Development Of Urban Heat Island Research Articles

Relationships between macrosynoptic weather types and development of the thermal excess in suburban areas in Debrecen, Hungary

Impacts of macrosynoptic weather patterns on the development of the thermal excess in suburban areas of Debrecen are examined in this paper. Temperature datasets have been recorded at two heights by three automatic weather stations mounted in Debrecen (east Hungary) and a small settlement in its vicinity. An additional automatic weather station is used as a reference station outside Debrecen. Urban heat island (UHI) intensities have been calculated from the raw datasets. Impacts of synoptic conditions have been analyzed on the base of Péczely’s macrosynoptic types. It has been found that anticyclone types are more favorable from the aspect of UHI development, while cyclone types, especially the passage of warm fronts can effectively hinder the formation of strong heat islands in Debrecen.

Local Climate Classification and Dublin’s Urban Heat Island

A recent re-evaluation of urban heat island (UHI) studies has suggested that the urban effect may be expressed more meaningfully as a difference between Local Climate Zones (LCZ), defined as areas with characteristic dimensions of between one and several kilometers that have distinct effects on climate at both micro-and local-scales (city streets to neighborhoods), rather than adopting the traditional method of comparing urban and rural air temperatures. This paper reports on a UHI study in Dublin (Ireland) which maps the urban area into LCZ and uses these as a basis for carrying out a UHI study. The LCZ map for Dublin is derived using a widely available land use/cover map as a basis. A small network of in-situ stations is deployed into different LCZ across Dublin and additional mobile temperature traverses carried out to examine the thermal characteristics of LCZ following mixed weather during a 1 week period in August 2010. The results show LCZ with high impervious/building coverage were on average >4 °C warmer at night than LCZ with high pervious/vegetated coverage during conditions conducive to strong UHI development. The distinction in mean LCZ nocturnal temperature allows for the generation of a heat map across the entire urban area.

ROLE OF URBAN MORPHOLOGY IN DEVELOPMENT OF THE THERMAL EXCESS IN THE CITY OF DEBRECEN, HUNGARY

The thermal excess in a settlement compared to its rural environment is called urban heat island (UHI). It has a significant effect on human comfort in open urban spaces and indoor environment. UHI intensities (the thermal difference between the settlement and its close-to natural environment) are determined by buildup characteristics of settlements as static endowments and synoptic weather conditions as dynamic factors. Effects of build-up characteristics are traced in the case of the city of Debrecen in East Hungary, in the present study. Debrecen is located on a nearly flat terrain, without rivers and lakes, which are favorable conditions from the aspect of UHI development. Mobile techniques were used in order to get abundant comparable data on the characteristics of the UHI in the city. On the base of the results spatial characteristics of UHI in Debrecen are described. Characteristic maximal UHI intensities have been determined for typical urban morphological units of the city.

How do variations in Urban Heat Islands in space and time influence household water use? The case of Phoenix, Arizona

This paper explores how urbanization, through its role in the evolution of Urban Heat Island (UHI), affects residential water consumption. Using longitudinal data and drawing on a mesoscale atmospheric model, we examine how variations in surface temperature at the census tract level have affected water use in single family residences in Phoenix, Arizona. Results show that each Fahrenheit rise in nighttime temperature increases water consumption by 1.4%. This temperature effect is found to vary significantly with lot size and pool size. The study provides insights into the links between urban form and water use, through the dynamics of UHI.

The Study for the Influencing Factors of Urban Heat Island Development

The impacts of some factors on the development of urban heat island are investigated in this paper. The results show that the development of urban heat island is influenced by many factors. Cold and try climate is more favorable for the development of urban heat island than warm and moist climate; Urban heat island develops slowly in those seashore cities that are influenced obviously by land and sea breezes. Closed topography (e.g., valleys, basins) is favorable for the development. The heat island development is direct proportional to urban developing speed; In the cities in which highly energy consumption industries concentrate, heat island is more obvious.

Erratum

International Journal of ClimatologyVolume 31, Issue 12 p. 1896-1896 ErratumFree Access Erratum This article corrects the following: Evolution of urban heat island in Khartoum Nadir Ahmed Elagib, Volume 31Issue 9International Journal of Climatology pages: 1377-1388 First Published online: June 2, 2010 First published: 14 September 2011 https://doi.org/10.1002/joc.2413AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL The article by Nadir Ahmed Elagib (2011) contained an error on page 1382. The units of the linear trend rates of temperature and urban heat island intensity (UHII) indicated in Table II and the relevant discussion should be ‘ °C decade−1’ instead of ‘ °C century−1’. References Elagib NA. 2011. Evolution of urban heat island in Khartoum. Int. J. Climatol. 31: 1377– 1388. Volume31, Issue12October 2011Pages 1896-1896 ReferencesRelatedInformation

The Urban Heat Island Intensity of Paris: A Case Study Based on a Simple Urban Surface Parametrization

We explore the ability of a simple urban surface parametrization, embedded in a mesoscale meteorological model, to correctly reproduce observed values of the urban heat island (UHI) intensity, which is defined as the urban-rural surface air temperature difference. To do so, a simple urban scheme was incorporated into the Advanced Regional Prediction System (ARPS). Subsequently, a simulation was performed with the coupled model over the wider area of Paris, for a 12-day period in June 2006 that was characterised by conditions prone to UHI development. Simulated 2-m air temperature was compared with observed values for urban and rural stations, yielding mean errors of 1.4 and 1.5 K, respectively. More importantly, it was found that the model also displayed an overall good capability of reproducing the observed temperature differences. In particular, the magnitude (up to 6 K) and timing of the diurnal cycle of the UHI intensity was simulated well, the model exhibiting a mean error of 1.15 K. As a result, our conclusion is that the ARPS model, extended with simple urban surface physics, is able to capture observed urban-rural air temperature differences well, at least for the domain and period studied.

Derivation of Birmingham's summer surface urban heat island from MODIS satellite images

AbstractThis study investigates the summer (June, July, August) night urban heat island (UHI) of Birmingham, the UK's second most populous city. Land surface temperature remote sensing data is used from the MODIS sensor on NASA's Aqua satellite, combined with UK Met Office station data to map the average variation in heat island intensity over the Birmingham conurbation. Results are presented of average UHI events over four Pasquill‐Gifford stability classes D, E, F, and G between 2003 and 2009, as well as a specific heatwave event in July 2006. The results quantify the magnitude of the Birmingham surface UHI as well as the impact of atmospheric stability on UHI development. During periods of high atmospheric stability, a UHI of the order of 5 °C is evident with a clear peak in the central business district. Also identified, are significant cold spots in the conurbation. In one city park, recorded surface temperatures are up to 7 °C lower than the city centre. Copyright © 2010 Royal Meteorological Society

Analysis of Impervious Surface and its Impact on Urban Heat Environment using the Normalized Difference Impervious Surface Index (NDISI)

The fast urban expansion has led to replacement of natural vegetation-dominated land surfaces by various impervious materials. This has a significant impact on the environment due to modification of heat energy balance. Timely understanding of spatiotemporal information of impervious surface has become more urgent as conventional methods for estimating impervious surface are very limited. In response to this need, this paper proposes a new index, normalized difference impervious surface index (NDISI), for estimating impervious surface. The application of the index to the Landsat ETM+ image of Fuzhou City and the ASTER image of Xiamen City in China has shown that the new index can efficiently enhance and extract impervious surfaces from satellite imagery, and the normalized NDISI can represent the real percentage of impervious surface. The index was further used as an indicator to investigate the impact of impervious surface on urban heat environment by examination of its quantitative relationship with land surface temperature ( LST ), vegetation, and water using multivariate statistical analysis. The result reveals that impervious surface has a positive exponential relationship with LST rather than a simple linear one. This suggests that the areas with high percent impervious surface will accelerate LST rise and urban heat island development.

Analysis of the impact of Land use/Land cover change on Land Surface Temperature with Remote Sensing

Nowadays, more than 40% of the population lives in Chinese cities. The rapid urbanization process brought about many ecoenvironmental problems, such as the drastic change of land use and development of urban heat island. Three Landsat TM and ETM+ images data of Beijing acquired on April 9, 1995 and April 30, 2000 were selected to this research. The land surface temperature (LST) and land use and land cover (LULC) classes were retrieved and extracted. The temperature-vegetation index (TVX) space was constructed to investigate the influence of land changes over LST. The result showed that the land use change was an important driver for LST increase, the temporal trajectory of pixels in the TVX space migrated from the dense-vegetationlow temperature condition to the sparse vegetation-high temperature condition.

Spatial–temporal dynamics of land surface temperature in relation to fractional vegetation cover and land use/cover in the Tabriz urban area, Iran

Rapid changes of land use and land cover (LULC) in urban areas have become a major environmental concern due to environmental impacts, such as the reduction of green spaces and development of urban heat islands (UHI). Monitoring and management plans are required to solve this problem effectively. The Tabriz metropolitan area in Iran, selected as a case study for this research, is an example of a fast growing city. Multi-temporal images acquired by Landsat 4, 5 TM and Landsat 7 ETM+ sensors on 30 June 1989, 18 August 1998, and 2 August 2001 respectively, were corrected for radiometric and geometric errors, and processed to extract LULC classes and land surface temperature (LST). The relationship between temporal dynamics of LST and LULC was then examined. The temperature vegetation index (TVX) space was constructed in order to study the temporal variability of thermal data and vegetation cover. Temporal trajectory of pixels in the TVX space showed that most changes due to urbanization were observable as the pixels migrated from the low temperature-dense vegetation condition to the high temperature-sparse vegetation condition in the TVX space. The uncertainty analysis revealed that the trajectory analysis in the TVX space involved a class-dependant noise component. This emphasized the need for multiple LULC control points in the TVX space. In addition, this research suggests that the use of multi-temporal satellite data together with the examination of changes in the TVX space is effective and useful in urban LULC change monitoring and analysis of urban surface temperature conditions as long as the uncertainty is addressed.

Satellite-based analysis of the role of land use/land cover and vegetation density on surface temperature regime of Delhi, India

The knowledge of the surface temperature is important to a range of issues and themes in earth sciences central to urban climatology, global environmental change and human-environment interactions. The study analyses land surface temperature (LST) estimation using temporal ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) datasets (day time and night time) over National Capital Territory Delhi using the surface emissivity information at pixel level. The spatial variations of LST over different land use/land cover (LU/LC) at day time and night time were analysed and relationship between the spatial distribution of LU/LC and vegetation density with LST was developed. Minimum noise fraction (MNF) was used for LU/LC classification which gave better accuracy than classification with original bands. The satellite derived emissivity values were found to be in good agreement with literature and field measured values. It was observed that fallow land, waste land/bare soil, commercial/industrial and high dense built-up area have high surface temperature values during day time, compared to those over water bodies, agricultural cropland, and dense vegetation. During night time high surface temperature values are found over high dense built-up, water bodies, commercial/industrial and low dense built-up than over fallow land, dense vegetation and agricultural cropland. It was found that there is a strong negative correlation between surface temperature and NDVI over dense vegetation, sparse vegetation and low dense built-up area while with fraction vegetation cover, it indicates a moderate negative correlation. The results suggest that the methodology is feasible to estimate NDVI, surface emissivity and surface temperature with reasonable accuracy over heterogeneous urban area. The analysis also indicates that the relationship between the spatial distribution of LU/LC and vegetation density is closely related to the development of urban heat islands (UHI).

Urban Expansion and Heat Island Dynamics in the Quanzhou Region, China

Urban spatial expansion in the Quanzhou region of southeastern China has been accelerated over the past 20 years. This has caused land cover changes and, thus, has significant impacts on the local ecosystem and climate. To study the urban expansion and heat island dynamics of the region over the past 20 years, multitemporal Landsat TM images of 1987, 1996, and 2006 were used. The estimation of the urban expansion was assisted by the index-based built-up index (IBI) through enhancing built-up land features in the images. The urban-heat-island (UHI) effect was assessed using the urban-heat-island ratio index (URI). Multitemporal analysis indicates that the great increase in urban area has resulted in the development of UHIs in the region. Regression statistics reveal that built-up land has a positive exponential relationship with land surface temperature (LST). Therefore, the increase in built-up land percentage can exponentially accelerate the rise of LST.

The urban heat island in Salamanca (Spain) and its relationship to meteorological parameters

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 34:39-46 (2007) - doi:10.3354/cr034039 The urban heat island in Salamanca (Spain) and its relationship to meteorological parameters M. S. Alonso*, M. R. Fidalgo, J. L. Labajo Department of General and Atmospheric Physics, University of Salamanca, 37008 Salamanca, Spain *Email: salgarci@terra.es ABSTRACT: An urban heat island (UHI) was found to exist in Salamanca, Spain—a medium-sized European city that has a continental climate and relatively little industrial pollution. We demonstrate that urban heating can occur in cities with these characteristics, giving rise to a microclimate that may alter the biological rhythm of the zone e.g. under these conditions, spring arrives earlier in the urban zone then in the rural zone. The study was carried out using data from 2 recording stations (one in and the other outside the city) for the years 1996–1998. The existence of a nocturnal UHI was observed, with a highest annual mean value of 3.6°C and a lowest annual mean value (cool island) of –0.9°C. The most intense nocturnal UHI was seen in autumn, while the strongest sinks occurred in spring and summer. As in other types of city with different characteristics, the UHI was seen to vary according to the atmospheric situation. The meteorological variables that most affected the UHI were found to be: (1) wind, which at speeds of >~6 m s–1 prevented the development of UHIs; (2) cloudiness, which altered the flux of incident solar radiation (the intensity of the nocturnal UHI was greater with high clouds); and (3) atmospheric pressure, which characterised the days of atmospheric stability or instability, leading to variations in the intensity of the UHI. KEY WORDS: Urban heat island · Local climate · UHI sink · Wind · Cloudiness · Synoptic conditions · Salamanca Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 34, No. 1. Online publication date: June 14, 2007 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2007 Inter-Research.

A canopy layer model and its application to Rome

An urban canopy layer model based on four energy balance equations at ground level and at building level was developed to simulate and describe the urban climate and the heat storage in an urban setting. Thermal and radiative characteristics of urban and rural surfaces as well as atmospheric parameters related to the general synoptic conditions were used as data input. In addition, buildings were modelled as parallelepipeds and the hysteresis of materials was taken into account. The model provides as output skin temperature of buildings, air temperature and humidity within the canopy layer and hence the mean surface temperature and the air temperature at 2 m above surface. The latter parameter was used for the comparison with in situ temperature observations. The model was applied to Rome in radiative summer and winter episodes. The results, which agree with observations, show that the Urban Heat Island (UHI) is a nocturnal phenomenon, present both in winter (the greatest difference between urban and rural temperatures is about 2 °C) and summer (the temperature difference is about 5 °C), mainly resulting from the urban geometry and the thermal properties of materials. The anthropogenic heat does not play an important role in the UHI development. A monthly nocturnal behaviour of temperature differences between urban and surrounding rural areas shows that the maximum mean value of 4.2 °C occurs in August. Moreover, the parks in the city centre, where temperatures are lower, define two distinct heat islands, east and west.

ANKARA’DA ŞEHİR ISI ADASININ İNCELENMESİ (Detection of Urban Heat Island in Ankara, Turkey)

Turkish Abstract: Turkiye’de hizli nufus artisi ve buna bagli olarak artan sehirlesme sicakliklarda degisimler meydana getirmektedir. Bunda ozellikle plansiz ve kacak yapilasmanin onemli bir payi vardir. Gecekondulasma sonucunda yesil alanlarin hizla yok olmasi ve hizli betonlasma sehir isi adasini (SIA) kuvvetlenmistir. Baskent oldugundan beri hizli bir sehirlesmeye sahne olan Ankara’da da SIA gelisimini, bunun alansal dagilisini ve buyuklugunu saptamak icin farkli sehir dokusunu yansitan bolgelere 7 adet istasyon kurulmus ve sicaklik olcumleri yapilmistir. Veriler degerlendirildiginde en buyuk SIA soguk donemde goruldugu icin bu calismada subat ayi incelenmistir. Oke (1979) esitligine gore Ankara’da maksimum isi adasi 9.0 °C’dir. 2 Subat 2002 saat 15:00’te bu deger 9.4 °C olmustur. Incelenen donemde gunduz zayif olan SIA aksam saatlerinde kuvvetlenerek sehir ve kirsal alanlar arasinda sicaklik farkliligi (∆T(s-k)) 7.7 °C’ye ulasmistir. Subat ayi suresince 24 aksamda SIA (∆T(s-k)≥ 1.0 °C) gorulmustur. Subat ayinda saat 21:00’da yasanan SIA’nin % 61’i 4.0 °C’nin uzerindedir. SIA goruldugu donemlerde ruzgar hizi genellikle 0.5 m sn-1’ten daha azdir. English Abstract: The rapid increase in population and corresponding rise in urbanization cause the change in temperature in Turkey. The unplanned and rapid construction has also a very big role in this process. The increase in the number of slums and rapid destruction of green areas and concretion has also strengthened urban heat island (UHI). There were seven station established in Ankara, representing the texture of the city in order to measure the temperature variation and define the development of UHI and its spatial variation. Since the biggest UHI is observed in cold period at investigation period, we investigated the month of February in this study. According to Oke (1979) equation the maximum heat island in Ankara is 9.0 °C. UHI observed 9.4°C at 15:00 on 2 February 2002. During the period of interest, UHI, which was weak during day time, strengthened in evening hours and ∆T (u-r) increased up to 7.7 °C. There were UHI (∆T (u-r)≥ 1.0 °C) in 24 evenings in February. 61% of UHIs observed at 21:00 in February was above 4.0 °C. The wind speed was less than 0.5 m s-1 during the periods of UHI.

Associations between varying magnitudes of the urban heat island and the synoptic climatology in Melbourne, Australia

This paper examines the characteristics of the urban heat island (UHI) in a large Australian city (Melbourne) using local area weather data and the US National Centers for Environmental Prediction (NCEP) reanalyses data of mean sea level pressure (MSLP). Conventional methods to determine the UHI from climatological data often involve comparing minimum temperature data between urban and rural environments. The findings presented in this paper show that comparing simultaneous measurements of temperature at one urban and three nearby airport sites at 0600 (Australian eastern standard time (EST)) provided a better estimate of the UHI magnitude. Analyses of these data between 1973–1991 were grouped according to the daily UHI magnitude. For each UHI group of the daily data, mean anomalous synoptic conditions from the 19-year mean monthly MSLP were examined for the influence of the different MSLP conditions on varying UHI magnitudes. These synoptic conditions included the entire range of weather conditions over the study period. Over the 19-year period, daily analyses of the regional climatological 0600 EST temperature data revealed a UHI between −3.16° and 6.0°C. The reanalyses of the NCEP MSLP data, in association with the local area climatological data, suggest that statistically significant anomalous anticyclonic conditions were associated with the warmest 17% and coolest 1% of UHI events. The position of the centre of the anticyclone was critical to UHI genesis and development. Statistically significant mean low pressure anomalies were associated with UHI values between 0° and 1°C. These occurred on 40% of the days between 1973–1991. Melbourne's urban area, independent of the topography, was found to inhibit early morning advection events of warm continent air and result in an urban cool island (UCI). Copyright © 2000 Royal Meteorological Society

Urban-rural vapour pressure differences and their role in the development of urban heat islands

Data for a 4-year period from Göteborg, Sweden was used to investigate the urban–rural humidity differences during clear and calm nights. The purpose was to analyse the impact of the Urban Moisture Excess (UME) on the Urban Heat Island (UHI) with focus on the longwave radiation balance and the latent heat flux. The statistical analysis demonstrated that a hot summer with reduced precipitation increased the mean UME to 3 hPa (‘normal’ summer conditions demonstrated an UME of about 1 hPa) and during some nights the UME was as high as 7 hPa. The analysis also demonstrated a positive correlation between UME and UHI, with the maximum UHI preceding the maximum UME by between 2 and 5 h. An analysis of the nocturnal development of UME demonstrated that the UME could develop from three combinations of urban and rural vapour pressure changes. The initial level of the rural vapour pressure, and thus the conditions for dewfall proved to be important. The influence of an UME of 3 hPa on the downward longwave radiation was calculated to about 3 W m−2, which is 12% of the urban–rural radiation difference giving a weak enhancing effect of the UME on the UHI. Advection of dry air from the UHI circulation was considered to influence the urban vapour pressure change. After correction of the advective effect on the urban vapour pressure change, the urban–rural difference in the latent heat flux ranged from −5 to −25 W m−2, which demonstrates that UME also has a considerable negative feedback on the UHI development. Copyright © 1999 Royal Meteorological Society

Urban–rural vapour pressure differences and their role in the development of urban heat islands

Urban–rural vapour pressure differences and their role in the development of urban heat islands

Application of high-resolution thermal infrared remote sensing and GIS to assess the urban heat island effect

Day and night airborne thermal infrared image data at 5 m spatial resolution acquired with the 15-channel (0.45mum-12.2mum) Advanced Thermal and Land Applications Sensor (ATLAS) over Alabama, Huntsville on 7 September, 1994 were used to study changes in the thermal signatures of urban land cover types between day and night. Thermal channel number 13 (9.60 mum-10.2mum) data with the best noise-equivalent temperature change (NEDeltaT) of 0.25 C after atmospheric corrections and temperature calibration were selected for use in this analysis. This research also examined the relation between land cover irradiance and vegetation amount, using the Normalized Difference Vegetation Index (NDVI), obtained by ratioing the difference and the sum of the red (channel number 3: 0.60-0.63mum) and reflected infrared (channel number 6: 0.76-0.90mum) ATLAS data. Based on the mean radiance values, standard deviations, and NDVI extracted from 351 pairs of polygons of day and night channel number 13 images for the city of Huntsville, a spatial model of warming and cooling characteristics of commercial, residential, agricultural, vegetation, and water features was developed using a GIS approach. There is a strong negative correlation between NDVI and irradiance of residential, agricultural, and vacant/transitional land cover types, indicating that the irradiance of a land cover type is greatly influenced by the amount of vegetation present. The predominance of forests, agricultural, and residential uses associated with varying degrees of tree cover showed great contrasts with commercial and services land cover types in the centre of the city, and favours the development of urban heat islands. The high-resolution thermal infrared images match the complexity of the urban environment, and are capable of characterizing accurately the urban land cover types for the spatial modeling of the urban heat island effect using a GIS approach.