate change projections we assessed the impact of climate change on human thermal comfort over the next century using two common human-biometeorological indices, the Physiological Equivalent Temperature and the Universal Thermal Climate Index. To account for uncertainties, we used a multimodel ensemble of 12 transient simulations (1971–2098) with a spatial resolution of 25 km. In addition, the regional differences were analysed by a single regional climate model run with a spatial resolution of 1.3 km. For the future, trends in air temperature, vapour pressure, and both human-biometeorological indices could be determined. Cold stress levels will decrease significantly in the near future up to 2050, while the increase in heat stress turns statistically significant in the far future up to 2100. This results in a temporarily reduced overall thermal stress level but further increasing air temperatures will shift the thermal comfort towards heat stress.

scholarly journals Evaluation of outdoor thermal comfort conditions in northern Russia over 30-year period: Arkhangelsk region

2020 ◽  
Vol 24 (4) ◽  
pp. 252-260
Author(s):  
Pavel Konstantinov ◽  
Natalia Shartova ◽  
Mikhail Varentsov ◽  
Boris Revich
Keyword(s):  
Cold Stress ◽  
Thermal Comfort ◽  
Arctic Region ◽  
Outdoor Thermal Comfort ◽  
The Arctic ◽  
Novaya Zemlya ◽  
Arkhangelsk Region ◽  
Climatic Period ◽  
Bioclimatic Comfort ◽  
Extreme Cold

The aim of the current paper is to evaluate spatial and temporal characteristics of the distribution of bioclimatic comfort within the Arkhangelsk region (Russian Federation) with two modern indices of thermal comfort: PET and UTCI. Its average values calculated for the modern climatic period (1981-2010) in the monthly mean give a clear picture of spatial heterogeneity for the warmest month (July) and for the coldest one (January). The spatial picture of both indices in July allows us to distinguish three large internal regions: the Arkhangelsk province, the continental part of the Nenets Autonomous Okrug (NAO) and Novaya Zemlya islands (NZ). Winter distribution of thermal discomfort is fundamentally different: the coldest regions (with extreme cold stress) are equally NZ and the Eastern half of NAO; intermediate position is occupied by the West of the NAO and the extreme northeast of the Arkhangelsk region, the highest winter UTCI values are observed in the rest of the region. In Archangelsk-city extreme cold stress in January has repeatability 6.7%, in February-4%, in December-2.2%, respectively. The average number of time points during the year at which thermal stress is not observed is only 19%. Obtained results will be the basis for planning relevant health measures and providing reliable forecasts of the effects of climate change in the Arctic region.

scholarly journals ANÁLISE DO CONFORTO TÉRMICO HUMANO NO MUNICÍPIO DE ARAPIRACA – ALAGOAS, UTILIZANDO SOFTWARE MATLAB (ANALYSIS OF THE HUMAN THERMAL COMFORT THE CITY OF ARAPIRACA - ALAGOAS USING SOFTWARE MATLAB)

2015 ◽  
Vol 7 (5) ◽  
pp. 939
Author(s):  
Juliete Baraúna dos Santos
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Effective Temperature ◽  
Rainy Season ◽  
Prolonged Exposure ◽  
Urban Climate ◽  
Heat Stroke ◽  
Human Thermal Comfort ◽  
Discomfort Index ◽  
The City

Foram obtidas medidas das variáveis meteorológicas temperatura do ar, umidade relativa do ar e velocidade do vento através da estação automática instalada em Arapiraca com a finalidade de monitorar as condições de tempo no município em diferentes períodos (época chuvosa e seca). Sendo utilizado o índice de desconforto (ID), o índice de desconforto de Kawamura (IDK), índice da temperatura efetiva (TE) e o índice de temperatura efetiva em função do vento (TEV). Os valores mais elevados dos índices que foram registrados para o período chuvoso, foram do índice id com aproximadamente 2,5 °C acima dos valores observados da temperatura do ar (em média 26,5 °C), caracterizando crescente desconforto para os indivíduos locais.  Para o período seco não houve registros de grandes variações entre os respectivos índices. E assim como no período chuvoso, os valores mais elevados no período seco foram do índice id, indicando nesse período também forte desconforto. Os valores obtidos estiveram condizentes com a literatura, sendo a sensação térmica mais preponderante durante o inverno. E, de acordo com as variações, em todo período de estudo (05 de maio de 2008 a 05 de maio de 2011) a população foi submetida aos alertas de atenção e muito cuidado, situação esta que pôde provocar fadiga ou cãibras, esgotamento e insolação nos casos de exposição prolongada e atividade física.      A B S T R A C T Measurements of meteorological variables air temperature, relative humidity and wind speed by automatic station installed in Arapiraca in order to monitor the weather conditions in the city in different periods (dry and rainy season) were obtained. Being used the discomfort index (ID), the discomfort index of Kawamura (IDK), index of effective temperature (TE) and the index of effective temperature as a function of wind (TEv). Higher index values ​​that were recorded for the rainy season, the index id were approximately 2.5 ° C above the observed values ​​of air temperature (average 26.5 ° C), indicating increasing discomfort for local individuals . For the dry period there were no reports of large variations between the respective indices. And just as the rainy season, the highest values ​​in the dry season were the index id, indicating that period also strong discomfort. The values ​​obtained were consistent with the literature, the most predominant wind chill during the winter. And, according to the variations in the study period (May 5, 2008 to 05 maio 2011) the population was subjected to warnings of attention and care, a situation that could cause fatigue or cramps, exhaustion and heat stroke in cases of prolonged exposure and physical activity.   Key-Words: Urban climate. Thermal comfort Human. Bioclimatic

scholarly journals Investigating Applicability of Evaporative Cooling Systems for Thermal Comfort of Poultry Birds in Pakistan

2020 ◽  
Vol 10 (13) ◽  
pp. 4445
Author(s):  
Hafiz M. U. Raza ◽  
Hadeed Ashraf ◽  
Khawar Shahzad ◽  
Muhammad Sultan ◽  
Takahiko Miyazaki ◽  
...  
Keyword(s):  
Heat Stress ◽  
Thermal Comfort ◽  
Developing Economies ◽  
Low Cost ◽  
Evaporative Cooling ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Poultry Birds ◽  
The City

In the 21st century, the poultry sector is a vital concern for the developing economies including Pakistan. The summer conditions of the city of Multan (Pakistan) are not comfortable for poultry birds. Conventionally, swamp coolers are used in the poultry sheds/houses of the city, which are not efficient enough, whereas compressor-based systems are not economical. Therefore, this study is aimed to explore a low-cost air-conditioning (AC) option from the viewpoint of heat stress in poultry birds. In this regard, the study investigates the applicability of three evaporative cooling (EC) options, i.e., direct EC (DEC), indirect EC (IEC), and Maisotsenko-cycle EC (MEC). Performance of the EC systems is investigated using wet-bulb effectiveness (WBE) for the climatic conditions of Multan. Heat stress is investigated as a function of poultry weight. Thermal comfort of the poultry birds is calculated in terms of temperature-humidity index (THI) corresponding to the ambient and output conditions. The heat production from the poultry birds is calculated using the Pederson model (available in the literature) at various temperatures. The results indicate a maximum temperature gradient of 10.2 °C (MEC system), 9 °C (DEC system), and 6.5 °C (IEC systems) is achieved. However, in the monsoon/rainfall season, the performance of the EC systems is significantly reduced due to higher relative humidity in ambient air.

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