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Norms of Apparent Temperature in Australia
Abstract
The apparent-temperature model has been refined, and is applied to a range of Australian climate data to analyse the diurnal and annual pattern of normal effects of vapour pressure, wind speed and extra (solar and sky) radiation, and to combine these into maps and charts of apparent temperature. Results show that dry-bulb temperature sometimes over or underestimates the total impact of climatic norms by 10K. Equations are presented to enable calculation of direct and diffuse solar radiation in a clear sky at any time and place on earth. Sunshine is commonly the greatest modifier of dry-bulb temperature in Australia. Daily AT typically reaches its normal maximum before dry-bulb temperature, but seasonal variation of AT lags. -Author
... The personal factors are the clothing and the level of physical activity (B. of M. Commonwealth of Australia 2010). There are many methods of combining these factors into a single number to assess the outdoor thermal environment-for example, the Wet Bulb Globe Temperature (WBGT) (B. of M. Commonwealth of Australia 2010), the Universal Thermal Climate Index (UTCI) (Jendritzky et al. 2001), the Physiologically Equivalent Temperature (PET) (Honjo 2009) as well as the Apparent Temperature (AT) (Steadman 1994). Another way to assess thermal comfort is to calculate the thermal comfort indices Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD), using the Fanger's method proposed in ISO Standard 7730 (Gameiro da Silva 2013), or the Human Thermal Model (HTM) which can be used for predicting thermal behavior of the human body under both steady-state and transient indoor environment conditions (Holopainen 2012). ...
... In order to validate the software, the simulation results are compared to measurement data collected in 2017 within the framework of the research project "Grün-PlusSchule" (Korjenic 2018), showing a good agreement. Based on these simulation results, the apparent temperature (Steadman 1994) is calculated to assess the impact of façade greening within a typical courtyard of a residential block on human thermal comfort. ...
... The evaluation of the simulation results clearly shows that the apparent temperature (Steadman 1994) in the greened inner courtyard is comparable to that of the adjacent streets and in some cases even higher (see Fig. 15). However, the air temperature, measured in the shadow and without the influence of radiation, is 2 °C below that of the surrounding area (see Fig. 16), which is due to the cooling capacity of the plants and the lower albedo. ...
Background
Increasing urbanization as well as global warming requires an investigation of the influence of different construction methods and ground surfaces on the urban heat island effect (UHI effect). The extent of the influence of the urban structure, the building materials used and their surfaces on the UHI effect can be significantly reduced already in the planning phase using a designated OpenFOAM-based solver “uhiSolver”.
Results
In the first part of this research work, it is shown that inner building details and components can be neglected while still obtaining sufficiently accurate results. For this purpose, the building model was divided into two layers: a surface layer without mass, where the interaction with radiation takes place, and a component layer, which contains all relevant components and cavities of the building represented with mass-averaged material properties. It has become apparent that the three parameters—albedo, heat capacity and thermal resistance—which have a decisive influence on the interaction, have different effects on the component temperatures and the surface temperatures. In the second part of this research work, dynamic 3D computational fluid dynamics (CFD) simulations are performed with uhiSolver for a residential block in Vienna. Comparing the simulation results with measurement data collected on site, it is shown that the simplified assumption of homogeneous material data for building bodies provides very good results for the validation case investigated. However, the influence of the greening measures in the courtyard of the residential block on the air temperature is found to be negligible. Furthermore, it was observed that due to locally higher radiation density, lower air velocities and higher air humidity, the apparent temperature in the courtyard is sometimes perceived to be higher than in the adjacent streets, despite the lower air temperature.
Conclusions
Simplifying the modeling process of the uhiSolver software by reducing the model complexity helps to reduce manual work for setting up appropriate boundary conditions of buildings. Compared to market competitors, good results are obtained for the validation case Kandlgasse presented in this research work, despite the simplifications proposed. Thus, uhiSolver can be used as a robust analytical tool for urban planning.
... Four thermal comfort definition models are used to measure comfort level of the living space [92]. A model called apparent temperature (AT) is developed by Steadman [93][94][95][96] and used by Australian Bureau of Meteorology (ABM) [97] for Australian climatic conditions. The model is a combination of solar radiation, wind and heat transfer [92,93]. ...
... A model called apparent temperature (AT) is developed by Steadman [93][94][95][96] and used by Australian Bureau of Meteorology (ABM) [97] for Australian climatic conditions. The model is a combination of solar radiation, wind and heat transfer [92,93]. The model is given as follows: ...
Rapidly increasing construction and agglomeration in urban areas have made the urban heat island (UHI) problem a turning point for the world, as a result of notably rising earth temperature every year. UHI and its impacts on climate are somewhat linked to weather-related matters, natural disasters and disease outbreaks. Given the challenges posed by urbanisation and industrialisation in achieving sustainability, it is crucial to adopt intelligent and decisive measures to mitigate the adverse outcomes of UHI. Greenery surfaces have long been a significant focus of scientific research and policy development, reflecting their pivotal role in combating urban heat islands and promoting sustainable urban environments. This study critically reviews the potential of green infrastructure, including green roofs, facades, shrubs, and trees, so as to minimise UHI impacts in severe urban contexts. By synthesising findings from a wide range of empirical studies, it highlights key outcomes such as reductions in surface temperatures by up to 2 °C and improvements in outdoor thermal comfort indices by over 10 °C under specific conditions. Additionally, the paper introduces a comprehensive framework for integrating greenery systems into urban planning, combining passive cooling, air quality enhancement, and energy efficiency strategies. The findings reveal that extensive green roofs, in particular, are highly effective in reducing indoor cooling demands, while strategically placed trees offer significant shading and evapotranspiration benefits. This work provides actionable insights for policymakers and urban planners to boost sustainable and climate-resilient cities whilst addressing gaps in current research related to the long-term performance and cost-effectiveness of green infrastructure solutions.
... For these daytime data for 11 h, paired two-sample t-tests were performed for each scenario, paired with the control as statistical analysis, and every pair of Most meteorological services, such as Australia, the United Kingdom, New Zealand and the United States, use AT as an index to interpret human comfort and performance. (Steadman 1994) refined AT as an Australian climate index, which combines the effects of temperature and humidity with wind and radiation over a typical, active person (Steadman 1994). Therefore, for an active human, walking at 0.5 m/s in a shady location, Where T a the ambient air temperature in °C P a vapour pressure in ambient conditions in kPa v 10 the wind speed measured 10 m above ground in m/s. ...
... For these daytime data for 11 h, paired two-sample t-tests were performed for each scenario, paired with the control as statistical analysis, and every pair of Most meteorological services, such as Australia, the United Kingdom, New Zealand and the United States, use AT as an index to interpret human comfort and performance. (Steadman 1994) refined AT as an Australian climate index, which combines the effects of temperature and humidity with wind and radiation over a typical, active person (Steadman 1994). Therefore, for an active human, walking at 0.5 m/s in a shady location, Where T a the ambient air temperature in °C P a vapour pressure in ambient conditions in kPa v 10 the wind speed measured 10 m above ground in m/s. ...
Heatwaves pose undesirable consequences to human health as a ‘silent killer’ and penalise the environmental, economic and social aspects. Future heatwaves are predicted to be more severe, longer and more frequent. Over the past decade, Melbourne, Australia, has experienced three notable summer heatwaves. This study presents a simulational experiment in Melbourne’s central business district for the 2014 heatwave, using ‘The Air Pollution Model’, a mesoscale urban climate model. The study evaluated the effectiveness of green and cool roofs as heat mitigation strategies, considering various scenarios that balanced their occupancy on city rooftops, with a maximum 50:50 combination. Temperature data for heatwave days, including average (Tave), maximum (Tmax), and minimum (Tmin) temperatures, were compared to the average seasonal summer temperatures. The results showed that heatwave temperatures exceeded seasonal averages significantly, with Tmax exceeding by 16.1 °C and Tmin and Tave by 5.8 °C and 12.5 °C, respectively. The temperature reduction behaviour of scenarios during heatwaves proved scenario d5 with 25% green roofs and 75% cool roofs with 0.7 albedo to be the best performance for Tmax with the highest reduction. For Tmin and Tave, d8, a scenario with 50:50 green and cool roofs (0.7 albedo) offered the best heat reduction. Moreover, d8 recorded the best reduction for the total average air temperature and apparent temperature, a measurement used to evaluate human thermal comfort. The combined scenarios exhibited complementary cooling potential for multiple heat indices, surpassing the individual effectiveness of either green or cool roofs for heat mitigation in Melbourne. Therefore, wise utilisation of total roof area by integrating both green and cool roofs in urban planning can offer a resource-efficient, cost-effective, and realistic strategy, making them a promising solution for addressing the challenges posed by rising heatwaves in urban areas.
... Two commonly used indices are the Apparent Temperature Index (ATI) and the HUMIDEX index. As reported by Brandani et al. (2016), the ATI considers several factors that influence an individual's perception of weather, including temperature, humidity, wind speed, and the rate at which the human body dissipates heat (Steadman, 1994). By incorporating these elements, the ATI offers a comprehensive and reliable assessment of the impact of temperature on human comfort and health. ...
... ( 2) where T air (°C) is the measured air temperature, V 10 is the wind speed measured at 10 m height (m s −1 ), e is the water vapor pressure (hPa), and Q g is the heat-flow rate per unit area of body surface due to net extra radiation (Steadman, 1994). Q g was computed using the Stefan-Boltzmann law, which states that the radiative heat flux depends on the fourth power of the temperature difference between the body and its surroundings: ...
... Thus, based on emergency visits (EVs) data, our study aims to investigate the exposure-response relationship between temperature and traumatic fractures using a distributed lag nonlinear model (DLNM). Researchers have suggested that raw temperature can be misrepresentative of the true thermal effects in previous studies, because temperature perception is influenced by both actual temperature and other meteorological factors, such as humidity and wind speed [12][13][14]. Therefore, we employed the apparent temperature (AT) that combines ambient temperature, relative humidity, and wind speed as the indicator of heat exposure, which could better reflect the thermal sensations perceived by the human, especially in cities where the humidity is high, such as Hangzhou, China [15]. ...
... cn/). AT was calculated as follows [14]: ...
Background
Traumatic fractures occur frequently worldwide. However, research remains limited on the association between short-term exposure to temperature and traumatic fractures. This study aims to explore the impact of apparent temperature (AT) on emergency visits (EVs) due to traumatic fractures.
Methods
Based on EVs data for traumatic fractures and the contemporary meteorological data, a generalized Poisson regression model along with a distributed lag nonlinear model (DLNM) were undertaken to determine the impact of AT on traumatic fracture EVs. Subgroup analysis by gender and age and sensitivity analysis were also performed.
Results
A total of 25,094 EVs for traumatic fractures were included in the study. We observed a wide “J”-shaped relationship between AT and risk of traumatic fractures, with AT above 9.5 °C positively associated with EVs due to traumatic fractures. The heat effects became significant at cumulative lag 0–11 days, and the relative risk (RR) for moderate heat (95th percentile, 35.7 °C) and extreme heat (99.5th percentile, 38.8 °C) effect was 1.311 (95% CI: 1.132–1.518) and 1.418 (95% CI: 1.191–1.688) at cumulative lag 0–14 days, respectively. The cold effects were consistently non-significant on single or cumulative lag days across 0–14 days. The heat effects were higher among male and those aged 18–65 years old. The sensitivity analysis results remained robust.
Conclusion
Higher AT is associated with cumulative and delayed higher traumatic fracture EVs. The male and those aged 18–65 years are more susceptible to higher AT.
... AT is a calculation that considers 'real-feel' temperature and is an indicator of thermal comfort as well as gives an indication of potential heat-health impacts based on defined thresholds. 16 AT was calculated as follows: ...
... Nevertheless, even with the application of thermal insulation, the reported temperatures remain within the range that poses a high risk of potential health impacts (27°C-32°C). 16 In the Philippines, different types of insulation such as foam and fibreglass batting did not improve the indoor thermal conditions of the shipping containers in a tropical (hot and humid) climate. 8 The marginal enhancement in thermal comfort achieved through the application of closed-cell spray polyurethane may be deemed questionable, especially in light of the associated expense. ...
Background Outdoor and indoor air temperature affects human health and wellbeing. Climate change projections suggest that global temperatures will continue to increase, and this poses a threat to health. Buildings (for housing and business purposes) that can protect humans from the adverse effects of temperature is essential, especially in the context of climate change. Method In this cross-sectional study, we measured indoor temperature inside shipping containers comprising a seven-storey block of apartments and businesses in Johannesburg, South Africa for 14 days. We assessed indoor temperature and relative humidity; evaluated measured temperatures in relation to thresholds known to be associated with adverse health risks; and sought to understand heat-health perceptions and symptoms of people living and working in shipping container units. Results Median indoor apparent temperature (AT) (a combination of temperature and relative humidity) was 16 °C with values ranging from 6 °C (observed at 8:00) to 42 °C (observed at 17:00). Insulated units had temperatures between 2°C and 9°C cooler than the uninsulated unit. Heat-health risks from AT exposure were likely in all units, although there was variation in the number of occurrences that AT measurements exceeded the four symptom bands of caution, extreme caution, danger and extreme danger. Some participants believed that their units were hot during hot weather and most people opened windows or did nothing during hot weather. Few participants reported experiencing adverse heat-health impacts, except for experiencing headaches (58%) and feeling tired or weak (40%). Conclusion Residents, tenants, or business owners using shipping containers should consider insulation installation and adequate windows/air conditioning for ventilation, especially in hot climates. Further research and awareness regarding heat-health risks of living or working in these spaces is needed.
... In addition, since ambient temperature may not accurately describe the body's perception of outdoor temperature, Steadman (Steadman 1994) introduced apparent temperature (AT) in 1984, a composite biometeorological index that includes ambient temperature, wind speed, and relative humidity, which was believed to be a more objective indicator of the human body's thermal experiences than ambient temperature alone. A growing number of scientists have focused on the impact of different AT exposure during pregnancy on children's health. ...
... In particular, exposure levels to meteorological factors are strongly influenced by monitoring concentrations from nearby monitoring stations, but less influenced by monitoring concentrations from remote monitoring stations (Rivera-González et al. 1995). Then, the AT (°C) was calculated from the ambient temperature, relative humidity, and relative wind speed by the following equations (Steadman 1994): ...
The objective of this study was to explore the impact of maternal AT during pregnancy on childhood asthma and wheezing, as well as the potential effect modifiers in this association. A cross-sectional study was implemented from December 2018 to March 2019 in Jinan to investigate the prevalence of childhood asthma and wheezing among aged 18 months to 3 years. Then, we conducted a case-control study based on population to explore the association between prenatal different AT exposure levels and childhood asthma and wheezing. The association was assessed by generalized additive models and logistic regression models, and stratified analyses were performed to explore potential effect modifiers. A total of 12,384 vaccinated children participated in screening for asthma and wheezing, 236 cases were screened, as well as 1445 controls were randomized. After adjusting for the covariates, childhood asthma and wheezing were significantly associated with cold exposure in the first trimester, with OR 1.731 (95% CI: 1.117–2.628), and cold exposure and heat exposure in the third trimester, with ORs 1.610 (95% CI: 1.030–2.473) and 2.039 (95% CI: 1.343–3.048). In the third trimester, enhanced impacts were found among girls, children whose distance of residence was close to the nearest main traffic road, and children whose parents have asthma. The study indicates that exposure to extreme AT during the first and third trimesters could increase the risk of childhood asthma and wheezing.
... The model assumes that the temperature is experienced outdoors but not in direct sunlight (Buzan et al., 2015). Although radiation is sometimes included in these calculations, we used the non-radiant version for our analysis, following the methodology by Steadman (1994). These calculations are performed using the apparentTemp function in the R package HeatStress (Casanueva, 2019). ...
International databases of disaster impacts are crucial for advancing disaster risk research, particularly as climate change intensifies the frequency and intensity of many natural hazards – including temperature extremes. However, many widely-used disaster impact databases lack information on the physical dimension of the hazards associated with an impact, and on the exposure to such hazards. This hinders analysing drivers of severe disaster outcomes. To bridge this knowledge gap, we present SHEDIS-Temperature, a dataset that provides Subnational Hazard and Exposure information for temperature-related DISaster impact records (https://doi.org/10.7910/DVN/WNOTTC; Lindersson and Messori, 2025). This open-access dataset links temperature-related impact records from the Emergency Events Database (EM-DAT) with subnational data on their locations, associated meteorological time series, and population maps. SHEDIS-Temperature provides hazard and exposure data for 2,835 subnational locations associated with 382 disaster records from 1979 to 2018 in 71 countries. Detailed hazard metrics, derived from 0.1° 3-hourly data, encompass absolute indicators, such as the heat stress measure apparent temperature accounting for humidity and wind speed, as well as percentile-based indicators of when and where temperatures exceeded local thresholds. Population exposure data include annual population figures for impacted subnational administrative units and person-days of exposure to threshold-exceeding temperatures. Outputs are available at grid-point level as well as zonally aggregated to administrative subdivision units, and disaster-record levels. By providing comprehensive attributes across the hazard-exposure spectrum, SHEDIS-Temperature supports interdisciplinary research on past temperature-related disasters, offering valuable insights for future risk mitigation and resilience strategies.
... In addition to evaluating a single indicator, there have also been studies on evaluating heat stress through a combination of multiple indicators. Oleson et al. (2013) evaluated the future relationship between urbanization and multiple heat stress indicators, including Heat Index (HI) (Rothfusz 1990), Apparent Temperature (AT) (Steadman 1994), Simplified Wet Bulb Globe Temperature (sWBGT) (Willett and Sherwood 2012), Humidex (Masterson and Richardson 1979) and Discomfort Index (DI) (Epstein and Moran 2006), which found that AT, HI and Humidex amplified the heat stress of future cities by 0.5-1.0 °C compared with temperature alone. ...
In this study, the fifth generation ECMWF reanalysis (ERA5) reanalysis datasets and three global climate models (GCMs) were selected as the inputs of the stepwise-clustered heat stress downscaling (SCHSD) method to simulate the future heat stress indices in East China. The heat stress indices included the Heat Index (HI), Humidex (HUMIDEX) and the simplified Wet Bulb Globe Temperature (sWBGT). Three GCMs (i.e., CanESM5, INM-CM4-8 and MPI-ESM1-2-HR) under two Shared Socioeconomic Pathway (SSP245 and SSP585) were input into the SCHSD model to develop downscaled climate projections. To verify the SCHSD model, the reproduction results from three GCMs during the period of 1990–2014 were compared to daily observational data (i.e., HI, HUMIDEX and sWBGT). The verification results suggest that the coefficient of determination (R²) of the stations in the northern part of East China mostly exceeds 0.8, while the R² of the stations in the southern part of East China is mostly in the range of 0.6 to 0.8. The projection results suggest that the future heat stress in East China would generally maintain an upward trend from 2021 to 2100. The largest change in heat stress is projected in June under the period of 2021–2100. The results also show that the highest average of days in the danger category is 78.9 in summer under the SSP585 scenario, accounting for 86% of the total summer (June, July and August).
... Hence, the convergence of heat and humidity stands as the paramount factor of significance (Sherwood & Huber, 2010). The wetbulb temperature (Twb) accounts for the impact of both temperature and humidity on heat stress, thus highlighting the role of moisture in augmenting the perceived temperature, creating a hotter sensation than the actual reading (Steadman, 1994). According to Sherwood and Huber (2010), heat stress imposes a threshold on the extent of global warming that humans can adapt to. ...
Nights with high temperatures and humidity often bring more fatal consequences during the human sleeping process. A significantly increasing trend in the intensity and frequency of humid‐heat nights has been observed in eastern China from 1961 to 2014. Detection analyses show that the fingerprinting of anthropogenic forcing, in which the greenhouse gas forcing is critical, can be identified for changes in the humid‐heat nights in eastern China. However, the roles of anthropogenic aerosols and external natural forcings cannot be detected, and their effects on the observed changes in humid‐heat nights over eastern China are generally negligible. Under different warming scenarios, there is a projected continuation of increasing intensity and frequency of humid‐heat nights, although the magnitudes are reduced after constraining. In eastern China, the areal mean intensity of humid‐heat nights is projected to increase by approximately 0.9, 1.5, 2.5, and 3.5°C (relative to 1995–2014) for 1.5, 2.0, 3.0, and 4.0°C global warming, while the occurrence of extreme humid‐heat night is 1.1, 1.2, 1.2, and 1.3 times more than the current period. Moreover, the population exposed to humid‐heat nights in eastern China, particularly in the northern regions, is expected to increase in the future. Our results enhance the understanding of the potential risks of humid‐heat nights, which is critical for climate‐change policy in China.
... In this paper, the evaporation from the free surface flow of water channels inside alleyways with varied aspect ratios (AR) is numerically simulated using the CFD approach and the volume of fluid (VOF) methodology to simulate free surface flow. Thermal comfort was predicted using Steadman's apparent temperature equation (Steadman 1994). The lowest apparent temperature was found in the deep alleyways, and the difference between shallow and deep alleyways can reach 1.2 o C. Increasing the wind speed from 1 to 10 m/s decreased the apparent temperature by 5 o C. The relative humidity in deep alleyways is higher than in shallow ones with a difference of around 2%. ...
The impact of an alleyway's aspect ratio on pedestrian thermal comfort has been extensively studied worldwide. However, there is a lack of research on the impact of water channels within an alleyway on thermal comfort. Several traditional villages in hot and arid areas have water channels that can lower temperatures through evaporative cooling while raising relative humidity, which influences thermal comfort negatively. Conducting research is necessary to understand such cases. In this paper, the evaporation from the free surface flow of water channels inside alleyways with varied aspect ratios (AR) is numerically simulated using the CFD approach and the volume of fluid (VOF) methodology to simulate free surface flow. Thermal comfort was predicted using Steadman's apparent temperature equation (Steadman 1994). The lowest apparent temperature was found in the deep alleyways, and the difference between shallow and deep alleyways can reach 1.2 o C. Increasing the wind speed from 1 to 10 m/s decreased the apparent temperature by 5 o C. The relative humidity in deep alleyways is higher than in shallow ones with a difference of around 2%. The drop in air temperature due to evaporative cooling was evident in all cases, but the highest drop was in deep alleyways (5 o C) compared to shallow alleyways (3 o C). It is concluded that despite the higher relative humidity, the deep alleyways are more suitable for urban fabrics under hot and arid conditions due to the lower apparent temperatures.
... The most frequently used metric in thermal comfort and environmental health studies is the apparent temperature parameter. In order to calculate the apparent temperature, Steadman developed a set of equations that took into account a number of variables, including air temperature, radiation, wind speed, vapor pressure, and the heat resistance of clothing and skin; then standardized these equations by making specific assumptions about personal circumstances in order to calculate them using only meteorological variables (Steadman 1994). Since the radiation was not measured within the study area, the approach using temperature, vapor pressure and wind speed was adopted, other AT formulas from the same study can be found in the Supplementary Material file. ...
Thermal indices and thermal comfort maps have great importance in developing health-minded climate action strategies and livable urban layouts. Especially in cities where vulnerability to heatwaves is high, it is necessary to detect the most appropriate indicators for the regional characteristics and action planning with respect to thermal comfort. The aim of the study is to examine thermal indices as indicators of regional climate characteristics by relating to meteorological parameters and spatial features. Atmospheric variables including air temperature, wind speed, cloud cover, and relative humidity data were obtained from 30 meteorological stations located in districts having different climatic features. Heat stress levels for apparent temperature (AT), heat index (HI), wet bulb globe temperature (WBGT), physiological equivalent temperature (PET), universal thermal climate index (UTCI), and perceived temperature (PT) indices were calculated and associated with meteorological parameters. Thermal comfort maps have been created with the daily mean and maximum values of all indices. As a result, the meteorological parameters with the strongest correlation with all thermal indices are air temperature (T a ) with r = 0.89 ± 0.01 and mean radiant temperature (T mrt ) with r = 0.75 ± 0.16. The differences in thermal stress levels over the city have been distinctively observed in the AT max , PET max , and PT max maps, which are generated by the daily maximum values of the indices. Çatalca, where forests cover large areas compared to highly urbanized districts, has the lowest heat stress defined by all indices.
... TSA R and TG R come from fraction-weighted corresponding variables in vegetated and crop fractions. Urban heat stress is assessed by a set of human-related indices , including the 2-m US National Weather Service Heat Index (NWS HI) (Steadman, 1979), 2-m apparent temperature (AT) (Steadman, 1994), ...
Increasing the albedo of urban surfaces, through strategies like white roof installations, has emerged as a promising approach for urban climate adaptation. Yet, modelling these strategies on a large scale is limited by the use of static urban surface albedo representations in the Earth system models. In this study, we developed a new transient urban surface albedo scheme in the Community Earth System Model and evaluated evolving adaptation strategies under varying urban surface albedo configurations. Our simulations model a gradual increase in the urban surface albedo of roofs, impervious roads, and walls from 2015 to 2099 under the SSP3-7.0 scenario. Results highlight the cooling effects of roof albedo modifications, which reduce the annual mean canopy urban heat island from 0.8°C in 2015 to 0.2°C by 2099. Compared to high-density and mid-density areas, higher albedo configurations are more effective in cooling environments within tall building districts. Additionally, urban surface albedo changes lead to changes in building energy consumption, where high albedo results in more indoor heating usage in urban areas located beyond 30°N and 25°S. The scheme developed in this study offers potential for non-policy applications, like simulating natural albedo variations across urban surfaces, and enables the inclusion of other urban canopy parameters, such as surface emissivity.
... AT was different from ambient temperature and was the comprehensive exposure metric of temperature. It was evaluated based on T mean (°C), RH (%), and WS (m/s) by the following formulas [24]: Such that T mean is mean ambient temperature; e represents water vapor pressure (hpa), which can be evaluated by Eq. (b). ...
Background: Non-optimum temperatures are associated with increased risk of respiratory diseases, but the effects of apparent temperature (AT) on respiratory diseases remain to be investigated.
Methods: Using daily data from 2016 to 2020 in Ganzhou, a large city in southern China, we analyzed the impact of AT on outpatient and inpatient visits for respiratory diseases. We considered total respiratory diseases and five subtypes (influenza and pneumonia, upper respiratory tract infection (URTI), lower respiratory tract infection (LRTI), asthma and chronic obstructive pulmonary disease [COPD]). Our analysis employed a distributed lag nonlinear model (DLNM) combined with a generalized additive model (GAM).
Results: We recorded 94,952 outpatients and 72,410 inpatients for respiratory diseases. We found AT significantly non-linearly associated with daily outpatient and inpatient visits for total respiratory diseases, influenza and pneumonia, and URTI, primarily during comfortable AT levels, while it was exclusively related with daily inpatient visits for LRTI and COPD. Moderate heat (32.1 °C, the 75.0th centile) was observed with a significant effect on both daily outpatient and inpatient visits for total respiratory diseases at a relative risk of 1.561 (1.161, 2.098) and 1.276 (1.027, 1.585), respectively (both P < 0.05), while the results of inpatients became insignificant with the adjustment for CO and O3. The attributable fractions in outpatients and inpatients were as follows: total respiratory diseases (24.43% and 18.69%), influenza and pneumonia (31.54% and 17.33%), URTI (23.03% and 32.91%), LRTI (37.49% and 30.00%), asthma (9.83% and 3.39%), and COPD (30.67% and 10.65%). Stratified analyses showed that children ≤5 years old were more susceptible to moderate heat than older participants.
Conclusions: In conclusion, our results indicated moderate heat increase the risk of daily outpatient and inpatient visits for respiratory diseases, especially among children under the age of 5.
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... 1g-l). Apparent temperature, calculated from dry-bulb temperature, relative humidity, and wind speed (excluding net radiation), is an estimate of the feel-like temperature in adults calculated from theSteadman (1994) model.To assess the robustness of AGCD observations, we calculate the heat indices using SILO data together with the 2-m observational winds(Sharples and Baron-Hay 2023) over the same 1990-2017 climatological period(supplemental Figs. 2). In general, both the HLI and CCI values are higher in SILO than for AGCD across the wet season. ...
Exposure to weather extremes, such as heatwaves, can cause discomfort, harm, or death in grazing cattle in pastures. While the Australian Bureau of Meteorology issues sheep graziers alerts when there is an exposure risk to chill for livestock, there is no equivalent alert for heat stress for Australian cattle. Before any such alert system can be developed, a robust assessment and comparison of relevant cattle thermal stress indices is required. This study evaluates and compares the multiyear climatology of three cattle thermal heat stress indices across Australia in the warm season months (October–March). The same indices are then used to assess historical Australian heat events where cattle died from heat exposure. These events are based off official records and survey responses from northern Australian graziers. In the seven historical heat events studied, high relative humidity combined with low wind speeds, or high solar exposure combined with high surface temperatures, exacerbated the impact of heat stress on cattle. In the two historic events where multiple compounding weather factors combined (e.g., high humidity, low winds, and high solar exposure), the cattle mortality levels were significantly high. These events were characterized by rainy conditions followed by a rapid warming, meaning cattle were likely unable to acclimatize to such dramatic temperature changes. This study highlights the need for using more than one thermal stress index when verifying cattle heat stress events and, importantly, calls for further research on standardizing the risk classifications of these thermal indices for cattle in Australia’s variable climate.
Significance Statement
Cattle across Australia’s northern tropical and semiarid regions often experience extreme hot and humid conditions in the summer months, which increases the risk of heat stress. This is the first study of its kind to evaluate observations of cattle heat stress across Australia using indices that describe the combined effects of solar exposure, wind speed, relative humidity, and surface temperatures. These cattle heat stress indices can be used to evaluate historical cattle mortality events in feedlots and in grazed pastures. This study lays the groundwork for the development of Australian-wide cattle heat stress forecast products on the 7-day to multiweek time scales.
... 9,16,17 From the China Meteorological Administration Land Data Assimilation System (CLDAS version 2.0), we extracted grid data (spatial resolution of 0.0625°× 0.0625°) on daily 24 h mean air temperature (°C), specific humidity (kg/kg), surface pressure (mb), and wind speed (m/s), and retrieved daily 24 h mean relative humidity (%) in Jiangsu province, China during 2015−2021. 18 For each day in 2015−2021, we used daily 24 h mean air temperature (T), specific humidity (q), wind speed (w), and surface pressure (p) to calculate daily 24 h mean apparent temperature (°C; AT) by the following formula, 19,20 and built a corresponding grid data set. ...
... Wang et al., 2021). There are various approaches to estimating how the weather conditions affect comfort, but apparent temperature is governed by air temperature, humidity, and wind speed (Steadman, 1984(Steadman, , 1994. These are known empirically to affect human thermal comfort (Jacobs et al., 2013), and thresholds have been designed to indicate danger and health risks under extreme heat events (Ho et al., 2016). ...
Apparent temperature (AP) and ground-level aerosol pollution (PM2.5) are important factors in human health, particularly in rapidly growing urban centers in the developing world. We quantify how changes in apparent temperature – that is, a combination of 2 m air temperature, relative humidity, surface wind speed, and PM2.5 concentrations – that depend on the same meteorological factors along with future industrial emission policy may impact people in the greater Beijing region. Four Earth system model (ESM) simulations of the modest greenhouse emissions RCP4.5 (Representative Concentration Pathway), the “business-as-usual” RCP8.5, and the stratospheric aerosol intervention G4 geoengineering scenarios are downscaled using both a 10 km resolution dynamic model (Weather Research and Forecasting, WRF) and a statistical approach (Inter-Sectoral Impact Model Intercomparison Project – ISIMIP). We use multiple linear regression models to simulate changes in PM2.5 and the contributions meteorological factors make in controlling seasonal AP and PM2.5. WRF produces warmer winters and cooler summers than ISIMIP both now and in the future. These differences mean that estimates of numbers of days with extreme apparent temperatures vary systematically with downscaling method, as well as between climate models and scenarios. Air temperature changes dominate differences in apparent temperatures between future scenarios even more than they do at present because the reductions in humidity expected under solar geoengineering are overwhelmed by rising vapor pressure due to rising temperatures and the lower wind speeds expected in the region in all future scenarios. Compared with the 2010s, the PM2.5 concentration is projected to decrease by 5.4 µg m-3 in the Beijing–Tianjin province under the G4 scenario during the 2060s from the WRF downscaling but decrease by 7.6 µg m-3 using ISIMIP. The relative risk of five diseases decreases by 1.1 %–6.7 % in G4, RCP4.5, and RCP8.5 using ISIMIP but has a smaller decrease (0.7 %–5.2 %) using WRF. Temperature and humidity differences between scenarios change the relative risk of disease from PM2.5 such that G4 results in 1 %–3 % higher health risks than RCP4.5. Urban centers see larger rises in extreme apparent temperatures than rural surroundings due to differences in land surface type, and since these are also the most densely populated, health impacts will be dominated by the larger rises in apparent temperatures in these urban areas.
... , v is the wind speed at 10 m height (m/s) and p v is the vapour pressure of air (hPa) and can be computed from Equation (2.33) [91]. ...
... , v is the wind speed at 10 m height (m/s) and p v is the vapour pressure of air (hPa) and can be computed from Equation (2.33) [91]. ...
... , v is the wind speed at 10 m height (m/s) and p v is the vapour pressure of air (hPa) and can be computed from Equation (2.33) [91]. ...
... , v is the wind speed at 10 m height (m/s) and p v is the vapour pressure of air (hPa) and can be computed from Equation (2.33) [91]. ...
... , v is the wind speed at 10 m height (m/s) and p v is the vapour pressure of air (hPa) and can be computed from Equation (2.33) [91]. ...
... Second, soil moisture-heat stress coupling is expected to depend on the adopted heat stress metrics (Mishra et al. 2020) since different metrics weight humidity differently (Sherwood 2018;Buzan and Huber 2020). Compared with other commonly used heat stress metrics such as apparent temperature (Steadman 1984(Steadman , 1994, heat index (Lans P. Rothfusz 1990;Steadman 1979), and WBGT (Yaglou and Minard 1957), is heavily humidity-weighted (Sherwood 2018) which may favor a positive soil moisture-heat stress coupling. To provide a baseline for comparison, we calculate the coupling sensitivity index between soil moisture and heat index (Fig. S6) which places much less weight on humidity compared with (Buzan et al. 2015). ...
Human heat stress depends jointly on atmospheric temperature and humidity. Wetter soils reduce temperature but also raise humidity, making the collective impact on heat stress unclear. To better understand these interactions, we use ERA5 to examine the coupling between daily average soil moisture and wet-bulb temperature ( T w ) and its seasonal and diurnal cycle at global scale. We identify a global soil moisture– T w coupling pattern with both widespread negative and positive correlations in contrast to the well-established cooling effect of wet soil on dry-bulb temperature. Regions showing positive correlations closely resemble previously identified land–atmosphere coupling hotspots where soil moisture effectively controls surface energy partition. Soil moisture– T w coupling varies seasonally closely tied to monsoon development, and the positive coupling is slightly stronger and more widespread during nighttime. Local-scale analysis demonstrates a nonlinear structure of soil moisture– T w coupling with stronger coupling under relatively dry soils. Hot days with high T w values show wetter-than-normal soil, anomalous high latent and low sensible heat flux from a cooler surface, and a shallower boundary layer. This supports the hypothesis that wetter soil increases T w by concentrating surface moist enthalpy flux within a shallower boundary layer and reducing free-troposphere-air entrainment. We identify areas of particular interest for future studies on the physical mechanisms of soil moisture–heat stress coupling. Our findings suggest that increasing soil moisture might amplify heat stress over large portions of the world including several densely populated areas. These results also raise questions about the effectiveness of evaporative cooling strategies in ameliorating urban heat stress.
Significance Statement
The purpose of this study is to provide a global picture of the relationship between soil moisture anomalies and a heat stress metric that includes the joint effects of temperature and humidity. This is important because a better understanding of this relationship will help improve the prediction of extreme heat stress events and inform strategies for ameliorating heat stress. We find a widespread positive correlation between soil moisture and heat stress, in contrast to studies relying on temperature alone. This raises the possibility that, over much of the world, and in the most populous regions, strategies like irrigation or “greening” that can reduce temperature might be ineffective or even harmful in reducing heat stress with humidity incorporated.
... For calculation of AT, a series of equations developed by considering factors such as dry bulb temperature, radiation, wind speed, vapor pressure, heat resistance of clothing and skin were standardized and Eq. (1) was created (Steadman, 1994). Hourly vapor pressure values were calculated using Eq. ...
Understanding heatwave characteristics is crucial for mitigating their adverse effects in ˙
Istanbul, a densely
populated metropolis characterized by a high concentration of buildings, concrete structures, and limited green
spaces. This study aims to develop a methodology for defining heatwaves by identifying appropriate thermal
indicators. Utilizing the Distributed Lag Nonlinear Model (DLNM), this research investigates the complex and
delayed effects of daily mean, maximum, and minimum temperatures, along with seven thermal indices, on daily
mortality rates during the summer months of 2013–2017, leveraging the DLNM approach’s flexibility in
modeling the nonlinear exposure-response relationships. Heatwaves are defined based on the Minimum Mortality Temperature (MMT) and 90th percentile thresholds, and heatwave maps are constructed by their frequency, intensity, duration, and cumulative intensity characteristics. PETmean emerges as the optimal thermal
index, exhibiting the lowest Akaike’s Information Criteria (AIC: 3553) and estimates relative risk (RR) of 1.080
(95% CI: 1.051–1.110) for a 1◦C increase above the 90th percentile. Additionally, Tmean, Tmax, PETmax, and
Tmrtmean indices demonstrate favorable characteristics, with low AIC values and high RR estimates. Notably,
heatwaves are intense and frequent in Çatalca despite low urban land use and abundant forests, but their
duration was short due to fast adaptation capability of the region.
... Nowadays more and more researches are focusing on the climatogenic determinism of desti nation choice and the climatic attractiveness of major tourist areas (Hamilton and Lau, 2005;Maddison, 2001;Lise and Tol, 2002;Scott and Lemieux, 2010). An important place is occupied by works on studying the experience and results of research on the meteorological factor and its parameters from the standpoint of assessing the tourist and recreational potential of various territories, the comfort of the natural landscape environment (Steadman, 1979a(Steadman, , 1979b(Steadman, , 1994. ...
The purpose of the research was to assess the degree of favorableness of the bioclimatic conditions of the territory of
Northern Kazakhstan by calculating the tourist climate index (TCI) and analyzing its spatial and temporal variability. Archival,
stock materials and data on the main meteorological and climatic indicators for 63 weather stations for the period 1966–2020
were used. The study used methods of mathematical and statistical analysis, GIS technologies. The level of climatic
attractiveness varies from "very unfavorable" in the winter months to "comfortable" in the summer. It was determined that the
territory of Northern Kazakhstan as a whole is relatively homogeneous in terms of the average annual TCI index (28-38).
Depending on the values of the index, 5 categories of climatic attractiveness of the territory of Northern Kazakhstan were
identified (comfortable, moderate, neutral, unfavorable, extremely unfavorable). The most favorable conditions for tourist and
recreational activities are formed in the summer months in the northeastern and southwestern sectors of the region.
Recommendations are given on the spatial placement of tourist and recreational facilities and types of tourist activities in
Northern Kazakhstan, taking into account the favorable weather and climatic conditions.
... Average temperature ( o C) was calculated as the mean of maximum and minimum temperatures. Apparent temperature ( o C) was calculated using the Steadman formula [33] incorporating average temperature, humidity, wind speed and atmospheric pressure (hPa). ...
Abstract Background Weather is a potentially important influence on how time is allocated to sleep, sedentary behaviour and physical activity across the 24-h day. Extremes of weather (very hot, cold, windy or wet) can create undesirable, unsafe outdoor environments for exercise or active transport, impact the comfort of sleeping environments, and increase time indoors. This 13-month prospective cohort study explored associations between weather and 24-h movement behaviour patterns. Methods Three hundred sixty-eight adults (mean age 40.2 years, SD 5.9, 56.8% female) from Adelaide, Australia, wore Fitbit Charge 3 activity trackers 24 h a day for 13 months with minute-by-minute data on sleep, sedentary behaviour, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) collected remotely. Daily weather data included temperature, rainfall, wind, cloud and sunshine. Multi-level mixed-effects linear regression analyses (one model per outcome) were used. Results Ninety thousand eight hundred one days of data were analysed. Sleep was negatively associated with minimum temperature (-12 min/day change across minimum temperature range of 31.2 °C, p = 0.001). Sedentary behaviour was positively associated with minimum temperature (+ 12 min/day, range = 31.2 oC, p = 0.006) and wind speed (+ 10 min/day, range = 36.7 km/h, p
... We chose to use T app as the main exposure variable of interest as it also accounts for the effect of RH and vapour pressure (hPa) along with temperature, thereby better capturing the physiologically 'felt' exposure. An average T app for Puducherry was calculated by combining individual station data with the Steadman's equation [30],as follows: ...
Background
Cardiovascular diseases (CVDs), the leading cause of death worldwide, are sensitive to temperature. In light of the reported climate change trends, it is important to understand the burden of CVDs attributable to temperature, both hot and cold. The association between CVDs and temperature is region-specific, with relatively few studies focusing on low-and middle-income countries. This study investigates this association in Puducherry, a district in southern India lying on the Bay of Bengal, for the first time.
Methods
Using in-hospital CVD mortality data and climate data from the Indian Meteorological Department, we analyzed the association between apparent temperature (Tapp) and in-hospital CVD mortalities in Puducherry between 2011 and 2020. We used a case-crossover model with a binomial likelihood distribution combined with a distributed lag non-linear model to capture the delayed and non-linear trends over a 21-day lag period to identify the optimal temperature range for Puducherry. The results are expressed as the fraction of CVD mortalities attributable to heat and cold, defined relative to the optimal temperature. We also performed stratified analyses to explore the associations between Tapp and age-and-sex, grouped and considered together, and different types of CVDs. Sensitivity analyses were performed, including using a quasi-Poisson time-series approach.
Results
We found that the optimal temperature range for Puducherry is between 30°C and 36°C with respect to CVDs. Both cold and hot non-optimal Tapp were associated with an increased risk of overall in-hospital CVD mortalities, resulting in a U-shaped association curve. Cumulatively, up to 17% of the CVD deaths could be attributable to non-optimal temperatures, with a slightly higher burden attributable to heat (9.1%) than cold (8.3%). We also found that males were more vulnerable to colder temperature; females above 60 years were more vulnerable to heat while females below 60 years were affected by both heat and cold. Mortality with cerebrovascular accidents was associated more with heat compared to cold, while ischemic heart diseases did not seem to be affected by temperature.
Conclusion
Both heat and cold contribute to the burden of CVDs attributable to non-optimal temperatures in the tropical Puducherry. Our study also identified the age-and-sex and CVD type differences in temperature attributable CVD mortalities. Further studies from India could identify regional associations, inform our understanding of the health implications of climate change in India and enhance the development of regional and contextual climate-health action-plans.
... For thermal comfort comparison, the apparent temperature analysis is used. The apparent temperature (AT) is the temperature perceived by the human body from the combined effects of ambient temperature, wind speed, humidity and solar radiation more objectively reflecting the thermal sensations experienced by the human body than temperature alone, especially in highly humid environments [17,18]. The apparent temperature (AT) is a suitable comfort index for climates with high temperatures and humidity. ...
Prior to COVID-19, densely occupied areas were already suspected of making employees sick. Post-COVID-19, there is an urgent need to improve air quality and ventilation standards shall change. However, any changes to ventilation must consider other negative consequences including energy and health and well-being impacts from thermal discomfort and exposure to pollutants. The need for moving away from traditional energy sources and to find alternate energy sources is undoubtedly one of the primary objectives for a sustainable progress to humankind. The design and construction of buildings in hot-humid climates requires high energy consumption typically for air conditioning due to higher thermal loads. A further increase in ventilation rates will have intensive impact in energy consumption and infrastructure loads. This chapter presents the performance of an innovative fully integrated smart ventilation system with low energy consumption. It is all in one ventilating and air conditioning system that provides efficient, cost-effective, and sustainable cooled fresh air for open or enclosed spaces whilst achieving thermal comfort. Based on the application, it consists of multistages that can dehumidify and cool the air to the required comfort level. The system has shown 50–60% reduction in energy consumption compared with conventional systems.
... The emission of thermal radiation in the infrared spectral region is caused by the formation of atoms forming the body at temperatures above absolute zero and returning to the non-excited state, which causes electromagnetic radiation to be emitted in the infrared region. Where the atoms are in the state of continuous excitation to the high levels of the excited level and then return to the level of ground energy state [2][3][4]. Figure 1 shows the structure of electromagnetic rays and its section. The rest of the paper is organized as follows. ...
... Apparent temperature uses Ta, Ur, e and air flow (ws) as parameters (Steadman 1994 ...
Globally extreme weather events are experienced most acutely in cities. While formal settlements can respond to such events, informal settlements are often vulnerable and ill-prepared. Sub-Saharan Africa is rapidly urbanising with informal settlements that require effective climate change adaptation measures. Two climate adaptation strategies for informal dwellings are considered for their success under 2100 Intergovernmental Panel on Climate Change (IPCC) climate scenarios. Using existing data collected from informal dwellings in South Africa, the findings from a digital simulation study reveal that cool roof paints can currently lower excessive heat stress conditions by 42–63% when applied to high thermal mass dwellings with poorly insulated lightweight corrugated sheeting roofing. However, for the future 2100 climate scenarios this strategy only lowers excessive heat stress conditions by 12–17%. This calls for the development of integrated multifaceted heat stress adaptation strategies for informal settlements in Sub-Saharan Africa. 'Practice relevance' This study assessed heat stress conditions and the application of two financially and practically feasible heat stress adaptation strategies in informal dwellings in South Africa. This involved assessing the efficacy of using cool roof paints and improved thermal insulation under current and future climate change-affected conditions. The findings reveal that Southern African informal dwellings experience extreme heat stress 32% of the time. Predicted climate change-affected conditions will increase heat stress exposure up to 40% over a full year. The study reveals that cool roof paints can improve the performance of uninsulated, low thermal mass homes in temperate climates by lowering heat stress conditions by 42–63%, yet this climate change adaptation strategy is only an interim solution with limited success (12–17% improvement) under future 2100 climate change-affected conditions. As a result multilayered integrated heat amelioration strategies are needed in informal communities.
... T app , a metric that combines temperature and relative humidity, was chosen as the exposure variable, as it ought to represent the 'real-feel' of temperature. T app was calculated using the Steadman equation shown below, where hPa is the vapour pressure [46]. [47], we conducted a time-series analysis to quantify the short-term association between T app and the proportion of admissions due to CVDs. ...
Cardiovascular diseases (CVDs) have a high disease burden both globally and in South Africa. They have also been found to be temperature-sensitive globally. The association between temperature and CVD morbidity has previously been demonstrated, but little is known about it in South Africa. It is important to understand how changes in temperature in South Africa will affect CVD morbidity, especially in rural regions, to inform public health interventions and adaptation strategies. This study aimed to determine the short-term effect of apparent temperature (Tapp) on CVD hospital admissions in Mopani District, Limpopo province, South Africa. A total of 3124 CVD hospital admissions records were obtained from two hospitals from 1 June 2009 to 31 December 2016. Daily Tapp was calculated using nearby weather station measurements. The association was modelled using a distributed lag non-linear model with a negative binomial regression over a 21-day lag period. The fraction of morbidity attributable to non-optimal Tapp, i.e., cold (6–25 °C) and warm (27–32 °C) Tapp was reported. We found an increase in the proportion of admissions due to CVDs for warm and cold Tapp cumulatively over 21 days. Increasing CVD admissions due to warm Tapp appeared immediately and lasted for two to four days, whereas the lag-structure for the cold effect was inconsistent. A proportion of 8.5% (95% Confidence Interval (CI): 3.1%, 13.7%) and 1.1% (95% CI: −1.4%, 3.5%) of the total CVD admissions was attributable to cold and warm temperatures, respectively. Warm and cold Tapp may increase CVD admissions, suggesting that the healthcare system and community need to be prepared in the context of global temperature changes.
... of monitoring stations was relatively concentrated (Fig. 1). The individual exposure level of 3 meteorological factors was calculated based on the daily average value, as well as the dates of conception and delivery. Then, the AT (°C) was calculated from the ambient temperature, relative humidity, and relative wind speed by the following equations (Steadman. 1994): ...
The objective of this study was to explore the impact of maternal AT during pregnancy on childhood asthma and wheezing, as well as the potential effect modifiers in this association. A cross-sectional study was implemented from December 2018 to March 2019 in Jinan to investigate the prevalence of childhood asthma and wheezing among aged 18 months to 3 years. Then, we conducted a case-control study based on population to explore the association between prenatal different AT exposure levels and childhood asthma and wheezing. The association was assessed by generalized additive model and logistic regression model, and stratified analyses were performed to explore potential effect modifiers. A total of 12,384 vaccinated children participated in screening for asthma and wheezing, and 236 cases were screened, as well as 1445 controls were randomized. After adjusting for the covariates, childhood asthma and wheezing was significantly associated with cold exposure in the first trimester, with OR 1.750 (95% CI: 1.145–2.673), and cold exposure and heat exposure in the third trimester, with ORs 1.583 (95% CI: 1.013–2.474) and 2.124 (95% CI: 1.415–3.188). In the third trimester, enhanced impacts were found among girls, children whose distance of residence was close to the nearest main traffic road, children whose mothers never had vitamin D supplementation, and children whose parents have asthma. The study indicates that exposure to extreme AT during the first trimester and the third trimester could increase the risk of childhood asthma and wheezing.
The urban overheating phenomenon, induced by both global warming and the urban heat island (UHI) effect, has been exacerbated by worsened urban wind environments. Urban lakes may aid in mitigating urban overheating through the process of lake breeze circulation (LBC). In this study, we developed a multi-scale water-energy coupled CFD model to simulate the transport of heat and moisture between lake surfaces and built-up areas and to resolve dynamics of atmospheric temperature, humidity, and wind at both street canyon scale (1m) and city scale (50km) with relatively low computational costs. Based on this model, we conducted sensitivity analyses to study the impact of urban, lake, and atmospheric parameters on thermal comfort conditions in the city. Our results show that the cooling capacity of LBC is more evident in hotter and denser cities. Furthermore, in the process of urban expansion, horizontal sprawl (i.e., increasing city size) is more advantageous than vertical growth (i.e., increasing building height) and infilling growth (i.e., increasing building density), considering the cooling potential of LBC. Our results can provide significant references for urban planning and city design for the sake of the mitigation of urban overheating via lake breezes.
In this paper we present a dataset that contains daily mean, maximum and minimum values of 12 heat stress indices averaged over Greek communes from January 1998 to December 2022. The heat indices contained in the dataset include Apparent Temperature (AT), Heat Index (HI), Humidity Index (Humidex), Normal Effective Temperature (NET), Wet Bulb Globe Temperature (simple version WBGT), Wet Bulb Globe Temperature (thermofeelWBGT), Wet Bulb Temperature (WBT), Wind Chill Temperature (WCT), Mean Radiant Temperature (MRT), and Universal Thermal Climate Index (UTCI) with two variations (UTCI indoor and UTCI outdoor).
To develop the dataset, we used hourly climate variables, acquired from the ERA5 and ERA5-Land datasets, produced by the European Centre for Medium-Range Weather Forecasts (ECMWF), which are accessible through the Copernicus Climate Change Service (C3S) Climate Data Store (CDS) Application Program Interface (API) client. We used freely available python scripts and resources (HiTiSEA repository, thermofeel library), to calculate 12 heat stress indices for Greece at an enhanced spatial resolution of 0.1° × 0.1°. To facilitate geospatial analysis over the Greek communes, boundary data in shapefile format were obtained from the Hellenic Statistical Authority (ELSTAT). The execution of a built-in QGIS function was implemented to geospatially aggregate the NetCDF files of 12 daily mean, maximum and minimum, indices to 326 Greek communes for 9131 days.
The high spatial and temporal resolution of the data, makes the dataset appropriate for analysis and comparison of climate change impacts, heatwave patterns, and the development of climate adaptation strategies at a regional scale in Greece. Additionally, it can be used as a basis of a system to inform and devise targeted interventions and policies aimed at mitigating the effects of extreme heat events. The attribution of heat stress indices at the commune level (also referred as municipalities or municipal units), which is the lowest level of government within the organizational structure in Greece, enhances the usefulness of the data for statistical analysis against other parameters, such as epidemiological or socio-economic data, which are often available at this level. Finally, the dataset can support educational purposes, providing a practical example of climate data analysis and geospatial statistics applications.
This paper examines how weather and time of day affect the way males and females use walking and cycling infrastructure in Sydney, Australia. Using observational data from three dedicated walking and cycling paths, the results show that more males than females engaged in walking and cycling, with cycling showing a greater gender disparity. While active travel volumes were influenced by weather and time of day, no significant gender differences were observed in how these factors affected the number of active travel users.
Increasing the albedo of urban surfaces, through strategies like white roof installations, has emerged as a promising approach for urban climate adaptation. Yet, modeling these strategies on a large scale is limited by the use of static urban surface albedo representations in the Earth system models. In this study, we developed a new transient urban surface albedo scheme in the Community Earth System Model and evaluated evolving adaptation strategies under varying urban surface albedo configurations. Our simulations model a gradual increase in the urban surface albedo of roofs, impervious roads, and walls from 2015 to 2099 under the SSP3‐7.0 scenario. Results highlight the cooling effects of roof albedo modifications, which reduce the annual‐mean canopy urban heat island intensity from 0.8°C in 2015 to 0.2°C by 2099. Compared to high‐density and medium‐density urban areas, higher albedo configurations are more effective in cooling environments within tall building districts. Additionally, urban surface albedo changes lead to changes in building energy consumption, where high albedo results in more indoor heating usage in urban areas located beyond 30°N and 25°S. This scheme offers potential applications like simulating natural albedo variations across urban surfaces and enables the inclusion of other urban parameters, such as surface emissivity.
Background Outdoor and indoor air temperature affects human health and wellbeing. Climate change projections suggest that global temperatures will continue to increase, and this poses a threat to health. Buildings (for housing and business purposes) that can protect humans from the adverse effects of temperature are essential, especially in the context of climate change. Method In this cross-sectional study, we measured the indoor temperature inside shipping containers comprising a seven-storey block of apartments and businesses in Johannesburg, South Africa for 14 days. We assessed indoor temperature and relative humidity; evaluated measured temperatures in relation to thresholds known to be associated with adverse health risks; and sought to understand heat-health perceptions and symptoms of people living and working in shipping container units. Results Median indoor apparent temperature (AT) (a combination of temperature and relative humidity) was 16°C with values ranging from 6°C (observed at 8:00) to 42°C (observed at 17:00). Insulated units had temperatures between 2°C and 9°C cooler than the uninsulated unit. Heat-health risks from AT exposure were likely in all units, although there was variation in the number of occurrences that AT measurements exceeded the four symptom bands of caution, extreme caution, danger and extreme danger. Indoor AT was found to be 7°C higher on average when compared to outdoor AT. Some participants believed that their units were hot during hot weather and most people opened windows or did nothing during hot weather. Few participants reported experiencing adverse heat-health impacts, except for experiencing headaches (58%) and feeling tired or weak (40%). Conclusion Residents, tenants, or business owners using shipping containers should consider insulation installation and adequate windows/air conditioning for ventilation, especially in hot climates. Further research and awareness regarding heat-health risks of living or working in these spaces is needed.
Biometeorologists typify climate change indication on the environment using indices such as the heat load index (HLI) with scales of HLI: ≤ 70.0 for cool, 70.1 to 77 for warm, 77.1 to 86.0 for hot, and ≥86.1 for a very hot environment. The current study adopted HLI computed from temperature, relative humidity, and wind speed data of 32 years (1987-2018) for five locations (Benin, Ondo, Bida, Minna, and Makurdi) and their environs, where rain-fed agriculture does favour yearly agricultural produce. The data were retrieved from the archive of Nigeria Meteorology office, Abuja, analysed with descriptive statistics, and further subjected to multivariate analysis. Average HLI indicated a hot environment for the wet periods except for April, when it was warm at Minna. December to February of dry periods had cool environments in Bida, Niger, Makurdi and their environs. Very strong correlations occurred from April to June, between September and October, and between November and December at a 0.01 significant level from Pearson’s Correlation. The Principal Component Analysis indicated eleven months with 61.00 % variance under Component 1, and four months (January, July, September, and October) among them had eigenvalue less than 0.8, indicating that the entire year except August had climate change indications. The study suggested that the five locations and their environs must understand how to cope with climate change heat load.
Purpose : To investigate the influence of shorter, more frequent rest breaks with per-cooling as an alternative heat-acclimation session on physiological, perceptual, and self-paced maximal cycling performance, compared with continuous heat exposure. Methods : Thirteen participants completed 1 continuous and 3 intermittent-heat-exposure (IHE) maximal self-paced cycling protocols in a random order in heat (36 °C, 80% relative humidity): 1 × 60-minute exercise (CON), 3 × 20-minute exercise with 7.5-minute rest between sets (IHE-20), 4 × 15-minute exercise with 5-minute rest between sets (IHE-15), and 6 × 10-minute exercise with 3-minute rest between sets (IHE-10). Mixed-method per-cooling (crushed-ice ingestion and cooling vest) was applied during rest periods of all IHE protocols. Results : Total distance completed was greater in IHE-10, IHE-15, and IHE-20 than in CON (+11%, +9%, and +8%, respectively), with no difference observed between IHE protocols. Total time spent above 38.5 °C core temperature was longer in CON compared with IHE-15 and IHE-20 (+62% and +78%, respectively) but similar to IHE-10 (+5%). Furthermore, a longer time above 38.5 °C core temperature occurred in IHE-10 versus IHE-15 and IHE-20 (+54% and +69%, respectively). Sweat loss did not differ between conditions. Conclusion : IHE with per-cooling may be a viable alternative heat-acclimation protocol in situations where training quality takes precedence over thermal stimulus or when both factors hold equal priority.
Purpose: Precooling (PreC) may only benefit performance when thermal strain experienced by an individual is sufficiently high. We explored the effect of mixed-method PreC on 20-km cycling time-trial (CTT) performance under 3 different apparent temperatures (AT). Methods: On separate days, 12 trained or highly trained male cyclists/triathletes completed six 20-km CTTs in 3 different ATs: hot-dry (35 °C AT), moderately hot-humid (40 °C AT), and hot-humid (46 °C AT). All trials were preceded by 30 minutes of mixed-method PreC or no PreC (control [CON]). Results: Faster 2.5-km-split completion times occurred in PreC compared with CON in 46 °C AT ( P = .02), but not in 40 °C AT ( P = .62) or 35 °C AT ( P = .57). PreC did not affect rectal and body temperature during the 20-km CTT. Skin temperature was lower throughout the CTT in PreC compared with CON in 46 °C AT ( P = .01), but not in 40 °C AT ( P = 1.00) and 35 °C AT ( P = 1.00). Heart rate had a greater rate of increase during the CTT for PreC compared with CON in 46 °C AT ( P = .01), but not in 40 °C AT ( P = .57) and 35 °C AT ( P = 1.00). Ratings of perceived exertion ( P < .001) and thermal comfort ( P = .04) were lower for PreC compared with CON in 46 °C AT only, while thermal sensation was not different between PreC and CON. Conclusion: Mixed-method PreC should be applied prior to 20-km CTTs conducted in hot-humid conditions (≥46 °C AT). Alternatively, mixed-method PreC may be a priority in moderately hot-humid (∼40 °C AT) conditions but should not be in hot-dry (∼35 °C AT) conditions for 20-km CTT.
Heat Index (HI) combines air temperature and relative humidity to determine how hot it actually feels. It has become a matter of great concern in the context of Bangladesh climatology along with most other countries. This paper demonstrates the trend analysis of extreme temperature and relative humidity and assessment of heat index effect on human health by dividing the whole Bangladesh into four regions (South-west region, central region, Northwest region, east region). Bangladesh experiences highest value of HI in the month of May-August when it crosses 38˚C. Heat-related illness is already thought to be the leading cause increasing patients especially diarrheal diseases and heat stroke in hospital among meteorological phenomena. This includes classical heat stress in addition to heat-induced episodes of pre-existing illnesses such as respiratory, cardio-vascular, nervous system etc. The trend drawn with the help of average HI anomalies from 1987-2017 has shown tremendous rise in apparent temperature in central and Northwest region.
Background : Outdoor and indoor air temperature affects human health and wellbeing. Climate change projections suggest that global temperatures will continue to increase and this poses a threat to health. Housing that can protect humans from the adverse effects of temperature is essential, especially in the context of climate change.
Method : In this cross-sectional study, we measured indoor temperature inside shipping containers comprising a seven-storey block of apartments and businesses in Johannesburg, South Africa. We assessed indoor temperature and relative humidity; evaluated measured temperatures in relation to thresholds known to be associated with adverse health risks; and sought to understand heat-health perceptions and symptoms of people living and working in shipping container units.
Results : Median indoor apparent temperature (AT) (a combination of temperature and relative humidity) was 16 °C with values ranging from 6 °C (observed at 8:00) to 42 °C (observed at 17:00). Insulated units had temperatures between 2°C and 9°C cooler than uninsulated units. Heat-health risks from AT exposure were likely in all units, although there was variation in the number of occurrences that AT measurements exceeded the four symptom bands of caution, extreme caution, danger and extreme danger. Some participants believed that their units were hot during hot weather and most people opened windows or did nothing during hot weather. Few participants reported experiencing adverse heat-health impacts, except for experiencing headaches (n=62, 58%) and feeling tired or weak (40%).
Conclusion : Container units should be insulated and have adequate windows for ventilation when used for residential and commercial purposes, especially in hot climates. Awareness regarding heat-health risks of living and working in hot spaces needs to be done, especially in the context of repurposed container units.
Objectives:
To identify and summarise the contextual factors associated with running demands in elite male Australian football (AF) gameplay that have been reported in the literature.
Design:
Scoping review.
Methods:
A contextual factor in sporting gameplay is a variable associated with the interpretation of results, yet is not the primary objective of gameplay. Systematic literature searches were performed in four databases to identify what contextual factors associated with running demands in elite male AF have been reported: Scopus, SPORTDiscus, Ovid Medline and CINAHL, for terms constructed around Australian football AND running demands AND contextual factors. The present scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and narrative synthesis was conducted.
Results and conclusion:
A total of 36 unique articles were identified by the systematic literature search, which included 20 unique contextual factors. The most studied contextual factors were position (n = 13), time in game (n = 9), phases of play (n = 8), rotations (n = 7) and player rank (n = 6). Multiple contextual factors, such as playing position, aerobic fitness, rotations, time within a game, stoppages, and season phase appear to correlate with running demands in elite male AF. Many identified contextual factors have very limited published evidence and thus additional studies would help draw stronger conclusions.
El viento local incide en el microclima urbano, en donde los edificios causan que el viento pierda intensidad al llegar a calles y plazas, afectando la ventilación y el confort peatonal. El presente estudio tiene por objeto evaluar el comportamiento del viento peatonal empleando morfometría, mecánica de fluidos computacional (CFD) e indicadores de ventilación para un área del centro histórico de Quito en un radio de 400 m. El modelo presenta cañones urbanos con orientaciones respecto al norte de 40° y 125°. Los cañones se modelan en base a su geometría para definir el ratio H/W. Posteriormente, se realizan simulaciones considerando el viento prevalente de la zona durante los periodos de día (6:00- 12:00) y tarde (12:00-18:00). Las simulaciones muestran una velocidad de viento peatonal entre 0,8 y 1,2 m/s, que ocasiona una reducción térmica de 2°C. Además, los indicadores de ventilación muestran un mejor comportamiento para los cañones menos profundos.
Specifying seasons is one of the most significant and arduous parts of climatology studies. In the present study, seasons are defined to apparent temperature index. For determining changes in the length, start, and end dates of the season in Iran in line with global climate change, in this research we used daily data of apparent temperature for 32 synoptic stations with locations and topography over a 60-year period (1959–2018). Temperature indices used for determining the start of seasons are thresholds of apparent temperatures of 0 and 20 degrees, with a 10-day continuation and without reverting to the initial conditions during this period for winter and summer, respectively. In the same vein, transitional seasons were specified and changes were analyzed using linear regression. The findings revealed that, in various regions, the start of spring and summer occur earlier while the start of fall and winter are delayed. The biggest statistically significant changes are observed at the start of the spring and fall seasons, as the increase is 2.25 days for summer and 1.5 days for winter per decade. Therefore, the duration of cold seasons have decreased and the duration of warm seasons have increased in climatic regions. These changes are statistically significant in foothill and high-altitude regions; the hot and dry climatic range is expanding with the increase and decrease of the summer and winter length, respectively. However, considering the inhomogeneity of altitude and geographical phenomena in the Iranian plateau and its flat northern and southern regions, these changes are not uniform or equivalent. We can say that, overall, climate change, as a direct factor influencing season change and climatic belts, plays a more influential role in comparison with local factors.
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