A summary of urban heat island uhi characteristics epa, 20 1 u. A simple methodology has been developed to calculate the urban heat island uhi from a set of gridded temperature data. High temperature in the city centers than its surroundings known as the urban heat island uhi effect, which is causing discomfort to the urban dwellers in the summer time is gaining much attention around the world because the world is getting urbanized as it advances in technology. Strong winds reduce the temperature contrast by mixing together the city and rural air. Phoenix regional heat and air quality knowledge repository. On a larger scale, the surface warming is characterized as an urban heat island uhi. Compendium of strategies describes the causes and impacts.
Numerical modelling of radiative and energetic balances in. Heat waves hws are among the most damaging climate extremes to human society. Zappala1,2 1osservatorio meteorologico di milanoduom, italy. In conclusion, the findings have indicated that on 22 june 20, surface heat island shi is critically present in the afternoon. The urban heat island uhi is the most stud ied of the climate. The wellstudied use of different materials, green areas and water reduces the thermal radiation in promenades. This paper investigates the impact of anthropogenic heat on formation of urban heat island uhi and also determines which factors can directly affect energy use in the city. Note the warmer urban surface temperatures left side of image and cooler.
Hourly air temperature data from four weather stations one in rural site and three in urban sites for the last five year are used to study the characteristics and intensities of uhi in bangkok area. Pdf the impact of urban texture in outdoor thermal comfort. Synergistic interactions between urban heat islands and heat. Jonathan winfrey, chris castro and zach bamman bsc 4932l. Surface urban heat island this image, taken from an aircraft, depicts a midday surface urban heat island in salt lake city, utah, on july, 1998. A gis extension model to calculate urban heat island intensity based on urban geometry. On a hot, sunny summer day, the sun can heat dry, exposed urban surfaces, like roofs and pavement, to temperatures 50 to 90f 27 to 50c hotter than the air,5 while shaded or moist surfacesoften in more rural surroundingsremain close to air temperatures. A quantitative assessment of surface urban heat islands using.
Mar 31, 2010 the effects of vegetative cooling and the urban heat island effect research by. The highest values of the urban heat island intensity, in the region of 38 c, are often reached between about 11 oclock at night and 3 oclock in the morning figure 2. Urban heat islands are created in areas like these. The united states 1epa recognizes the importance of these small scale regions of temperature perturbation and has characterized them as listed in table 1. This paper presents a simulation model, which was incorporated into a geographic information system gis, in order to calculate the maximum. Use the link below to share a fulltext version of this article with your friends and colleagues. White areas are around 160f 70c, while dark blue areas are near 85f 30c. The energetic basis of the urban heat island oke 1982. This methodology allows the uhi to be calculated on a monthly basis and downscaled to hourly for addition to weather generator data. Introduction examining the effect of urban vegetation on the radiative budget of a city helps to guide the development of thermally comfortable urban spaces and to mitigate the uhi effect.
In this study, the interactions between urban heat islands and heat waves are investigated using a combination of observational, numerical, and analytical analyses. Synergies between urban heat island and heat waves in athens. This paper addresses the methodological concerns in quantifying urban heat island uhi intensity in hong kong sar, china. An analysis on the urban heat island effect using radiosonde profiles and. Urban heat island uhi is a phenomenon that occurs in cities worldwide. This compendium was developed by the climate protection partnership division in the u. Surface temperature has been established as a major indicator of the presence of surface urban heat island in cities and urban areas. United states environmental protection agency the crosssection that is also the icon through which the uhi is represented typically possesses cliffs at the urbanrural fringe and a peak in correspondence of the most builtup core of the cities pon, 2007. The urban heat island effect as defined on the basis of 2m air temperature and surface temperature during a heat wave event 710 june 2008 over the baltimore area is quantified.
Heat is created by energy from all the people, cars, buses, and trains in big cities like new york, paris, and london. An energy and comfort comparison between passive cooling and mitigation urban heat island techniques for residential buildings in the mediterranean region. The uhi effect has important implications for energy consumption, air quality, and urban ecosystems. The temperature of urban areas can be significantly higher than that of the surrounding rural areas. Jun 23, 2010 extreme heat events ehes are increasing in frequency in large u. Compendium of strategies describes the causes and impacts of summertime urban heat islands and promotes strategies for lowering temperatures in u. Thereafter slightly greater urban cooling reduces the intensity until the early daytime rural heating virtually erases the heat island. The impact of anthropogenic heat on formation of urban heat. The energetic basis of urban heat island article pdf available in quarterly journal of the royal meteorological society 108 455. An urban heat island, or uhi, is a metropolitan area thats a lot warmer than the rural areas surrounding it. Systems sustaina slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. Interactions between urban heat islands and heat waves. S56 seasonalvariabilityandtrendsofthemiamiurbanheat.
Climate scientists routinely adjust down historical. No, this is a separate phenomenon where cities are 68f warmer than surrounding rural areas. The urban canopy layer heat island international association for. Urban heat island uhi effect is a kind of heat accumulation phenomenon within urban area due to. Larger solar power plants increase local temperatures. Quarterly journal of the royal meteorological society 108 455, 124, 1982. The energetic basis of the urban heat island symons memorial lecture, 20. Estimation of the urban heat island for uk climate change. Upscaling urban data science for global climate solutions.
An observational and modeling study of characteristics of. Climate models consistently project that hw frequency, severity, and duration will increase markedly over this century. Heat waves hws are recognized as a serious threat for human health worldwide, with urban areas being more vulnerable due to the urban heat. The energetic basis of the urban heat island symons memorial lecture, 20 may 1980.
The characteristics of urban heat island in bangkok, thailand. For urban residents, the urban heat island uhi effect further exacerbates the heat stress resulting from hws. Synergies between urban heat island and heat waves in. Oke and others published the energetic basis of urban heat island find, read and cite all the research you need on researchgate. Quality and sensitivity of highresolution numerical. The temperature difference between the city and surrounding areas is also a function of winds.
An urban cool island is an urban area that is cooler than its surrounding rural areas. The urban heat island effects can also be reduced by weather phenomona. Dec 29, 2015 these materials can increase the temperatures of an urban area in comparison to the surrounding rural land, generating an urban heat island oke, 2011. The energetic basis of the urban heat island oke 1982 quarterly. An urban heat island uhi is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. Impact of urban heat island on regional atmospheric pollution. High temperature in the city centers than its surroundings known as the urban heat island uhi effect, which is causing discomfort to the urban dwellers in the summer time is gaining much. Department of geography, the university of british columbia, vancouver. Quality and sensitivity of highresolution numerical simulation of urban heat islands view the table of contents for this issue, or go to the journal homepage for more home search collections journals about contact us my iopscience. Measures to reduce the urban heat island effect in rosemont. Quantifying urban heat island intensity in hong kong sar, china.
The relationship between land cover and surface temperature was analyzed for each year by producing images that provided a visual resource for analyzing the intensity and spatiality of lst change. Measures to reduce the urban heat island effect in rosemontla petitepatrie. Quantifying urbanrural temperature differences for. A gis extension model to calculate urban heat island. It explores literally the conceptual framework of confliction between anthropogenic heat and urban structure, which produced uhi intensity and affected energy consumption balance. Lamb, timon mcphearson, jan minx, esteban munoz, brenna walsh. Urban materials contribute heat to their surroundings through the way they store and release heat energy from the sun. The importance of distinguishing between different types is stressed and a simple classification scheme is forwarded.
A lot of the classic work done on quantifying urban heat island effects was done by oke in the 1980s, e. Emphasis in this paper is upon the heat island in the urban boundary layer ubl above rooflevel the uhi ubl. Heat waves hws are recognized as a serious threat for human health worldwide, with urban areas being more vulnerable due to the urban heat island uhi effect and population density. The study focuses on the characteristics of urban heat island uhi in bangkok, thailand. After that, the findings are evaluated in terms of urban thermal comfort. United states environmental protection agency the crosssection that is also the icon through which the uhi is represented typically possesses cliffs at the urbanrural fringe and a peak in correspondence of the most builtup core of the cities pon. Although the urban heat island in hong kong has been widely investigated, there is no consensus on the most appropriate fixed point meteorological sites to be used to calculate heat island intensity. Numerical modelling of radiative and energetic balances in the urban canopy layer s. The energetic basis of the urban heat island pat arnott web site. Pdf the energetic basis of urban heat island researchgate.
698 1281 1410 516 205 1650 605 349 1081 992 477 773 1523 630 898 1114 1323 30 1443 717 1165 99 848 734 54 287 1445 936 986 776 891 344 761 130