Projected changes in the frequency of thermal comfort conditions at cold and warm cities, based on advanced bioclimatic indices

<p>Climate change and global warming affect heat or cold related stress in humans and ecosystems. Human thermal comfort or discomfort conditions in particular, are assessed through the application of simple or rational thermal (or bioclimatic) indices. In contrast to simple, advanced indices like the Universal Thermal Climate Index (UTCI) are based on human energy balance between the human body and thermal environment and involve multiple meteorological parameters, like air temperature, air humidity, wind speed and mean radiant temperature. Accelerating warming is expected to affect both heat and cold related stress conditions in the future, resulting in increased frequency of heat related stress, especially at warmer cities like the cities of Mediterranean, and at the same time reduced frequency of cold related stress at colder cities, like the cities of northern Europe. Asymmetrical changes in the frequency of heat or cold related stress conditions will eventually determine the future changes (increases or decreases) in the frequency of conditions of no thermal stress at cities of different background climate. The study will investigate future changes in &#8216;thermal comfort&#8217; or &#8216;favourable&#8217; conditions at cities with different base climate. Simulations by a set of state-of-the-art Regional Climate Models (RCMs) in the frame of EURO-CORDEX (Coordinated Regional Climate Downscaling Experiment) modeling experiment (http://www.euro-cordex.net) with a horizontal resolution of about 12 km (0.11&#176;) downscaled over the areas of interest will be realized for a control period and for two periods in the near and distant future, under the RCP4.5 and RCP8.5 future emissions scenarios. Simulations of meteorological variables for the estimation of UTCI at 3-hourly step will be retrieved for the closest land model grid point to the observation sites, while the performance of the RCMs will be evaluated against results from observations for the control period.</p>

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Climate Change and Thermal Comfort in Top Tourist Destinations—The Case of Santorini (Greece)

Sustainability ◽

10.3390/su13169107 ◽

2021 ◽

Vol 13 (16) ◽

pp. 9107

Author(s):

George Katavoutas ◽

Dimitra Founda ◽

Gianna Kitsara ◽

Christos Giannakopoulos

Keyword(s):

Climate Change ◽

Heat Stress ◽

Thermal Environment ◽

Stress Conditions ◽

Climate Index ◽

Mitigation Scenario ◽

Future Projections ◽

Tourist Destinations ◽

The Future ◽

The Mediterranean

The Mediterranean area is one of the most visited tourist destinations of the world, but it has also been recognized as one of the most vulnerable to climate change areas worldwide with respect to increased thermal risk. The study focuses on a top worldwide tourist destination of the Mediterranean, Santorini Island in Greece, and aims to assess the past, present and future thermal environment in the island based on the advanced Universal Thermal Climate Index (UTCI). The study utilizes historical observations capturing past (late 19th to early 20th century) and more recent (1982–2019) time periods, while future projections are realized based on four regional climate models (RCMs) under the weak mitigation scenario (RCP4.5) and the non-mitigation scenario with high emissions (RCP8.5). The frequency of cold stress conditions at midday decreases during winter and early spring months by up to 19.8% (January) in the recent period compared to the historical one, while heat stress conditions increase in summer by up to 22.4% (August). Future projections suggest progressive shifts of the UTCI towards higher values in the future and an increase in the exposure time under heat stress depending on the RCM and adopted scenario. The increase in moderate and strong heat stress conditions is mainly expected during the summer months (June, July, August); nevertheless, a noticeable increase is also foreseen in September and May. The highest occurrences of favorable (no thermal stress) conditions are also projected to shift by one month, from June to May and from September to October, in the future.

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Experimental study on coupling effect of indoor air temperature and radiant temperature on human thermal comfort in non-uniform thermal environment

Building and Environment ◽

10.1016/j.buildenv.2019.106387 ◽

2019 ◽

Vol 165 ◽

pp. 106387 ◽

Cited By ~ 3

Author(s):

Dengjia Wang ◽

Guixia Chen ◽

Cong Song ◽

Yanfeng Liu ◽

Wenfang He ◽

...

Keyword(s):

Experimental Study ◽

Thermal Comfort ◽

Air Temperature ◽

Indoor Air ◽

Thermal Environment ◽

Coupling Effect ◽

Human Thermal Comfort ◽

Radiant Temperature

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Outdoor Thermal Comfort at a University Campus: Studies from Personal and Long-Term Thermal History Perspectives

Sustainability ◽

10.3390/su12219284 ◽

2020 ◽

Vol 12 (21) ◽

pp. 9284

Author(s):

Jiao Xue ◽

Xiao Hu ◽

Shu Nuke Sani ◽

Yuanyuan Wu ◽

Xinyu Li ◽

...

Keyword(s):

Thermal Comfort ◽

Thermal History ◽

Thermal Environment ◽

Thermal Sensation ◽

Cold Climate ◽

Outdoor Thermal Comfort ◽

Climate Index ◽

University Campus ◽

Winter Climate

Thermally comfortable outdoor spaces have contributed to high-quality urban living. In order to provide a further understanding of the influences of gender and long-term thermal history on outdoor thermal comfort, this study conducted field surveys at a university campus in Shanghai, China by carrying out microclimatic monitoring and subjective questionnaires from May to October, 2019. The analysis of collected data found that, during our survey, 57% of the occupants felt comfortable overall and 40–60% of them perceived the microclimate variables (air temperature, humidity, solar radiation, and wind speed) as “neutral”. The universal thermal climate index (UTCI) provided a better correlation with occupant thermal sensation than the physiologically equivalent temperature (PET). Females were more sensitive to the outdoor thermal environment than males. Older age led to lower thermal sensation, but the thermal sensitivities for age groups of <20, 20–50, and >50 were similar. Occupants who had resided in Shanghai for a longer period showed higher overall comfort rating and lower thermal sensation. Interviewees who came from hot summer and cold winter climate regions were less effected by the change of UTCI than those from severe cold or cold climate regions.

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Experimental study on dynamic thermal environment of passenger compartment based on thermal evaluation indexes

Science Progress ◽

10.1177/0036850420942991 ◽

2020 ◽

Vol 103 (3) ◽

pp. 003685042094299

Author(s):

Liang Zhang ◽

Liangkui Qi ◽

Jianhua Liu ◽

Qingqing Wu

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Prediction Accuracy ◽

Thermal Environment ◽

Temperature Model ◽

Equivalent Temperature ◽

Vote Model ◽

Evaluation Indexes ◽

Human Thermal Comfort ◽

Experimental Values

In this article, the thermal environment and the human thermal comfort of car cabin under different driving states in summer were studied experimentally. The weighted predictive mean vote model and the weighted equivalent temperature model were used for calculation and compared with the experimental values. The experimental results show that the air temperature and relative humidity distribution in cabin are affected by the space position and driving state. The temperature of the cabin seat, which is affected by solar radiation and crew, in the heating stage is slightly higher than the air temperature, while the cooling rate in the cooling stage is much lower than the air temperature. The predictive mean vote model and the equivalent temperature model are basically consistent with the actual thermal comfort of human body under the idle and driving conditions with the change of time. The prediction accuracy of the two models under the idle condition is higher than that under the driving condition, and the overall prediction accuracy of the equivalent temperature model is higher than that of the predictive mean vote model.

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Quantification of the Expected Changes in Annual Maximum Daily Precipitation Quantiles under Climate Change in the Iberian Peninsula

Proceedings ◽

10.3390/ecws-3-05819 ◽

2018 ◽

Vol 7 (1) ◽

pp. 23 ◽

Cited By ~ 1

Author(s):

Carlos Garijo ◽

Luis Mediero

Keyword(s):

Climate Change ◽

Iberian Peninsula ◽

Climate Models ◽

Climate Model ◽

Global Climate ◽

Global Climate Model ◽

Regional Climate ◽

Control Period ◽

Regional Climate Models ◽

The Future

Climate model projections can be used to assess the expected behaviour of extreme precipitations in the future due to climate change. The European part of the Coordinated Regional Climate Downscalling Experiment (EURO-CORDEX) provides precipitation projections for the future under various representative concentration pathways (RCPs) through regionalised Global Climate Model (GCM) outputs by a set of Regional Climate Models (RCMs). In this work, 12 combinations of GCM and RCM under two scenarios (RCP 4.5 and RCP 8.5) supplied by the EURO-CORDEX are analysed for the Iberian Peninsula. Precipitation quantiles for a set of probabilities of non-exceedance are estimated by using the Generalized Extreme Value (GEV) distribution and L-moments. Precipitation quantiles expected in the future are compared with the precipitation quantiles in the control period for each climate model. An approach based on Monte Carlo simulations is developed in order to assess the uncertainty from the climate model projections. Expected changes in the future are compared with the sampling uncertainty in the control period. Thus, statistically significant changes are identified. The higher the significance threshold, the fewer cells with significant changes are identified. Consequently, a set of maps are obtained in order to assist the decision-making process in subsequent climate change studies.

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

Advances in Meteorology ◽

10.1155/2015/323856 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 5

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.

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Thermal Environment of Urban Schoolyards: Current and Future Design with Respect to Children’s Thermal Comfort

Atmosphere ◽

10.3390/atmos11111144 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1144

Author(s):

Dimitrios Antoniadis ◽

Nikolaos Katsoulas ◽

Dimitris Κ. Papanastasiou

Keyword(s):

Heat Stress ◽

Adverse Effects ◽

Thermal Comfort ◽

Vegetation Cover ◽

Thermal Environment ◽

Positive Impact ◽

High Surface ◽

Well Being ◽

Ambient Conditions ◽

Human Thermal Comfort

Urban outdoor thermal conditions, and its impacts on the health and well-being for the city inhabitants have reached increased attention among biometeorological studies during the last two decades. Children are considered more sensitive and vulnerable to hot ambient conditions compared to adults, and are affected strongly by their thermal environment. One of the urban outdoor environments that children spend almost one third of their school time is the schoolyard. The aims of the present manuscript were to review studies conducted worldwide, in order to present the biophysical characteristics of the typical design of the urban schoolyard. This was done to assess, in terms of bioclimatology, the interactions between the thermal environment and the children’s body, to discuss the adverse effects of thermal environment on children, especially the case of heat stress, and to propose measures that could be applied to improve the thermal environment of schoolyards, focusing on vegetation. Human thermal comfort monitoring tools are mainly developed for adults, thus, further research is needed to adapt them to children. The schemes that are usually followed to design urban schoolyards create conditions that favour the exposure of children to excessive heat, inducing high health risks to them. The literature survey showed that typical urban schoolyard design (i.e., dense surface materials, absence of trees) triggered high surface temperatures (that may exceed 58 °C) and increased absorption of radiative heat load (that may exceed 64 °C in terms of Mean Radiant Temperature) during a clear day with intense solar radiation. Furthermore, vegetation cover has a positive impact on schoolyard’s microclimate, by improving thermal comfort and reducing heat stress perception of children. Design options for urban schoolyards and strategies that can mitigate the adverse effects of heat stress are proposed with focus on vegetation cover that affect positively their thermal environment and improve their aesthetic and functionality.

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Microclimate Environmental Assessment and Impact of Mountain City Pedestrian Streets in Summer

E3S Web of Conferences ◽

10.1051/e3sconf/202017211001 ◽

2020 ◽

Vol 172 ◽

pp. 11001

Author(s):

Ke Xiong ◽

Zhenjing Yang ◽

Canhua Cheng

Keyword(s):

Thermal Comfort ◽

Environmental Assessment ◽

Thermal Environment ◽

Climate Index ◽

View Factor ◽

City Street ◽

Thermal Climate ◽

The One ◽

Microclimate Environment ◽

Important Form

In mountainous cities, walking is an important form of transportation. The microclimate environment of pedestrian streets in summer affects the comfort of pedestrians, especially in hot summer cities. Besides, there are many height differences in mountainous city pedestrian streets, while existing researches of the thermal environment were mainly aimed at plain cities. We used typology to analyze different spatial patterns and tested microclimate of five kinds of streets in the Shanchengxiang of Chongqing. Then the universal thermal climate index (UTCI) was used to evaluate the thermal comfort of different spatial spaces. Firstly, the thermal environment of the mountain city street in summer is extremely uncomfortable and needs to be improved. Secondly, the sky view factor (SVF) has a great impact on the street thermal environment. Among all kinds of streets, the one-sided open B-N (SVF = 0.474) has the worst thermal environment, with an average UTCI of 44.7℃. However, the two-sided enclosed B2-B2 (SVF = 0.052) represents a better thermal environment, with an average UTCI of 35.5℃. The R2 value of 0.88 reflects that the linear correlation between UTCI and SVF is larger than that of H/W, whose R2 value is mere 0.04. Finally, different interfaces and enclosure forms have a great impact on space thermal comfort. This study quantifies the parameters that influence the design of pedestrian streets in mountain cities from the perspective of outdoor microclimate environmental assessment and provide a reference for the sustainable design of regional streets.

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A Human Energy Balance Model With Clothing Effects for Estimating Human Thermal Comfort

2010 14th International Heat Transfer Conference, Volume 1 ◽

10.1115/ihtc14-22070 ◽

2010 ◽

Author(s):

Atsumasa Yoshida ◽

Yasuhiro Shimazaki ◽

Shinichi Kinoshita ◽

Ryota Suzuki

Keyword(s):

Heat Transfer ◽

Energy Balance ◽

Thermal Comfort ◽

Human Body ◽

Thermal Load ◽

Thermal Environment ◽

Energy Balance Model ◽

Balance Model ◽

Comfort Index ◽

Human Thermal Comfort

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.

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