Estimation of Anthropogenic Heat Emissions in Delhi, India and Their Role in Urban Heat Island Effect

NASA Astrophysics Data System (ADS)

Bhati, S.; Mohan, M.

2016-12-01

Energy consumption in the urban environment impacts the urban surface energy budget and leads to the emission of anthropogenic sensible heat into the atmosphere. Anthropogenic heat (AH) can vary both in time and space, and are not readily measured. In present study, anthropogenic heat emissions have been estimated using an inventory approach for Delhi. The main sources that have been considered are electricity consumption, vehicular emissions, fuel consumption in domestic sector and waste heat from power plants. Total estimated anthropogenic heat is apportioned gridwise (2 km2) and incorporated in the WRF (version 3.5) model coupled with single-layer Urban canopy model (UCM) to assess the impact of these emissions on urban heat island effect in Delhi. Vehicular emissions have been found to be highest contributor to anthropogenic heat emissions (47%) followed by electricity consumption (28%), domestic fuel consumption (16%) and waste heat from power plants (9%). Highest annual average anthropogenic heat flux was estimated to be 25.2 Wm-2. High flux zones are observed in east Delhi and densely occupied and commercial zones of Sitaram Bazar and Connaught Place. Inclusion of anthropogenic heat emissions in the model improves model performance for near surface temperature as well as urban heat island intensities. Maximum simulated night-time UHI improves from 5.95°C (without AH) to 6.24°C (with AH) against observed value of 6.68°C, thereby indicating positive contribution of anthropogenic heat emissions along with urban canopy towards UHI effect in Delhi. Similarly, spatial distribution and UHI hotspots are found to be comparatively closer to corresponding observed distribution and hotspots with anthropogenic heat emissions being added to the WRF model. Overall, relatively improved model performance is indicative of the impact of anthropogenic heat emissions in local urban meteorology and urban heat island effect in Delhi. Hence, rising population and change in land

The impact of heat waves on surface urban heat island and local economy in Cluj-Napoca city, Romania

NASA Astrophysics Data System (ADS)

Herbel, Ioana; Croitoru, Adina-Eliza; Rus, Adina Viorica; Roşca, Cristina Florina; Harpa, Gabriela Victoria; Ciupertea, Antoniu-Flavius; Rus, Ionuţ

2017-07-01

The association between heat waves and the urban heat island effect can increase the impact on environment and society inducing biophysical hazards. Heat stress and their associated public health problems are among the most frequent. This paper explores the heat waves impact on surface urban heat island and on the local economy loss during three heat periods in Cluj-Napoca city in the summer of 2015. The heat wave events were identified based on daily maximum temperature, and they were divided into three classes considering the intensity threshold: moderate heat waves (daily maximum temperature exceeding the 90th percentile), severe heat waves (daily maximum temperature over the 95th percentile), and extremely severe heat waves (daily maximum temperature exceeding the 98th percentile). The minimum length of an event was of minimum three consecutive days. The surface urban heat island was detected based on land surface temperature derived from Landsat 8 thermal infrared data, while the economic impact was estimated based on data on work force structure and work productivity in Cluj-Napoca derived from the data released by Eurostat, National Bank of Romania, and National Institute of Statistics. The results indicate that the intensity and spatial extension of surface urban heat island could be governed by the magnitude of the heat wave event, but due to the low number of satellite images available, we should consider this information only as preliminary results. Thermal infrared remote sensing has proven to be a very efficient method to study surface urban heat island, due to the fact that the synoptic conditions associated with heat wave events usually favor cloud free image. The resolution of the OLI_TIRS sensor provided good results for a mid-extension city, but the low revisiting time is still a drawback. The potential economic loss was calculated for the working days during heat waves and the estimated loss reached more than 2.5 mil. EUR for each heat wave day

A GIS approach to urban heat island research: The case of Huntsville, Alabama

NASA Technical Reports Server (NTRS)

Lo, Chor Pong

1994-01-01

The urban heat island represents a case of inadvertent human modification of climate in an urban environment. Urbanization changes the nature of the surface and atmospheric properties of a region. As a result, radiation balance in the urban areas is altered and sensible heat is added to the point that urban areas are warmer than surrounding rural areas. At the boundary between the rural and urban area, a sharp rise in temperature occurs, culminating to a peak temperature at the central business district of the city, hence the name 'urban heat island'. The extent and intensity of the urban heat island are a function of population size, land use, and topography. Because the urban heat island exhibits spatial variations of temperatures, the use of Geographic Information System (GIS) is appropriate. The research on the urban heat island focuses on the acquisition of 15 bands of visible and thermal infrared data (ranging from 0.45 to 12.2 microns) from an aerial platform using NASA's ATLAS (Airborne Thermal/Visible Land Application Sensor) over Huntsville, Alabama. The research reported in this paper is an analysis of the impact of population, land use, and topography on the shape of the urban heat island that could be developed in Huntsville using the GIS approach. The outcome of this analysis can then be verified using the acquired remotely sensed data.

Impact of the urban heat island on residents’ energy consumption: a case study of Qingdao

NASA Astrophysics Data System (ADS)

Ding, Feng; Pang, Huaji; Guo, Wenhui

2018-02-01

This paper examines impact of urban heat island on residents’ energy consumption through comparative analyses of monthly air temperature data observed in Qingdao, Laoshan and Huangdao weather stations. The results show effect of urban heat island is close related with urbanization speed. Recently, effects of urban heat island of Laoshan and Huangdao exceed that of Qingdao, consistent with rapid urbanization in Laoshan and Huangdao. Enhanced effect of urban heat island induces surface air temperature to rise up, further increase electricity energy consumption for air conditioning use in summer and reduce coal consumption for residents heating in winter. Comparing change of residents’ energy consumption in summer and winter, increments in summer are less than reduction in winter. This implicates effect of urban heat island is more obvious in winter than in summer.

The effect of anisotropic heat transport on magnetic islands in 3-D configurations

NASA Astrophysics Data System (ADS)

Schlutt, M. G.; Hegna, C. C.

2012-08-01

An analytic theory of nonlinear pressure-induced magnetic island formation using a boundary layer analysis is presented. This theory extends previous work by including the effects of finite parallel heat transport and is applicable to general three dimensional magnetic configurations. In this work, particular attention is paid to the role of finite parallel heat conduction in the context of pressure-induced island physics. It is found that localized currents that require self-consistent deformation of the pressure profile, such as resistive interchange and bootstrap currents, are attenuated by finite parallel heat conduction when the magnetic islands are sufficiently small. However, these anisotropic effects do not change saturated island widths caused by Pfirsch-Schlüter current effects. Implications for finite pressure-induced island healing are discussed.

Heat transport in the quasi-single-helicity islands of EXTRAP T2R

NASA Astrophysics Data System (ADS)

Frassinetti, L.; Brunsell, P. R.; Drake, J.

2009-03-01

The heat transport inside the magnetic island generated in a quasi-single-helicity regime of a reversed-field pinch device is studied by using a numerical code that simulates the electron temperature and the soft x-ray emissivity. The heat diffusivity χe inside the island is determined by matching the simulated signals with the experimental ones. Inside the island, χe turns out to be from one to two orders of magnitude lower than the diffusivity in the surrounding plasma, where the magnetic field is stochastic. Furthermore, the heat transport properties inside the island are studied in correlation with the plasma current and with the amplitude of the magnetic fluctuations.

Can Aerosol Offset Urban Heat Island Effect?

NASA Astrophysics Data System (ADS)

Jin, M. S.; Shepherd, J. M.

2009-12-01

The Urban Heat Island effect (UHI) refers to urban skin or air temperature exceeding the temperatures in surrounding non-urban regions. In a warming climate, the UHI may intensify extreme heat waves and consequently cause significant health and energy problems. Aerosols reduce surface insolation via the direct effect, namely, scattering and absorbing sunlight in the atmosphere. Combining the National Aeronautics and Space Administration (NASA) AERONET (AErosol RObotic NETwork) observations over large cities together with Weather Research and Forecasting Model (WRF) simulations, we find that the aerosol direct reduction of surface insolation range from 40-100 Wm-2, depending on seasonality and aerosol loads. As a result, surface skin temperature can be reduced by 1-2C while 2-m surface air temperature by 0.5-1C. This study suggests that the aerosol direct effect is a competing mechanism for the urban heat island effect (UHI). More importantly, both aerosol and urban land cover effects must be adequately represented in meteorological and climate modeling systems in order to properly characterize urban surface energy budgets and UHI.

Urban Heat Islands and Their Mitigation vs. Local Impacts of Climate Change

NASA Astrophysics Data System (ADS)

Taha, H.

2007-12-01

Urban heat islands and their mitigation take on added significance, both negative and positive, when viewed from a climate-change perspective. In negative terms, urban heat islands can act as local exacerbating factors, or magnifying lenses, to the effects of regional and large-scale climate perturbations and change. They can locally impact meteorology, energy/electricity generation and use, thermal environment (comfort and heat waves), emissions of air pollutants, photochemistry, and air quality. In positive terms, on the other hand, mitigation of urban heat islands (via urban surface modifications and control of man-made heat, for example) can potentially have a beneficial effect of mitigating the local negative impacts of climate change. In addition, mitigation of urban heat islands can, in itself, contribute to preventing regional and global climate change, even if modestly, by helping reduce CO2 emissions from power plants and other sources as a result of decreased energy use for cooling (both direct and indirect) and reducing the rates of meteorology-dependent emissions of air pollutants. This presentation will highlight aspects and characteristics of heat islands, their mitigation, their modeling and quantification techniques, and recent advances in meso-urban modeling of California (funded by the California Energy Commission). In particular, the presentation will focus on results from quantitative, modeling-based analyses of the potential benefits of heat island mitigation in 1) reducing point- and area-source emissions of CO2, NOx, and VOC as a result of reduced cooling energy demand and ambient/surface temperatures, 2) reducing evaporative and fugitive hydrocarbon emissions as a result of lowered temperatures, 3) reducing biogenic hydrocarbon emissions from existing vegetative cover, 4) slowing the rates of tropospheric/ground-level ozone formation and/or accumulation in the urban boundary layer, and 5) helping improve air quality. Quantitative estimates

[Heat island effect and human body comfortable degree in Zhengzhou city].

PubMed

Zheng, Jinggang; Zhang, Jingguang; Li, You

2005-10-01

In this paper, the key factors of heat island effect in Zhengzhou city were monitored by grid method to study the diurnal and seasonal changes and the spatial distribution of the effect, and to evaluate the comfortable degree of human bodies at different sites of the city. The results showed that on the whole, the heat island effect had a unimodal diurnal change, while its intensity was distinctly different among seasons, being decreased in order of winter > spring > autumn > summer. The spatial distribution of heat island center was significantly related to its nearby industrial heat resources. As for the comfortable degree of human bodies, the People's Park was the best site because of its arbor virescence, while in the Xiliu Lake Park with lawn as its main greening type, its capability of improving microclimate was weaker. The railway station square still had 16% frequency of most comfortable degree, because of its open space and better air fluidity.

Cooling urban heat islands with sustainable landscapes

Treesearch

E. Gregory McPherson

1994-01-01

This paper is directed to the policy-makers who are responsible for urban design and its climatological consequences. It summarizes our current knowledge on the structure, energetics, and mitigation of the urban heat island. Special attention is given to physical features of the environment that can be easily manipulated, particularly vegetation. Prototypical designs...

Land use planning and surface heat island formation: A parcel-based radiation flux approach

NASA Astrophysics Data System (ADS)

Stone, Brian; Norman, John M.

This article presents a study of residential parcel design and surface heat island formation in a major metropolitan region of the southeastern United States. Through the integration of high-resolution multispectral data (10 m) with property tax records for over 100,000 single-family residential parcels in the Atlanta, Georgia, metropolitan region, the influence of the size and material composition of residential land use on an indicator of surface heat island formation is reported. In contrast to previous work on the urban heat island, this study derives a parcel-based indicator of surface warming to permit the impact of land use planning regulations governing the density and design of development on the excess surface flux of heat energy to be measured. The results of this study suggest that the contribution of individual land parcels to regional surface heat island formation could be reduced by approximately 40% through the adoption of specific land use planning policies, such as zoning and subdivision regulations, and with no modifications to the size or albedo of the residential structure.

Using Remote Sensing Data and Research Results for Urban Heat Island Mitigation

NASA Technical Reports Server (NTRS)

Estes, Maury; Luvall, Jeffrey

1999-01-01

This paper provides information on the characteristics of the urban heat island, research designed to provide the data needed to develop effective urban heat island reduction strategies, and the development of local working groups to develop implementation plans. As background, an overview of research results on the urban heat island phenomenon and the resultant effect on energy usage and air quality will be explored. The use of more reflective roofing materials, paving materials, tree planting, and other initiatives will be explored as a basis for strategies to mitigate urban heat islands and improve the urban environment. Current efforts to use aircraft remote sensing data in Atlanta, Baton Rouge, Sacramento, and Salt Lake City and our work with non-profit organizations designated to lead public education and strategic development efforts will be presented. Efforts to organize working groups comprised of key stakeholders, the process followed in communicating research results, and methodology for soliciting feedback and incorporating ideas into local plans, policies and decision-making will be discussed. Challenges in developing and transferring data products and research results to stakeholders will be presented. It is our ultimate goal that such efforts be integrated into plans and/or decision models that encourage sustainable development.

Impact of pavements on the urban heat island : final project report.

DOT National Transportation Integrated Search

2016-10-01

Increasing urbanization has led to the development of Urban Heat Islands (UHIs), with serious implications for the environment. Pavements play a role in this by absorbing and storing more heat than the natural surfaces that they replace. To quantify ...

A review on the generation, determination and mitigation of urban heat island.

PubMed

Memon, Rizwan Ahmed; Leung, Dennis Y C; Chunho, Liu

2008-01-01

Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generated from urban structures, as they consume and re-radiate solar radiations, and from the anthropogenic heat sources are the main causes of UHI. The two heat sources increase the temperatures of an urban area as compared to its surroundings, which is known as Urban Heat Island Intensity (UHII). The problem is even worse in cities or metropolises with large population and extensive economic activities. The estimated three billion people living in the urban areas in the world are directly exposed to the problem, which will be increased significantly in the near future. Due to the severity of the problem, vast research effort has been dedicated and a wide range of literature is available for the subject. The literature available in this area includes the latest research approaches, concepts, methodologies, latest investigation tools and mitigation measures. This study was carried out to review and summarize this research area through an investigation of the most important feature of UHI. It was concluded that the heat re-radiated by the urban structures plays the most important role which should be investigated in details to study urban heating especially the UHI. It was also concluded that the future research should be focused on design and planning parameters for reducing the effects of urban heat island and ultimately living in a better environment.

Observation of reduced heat transport inside the magnetic island O point in the large helical device.

PubMed

Inagaki, S; Tamura, N; Ida, K; Nagayama, Y; Kawahata, K; Sudo, S; Morisaki, T; Tanaka, K; Tokuzawa, T

2004-02-06

Evidence for a reduction of heat transport inside the magnetic island O point is observed from the propagation of a cold pulse produced by a tracer encapsulated solid pellet in the Large Helical Device. A small peak and slow propagation of the cold pulse are observed inside the island. A significant result is that electron heat diffusivity inside the island is estimated to be 0.2 m(2)/s which is smaller than that outside the island by an order of magnitude.

Current and Projected Heat-Related Morbidity and Mortality in Rhode Island.

PubMed

Kingsley, Samantha L; Eliot, Melissa N; Gold, Julia; Vanderslice, Robert R; Wellenius, Gregory A

2016-04-01

Climate change is expected to cause increases in heat-related mortality, especially among the elderly and very young. However, additional studies are needed to clarify the effects of heat on morbidity across all age groups and across a wider range of temperatures. We aimed to estimate the impact of current and projected future temperatures on morbidity and mortality in Rhode Island. We used Poisson regression models to estimate the association between daily maximum temperature and rates of all-cause and heat-related emergency department (ED) admissions and all-cause mortality. We then used downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5; a standardized set of climate change model simulations) projections to estimate the excess morbidity and mortality that would be observed if this population were exposed to the temperatures projected for 2046-2053 and 2092-2099 under two representative concentration pathways (RCP): RCP 8.5 and 4.5. Between 2005 and 2012, an increase in maximum daily temperature from 75 to 85°F was associated with 1.3% and 23.9% higher rates of all-cause and heat-related ED visits, respectively. The corresponding effect estimate for all-cause mortality from 1999 through 2011 was 4.0%. The association with all-cause ED admissions was strongest for those < 18 or ≥ 65 years of age, whereas the association with heat-related ED admissions was most pronounced among 18- to 64-year-olds. If this Rhode Island population were exposed to temperatures projected under RCP 8.5 for 2092-2099, we estimate that there would be 1.2% (range, 0.6-1.6%) and 24.4% (range, 6.9-41.8%) more all-cause and heat-related ED admissions, respectively, and 1.6% (range, 0.8-2.1%) more deaths annually between April and October. With all other factors held constant, our findings suggest that the current population of Rhode Island would experience substantially higher morbidity and mortality if maximum daily temperatures increase further as projected. Kingsley SL

The correlation of urban heat island in tropical middle-class housing

NASA Astrophysics Data System (ADS)

Wazir, Zuber Angkasa

2017-11-01

A very limited number of green and sustainable construction studies have explored factors related to Urban Heat Island (UHI) in tropical middle-class housing. This paper aimed to investigate the correlation of Urban Heat Island in tropical middle-class housing in three urban housing for middle-class residents of Palembang, which were Taman Sari Kenten, TOP Jakabaring, and Talang Kelapa. Samples consisted of 125 Taman Sari Kenten housing, 27 Talang Kelapa housing, and 12 TOP Jakabaring housing. Independent variables were the resident density, socioeconomic status, house location, roof type, green area ratio, weather, time, air conditioner, pro-environment institution, and NEP scale. The Analytic method included correlation and regression. We identified that all housing had different UHI profiles where Taman Sari Kenten had the highest UHI (4.17 K), followed by Talang Kelapa (2.66 K) and TOP Jakabaring (0.66 K) against temperature in measuring station nearby, owned by BMKG (National Meteorological Station). UHI correlated with the resident density, roof type, green area ratio, weather, time, and air conditioner. The results should add to the design of ideal housing in the tropical climate for middle-class residents, focusing on its ability to mitigate Urban Heat Island.

Heat Island Mitigation Measures in Response to Climate Change Impacts

NASA Technical Reports Server (NTRS)

Quattrochi, Dale a.; Estes, Maurice, Jr.; Crosson, William; Al-Hamdan, Mohammad

2010-01-01

This slide presentation examines the effect of cities, the accompanying heat island effect, and other impacts that urbanization has had on the environment. Various satellite views of several urban areas are shown.

Urban heat islands in the subsurface of German cities

NASA Astrophysics Data System (ADS)

Menberg, K.; Blum, P.; Zhu, K.; Bayer, P.

2012-04-01

In the subsurface of many cities there are widespread and persistent thermal anomalies (subsurface urban heat islands) that result in a warming of urban aquifers. The reasons for this heating are manifold. Possible heat sources are basements of buildings, leakage of sewage systems, buried district heating networks, re-injection of cooling water and solar irradiation on paved surfaces. In the current study, the reported groundwater temperatures in several German cities, such as Berlin, Munich, Cologne and Karlsruhe, are compared. Available data sets are supplemented by temperature measurements and depth profiles in observation wells. Trend analyses are conducted with time series of groundwater temperatures, and three-dimensional groundwater temperature maps are provided. In all investigated cities, pronounced positive temperature anomalies are present. The distribution of groundwater temperatures appears to be spatially and temporally highly variable. Apparently, the increased heat input into the urban subsurface is controlled by very local and site-specific parameters. In the long-run, the superposition of various heat sources results in an extensive temperature increase. In many cases, the maximum temperature elevation is found close to the city centre. Regional groundwater temperature differences between the city centre and the rural background are up to 5 °C, with local hot spots of even more pronounced anomalies. Particular heat sources, like cooling water injections or case-specific underground constructions, can cause local temperatures > 20°C in the subsurface. Examination of the long-term variations in isotherm maps shows that temperatures have increased by about 1°C in the city, as well as in the rural background areas over the last decades. This increase could be reproduced with trend analysis of temperature data gathered from several groundwater wells. Comparison between groundwater and air temperatures in Karlsruhe, for example, also indicates a

Modifications of the urban heat island characteristics under exceptionally hot weather - A case study

NASA Astrophysics Data System (ADS)

Founda, Dimitra; Pierros, Fragiskos; Santamouris, Mathew

2016-04-01

Considerable recent research suggests that heat waves are becoming more frequent, more intense and longer in the future. Heat waves are characterised by the dominance of prolonged abnormally hot conditions related to synoptic scale anomalies, thus they affect extensive geographical areas. Heat waves (HW) have a profound impact on humans and they have been proven to increase mortality. Urban areas are known to be hotter than the surrounding rural areas due to the well documented urban heat island (UHI) phenomenon. Urban areas face increased risk under heat waves, due to the added heat from the urban heat island and increased population density. Given that urban populations keep increasing, citizens are exposed to significant heat related risk. Mitigation and adaptation strategies require a deep understanding of the response of the urban heat islands under extremely hot conditions. The response of the urban heat island under selected episodes of heat waves is examined in the city of Athens, from the comparison between stations of different characteristics (urban, suburban, coastal and rural). Two distinct episodes of heat waves occurring during summer 2000 were selected. Daily maximum air temperature at the urban station of the National Observatory of Athens (NOA) exceeded 40 0C for at least three consecutive days for both episodes. The intensity of UHI during heat waves was compared to the intensity under 'normal' conditions, represented from a period 'before' and 'after' the heat wave. Striking differences of UHI features between HW and no HW cases were observed, depending on the time of the day and the type of station. The comparison between the urban and the coastal station showed an increase of the order of 3 0C in the intensity of UHI during the HW days, as regards both daytime and nighttime conditions. The comparison between urban and a suburban (inland) station, revealed some different behaviour during HWs, with increases of the order of 3 0C in the nocturnal

[Urban heat island effect based on urban heat island source and sink indices in Shenyang, Northeast China].

PubMed

Li, Li-Guang; Xu, Shen-Lai; Wang, Hong-Bo; Zhao, Zi-Qi; Cai, Fu; Wu, Jin-Wen; Chen, Peng-Shi; Zhang, Yu-Shu

2013-12-01

Based on the remote images in 2001 and 2010, the source and sink areas of urban heat island (UHI) in Shenyang City, Northeast China were determined by GIS technique. The effect of urban regional landscape pattern on UHI effect was assessed with land surface temperature (LST), area rate index (CI) of the source and sink areas and intensity index (LI) of heat island. The results indicated that the land use type changed significantly from 2001 to 2010, which significantly changed the source and sink areas of UHI, especially in the second and third circle regions. The source and sink areas were 94.3% and 5.7% in the first circle region, 64.0% and 36.0% in the third circle region in 2001, while they were 93.4% and 6.6%, 70.2% and 29.8% in 2010, respectively. It suggested that the land use pattern extended by a round shape in Shenyang led to the corresponding UHI pattern. The LST in the study area tended to decrease from the first circle region to the third. The UHI intensity was characterized with a single center in 2001 and with several centers in 2010, and the grade of UHI intensity was in a decreasing trend from 2001 to 2010. The absolute value of CI increased from the first circle region to the third, and the L1 was close to 1, suggesting the change in land use pattern had no significant influence on UHI in Shenyang.

Monitoring the effects of land use/landcover changes on urban heat island

NASA Astrophysics Data System (ADS)

Gee, Ong K.; Sarker, Md Latifur Rahman

2013-10-01

Urban heat island effects are well known nowadays and observed in cities throughout the World. The main reason behind the effects of urban heat island (UHI) is the transformation of land use/ land cover, and this transformation is associated with UHI through different actions: i) removal of vegetated areas, ii) land reclamation from sea/river, iii) construction of new building as well as other concrete structures, and iv) industrial and domestic activity. In rapidly developing cities, urban heat island effects increases very hastily with the transformation of vegetated/ other types of areas into urban surface because of the increasing population as well as for economical activities. In this research the effect of land use/ land cover on urban heat island was investigated in two growing cities in Asia i.e. Singapore and Johor Bahru, (Malaysia) using 10 years data (from 1997 to 2010) from Landsat TM/ETM+. Multispectral visible band along with indices such as Normalized Difference Vegetation Index (NDVI), Normalized Difference Build Index (NDBI), and Normalized Difference Bareness Index (NDBaI) were used for the classification of major land use/land cover types using Maximum Likelihood Classifiers. On the other hand, land surface temperature (LST) was estimated from thermal image using Land Surface Temperature algorithm. Emissivity correction was applied to the LST map using the emissivity values from the major land use/ land cover types, and validation of the UHI map was carried out using in situ data. Results of this research indicate that there is a strong relationship between the land use/land cover changes and UHI. Over this 10 years period, significant percentage of non-urban surface was decreased but urban heat surface was increased because of the rapid urbanization. With the increase of UHI effect it is expected that local urban climate has been modified and some heat related health problem has been exposed, so appropriate measure should be taken in order to

Classifying Urban Space Types of Seoul using Time-series Heat Island map

NASA Astrophysics Data System (ADS)

Jung, S.; KIM, H.; JE, M.

2017-12-01

In August 2016, the hottest heat occurred in Korea since the weather observation started in Korea. Due to climate changes, this heat phenomenon is expected to be severe more in the future. Thus, this study analyzed the heatwave occurred in 2016 with regard to Seoul from various angles to identify the characteristics of urban regions where the heat island phenomenon occurred. To do this, first, temperature data for two days on August 6 and 12 in 2016 when the hottest heatwave occurred were collected from 287 places of automatic weather stations (AWS) installed in Seoul and adjacent suburbs. The temperature distribution of Seoul was mapped using interpolation in every hour using the collected temperature data. Second, regions in Seoul were classified using statistical methods based on spatial characteristics such as land coverage, density, use type, and traffic volume in Seoul. Third, a daily pattern of change in temperature in the classified regions was depicted with a graph, and regions were re-classified based on the daily pattern of change in temperature. Finally, the characteristics of the classified regions were re-reviewed and then, heat island occurrence, continuation, and reduction measure by region type were discussed. The analysis results showed that a pattern of heatwave occurrence was exhibited differently by the classified region type. The results also showed that not only physical characteristics such as land coverage but also socioeconomic index such as population density and floating population that induced a traffic volume influenced the pattern of heatwave occurrence despite of the same land usage regions. This study not only classified urban climate regions by existing mean temperature and specific time-point temperature but also proposed a methodology that analyzed heat island phenomenon inside cities by using time-series temperature data in a day. Furthermore, this study enabled regional classification based on heat island characteristics to

Current and Projected Heat-Related Morbidity and Mortality in Rhode Island

PubMed Central

Kingsley, Samantha L.; Eliot, Melissa N.; Gold, Julia; Vanderslice, Robert R.; Wellenius, Gregory A.

2015-01-01

Background: Climate change is expected to cause increases in heat-related mortality, especially among the elderly and very young. However, additional studies are needed to clarify the effects of heat on morbidity across all age groups and across a wider range of temperatures. Objectives: We aimed to estimate the impact of current and projected future temperatures on morbidity and mortality in Rhode Island. Methods: We used Poisson regression models to estimate the association between daily maximum temperature and rates of all-cause and heat-related emergency department (ED) admissions and all-cause mortality. We then used downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5; a standardized set of climate change model simulations) projections to estimate the excess morbidity and mortality that would be observed if this population were exposed to the temperatures projected for 2046–2053 and 2092–2099 under two representative concentration pathways (RCP): RCP 8.5 and 4.5. Results: Between 2005 and 2012, an increase in maximum daily temperature from 75 to 85°F was associated with 1.3% and 23.9% higher rates of all-cause and heat-related ED visits, respectively. The corresponding effect estimate for all-cause mortality from 1999 through 2011 was 4.0%. The association with all-cause ED admissions was strongest for those < 18 or ≥ 65 years of age, whereas the association with heat-related ED admissions was most pronounced among 18- to 64-year-olds. If this Rhode Island population were exposed to temperatures projected under RCP 8.5 for 2092–2099, we estimate that there would be 1.2% (range, 0.6–1.6%) and 24.4% (range, 6.9–41.8%) more all-cause and heat-related ED admissions, respectively, and 1.6% (range, 0.8–2.1%) more deaths annually between April and October. Conclusions: With all other factors held constant, our findings suggest that the current population of Rhode Island would experience substantially higher morbidity and mortality if

In the Shade of Affluence: The Inequitable Distribution of the Urban Heat Island

NASA Technical Reports Server (NTRS)

Harlan, Sharon L.; Brazel, Anthony J.; Jenerette, G. Darrel; Jones, Nancy S.; Larsen, Larissa; Prashad, Lela

2008-01-01

The urban heat island is an unintended consequence of humans building upon rural and native landscapes. We hypothesized that variations in vegetation and land use patterns across an urbanizing regional landscape would produce a temperature distribution that was spatially heterogeneous and correlated with the social characteristics of urban neighborhoods. Using biophysical and social data scaled to conform to US census geography, we found that affluent whites were more likely to live in vegetated and less climatically stressed neighborhoods likely to live in than low-income Latinos in Phoenix, Arizona. Affluent neighborhoods had cooler summer temperatures that reduced exposure to outdoor heat-related health risks, especially during a heat wave period. In addition to being warmer, poorer neighborhoods lacked critical resources in their physical and social environments to help them cope with extreme heat. Increased average temperatures due to climate change are expected to exacerbate the impacts of urban heat islands.

A global analysis of the urban heat island effect based on multisensor satellite data

NASA Astrophysics Data System (ADS)

Xiao, J.; Frolking, S. E.; Milliman, T. E.; Schneider, A.; Friedl, M. A.

2017-12-01

Human population is rapidly urbanizing. In much of the world, cities are prone to hotter weather than surrounding rural areas - so-called `urban heat islands' - and this effect can have mortal consequences during heat waves. During the daytime, when the surface energy balance is driven by incoming solar radiation, the magnitude of urban warming is strongly influenced by surface albedo and the capacity to evaporate water (i.e., there is a strong relationship between vegetated land fraction and the ratio of sensible to latent heat loss or Bowen ratio). At nighttime, urban cooling is often inhibited by the thermal inertia of the built environment and anthropogenic heat exhaust from building and transportation energy use. We evaluated a suite of global remote sensing data sets representing a range of urban characteristics against MODIS-derived land-surface temperature differences between urban and surrounding rural areas. We included two new urban datasets in this analysis - MODIS-derived change in global urban extent and global urban microwave backscatter - along with several MODIS standard products and DMSP/OLS nighttime lights time series data. The global analysis spanned a range of urban characteristics that likely influence the magnitude of daytime and/or nighttime urban heat islands - urban size, population density, building density, state of development, impervious fraction, eco-climatic setting. Specifically, we developed new satellite datasets and synthesizing these with existing satellite data into a global database of urban land surface parameters, used two MODIS land surface temperature products to generate time series of daytime and nighttime urban heat island effects for 30 large cities across the globe, and empirically analyzed these data to determine specifically which remote sensing-based characterizations of global urban areas have explanatory power with regard to both daytime and nighttime urban heat islands.

Comparative and Combinative Study of Urban Heat island in Wuhan City with Remote Sensing and CFD Simulation

PubMed Central

Li, Kun; Yu, Zhuang

2008-01-01

Urban heat islands are one of the most critical urban environment heat problems. Landsat ETM+ satellite data were used to investigate the land surface temperature and underlying surface indices such as NDVI and NDBI. A comparative study of the urban heat environment at different scales, times and locations was done to verify the heat island characteristics. Since remote sensing technology has limitations for dynamic flow analysis in the study of urban spaces, a CFD simulation was used to validate the improvement of the heat environment in a city by means of wind. CFD technology has its own shortcomings in parameter setting and verification, while RS technology is helpful to remedy this. The city of Wuhan and its climatological condition of being hot in summer and cold in winter were chosen to verify the comparative and combinative application of RS with CFD in studying the urban heat island. PMID:27873893

Subsurface urban heat islands in German cities.

PubMed

Menberg, Kathrin; Bayer, Peter; Zosseder, Kai; Rumohr, Sven; Blum, Philipp

2013-01-01

Little is known about the intensity and extension of subsurface urban heat islands (UHI), and the individual role of the driving factors has not been revealed either. In this study, we compare groundwater temperatures in shallow aquifers beneath six German cities of different size (Berlin, Munich, Cologne, Frankfurt, Karlsruhe and Darmstadt). It is revealed that hotspots of up to +20K often exist, which stem from very local heat sources, such as insufficiently insulated power plants, landfills or open geothermal systems. When visualizing the regional conditions in isotherm maps, mostly a concentric picture is found with the highest temperatures in the city centers. This reflects the long-term accumulation of thermal energy over several centuries and the interplay of various factors, particularly in heat loss from basements, elevated ground surface temperatures (GST) and subsurface infrastructure. As a primary indicator to quantify and compare large-scale UHI intensity the 10-90%-quantile range UHII(10-90) of the temperature distribution is introduced. The latter reveals, in comparison to annual atmospheric UHI intensities, an even more pronounced heating of the shallow subsurface. Copyright © 2012 Elsevier B.V. All rights reserved.

Analysis of the effect of local heat island in Seoul using LANDSAT image

NASA Astrophysics Data System (ADS)

Lee, K. I.; Ryu, J.; Jeon, S. W.

2017-12-01

The increase in the rate of industrialization due to urbanization has caused the Urban Heat Island phenomenon which means that the temperature of the city is higher than the surrounding area, and its intensity is increasing with climate change. Among the cities where heat island phenomenon occur, Seoul city has different degree of urbanization, green area ratio, energy consumption, and population density by each district unit. As a result, the strength of heat island phenomenon is also different. The average maximum temperature in each region may differ by more than 3 °, which is bigger than the suburbs in Seoul and it means that analysis of UHI effect by regional unit is needed. Therefore, this study is to extract the UHI Intensity of the regional unit of the Seoul Metropolitan City using the satellite image, analyzed the difference of intensity according to the regional unit. And do linear regression analysis with variables included in three categories(regional meteorological conditions, anthropogenic heat generation, land use factors). As a result, The UHI Intensity value of the Gu unit is significantly different from the UHI Intensity distribution of the Dong unit. The variable having the greatest positive correlation with UHI Intensity was NDBI(Normalized Difference Built-up Index) which shows the distribution of urban area, and Urban area ratio also has high correlation. There was a negative correlation between mean wind speed but there was no significant correlation between population density and power consumption. The result of this study is to identify the regional difference of UHI Intensity and to identify the factors inducing heat island phenomenon. so It is expected that it will provide direction in urban thermal environment design and policy development in the future.

One Hundred Years of New York City's "Urban Heat Island": Temperature Trends and Public Health Impacts

NASA Astrophysics Data System (ADS)

Rosenthal, J. E.; Knowlton, K. M.; Rosenzweig, C.; Goldberg, R.; Kinney, P. L.

2003-12-01

In this paper, we examine the relationship between the historical development of New York City and its effect on the urban climate. Urban "heat islands" (UHI) are created principally by man-made surfaces, including concrete, dark roofs, asphalt lots and roads, which absorb most of the sunlight falling on them and reradiate that energy as heat. Many urban streets have fewer trees and other vegetation to shade buildings, block solar radiation and cool the air by evapotranspiration. The historical development of the NYC heat island effect was assessed in terms of average temperature differences of the city center relative to its surrounding 31-county metropolitan region, comprised of parts of New York State, New Jersey, and Connecticut. Monthly maximum and minimum temperatures for 1900-1997 were obtained from NOAA's National Climatic Data Center, the NASA-Goddard Institute for Space Studies, and the Lamont-Doherty Earth Observatory of Columbia University for 24 weather stations within the region that are part of the U.S. Historical Climatology Network. Analysis of annual mean temperatures shows an increasing difference between NYC (Central Park weather station) and its surrounding region over the twentieth century. Analysis of the temperature differences over time between NY Central Park (NYCP) station and 23 regional weather stations classified according to distance and level of urbanization show a heat island effect existing in NYC, with mean temperatures in the NYCP Station generally higher than the surrounding stations, ranging from 1.20\\deg C to 3.02\\deg C. A difference of at least 1\\deg C already existed at the beginning of the 20th century between the mean temperature in NYC and its surrounding rural areas, and this difference increased over the twentieth century. There was a significant decrease in the monthly and seasonal variability of the UHI effect over the century. Temperature extremes and summertime heat can create heat stress and other health

Measuring and Interpreting the Urban Heat Island: A Student Field Project

ERIC Educational Resources Information Center

Nicholas, Frank

1976-01-01

Climatology field experiences are described showing that midlatitude cities show manifestations of the modified thermal environment known as the heat island. Suggestions for project planning and precautions regarding weather, timing, and safety are included. (AV)

Interactions between urban heat islands and heat waves

NASA Astrophysics Data System (ADS)

Zhao, Lei; Oppenheimer, Michael; Zhu, Qing; Baldwin, Jane W.; Ebi, Kristie L.; Bou-Zeid, Elie; Guan, Kaiyu; Liu, Xu

2018-03-01

Heat waves (HWs) are among the most damaging climate extremes to human society. Climate models consistently project that HW frequency, severity, and duration will increase markedly over this century. For urban residents, the urban heat island (UHI) effect further exacerbates the heat stress resulting from HWs. Here we use a climate model to investigate the interactions between the UHI and HWs in 50 cities in the United States under current climate and future warming scenarios. We examine UHI2m (defined as urban-rural difference in 2m-height air temperature) and UHIs (defined as urban-rural difference in radiative surface temperature). Our results show significant sensitivity of the interaction between UHI and HWs to local background climate and warming scenarios. Sensitivity also differs between daytime and nighttime. During daytime, cities in the temperate climate region show significant synergistic effects between UHI and HWs in current climate, with an average of 0.4 K higher UHI2m or 2.8 K higher UHIs during HWs than during normal days. These synergistic effects, however, diminish in future warmer climates. In contrast, the daytime synergistic effects for cities in dry regions are insignificant in the current climate, but emerge in future climates. At night, the synergistic effects are similar across climate regions in the current climate, and are stronger in future climate scenarios. We use a biophysical factorization method to disentangle the mechanisms behind the interactions between UHI and HWs that explain the spatial-temporal patterns of the interactions. Results show that the difference in the increase of urban versus rural evaporation and enhanced anthropogenic heat emissions (air conditioning energy use) during HWs are key contributors to the synergistic effects during daytime. The contrast in water availability between urban and rural land plays an important role in determining the contribution of evaporation. At night, the enhanced release of stored

Using USEPA’s EnviroAtlas to Identify Locations for Urban Heat Island Abatement

EPA Science Inventory

Excessive heat in the summer months can be dangerous to human health and increases demand for water and electricity. Cities tend to experience higher temperatures than the surrounding natural area, a phenomenon known as an urban heat island (UHI). Trees are provisioners of ecosys...

Methods to Estimate Acclimatization to Urban Heat Island Effects on Heat- and Cold-Related Mortality.

PubMed

Milojevic, Ai; Armstrong, Ben G; Gasparrini, Antonio; Bohnenstengel, Sylvia I; Barratt, Benjamin; Wilkinson, Paul

2016-07-01

Investigators have examined whether heat mortality risk is increased in neighborhoods subject to the urban heat island (UHI) effect but have not identified degrees of difference in susceptibility to heat and cold between cool and hot areas, which we call acclimatization to the UHI. We developed methods to examine and quantify the degree of acclimatization to heat- and cold-related mortality in relation to UHI anomalies and applied these methods to London, UK. Case-crossover analyses were undertaken on 1993-2006 mortality data from London UHI decile groups defined by anomalies from the London average of modeled air temperature at a 1-km grid resolution. We estimated how UHI anomalies modified excess mortality on cold and hot days for London overall and displaced a fixed-shape temperature-mortality function ("shifted spline" model). We also compared the observed associations with those expected under no or full acclimatization to the UHI. The relative risk of death on hot versus normal days differed very little across UHI decile groups. A 1°C UHI anomaly multiplied the risk of heat death by 1.004 (95% CI: 0.950, 1.061) (interaction rate ratio) compared with the expected value of 1.070 (1.057, 1.082) if there were no acclimatization. The corresponding UHI interaction for cold was 1.020 (0.979, 1.063) versus 1.030 (1.026, 1.034) (actual versus expected under no acclimatization, respectively). Fitted splines for heat shifted little across UHI decile groups, again suggesting acclimatization. For cold, the splines shifted somewhat in the direction of no acclimatization, but did not exclude acclimatization. We have proposed two analytical methods for estimating the degree of acclimatization to the heat- and cold-related mortality burdens associated with UHIs. The results for London suggest relatively complete acclimatization to the UHI effect on summer heat-related mortality, but less clear evidence for cold-related mortality. Milojevic A, Armstrong BG, Gasparrini A

Summer in the City - Assessing and Communicating the Richmond, VA Urban Heat Island to the Public and Policymakers

NASA Astrophysics Data System (ADS)

Hoffman, J. S.; Maurakis, E. G.; Shandas, V.

2017-12-01

The local impacts of global climate change are generally underestimated or misunderstood by the public and policymakers as far-off, future problems. However, differential and regional surface warming trends are exacerbated in urban areas due to the radiative properties of impervious surfaces like buildings and roads relative to natural landscapes. Decades of research illustrate that this unnatural radiative imbalance in the built environment gives rise to the well-studied urban heat island effect, whereby air temperatures in urban areas are several degrees warmer than in surrounding non-urbanized areas. In this way, the urban heat island effect presents a unique opportunity to highlight the human influence on Earth systems and at the same time mobilize local community-scale action to mitigate and become resilient to climate change impacts on tangible, experiential time scales. However, public stakeholders, city planners, and policymakers may view the urban heat island effect and its mitigation strategies through varying degrees of climatological, public health, and urban development knowledge and interest. This variation in stakeholder engagement highlights the need for individualized science communication strategies for each audience in order to maximize understanding of the scientific outcomes and tactics for mitigating the urban heat island effect. The City of Richmond, Virginia is currently developing a climate action plan as part of their greenhouse gas emission reduction initiative, RVAgreen 2050, and its recently announced "Richmond 300," a 20-year city development master plan. These initiatives provide the policy backdrop for a public and stakeholder education campaign centered on communicating urban heat island effects and resilience strategies. As such, the Science Museum of Virginia led the city's first urban heat island assessment using citizen science and leveraging a network of local university, non-profit, and city government stakeholders. Here, we

The Urban Heat Island Phenomenon: How Its Effects Can Influence Environmental Decision Making in Your Community

NASA Technical Reports Server (NTRS)

Estes, Maurice G., Jr.; Quattrochi, Dale; Stasiak, Elizabeth

2003-01-01

Reinvestment in urban centers is breathing new life into neighborhoods that have been languishing as a result of explosive suburban development over the past several decades. In cities all over the country, adaptive reuse, brownfields redevelopment, transforming urban landscapes, economies, and quality of life. However, the way in which this development occurs has the potential to exacerbate the urban heat island (UHI) phenomenon, an existing problem in many areas and one which poses a threat to the long-term sustainability and environmental quality of cities. The UHI phenomenon is rooted in the science of how the land covers respond to solar heating and can adversely effect the environment. This phenomenon is responsible for urban centers having higher air temperatures and poorer air quality than suburban areas. In addition, the UHI phenomenon causes metrological occurrences, degrades water quality, increases energy demands, poses threats to public health and contributes to global warming. While the name of the phenomenon implies that is solely an urban issue, research has shown that the effects of the UHI are becoming prevalent in suburbs, as well. The UHI phenomenon can plague regions - urban centers and their suburbs. Furthermore, heat islands have been found to exist in both city centers and suburban communities. As suburban areas increasingly develop using land covers and building materials common to urban areas, they are inheriting urban problems - such as heat islands. In this way, it may be necessary for non-urban communities to engage in heat island mitigation. The good news is that through education and planning, the effects of the UHI phenomenon can be prevented and mitigated. Heat islands are more a product of urban design rather than the density of development. Therefore, cities can continue to grow and develop without exacerbating the UHI by employing sustainable development strategies.

Bifurcation physics of magnetic islands and stochasticity explored by heat pulse propagation studies in toroidal plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ida, K.; Kobayashi, T.; Yoshinuma, M.

Bifurcation physics of the magnetic island was investigated using the heat pulse propagation technique produced by the modulation of electron cyclotron heating. There are two types of bifurcation phenomena observed in LHD and DIII-D. One is a bifurcation of the magnetic topology between nested and stochastic fields. The nested state is characterized by the bi-directional (inward and outward) propagation of the heat pulse with slow propagation speed. The stochastic state is characterized by the fast propagation of the heat pulse with electron temperature flattening. The other bifurcation is between magnetic island with larger thermal diffusivity and that with smaller thermalmore » diffusivity. The damping of toroidal flow is observed at the O-point of the magnetic island both in helical plasmas and in tokamak plasmas during a mode locking phase with strong flow shears at the boundary of the magnetic island. Associated with the stochastization of the magnetic field, the abrupt damping of toroidal flow is observed in LHD. The toroidal flow shear shows a linear decay, while the ion temperature gradient shows an exponential decay. Lastly, this observation suggests that this flow damping is due to the change in the non-diffusive term of momentum transport.« less

Bifurcation physics of magnetic islands and stochasticity explored by heat pulse propagation studies in toroidal plasmas

DOE PAGES

Ida, K.; Kobayashi, T.; Yoshinuma, M.; ...

2016-07-29

Bifurcation physics of the magnetic island was investigated using the heat pulse propagation technique produced by the modulation of electron cyclotron heating. There are two types of bifurcation phenomena observed in LHD and DIII-D. One is a bifurcation of the magnetic topology between nested and stochastic fields. The nested state is characterized by the bi-directional (inward and outward) propagation of the heat pulse with slow propagation speed. The stochastic state is characterized by the fast propagation of the heat pulse with electron temperature flattening. The other bifurcation is between magnetic island with larger thermal diffusivity and that with smaller thermalmore » diffusivity. The damping of toroidal flow is observed at the O-point of the magnetic island both in helical plasmas and in tokamak plasmas during a mode locking phase with strong flow shears at the boundary of the magnetic island. Associated with the stochastization of the magnetic field, the abrupt damping of toroidal flow is observed in LHD. The toroidal flow shear shows a linear decay, while the ion temperature gradient shows an exponential decay. Lastly, this observation suggests that this flow damping is due to the change in the non-diffusive term of momentum transport.« less

Methods to Estimate Acclimatization to Urban Heat Island Effects on Heat- and Cold-Related Mortality

PubMed Central

Milojevic, Ai; Armstrong, Ben G.; Gasparrini, Antonio; Bohnenstengel, Sylvia I.; Barratt, Benjamin; Wilkinson, Paul

2016-01-01

Background: Investigators have examined whether heat mortality risk is increased in neighborhoods subject to the urban heat island (UHI) effect but have not identified degrees of difference in susceptibility to heat and cold between cool and hot areas, which we call acclimatization to the UHI. Objectives: We developed methods to examine and quantify the degree of acclimatization to heat- and cold-related mortality in relation to UHI anomalies and applied these methods to London, UK. Methods: Case–crossover analyses were undertaken on 1993–2006 mortality data from London UHI decile groups defined by anomalies from the London average of modeled air temperature at a 1-km grid resolution. We estimated how UHI anomalies modified excess mortality on cold and hot days for London overall and displaced a fixed-shape temperature-mortality function (“shifted spline” model). We also compared the observed associations with those expected under no or full acclimatization to the UHI. Results: The relative risk of death on hot versus normal days differed very little across UHI decile groups. A 1°C UHI anomaly multiplied the risk of heat death by 1.004 (95% CI: 0.950, 1.061) (interaction rate ratio) compared with the expected value of 1.070 (1.057, 1.082) if there were no acclimatization. The corresponding UHI interaction for cold was 1.020 (0.979, 1.063) versus 1.030 (1.026, 1.034) (actual versus expected under no acclimatization, respectively). Fitted splines for heat shifted little across UHI decile groups, again suggesting acclimatization. For cold, the splines shifted somewhat in the direction of no acclimatization, but did not exclude acclimatization. Conclusions: We have proposed two analytical methods for estimating the degree of acclimatization to the heat- and cold-related mortality burdens associated with UHIs. The results for London suggest relatively complete acclimatization to the UHI effect on summer heat–related mortality, but less clear evidence for

The footprint of urban heat island effect in China

Treesearch

Decheng Zhou; Shuqing Zhao; Liangxia Zhang; Ge Sun; Yongqiang Liu

2015-01-01

Urban heat island (UHI) is one major anthropogenic modification to the Earth system that transcends its physical boundary. Using MODIS data from 2003 to 2012, we showed that the UHI effect decayed exponentially toward rural areas for majority of the 32 Chinese cities. We found an obvious urban/ rural temperature “cliff”, and estimated that the footprint of UHI effect (...

Combined Geothermal Potential of Subsurface Urban Heat Islands

NASA Astrophysics Data System (ADS)

Benz, Susanne; Bayer, Peter; Menberg, Kathrin; Blum, Philipp

2016-04-01

The subsurface urban heat island (SUHI) can be seen as a geothermal potential in form of elevated groundwater temperatures caused by anthropogenic heat fluxes into the subsurface. In this study, these fluxes are quantified for an annual timeframe in two German cities, Karlsruhe and Cologne. Our two-dimensional (2D) statistical analytical model determines the renewable and sustainable geothermal potential caused by six vertical anthropogenic heat fluxes into the subsurface: from (1) elevated ground surface temperatures, (2) basements, (3) sewage systems, (4) sewage leakage, (5) subway tunnels, and (6) district heating networks. The results show that at present 2.15 ± 1.42 PJ and 0.99 ± 0.32 PJ of heat are annually transported into the shallow groundwater of Karlsruhe and Cologne, respectively, due to anthropogenic heat fluxes into the subsurface. This is sufficient to sustainably cover 32% and 9% of the annual residential space heating demand of Karlsruhe and Cologne, respectively. However, most of the discussed anthropogenic fluxes into the subsurface are conductive heat fluxes and therefore dependent on the groundwater temperature itself. Accordingly, a decrease in groundwater temperature back to its natural (rural) state, achieved through the use of geothermal heat pumps, will increase these fluxes and with them the sustainable potential. Hence, we propose the introduction of a combined geothermal potential that maximizes the sustainability of urban shallow geothermal energy use and the efficiency of shallow geothermal systems by balancing groundwater temperature with anthropogenic heat fluxes into the subsurface. This will be a key element in the development of a demand-oriented, cost-efficient geothermal management tool with an additional focus on the sustainability of the urban heat sources.

[Applicability of traditional landscape metrics in evaluating urban heat island effect].

PubMed

Chen, Ai-Lian; Sun, Ran-Hao; Chen, Li-Ding

2012-08-01

By using 24 landscape metrics, this paper evaluated the urban heat island effect in parts of Beijing downtown area. QuickBird (QB) images were used to extract the landscape type information, and the thermal bands from Landsat Enhanced Thematic Mapper Plus (ETM+) images were used to extract the land surface temperature (LST) in four seasons of the same year. The 24 landscape pattern metrics were calculated at landscape and class levels in a fixed window with 120 mx 120 m in size, with the applicability of these traditional landscape metrics in evaluating the urban heat island effect examined. Among the 24 landscape metrics, only the percentage composition of landscape (PLAND), patch density (PD), largest patch index (LPI), coefficient of Euclidean nearest-neighbor distance variance (ENN_CV), and landscape division index (DIVISION) at landscape level were significantly correlated with the LST in March, May, and November, and the PLAND, LPI, DIVISION, percentage of like adjacencies, and interspersion and juxtaposition index at class level showed significant correlations with the LST in March, May, July, and December, especially in July. Some metrics such as PD, edge density, clumpiness index, patch cohesion index, effective mesh size, splitting index, aggregation index, and normalized landscape shape index showed varying correlations with the LST at different class levels. The traditional landscape metrics could not be appropriate in evaluating the effects of river on LST, while some of the metrics could be useful in characterizing urban LST and analyzing the urban heat island effect, but screening and examining should be made on the metrics.

Urban Heat Island phenomenon in extreme continental climate (Astana, Kazakhstan)

NASA Astrophysics Data System (ADS)

Konstantinov, Pavel; Akhmetova, Alina

2015-04-01

Urban Heat Island (UHI) phenomenon is well known in scientific literature since first half of the 19th century [1]. By now a wide number of world capitals is described from climatological point of view, especially in mid-latitudes. In beginning of XXI century new studies focus on heat island of tropical cities. However dynamics UHI in extreme continental climates is insufficiently investigated, due to the fact that there isn't large cities in Europe and Northern America within that climate type. In this paper we investigate seasonal and diurnal dynamics UHI intensity for Astana, capital city of Kazakhstan (population larger than 835 000 within the city) including UHI intensity changes on different time scales. Now (since 1998) Astana is the second coldest capital city in the world after Ulaanbaatar, Mongolia [3] For this study we use the UHI investigation technology, described in [2]. According to this paper, we selected three stations: one located into city in high and midrise buildings area (including extensive lowrise and high-energy industrial - LCZ classification) and two others located in rural site (sparsely built or open-set and lightweight lowrise according LCZ classification). Also these stations must be close by distance (less than 100 km) and altitude. Therefore, first for Astana city were obtained numerical evaluations for UHI climate dynamics, UHI dependence of synoptic situations and total UHI climatology on monthly and daily averages. References: 1.Howard, L. (1833) The Climate of London, Deduced from Meteorological Observations. Volume 2, London. 2.Kukanova E.A., Konstantinov P.I. An urban heat islands climatology in Russia and linkages to the climate change In Geophysical Research Abstracts, volume 16 of EGU General Assembly, pages EGU2014-10833-1, Germany, 2014. Germany. 3.www.pogoda.ru.net

Monitoring Spatiotemporal Changes of Heat Island in Babol City due to Land Use Changes

NASA Astrophysics Data System (ADS)

Alavi Panah, S. K.; Kiavarz Mogaddam, M.; Karimi Firozjaei, M.

2017-09-01

Urban heat island is one of the most vital environmental risks in urban areas. The advent of remote sensing technology provides better visibility due to the integrated view, low-cost, fast and effective way to study and monitor environmental and humanistic changes. The aim of this study is a spatiotemporal evaluation of land use changes and the heat island in the time period of 1985-2015 for the studied area in the city of Babol. For this purpose, multi-temporal Landsat images were used in this study. For calculating the land surface temperature (LST), single-channel and maximum likelihood algorithms were used, to classify Images. Therefore, land use changes and LST were examined, and thereby the relationship between land-use changes was analyzed with the normalized LST. By using the average and standard deviation of normalized thermal images, the area was divided into five temperature categories, inter alia, very low, low, medium, high and very high and then, the heat island changes in the studied time period were investigated. The results indicate that land use changes for built-up lands increased by 92%, and a noticeable decrease was observed for agricultural lands. The Built-up land changes trend has direct relation with the trend of normalized surface temperature changes. Low and very low-temperature categories which follow a decreasing trend, are related to lands far away from the city. Also, high and very high-temperature categories whose areas increase annually, are adjacent to the city center and exit ways of the town. The results emphasize on the importance of attention of urban planners and managers to the urban heat island as an environmental risk.

Agriculture and irrigation as potential drivers of urban heat island

NASA Astrophysics Data System (ADS)

Kumar, R.; Buzan, J. R.; Mishra, V.; Kumar, R.; Shindell, D. T.; Huber, M.

2017-12-01

More than half the population are urban dwellers and are most vulnerable to global environmental changes. Urban extents are more prone to intense heating as compared to the surroundings rural area. Presently about 33% of India's population lives in the urban area and is expected to rise steeply, so a better understanding of the phenomenon affecting the urban population is very much important. Urban Heat Island (UHI) is a well-known phenomenon which potentially affects energy consumption, spreading of diseases and mortality. In general, almost all (90%) of the major urban area of the country faces UHI at night time in the range (1-5 °C) while 60% of the regions face Urban Cool Island (UCI) in the range of -1 to 6 °C in day time. Our observations and simulations show that vegetation and irrigation in the surrounding non urban directly affects day time Urban Cool Island effects. This is due to the relative cooling by vegetation and irrigated lands in the vicinity of these urban regions. There is a contrasting variation in UHI/UCI intensities in different seasons and in different time of the day. Most of the urban regions face UHI effect in summers whereas this phenomenton reverses in winters. Daytime UCI is more prominent in the months of April and May due to minimum availability of moisture. We observed that apart from vegetation and irrigation, aerosol is also an important factor governing UHI phenomenon.

Trends of urban surface temperature and heat island characteristics in the Mediterranean

NASA Astrophysics Data System (ADS)

Benas, Nikolaos; Chrysoulakis, Nektarios; Cartalis, Constantinos

2017-11-01

Urban air temperature studies usually focus on the urban canopy heat island phenomenon, whereby the city center experiences higher near surface air temperatures compared to its surrounding non-urban areas. The Land Surface Temperature (LST) is used instead of urban air temperature to identify the Surface Urban Heat Island (SUHI). In this study, the nighttime LST and SUHI characteristics and trends in the seventeen largest Mediterranean cities were investigated, by analyzing satellite observations for the period 2001-2012. SUHI averages and trends were based on an innovative approach of comparing urban pixels to randomly selected non-urban pixels, which carries the potential to better standardize satellite-derived SUHI estimations. A positive trend for both LST and SUHI for the majority of the examined cities was documented. Furthermore, a 0.1 °C decade-1 increase in urban LST corresponded to an increase in SUHI by about 0.04 °C decade-1. A longitudinal differentiation was found in the urban LST trends, with higher positive values appearing in the eastern Mediterranean. Examination of urban infrastructure and development factors during the same period revealed correlations with SUHI trends, which can be used to explain differences among cities. However, the majority of the cities examined show considerably increased trends in terms of the enhancement of SUHI. These findings are considered important so as to promote sustainable urbanization, as well as to support the development of heat island adaptation and mitigation plans in the Mediterranean.

Role of City Texture in Urban Heat Islands at Nighttime

NASA Astrophysics Data System (ADS)

Sobstyl, J. M.; Emig, T.; Qomi, M. J. Abdolhosseini; Ulm, F.-J.; Pellenq, R. J.-M.

2018-03-01

An urban heat island (UHI) is a climate phenomenon that results in an increased air temperature in cities when compared to their rural surroundings. In this Letter, the dependence of an UHI on urban geometry is studied. Multiyear urban-rural temperature differences and building footprints data combined with a heat radiation scaling model are used to demonstrate for more than 50 cities worldwide that city texture—measured by a building distribution function and the sky view factor—explains city-to-city variations in nocturnal UHIs. Our results show a strong correlation between nocturnal UHIs and the city texture.

Role of City Texture in Urban Heat Islands at Nighttime.

PubMed

Sobstyl, J M; Emig, T; Qomi, M J Abdolhosseini; Ulm, F-J; Pellenq, R J-M

2018-03-09

An urban heat island (UHI) is a climate phenomenon that results in an increased air temperature in cities when compared to their rural surroundings. In this Letter, the dependence of an UHI on urban geometry is studied. Multiyear urban-rural temperature differences and building footprints data combined with a heat radiation scaling model are used to demonstrate for more than 50 cities worldwide that city texture-measured by a building distribution function and the sky view factor-explains city-to-city variations in nocturnal UHIs. Our results show a strong correlation between nocturnal UHIs and the city texture.

Opportunities for Saving Energy and Improving Air Quality in Urban Heat Islands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akbari, Hashem

2007-07-01

World energy use is the main contributor to atmospheric CO2. In 2002, about 7.0 giga metric tons of carbon (GtC) were emitted internationally by combustion of gas, liquid, and solid fuels (CDIAC, 2006), 2 to 5 times the amount contributed by deforestation (Brown et al., 1988). The share of atmospheric carbon emissions for the United States from fossil fuel combustion was 1.6 GtC. Increasing use of fossil fuel and deforestation together have raised atmospheric CO{sub 2} concentration some 25% over the last 150 years. According to global climate models and preliminary measurements, these changes in the composition of the atmospheremore » have already begun raising the Earth's average temperature. If current energy trends continue, these changes could drastically alter the Earth's temperature, with unknown but potentially catastrophic physical and political consequences. During the last three decades, increased energy awareness has led to conservation efforts and leveling of energy consumption in the industrialized countries. An important byproduct of this reduced energy use is the lowering of CO{sub 2} emissions. Of all electricity generated in the United States, about one-sixth is used to air-condition buildings. The air-conditioning use is about 400 tera-watt-hours (TWh), equivalent to about 80 million metric tons of carbon (MtC) emissions, and translating to about $40 billion (B) per year. Of this $40 B/year, about half is used in cities that have pronounced 'heat islands'. The contribution of the urban heat island to the air-conditioning demand has increased over the last 40 years and it is currently at about 10%. Metropolitan areas in the United States (e.g., Los Angeles, Phoenix, Houston, Atlanta, and New York City) have typically pronounced heat islands that warrant special attention by anyone concerned with broad-scale energy efficiency (HIG, 2006). The ambient air is primarily heated through three processes: direct absorption of solar radiation, convection

Thermal signatures of urban land cover types: High-resolution thermal infrared remote sensing of urban heat island in Huntsville, AL

NASA Technical Reports Server (NTRS)

Lo, Chor Pang

1996-01-01

The main objective of this research is to apply airborne high-resolution thermal infrared imagery for urban heat island studies, using Huntsville, AL, a medium-sized American city, as the study area. The occurrence of urban heat islands represents human-induced urban/rural contrast, which is caused by deforestation and the replacement of the land surface by non-evaporating and non-porous materials such as asphalt and concrete. The result is reduced evapotranspiration and more rapid runoff of rain water. The urban landscape forms a canopy acting as a transitional zone between the atmosphere and the land surface. The composition and structure of this canopy have a significant impact on the thermal behavior of the urban environment. Research on the trends of surface temperature at rapidly growing urban sites in the United States during the last 30 to 50 years suggests that significant urban heat island effects have caused the temperatures at these sites to rise by 1 to 2 C. Urban heat islands have caused changes in urban precipitation and temperature that are at least similar to, if not greater than, those predicted to develop over the next 100 years by global change models. Satellite remote sensing, particularly NOAA AVHRR thermal data, has been used in the study of urban heat islands. Because of the low spatial resolution (1.1 km at nadir) of the AVHRR data, these studies can only examine and map the phenomenon at the macro-level. The present research provides the rare opportunity to utilize 5-meter thermal infrared data acquired from an airplane to characterize more accurately the thermal responses of different land cover types in the urban landscape as input to urban heat island studies.

Sustainable Management of Urban Heat Islands

NASA Astrophysics Data System (ADS)

Zhu, K.; Rumohr, S.; Balke, K.-D.; Bayer, P.; Blum, P.

2009-04-01

In recent years, geothermal energy has become increasingly popular, because it offers a number of advantages over traditional energy sources based on fossil fuels. It is a renewable energy source, it is clean and safe for the surrounding environment, and it also contributes to reduction of CO2 emissions. Geothermal energy systems are recognized as one of the most efficient heating and cooling systems on the market. Therefore, there is great chance for future growth of geothermal energy use, particularly in densely populated urban regions. But there are also drawbacks: In many large cities, groundwater is heated up by several degrees (~ 5˚ C) compared to the surrounding areas. Causes might be microclimatic changes in the urban environment and the heating effect of sewage effluents. In fact, a major role plays overutilization of the ground as a cooling medium during the hot seasons for the air conditioning of large office buildings. The focus of this project is set on sustainable geothermal use in such large and densely populated areas, which are also called "urban heat islands". Previous studies focus on spatial temperature trends in the subsurface, and only a few have been able to reveal temporal trends, for which long-term measurement records are needed. This study is dedicated to two German locations: the city of Frankfurt/Main and the city of Cologne. The purpose of the study in Frankfurt is a comprehensive field investigation of the spatial temperature variations in the underlying aquifers, while in Cologne the attention is also on the temporal trends of urban groundwater temperatures. Of particular interest is not only to develop a sustainable management concept, but also a quantitative geophysical and hydrogeological assessment. For the city of Frankfurt/Main, the Hessian Agency for the Environment and Geology (HLUG) provides access to ongoing, highly spatially resolved field measurement locations. For Cologne, about 40 years old intensive temperature

Satellite-based detection of global urban heat-island temperature influence

USGS Publications Warehouse

Gallo, K.P.; Adegoke, Jimmy O.; Owen, T.W.; Elvidge, C.D.

2002-01-01

This study utilizes a satellite-based methodology to assess the urban heat-island influence during warm season months for over 4400 stations included in the Global Historical Climatology Network of climate stations. The methodology includes local and regional satellite retrievals of an indicator of the presence green photosynthetically active vegetation at and around the stations. The difference in local and regional samples of the normalized difference vegetation index (NDVI) is used to estimate differences in mean air temperature. Stations classified as urban averaged 0.90??C (N. Hemisphere) and 0.92??C (S. Hemisphere) warmer than the surrounding environment on the basis of the NDVI-derived temperature estimates. Additionally, stations classified as rural averaged 0.19??C (N. Hemisphere) and 0.16??C (S. Hemisphere) warmer than the surrounding environment. The NDVI-derived temperature estimates were found to be in reasonable agreement with temperature differences observed between climate stations. The results suggest that satellite-derived data sets can be used to estimate the urban heat-island temperature influence on a global basis and that a more detailed analysis of rural stations and their surrounding environment may be necessary to assure that temperature trends derived from assumed rural environments are not influenced by changes in land use/land cover. Copyright 2002 by the American Geophysical Union.

The urban physical environment: temperature and urban heat islands. Chapter 2

Treesearch

Gordon M. Heisler; Anthony J. Brazel

2010-01-01

The term urban heat island (UHI) describes the phenomenon in which cities are generally warmer than adjacent rural areas. The UHI effect is strongest with skies free of clouds and with low wind speeds. In moist temperate climates, the UHI effect causes cities to be slightly warmer in midday than rural areas, whereas in dry climates, irrigation of vegetation in cites...

Comparison of different methods for the assessment of the urban heat island in Stuttgart, Germany.

PubMed

Ketterer, Christine; Matzarakis, Andreas

2015-09-01

This study of the urban heat island (UHI) aims to support planning authorities by going beyond the traditional way of urban heat island studies. Therefore, air temperature as well as the physiologically equivalent temperature (PET) were applied to take into account the effect of the thermal atmosphere on city dwellers. The analysis of the urban heat island phenomenon of Stuttgart, Germany, includes a long-term frequency analysis using data of four urban and one rural meteorological stations. A (high resolution map) of the UHI intensity and PET was created using stepwise multiple linear regression based on data of car traverses as well as spatial data. The mapped conditions were classified according to the long-term frequency analysis. Regarding climate change, the need for adaptation measures as urban greening is obvious. Therefore, a spatial analysis of quantification of two scenarios of a chosen study area was done by the application of a micro-scale model. The nocturnal UHI of Stuttgart is during 15 % stronger than 4 K in the city center during summer when daytime heat stress occurs during 40 %. A typical summer condition is mapped using statistical approach to point out the most strained areas in Stuttgart center and west. According to the model results, the increase in number of trees in a chosen area (Olga hospital) can decrease PET by 0.5 K at 22:00 CET but by maximum 27 K at 14:00 CET.

Impact of Land Use/Land Cover Conditions on WRF Model Evaluation for Heat Island Assessment

NASA Astrophysics Data System (ADS)

Bhati, S.; Mohan, M.

2017-12-01

Urban heat island effect has been assessed using Weather Research and Forecasting model (WRF v3.5) focusing on air temperature and surface skin temperature in the sub-tropical urban Indian megacity of Delhi. Impact of urbanization related changes in land use/land cover (LULC) on model outputs has been analyzed. Four simulations have been carried out with different types of LULC data viz. (1) USGS , (2) MODIS, (3) user-modified USGS and (4) user modified land use data coupled with urban canopy model (UCM) for incorporation of canopy features. Heat island intensities have been estimated based on these simulations and subsequently compared with those derived from in-situ and satellite observations. There is a significant improvement in model performance with modification of LULC and inclusion of UCM. Overall, RMSEs for near surface temperature improved from 6.3°C to 3.9°C and index of agreement for mean urban heat island intensities (UHI) improved from 0.4 to 0.7 with modified land use coupled with UCM. In general, model is able to capture the magnitude of UHI as well as high UHI zones well. The study highlights the importance of appropriate and updated representation of landuse-landcover and urban canopies for improving predictive capabilities of the mesoscale models.

Analysis of the ability of water resources to reduce the urban heat island in the Tokyo megalopolis.

PubMed

Nakayama, Tadanobu; Hashimoto, Shizuka

2011-01-01

Simulation procedure integrated with multi-scale in horizontally regional-urban-point levels and in vertically atmosphere-surface-unsaturated-saturated layers, was newly developed in order to predict the effect of urban geometry and anthropogenic exhaustion on the hydrothermal changes in the atmospheric/land and the interfacial areas of the Japanese megalopolis. The simulated results suggested that the latent heat flux in new water-holding pavement (consisting of porous asphalt and water-holding filler made of steel by-products based on silica compound) has a strong impact on hydrologic cycle and cooling temperature in comparison with the observed heat budget. We evaluated the relationship between the effect of groundwater use as a heat sink to tackle the heat island and the effect of infiltration on the water cycle in the urban area. The result indicates that effective management of water resources would be powerful for ameliorating the heat island and recovering sound hydrologic cycle there. Copyright © 2010 Elsevier Ltd. All rights reserved.

Mechanisms Involved in the Mitigation of Urban Heat Islands through Vegetation

NASA Astrophysics Data System (ADS)

Montalto, F. A.; Smalls-Mantey, L.

2016-12-01

Urban heat islands are one of many challenges presented by today's unprecedented patterns of urbanization. At higher densities, urban populations are more vulnerable to the increased temperatures that accompany urban landscape change. Though in the US it is funded principally as a means of stormwater management, urban green infrastructure (GI) actually alters hydrologic, energetic, and thermal budgets of urban environments, with a suite of potential co-benefits related to the health of people and ecosystems. Recent research has underscored the roles that vegetation plays in such processes, for example by facilitating evapotranspiration, and regulating air temperature and water availability. While the magnitude of these and other impacts is determined in part by the size, type, location, and configuration of GI facilities, few studies have attempted to characterize and to quantify how various vegetation-mediated processes in GI systems impact the energy and thermal properties of their surroundings. Using data collected at rooftop and ground level GI facilities including green roofs and bioretention areas monitored by Drexel University, this research illustrates the role that processes such as evapotranspiration play in the individual GI site cooling potential, reducing neighborhood vulnerability to the urban heat island effect.

Temperature trends in desert cities: how vegetation and urbanization affect the urban heat island dynamics in hyper-arid climates

NASA Astrophysics Data System (ADS)

Marpu, P. R.; Lazzarini, M.; Molini, A.; Ghedira, H.

2013-12-01

Urban areas represent a unique micro-climatic system, mainly characterized by scarcity of vegetation and ground moisture, an albedo strictly dependent on building materials and urban forms, high heat capacity, elevated pollutants emissions, anthropogenic heat production, and a characteristic boundary layer dynamics. For obvious historical reasons, the first to be addressed in the literature were the effects of urbanization on the local microclimate of temperate regions, where most of the urban development took place in the last centuries. Here micro-climatic characteristics all contribute to the warming of urban areas, also known as 'urban heat island' effect, and are expected to crucially impact future energy and water consumption, air quality, and human health. However, rapidly increasing urbanization rates in arid and hyper-arid developing countries could soon require more attention towards studying the effects of urban development on arid climates, which remained mainly unexplored till now. In this talk we investigate the climatology of urban heat islands in seven highly urbanized desert cities based on day and night temporal trends of land surface temperature (LST) and normalized difference vegetation index (NDVI) acquired using MODIS satellite during 2000-2012. Urban and rural areas are distinguished by analyzing the high-resolution temporal variability and averaged monthly values of LST, NDVI and Surface Urban Heat Island (SUHI) for all the seven cities and adjacent sub-urban areas. Different thermal behaviors were observed at the selected sites, also including temperature mitigation and inverse urban heat island, and are here discussed together with detailed analysis of the corresponding trends.

Parks and the urban heat island: A longitudinal study in Westfield, Massachusetts

Treesearch

Robert S. Bristow; Robert Blackie; Nicole Brown

2012-01-01

Urban landscapes often have warmer temperatures than the surrounding countryside, a phenomenon known as the urban heat island (UHI) effect. This study compares and contrasts temperatures across Westfield, Massachusetts, a moderate size New England city, and considers the influence that the city’s parks and protected areas have on the local microclimate. The data show a...

Isabela Island, Galapagos Islands

NASA Image and Video Library

1996-01-20

STS072-732-072 (11-20 Jan. 1996) --- Three of the nineteen Galapagos Islands are visible in this image, photographed from the Earth-orbiting Space Shuttle Endeavour. The Galapagos Islands are located 600 miles (1,000 kilometers) to the west of Ecuador. The largest of the islands, Isabela, is at center (north is toward the upper right corner). The numerous circular features on the island, highlighted by clouds, are volcanoes. The Galapagos Islands owe their existence to a hot spot, or persistent heat source in the mantle, which also is located over a rift, or place where plates are separating and new crust is being created. The rift is located between the Cocos and Nazca Plates. The dark linear features on the islands are lava flows from past eruptions. The island to the left of Isabela is Fernandina, while the island to the right is San Salvador. The Galapagos Islands were visited by the English naturalist Charles Darwin in 1835.

The other side of the coin: urban heat islands as shields from extreme cold

NASA Astrophysics Data System (ADS)

Yang, J.; Bou-Zeid, E.

2017-12-01

Extensive studies focusing on urban heat islands (UHIs) during hot periods create a perception that UHIs are invariably hazardous to human health and the sustainability of cities. Consequently, cities have invested substantial resources to try to mitigate UHIs. These urban policies can have serious repercussions since the health risks associated with cold weather are in fact higher than for heat episodes, yet wintertime UHIs have hardly been explored. We combine ground observations from 12 U.S. cities and high-resolution simulations to show that UHIs not only warm urban areas in the winter, but also further intensify during cold waves by up to 1.32 ± 0.78 oC (mean ± standard deviation) at night. Urban heat islands serve as shelters against extreme colds and provide invaluable benefits of reducing health risks and heating demand. More importantly, our simulations indicate that standard UHI mitigation measures such as green or cool roofs reduce these cold time amenities to different extents. Cities, particularly in cool and cold temperate climates, should hence revisit policies and efforts that are only desgined for hot periods. A paradigm shift is urgently needed to give an equal weight to the wintertime benefits of UHIs in the sustainability and resilience blueprints of cities.

Geospatial Strategy for Adverse Impact of Urban Heat Island in upper atmospheres of the earth Mountain Areas using LANDSAT ETM+ Sensors

NASA Astrophysics Data System (ADS)

Kumar, Amit; Vandana, Vandana

2016-07-01

We are living in the age of the rapidly growing population and changing environmental conditions with advanced technical capacity. This has been resulting in widespread land cover change. Among several human-induced environmental and urban thermal problems are reported to be negatively affecting urban residents in many ways. Urban Heat Islands exist in many large cities especially metropolitan cities and can significantly affect the permafrost layer in mountain areas. The adverse effect of urban heat island has become the subject of numerous studies in recent decades and is reflected in many major mountain cities around the world. The built-up structures in urbanized areas considerably alter land cover thereby affecting thermal energy flow which leads to the development of elevated surface and air temperature. The phenomenon Urban Heat Island implies 'island' of high temperature in cities, surrounded by relatively lower temperature in rural areas. The Urban Heat Island for the temporal period is estimated using geospatial techniques which are then utilized for the impact assessment of the climate of the surrounding regions and how it reduce the sustainability of the natural resources like air, vegetation. The knowledge of surface temperature is important for the study of urban climate and human health. The rapid growth of industries in peri-urban areas results in excessive warming and variations in weather conditions. It leads to soil degradation in frozen areas due to high temperature which leads to melting of snow in mountain areas Remotely sensed data of thermal infrared band in the region of 10.4-12.5 µm of EMR spectrum, available from LANDSAT- ETM+ is proved to be very helpful to identify urban heat islands. Thermal infrared data acquired during the daytime and night time can be used to monitor the heat island associated with urban areas as well as atmospheric pollution. The present paper describes the methodology and resolution dynamic urban heat island

What land covers are effective in mitigating a heat island in urban building rooftop?

NASA Astrophysics Data System (ADS)

Lee, S.; Ryu, Y.

2014-12-01

Since the 20th century, due to the rapid urbanization many urban environment problems have got blossomed and above all heat island has been recognized as an important issue. There are several causes of urban heat island, but land cover change occupies the largest portion of them. Owing to urban expansion, vegetation is changed into asphalt pavements and concrete buildings, which reduces latent heat flux. To mitigate the problems, people enlarge vegetation covers such as planting street trees, making rooftop gardens and constructing parks or install white roofs that feature high albedo on a building. While the white roofs reflect about 70% of solar radiation and absorb less radiation, vegetation has low albedo but cools the air through transpiration and fixes carbon dioxide through photosynthesis. There are some studies concerning which one is more effective to mitigate heat island between the green roof and white roof. This study compares the green roof and white roof and additionally considers carbon fixation that has not been treated in other studies. Furthermore, this study ascertains an efficiency of solar-cell panel that is used for building roof recently. The panel produces electric power but has low albedo which could warm the air. The experiment is conducted at the rooftop in Seoul, Korea and compares green roof (grass), white roof (painted cover), black roof (solar panel) and normal painted roof. Surface temperature and albedo are observed for the four roof types and incoming shortwave, outgoing longwave and carbon flux are measured in green roof solely. In the case of solar panels, the electricity generation is calculated from the incoming radiation. We compute global warming potentials for the four roof types and test which roof type is most effective in reducing global warming potential.

An energy and mortality impact assessment of the urban heat island in the US

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowe, Scott A., E-mail: Scott.lowe@manhattan.edu

Increased summer energy use and increased summer heat related mortality are the two most cited detrimental impacts of the urban heat island (UHI). An assessment of these impacts was made that considered the annual impact of the UHI, not just the summer impact. It was found that in north of the US there was a net decrease in energy use from the UHI, as heating energy reductions were larger than the increase in cooling energy. In the south there was a net energy increase from the UHI. The impact of the UHI on heat related deaths was an estimated increasemore » of 1.1 deaths per million people. The impact of the UHI on cold related deaths was an estimated decrease of 4.0 deaths per million people. These estimates are caveated by the acknowledgement that compounding factors influence mortality. Hypothermia related death rates were three times higher in rural areas than urban areas. This is surprising as the homeless population is usually considered the most at risk, yet they mostly live in urban areas. - Highlights: • The urban heat island (UHI) may actually be beneficial in colder cities in the US in terms of energy use • The UHI may cause an increase in heat related mortality of ~ 1 deaths per million • In winter the UHI may decrease cold related mortality by ~ 4 deaths per million • Cold related death rates were 3 times higher in rural areas although the homeless population live mainly in urban areas.« less

Identifying and monitoring urban heat island in Bucharest using satellite time series and low cost meteorological sensors

NASA Astrophysics Data System (ADS)

Sandric, Ionut; Onose, Diana; Vanau, Gabriel; Ioja, Cristian

2016-04-01

The present study is focusing on the identification of urban heat island in Bucharest using both remote sensing products and low cost temperature sensors. The urban heat island in Bucharest was analyzed through a network of sensors located in 56 points (47 inside the administrative boundary of the city, 9 outside) 2009-2011. The network lost progressively its initial density, but was reformed during a new phase, 2013-2015. Time series satellite images from MODIS were intersected with the sensors for both phases. Statistical analysis were conducted to identify the temporal and spatial pattern of extreme temperatures in Bucharest. Several environmental factors like albedou, presence and absence of vegetation were used to fit a regression model between MODIS satellite products sensors in order to upscale the temperatures values recorded by MODIS For Bucharest, an important role for air temperature values in urban environments proved to have the local environmental conditions that leads to differences in air temperature at Bucharest city scale between 3-5 °C (both in the summer and in the winter). The UHI maps shows a good correlation with the presence of green areas. Differences in air temperature between higher tree density areas and isolated trees can reach much higher values, averages over 24 h periods still are in the 3-5 °C range The results have been obtained within the project UCLIMESA (Urban Heat Island Monitoring under Present and Future Climate), ongoing between 2013 and 2015 in the framework of the Programme for Research-DevelopmentInnovation for Space Technology and Advanced Research (STAR), administrated by the Romanian Space Agency Keywords: time series, urban heat island

Are cooler surfaces a cost-effect mitigation of urban heat islands?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomerantz, Melvin

Much research has gone into technologies to mitigate urban heat islands by making urban surfaces cooler by increasing their albedos. To be practical, the benefit of the technology must be greater than its cost. Here, this report provides simple methods for quantifying the maxima of some benefits that albedo increases may provide. The method used is an extension of an earlier paper that estimated the maximum possible electrical energy saving achievable in an entire city in a year by a change of albedo of its surfaces. The present report estimates the maximum amounts and monetary savings of avoided CO 2more » emissions and the decreases in peak power demands. As examples, for several warm cities in California, a 0.2 increase in albedo of pavements is found to reduce CO 2 emissions by < 1 kg per m 2 per year. At the current price of CO 2 reduction in California, the monetary saving is < US$ 0.01 per year per m 2 modified. The resulting maximum peak-power reductions are estimated to be < 7% of the base power of the city. In conclusion, the magnitudes of the savings are such that decision-makers should choose carefully which urban heat island mitigation techniques are cost effective.« less

Are cooler surfaces a cost-effect mitigation of urban heat islands?

DOE PAGES

Pomerantz, Melvin

2017-04-20

Much research has gone into technologies to mitigate urban heat islands by making urban surfaces cooler by increasing their albedos. To be practical, the benefit of the technology must be greater than its cost. Here, this report provides simple methods for quantifying the maxima of some benefits that albedo increases may provide. The method used is an extension of an earlier paper that estimated the maximum possible electrical energy saving achievable in an entire city in a year by a change of albedo of its surfaces. The present report estimates the maximum amounts and monetary savings of avoided CO 2more » emissions and the decreases in peak power demands. As examples, for several warm cities in California, a 0.2 increase in albedo of pavements is found to reduce CO 2 emissions by < 1 kg per m 2 per year. At the current price of CO 2 reduction in California, the monetary saving is < US$ 0.01 per year per m 2 modified. The resulting maximum peak-power reductions are estimated to be < 7% of the base power of the city. In conclusion, the magnitudes of the savings are such that decision-makers should choose carefully which urban heat island mitigation techniques are cost effective.« less

Urban heat island in Krakow, Poland: Land use versus land form interaction

NASA Astrophysics Data System (ADS)

Bokwa, A.

2012-04-01

Urban heat island is a well known feature of urban climate, related mainly to the changes in land use in urban areas and anthropogenic heat emission. However, the interaction between the land use and land form in urban areas and its impact on air temperature spatial patterns is much less known. Krakow is a medium size city located in southern Poland, in the valley of the Vistula River. The city is surrounded with convex land forms from three sides, with height differences up to 100 m. Built-up areas of the city can be found in both the valley bottom and on nearby slopes. Numerous studies completed after the Second World War (e.g. Hess 1974, Lewinska et al. 1982, Morawska-Horawska, Cebulak 1981) showed that the characteristic features of the climate of Krakow are e.g. frequent air temperature inversions, poor natural ventilation, large precipitation horizontal gradients. More recent research (e.g. Bokwa 2010) revealed e.g. a thermal asymmetry of the area. On the basis of 3-year (2009-2011) air temperature measurements in 21 points, completed with mobile measurements and analysis of available long-term series, it was proposed to define urban heat island separately in particular vertical zones of the city. Bokwa, A., 2010, Wieloletnie zmiany struktury mezoklimatu miasta na przykladzie Krakowa [Multi-annual changes of the urban mesoclimate structure (using an example of Kraków)], Institute of Geography and Spatial Management, Jagiellonian University, Kraków, 258 pp.; available on-line: http://www.geo.uj.edu.pl/publikacje.php?&lang=1&page=monografie&menu=3&id=000155 Hess M., 1974, Klimat Krakowa {Climate of Krakow], Folia Geogr., ser. Geogr.-Phys., 8, 45-102. Lewińska J., Bartosik J., Baścik J., Czerwieniec M., Zgud K., 1982, Wpływ miasta na klimat lokalny (na przykładzie aglomeracji krakowskiej) [Impact of a city on the local climate using an example of Krakow], Inst. Kształt. Środ., Warszawa. Morawska-Horawska M., Cebulak E., 1981, Badania pionowego zasi

Characteristics of Surface Urban Heat Island (SUHI) over the Gangetic Plain of Bihar, India

NASA Astrophysics Data System (ADS)

Barat, Archisman; Kumar, Sunny; Kumar, Praveen; Parth Sarthi, P.

2018-05-01

The rapid urbanisation impacts on environment, climate, agriculture, water resources trigger several problems to human beings. The present study is carried out to estimate intensity and trend of Urban Heat Island (UHI) as Surface UHI (SUHI) over towns/cities of the Gangetic plain of the state of Bihar, India, in which urban areas show relatively greater Land Surface Temperature (LST) than its rural surroundings especially during night times. The LST data (2001-14) of Moderate Resolution Imaging Spectroradiometer (MODIS) is used for five major towns/cities of Bihar namely, Bhagalpur, Gaya, Patna, Purnea and Muzzaffarpur. Each city is classified into Urban, Suburban and Rural zones as per land cover of the area. During winter months (January, February, November and December), UHI is more intense over all towns/cities. Mann-Kendall Test is applied on Surface Urban Heat Island Intensity (SUHII) in which MK-Test Statistic (S) shows a significant increasing trend. This trend would alarm a risk to increase in air pollution, heat related biohazards, energy demand in the region. This study shows the need of urban greening and proper town planning over the considered areas to mitigate the changes.

Effect modification of the association between short-term meteorological factors and mortality by urban heat islands in Hong Kong.

PubMed

Goggins, William B; Chan, Emily Y Y; Ng, Edward; Ren, Chao; Chen, Liang

2012-01-01

Prior studies from around the world have indicated that very high temperatures tend to increase summertime mortality. However possible effect modification by urban micro heat islands has only been examined by a few studies in North America and Europe. This study examined whether daily mortality in micro heat island areas of Hong Kong was more sensitive to short term changes in meteorological conditions than in other areas. An urban heat island index (UHII) was calculated for each of Hong Kong's 248 geographical tertiary planning units (TPU). Daily counts of all natural deaths among Hong Kong residents were stratified according to whether the place of residence of the decedent was in a TPU with high (above the median) or low UHII. Poisson Generalized Additive Models (GAMs) were used to estimate the association between meteorological variables and mortality while adjusting for trend, seasonality, pollutants and flu epidemics. Analyses were restricted to the hot season (June-September). Mean temperatures (lags 0-4) above 29 °C and low mean wind speeds (lags 0-4) were significantly associated with higher daily mortality and these associations were stronger in areas with high UHII. A 1 °C rise above 29 °C was associated with a 4.1% (95% confidence interval (CI): 0.7%, 7.6%) increase in natural mortality in areas with high UHII but only a 0.7% (95% CI: -2.4%, 3.9%) increase in low UHII areas. Lower mean wind speeds (5(th) percentile vs. 95(th) percentile) were associated with a 5.7% (95% CI: 2.7, 8.9) mortality increase in high UHII areas vs. a -0.3% (95% CI: -3.2%, 2.6%) change in low UHII areas. The results suggest that urban micro heat islands exacerbate the negative health consequences of high temperatures and low wind speeds. Urban planning measures designed to mitigate heat island effects may lessen the health effects of unfavorable summertime meteorological conditions.

Effect Modification of the Association between Short-term Meteorological Factors and Mortality by Urban Heat Islands in Hong Kong

PubMed Central

Goggins, William B.; Chan, Emily Y. Y.; Ng, Edward; Ren, Chao; Chen, Liang

2012-01-01

Background Prior studies from around the world have indicated that very high temperatures tend to increase summertime mortality. However possible effect modification by urban micro heat islands has only been examined by a few studies in North America and Europe. This study examined whether daily mortality in micro heat island areas of Hong Kong was more sensitive to short term changes in meteorological conditions than in other areas. Method An urban heat island index (UHII) was calculated for each of Hong Kong’s 248 geographical tertiary planning units (TPU). Daily counts of all natural deaths among Hong Kong residents were stratified according to whether the place of residence of the decedent was in a TPU with high (above the median) or low UHII. Poisson Generalized Additive Models (GAMs) were used to estimate the association between meteorological variables and mortality while adjusting for trend, seasonality, pollutants and flu epidemics. Analyses were restricted to the hot season (June-September). Results Mean temperatures (lags 0–4) above 29°C and low mean wind speeds (lags 0–4) were significantly associated with higher daily mortality and these associations were stronger in areas with high UHII. A 1°C rise above 29°C was associated with a 4.1% (95% confidence interval (CI): 0.7%, 7.6%) increase in natural mortality in areas with high UHII but only a 0.7% (95% CI: −2.4%, 3.9%) increase in low UHII areas. Lower mean wind speeds (5th percentile vs. 95th percentile) were associated with a 5.7% (95% CI: 2.7, 8.9) mortality increase in high UHII areas vs. a −0.3% (95% CI: −3.2%, 2.6%) change in low UHII areas. Conclusion The results suggest that urban micro heat islands exacerbate the negative health consequences of high temperatures and low wind speeds. Urban planning measures designed to mitigate heat island effects may lessen the health effects of unfavorable summertime meteorological conditions. PMID:22761684

The effect of urban heat island on Izmir's city ecosystem and climate.

PubMed

Corumluoglu, Ozsen; Asri, Ibrahim

2015-03-01

Depending on the researches done on urban landscapes, it is found that the heat island intensity caused by the activities in any city has some impact on the ecosystem of the region and on the regional climate. Urban areas located in arid and semiarid lands somehow represent heat increase when it is compared with the heat in the surrounding rural areas. Thus, cities located amid forested and temperate climate regions show moderate temperatures. The impervious surfaces let the rainfall leave the city lands faster than undeveloped areas. This effect reduces water's cooling effects on these lands. More significantly, if trees and other vegetations are rare in any region, it means less evapotranspiration-the process by which trees "exhale" water. Trees also contribute to the cooling of urban lands by their shade. Land cover and land use maps can easily be produced by processing of remote sensing satellites' images, like processing of Landsat's images. As a result of this process, urban regions can be distinguished from vegetation. Analyzed GIS data produced and supported by these images can be utilized to determine the impact of urban land on energy, water, and carbon balances at the Earth's surface. Here in this study, it is found that remote sensing technique with thermal images is a liable technique to asses where urban heat islands and hot spots are located in cities. As an application area, in Izmir, it was found that the whole city was in high level of surface temperature as it was over 28 °C during the summer times. Beside this, the highest temperature values which go up to 47 °C are obtained at industrial regions especially where the iron-steel factories and the related industrial activities are.

Results from the Phoenix Urban Heat Island (UHI) experiment: effects at the local, neighbourhood and urban scales

NASA Astrophysics Data System (ADS)

di Sabatino, S.; Leo, L. S.; Hedquist, B. C.; Carter, W.; Fernando, H. J. S.

2009-04-01

This paper reports on the analysis of results from a large urban heat island experiment (UHI) performed in Phoenix (AZ) in April 2008. From 1960 to 2000, the city of Phoenix experienced a minimum temperature rise of 0.47 °C per decade, which is one of the highest rates in the world for a city of this size (Golden, 2004). Contemporaneously, the city has recorded a rapid enlargement and large portion of the land and desert vegetation have been replaced by buildings, asphalt and concrete (Brazel et al., 2007, Emmanuel and Fernando, 2007). Besides, model predictions show that minimum air temperatures for Phoenix metropolitan area in future years might be even higher than 38 °C. In order to make general statements and mitigation strategies of the UHI phenomenon in Phoenix and other cities in hot arid climates, a one-day intensive experiment was conducted on the 4th-5th April 2008 to collect surface and ambient temperatures within various landscapes in Central Phoenix. Inter alia, infrared thermography (IRT) was used for UHI mapping. The aim was to investigate UHI modifications within the city of Phoenix at three spatial scales i.e. the local (Central Business District, CBD), the neighborhood and the city scales. This was achieved by combining IRT measurements taken at ground level by mobile equipment (automobile-mounted and pedicab) and at high elevation by a helicopter. At local scale detailed thermographic images of about twenty building façades and several street canyons were collected. In total, about two thousand images were taken during the 24-hour campaign. Image analysis provides detailed information on building surface and pavement temperatures at fine resolution (Hedquist et al. 2009, Di Sabatino et al. 2009). This unique dataset allows us several investigations on local air temperature dependence on albedo, building thermal inertia, building shape and orientation and sky view factors. Besides, the mosaic of building façade temperatures are being analyzed

Dominant control of agriculture and irrigation on urban heat island in India.

PubMed

Kumar, Rahul; Mishra, Vimal; Buzan, Jonathan; Kumar, Rohini; Shindell, Drew; Huber, Matthew

2017-10-25

As is true in many regions, India experiences surface Urban Heat Island (UHI) effect that is well understood, but the causes of the more recently discovered Urban Cool Island (UCI) effect remain poorly constrained. This raises questions about our fundamental understanding of the drivers of rural-urban environmental gradients and hinders development of effective strategies for mitigation and adaptation to projected heat stress increases in rapidly urbanizing India. Here we show that more than 60% of Indian urban areas are observed to experience a day-time UCI. We use satellite observations and the Community Land Model (CLM) to identify the impact of irrigation and prove for the first time that UCI is caused by lack of vegetation and moisture in non-urban areas relative to cities. In contrast, urban areas in extensively irrigated landscapes generally experience the expected positive UHI effect. At night, UHI warming intensifies, occurring across a majority (90%) of India's urban areas. The magnitude of rural-urban temperature contrasts is largely controlled by agriculture and moisture availability from irrigation, but further analysis of model results indicate an important role for atmospheric aerosols. Thus both land-use decisions and aerosols are important factors governing, modulating, and even reversing the expected urban-rural temperature gradients.

Simulations of the Montréal urban heat island

NASA Astrophysics Data System (ADS)

Roberge, François; Sushama, Laxmi; Fanta, Gemechu

2017-04-01

The current population of Montreal is around 3.8 million and this number is projected to go up in the coming years to decades, which will lead to vast expansion of urban areas. It is well known that urban morphology impacts weather and climate, and therefore should be taken into consideration in urban planning. This is particularly important in the context of a changing climate, as the intensity and frequency of temperature extremes such as hot spells are projected to increase in future climate, and Urban Heat Island (UHI) can potentially raise already stressful temperatures during such events, which can have significant effects on human health and energy consumption. High-resolution regional climate model simulations can be utilized to understand better urban-weather/climate interactions in current and future climates, particularly the spatio-temporal characteristics of the Urban Heat Island and its impact on other weather/climate characteristics such as urban flows, precipitation etc. This paper will focus on two high-resolution (250 m) simulations performed with (1) the Canadian Land Surface Scheme (CLASS) and (2) CLASS and TEB (Town Energy Balance) model; TEB is a single layer urban canopy model and is used to model the urban fractions. The two simulations are performed over a domain covering Montreal for the 1960-2015 period, driven by atmospheric forcing data coming from a high-resolution Canadian Regional Climate Model (CRCM5) simulation, driven by ERA-Interim. The two simulations are compared to assess the impact of urban regions on selected surface fields and the simulation with both CLASS and TEB is then used to study the spatio-temporal characteristics of the UHI over the study domain. Some preliminary results from a coupled simulation, i.e. CRCM5+CLASS+TEB, for selected years, including extreme warm years, will also be presented.

Sensitivities Affecting Heat and Urban Heat Island Effect on Local Scale Projected to Neighborhood Scale in Baltimore, Maryland

NASA Astrophysics Data System (ADS)

Sze, C.; Zaitchik, B. F.; Scott, A.

2015-12-01

Urban regions are often impacted more by heat than adjacent rural areas, which is a phenomenon known as the urban heat island (UHI) effect. Urban areas are also highly heterogeneous and notoriously difficult to monitor using standard meteorological protocols—the hottest microclimates within a city often occur in locations that lack open, representative installation sites that are an adequate distance from buildings and direct heat sources. To investigate the challenges of monitoring urban heat, this study examines the sensitivity of temperature and humidity sensors currently used in a Baltimore UHI monitoring network to differences in sun exposure, material on which the data collecting instrument is attached, and land cover class of the vicinity. Sensitivity to sun exposure and attachment site can be interpreted as sources of uncertainty for urban heat monitoring, while sensitivity to land cover may reflect a true source of local temperature and humidity variability. In this study, we present results from a test deployment designed to assess the sensitivity of heat measurements to each of these three factors. We then apply these results to interpret measurements taken across the entire Baltimore UHI monitoring network. These results can then be used to improve heat measurements and more accurately represent and quantify the UHI effect on a broader scale, such as in neighborhoods or urban centers.

Factors Contributing to Urban Heat Island Development: A Global Perspective

NASA Astrophysics Data System (ADS)

Hertel, W.; Snyder, P. K.; Twine, T. E.

2012-12-01

Urban heat islands (UHIs) are the result of the urban core of a city encountering temperatures that are warmer than the surrounding rural areas. Temperature in the urban core can be 2-5°C warmer during the day and as much as 10°C warmer at night compared to outlying areas. This modification of the local climate can contribute to significant health-related impacts during heat waves, increased energy consumption, a decrease in air quality, deteriorating urban ecosystems, and enhancing the thermal pollution into urban water bodies. To understand the mechanisms contributing to the formation of UHIs and to identify sound mitigation strategies requires examining the UHIs of cities around the world to look for factors that enhance or minimize the heat island effect. Numerous factors influence the strength of the UHI, and vary from city to city. Population size and density influence the magnitude and spatial extent of the UHI. The ecosystem in which the city resides affects the rural climatology. Regional weather patterns can also influence the development of UHIs, with the frequency of certain types of weather conducive to the development of strong UHIs. Local geography such as proximity to water bodies and topography can influence UHI development. Cultural and regional influences such as the use of certain types of building materials, architecture, and the density of vegetation can all contribute towards the strength of a city's UHI. To better understand how UHIs develop and to understand the factors that influence them, we have undertaken the Islands in the Sun project, which includes an analysis of the UHIs of the largest cities in the world. In this study we examine how different factors have influenced the structure of the UHI and to identify factors that can mitigate and minimize their impact. Here we present a preliminary analysis of four metropolitan areas: Minneapolis-St. Paul, Buenos Aires, Riyadh, and Jakarta. In this study we investigate how various factors

Wintertime urban heat island modified by global climate change over Japan

NASA Astrophysics Data System (ADS)

Hara, M.

2015-12-01

Urban thermal environment change, especially, surface air temperature (SAT) rise in metropolitan areas, is one of the major recent issues in urban areas. The urban thermal environmental change affects not only human health such as heat stroke, but also increasing infectious disease due to spreading out virus vectors habitat and increase of industry and house energy consumption. The SAT rise is mostly caused by global climate change and urban heat island (hereafter UHI) by urbanization. The population in Tokyo metropolitan area is over 30 millions and the Tokyo metropolitan area is one of the biggest megacities in the world. The temperature rise due to urbanization seems comparable to the global climate change in the major megacities. It is important to project how the urbanization and the global climate change affect to the future change of urban thermal environment to plan the adaptation and mitigation policy. To predict future SAT change in urban scale, we should estimate future UHI modified by the global climate change. This study investigates change in UHI intensity (UHII) of major metropolitan areas in Japan by effects of the global climate change. We performed a series of climate simulations. Present climate simulations with and without urban process are conducted for ten seasons using a high-resolution numerical climate model, the Weather Research and Forecasting (WRF) model. Future climate projections with and without urban process are also conducted. The future projections are performed using the pseudo global warming method, assuming 2050s' initial and boundary conditions estimated by a GCM under the RCP scenario. Simulation results indicated that UHII would be enhanced more than 30% in Tokyo during the night due to the global climate change. The enhancement of urban heat island is mostly caused by change of lower atmospheric stability.

Does the Heat Island Effect Affect Lake Chabot

NASA Astrophysics Data System (ADS)

Singh, K. A.; Mock, Y.; Pun, C.

2014-12-01

Lake Chabot is a backup water supply source and it is important to know if the water is healthy because California is experiencing a drought. To check the quality of the water we used a submersible, waterproof thermometer to measure the temperature of the water at different depths. We hypothesized that the heat-island effect would cause the runoff from the surrounding developed areas to be warmer. This is because paving roads causes areas to become impermeable and absorb heat. Water runs off these impermeable surfaces, absorbing heat from the ground and enters larger bodies of water via stream. To locate streams we used a topography map. We located close lines followed by lines that were farther apart and then once again followed by close lines. This indicates that there is a concave area between two high points, allowing water to possibly flow through. We found that areas where the water came from highly populated areas were warmer. The increase in temperature was shown throughout all depths of the water at each site that was measured. The temperature throughout the lake was in between 19°C and 25°C. This warm temperature makes it hard for gases to mix. The lower the dissolved oxygen level, the less desirable it is for a variety of organisms to survive. Higher temperatures also increase bacterial growth and can causes water to be unhealthy. This indicates that the water at Lake Chabot is not suitable for human consumption and should not be considered a suitable backup water source for our area.

The relationship between land cover and the urban heat island in northeastern Puerto Rico

Treesearch

D. J. Murphy; M. H. Hall; C. A. S. Hall; G. M. Heisler; S. V. Stehman; C. Anselmi-Molina; NO-VALUE

2011-01-01

Throughout the tropics, population movements, urban growth, and industrialization are causing conditions that result in elevated temperatures within urban areas when compared with that in surrounding rural areas, a phenomenon known as the urban heat island (UHI). One such example is the city of San Juan, Puerto Rico. Our objective in this study was to quantify the UHI...

The relation between land-cover and the urban heat island in northeastern Puerto Rico

Treesearch

David J.R. Murphy; Myrna Hall; Charles Hall; Gordon Heisler; Steve Stehman

2007-01-01

As development continues in Puerto Rico, forests and grasslands are being converted to impervious cover, changing the magnitude and geographic range of the Urban Heat Island (UHI). As part of the U.S. National Science Foundation Long Term Ecological Research Program, this study aims to quantify the various meteorological effects that urbanization may be imparting on...

Temperature trends and Urban Heat Island intensity mapping of the Las Vegas valley area

NASA Astrophysics Data System (ADS)

Black, Adam Leland

Modified urban climate regions that are warmer than rural areas at night are referred to as Urban Heat Islands or UHI. Islands of warmer air over a city can be 12 degrees Celsius greater than the surrounding cooler air. The exponential growth in Las Vegas for the last two decades provides an opportunity to detect gradual temperature changes influenced by an increasing presence of urban materials. This thesis compares ground based thermometric observations and satellite based remote sensing temperature observations to identify temperature trends and UHI areas caused by urban development. Analysis of temperature trends between 2000 and 2010 at ground weather stations has revealed a general cooling trend in the Las Vegas region. Results show that urban development accompanied by increased vegetation has a cooling effect in arid climates. Analysis of long term temperature trends at McCarran and Nellis weather stations show 2.4 K and 1.2 K rise in temperature over the last 60 years. The ground weather station temperature data is related to the land surface temperature images from the Landsat Thematic Mapper to estimate and evaluate urban heat island intensity for Las Vegas. Results show that spatial and temporal trends of temperature are related to the gradual change in urban landcover. UHI are mainly observed at the airport and in the industrial areas. This research provides useful insight into the temporal behavior of the Las Vegas area.

Use of GLOBE Observations to Derive a Landsat 8 Split Window Algorithm for Urban Heat Island

NASA Astrophysics Data System (ADS)

Fagerstrom, L.; Czajkowski, K. P.

2017-12-01

Surface temperature has been studied to investigate the warming of urban climates, also known as urban heat islands, which can impact urban planning, public health, pollution levels, and energy consumption. However, the full potential of remotely sensed images is limited when analyzing land surface temperature due to the daunting task of correcting for atmospheric effects. Landsat 8 has two thermal infrared sensors. With two bands in the infrared region, a split window algorithm (SWA), can be applied to correct for atmospheric effects. This project used in situ surface temperature measurements from NASA's ground observation program, the Global Learning and Observations to Benefit the Environment (GLOBE), to derive the correcting coefficients for use in the SWA. The GLOBE database provided land surface temperature data that coincided with Landsat 8 overpasses. The land surface temperature derived from Landsat 8 SWA can be used to analyze for urban heat island effect.

Spatiotemporal trends of urban heat island effect along the urban development intensity gradient in China

Treesearch

Decheng Zhou; Liangxia Zhang; Lu Hao; Ge Sun; Yongqiang Liu; Chao Zhu

2016-01-01

Urban heat island (UHI) represents a major anthropogenic modification to the Earth system and its relationshipwith urban development is poorly understood at a regional scale. Using AquaMODIS data and LandsatTM/ETM+images, we examined the spatiotemporal trends of the UHI effect (ΔT, relative to the rural reference) along theurban...

Analysis of the Intra-City Variation of Urban Heat Island and its Relation to Land Surface/cover Parameters

NASA Astrophysics Data System (ADS)

Gerçek, D.; Güven, İ. T.; Oktay, İ. Ç.

2016-06-01

Along with urbanization, sealing of vegetated land and evaporation surfaces by impermeable materials, lead to changes in urban climate. This phenomenon is observed as temperatures several degrees higher in densely urbanized areas compared to the rural land at the urban fringe particularly at nights, so-called Urban Heat Island. Urban Heat Island (UHI) effect is related with urban form, pattern and building materials so far as it is associated with meteorological conditions, air pollution, excess heat from cooling. UHI effect has negative influences on human health, as well as other environmental problems such as higher energy demand, air pollution, and water shortage. Urban Heat Island (UHI) effect has long been studied by observations of air temperature from thermometers. However, with the advent and proliferation of remote sensing technology, synoptic coverage and better representations of spatial variation of surface temperature became possible. This has opened new avenues for the observation capabilities and research of UHIs. In this study, "UHI effect and its relation to factors that cause it" is explored for İzmit city which has been subject to excess urbanization and industrialization during the past decades. Spatial distribution and variation of UHI effect in İzmit is analysed using Landsat 8 and ASTER day & night images of 2015 summer. Surface temperature data derived from thermal bands of the images were analysed for UHI effect. Higher temperatures were classified into 4 grades of UHIs and mapped both for day and night. Inadequate urban form, pattern, density, high buildings and paved surfaces at the expanse of soil ground and vegetation cover are the main factors that cause microclimates giving rise to spatial variations in temperatures across cities. These factors quantified as land surface/cover parameters for the study include vegetation index (NDVI), imperviousness (NDISI), albedo, solar insolation, Sky View Factor (SVF), building envelope

The Urban Heat Island Behavior of a Large Northern Latitude Metropolitan Area

NASA Astrophysics Data System (ADS)

Twine, T. E.; Snyder, P. K.; Hertel, W.; Mykleby, P.

2012-12-01

Urban heat islands (UHIs) occur when urban and suburban areas experience elevated temperatures relative to their rural surroundings because of differences in vegetation cover, buildings and other development, and infrastructure. Most cities in the United States are warming at twice the rate of the outlying rural areas and the planet as a whole. Temperatures in the urban center can be 2-5°C warmer during the daytime and as much as 10°C at night. Urban warming is responsible for excessive energy consumption, heat-related health effects, an increase in urban pollution, degradation of urban ecosystems, changes in the local meteorology, and an increase in thermal pollution into urban water bodies. One mitigation strategy involves manipulating the surface energy budget to either reduce the amount of solar radiation absorbed at the surface or offset absorbed energy through latent cooling. Options include using building materials with different properties of reflectivity and emissivity, increasing the reflectivity of parking lots, covering roofs with vegetation, and increasing the amount of vegetation overall through tree planting or increasing green space. The goal of the Islands in the Sun project is to understand the formation and behavior of urban heat islands and to mitigate their effects through sensible city engineering and design practices. As part of this project, we have been characterizing the UHI of the Twin Cities Metropolitan Area (TCMA), a 16,000 square kilometer urban and suburban region located in east central Minnesota that includes the two cities of Minneapolis and Saint Paul, and evaluating mitigation strategies for reducing urban warming. Annually, the TCMA has a modest 2-3°C UHI that is especially apparent in winter when the urban core can be up to 5-6°C warmer than the surrounding countryside. We present an analysis of regional temperature variations from a dense network of sensors located throughout the TCMA. We focus on the diurnal and seasonal

Contributions to Global Augmented Compound Urban Heat Extreme (ACUTE) from Climate Change and the Urban Heat Island Effect

NASA Astrophysics Data System (ADS)

Huang, K.

2017-12-01

Over the next decades, climate change is projected to increase the intensity and frequency of extreme heat events (EHEs). The severity and periodicity of these hazards are likely to be further compounded by stronger urban heat island (UHI) effects as the world continues to urbanize. However, there is little known about how greenhouse gases (GHG) induced changes in EHE will interact with UHI, and what this will mean for the exposure of urban populations to high temperature. This work aims to fill this knowledge gap by combining a mesoscale meteorological model (Weather Research Forecasting, WRF) with a global urban expansion forecast, to generate spatially explicit projections of compound urban temperature extremes through 2050. These global projections include all the urban areas in developing world. The respective contributions from GHG-induced climate change, the UHI effect, and their interaction vary across different types of urban areas. The resulting compound heat extremes will be more intense and frequent in emerging Asian and African mega urban regions, located in tropical/subtropical climates, due to their unprecedented sizes and the significantly reduced evaporation. Previous studies neglecting the interaction between global climate change and regional UHI effect have underestimated exposure to heat extremes in urban areas.

Urban heat island-induced increases in evapotranspirative demand

NASA Astrophysics Data System (ADS)

Zipper, Samuel C.; Schatz, Jason; Kucharik, Christopher J.; Loheide, Steven P.

2017-01-01

Although the importance of vegetation in mitigating the urban heat island (UHI) is known, the impacts of UHI-induced changes in micrometeorological conditions on vegetation are not well understood. Here we show that plant water requirements are significantly higher in urban areas compared to rural areas surrounding Madison, WI, driven by increased air temperature with minimal effects of decreased air moisture content. Local increases in impervious cover are strongly associated with increased evapotranspirative demand in a consistent manner across years, with most increases caused by elevated temperatures during the growing season rather than changes in changes in growing season length. Potential evapotranspiration is up to 10% higher due to the UHI, potentially mitigating changes to the water and energy balances caused by urbanization. Our results indicate that local-scale land cover decisions (increases in impervious cover) can significantly impact evapotranspirative demand, with likely implications for water and carbon cycling in urban ecosystems.

Urban Heat Islands in China Enhanced by Haze Pollution

NASA Astrophysics Data System (ADS)

Cao, C.; Lee, X.; Liu, S.; Oleson, K. W.; Schultz, N. M.; Xiao, W.; Zhang, M.; Zhao, L.

2015-12-01

Land conversion from natural surfaces to artificial urban structures has led to the phenomenon of urban heat island (UHI). The intensity of UHI is thought to be controlled primarily by biophysical factors such as changes in albedo, aerodynamic resistance and evapotranspiration, while influences of biogeochemical factors such as aerosol pollution have long been ignored. We hypothesize that increased downward longwave radiation associated with anthropogenic aerosols in urban air will exacerbate nighttime UHI intensity. Here we tested this hypothesis by using the MODIS satellite land surface temperature product and the Community Land Model (CLM) for 39 cities in China. Our results showed that in contrast to observations in North America and elsewhere, nighttime surface UHI of these Chinese cities (3.34 K) was greater than daytime UHI (2.06 K). Variations in the nighttime UHI among the cities were positively correlated with difference in the aerosol optical depth between urban and the adjacent rural area (confidence level p < 0.01). The CLM was able to reproduce the MODIS UHI intensity in the daytime but underestimated the observed UHI intensity at night. The model performance was improved by including an aerosol-enhanced downward longwave radiation in urban land and a more realistic anthropogenic heat flux. Our study illustrates that although climate background largely determine spatial differences in the daytime UHI, in countries like China with serious air quality problems, aerosol-induced pollution plays an important role in the night-time UHI formation. Mitigation of particulate pollution therefore has the added co-benefit by reducing UHI-related heat stress on urban residents.

[Temporal change in annual air temperature and heat island effect in a coastal city and an inland city at mid-latitude in China during 1956-1998].

PubMed

Chao, Lu-men; Sun, Jian-xin

2009-12-01

Temporal changes in air temperature and urban heat island (UHI) effects during 1956-1998 were compared between a coastal city, Ji' nan, and an inland city, Xi' an, which were similar in latitude, size and development. During 1956-1978, except that the annual mean minimum temperature in Ji' nan increased by 0.37 degrees C x 10 a(-1), the temperature variables in the two cities did not display any apparent trend. During 1979-1998, all temperature variables of the two cities showed an increasing trend. Comparing with that in Ji' nan, the increasing rate of annual mean maximum temperature and annual mean temperature in Xi' an was greater, but that of annual mean minimum temperature was smaller. In the two cities, heat island effect occurred during 1956-1978 but without any apparent trend, whereas during 1979-1998, this effect increased with time, especially in Xi' an where the annual mean minimum temperature and annual mean temperature increased by 0.22 degrees C x 10 a(-1) and 0.32 degrees C x 10 a(-1), respectively. Both the level and the inter-annual variation of the heat island effect were much greater in Ji' nan than in Xi' an, but the increasing rate of this effect was greater in Xi' an than in Ji' nan. Obvious differences were observed in the increasing rate of annual mean maximum air temperature, annual mean air temperature, and annual mean minimum temperature as well as the heat island effect in Ji' nan, whereas negligible differences were found in Xi' an. Among the three temperature variables, annual mean minimum temperature displayed the most obvious increasing trend and was most affected by heat island effect, while annual mean maximum temperature was most variable inter-annually. Geographical location not only affected the magnitude of urban warming, but also affected the mode of urban warming and the strength of heat island effect.

Linking potential heat source and sink to urban heat island: Heterogeneous effects of landscape pattern on land surface temperature.

PubMed

Li, Weifeng; Cao, Qiwen; Lang, Kun; Wu, Jiansheng

2017-05-15

Rapid urbanization has significantly contributed to the development of urban heat island (UHI). Regulating landscape composition and configuration would help mitigate the UHI in megacities. Taking Shenzhen, China, as a case study area, we defined heat source and heat sink and identified strong and weak sources as well as strong and weak sinks according to the natural and socioeconomic factors influencing land surface temperature (LST). Thus, the potential thermal contributions of heat source and heat sink patches were differentiated. Then, the heterogeneous effects of landscape pattern on LST were examined by using semiparametric geographically weighted regression (SGWR) models. The results showed that landscape composition has more significant effects on thermal environment than configuration. For a strong source, the percentage of patches has a positive impact on LST. Additionally, when mosaicked with some heat sink, even a small improvement in the degree of dispersion of a strong source helps to alleviate UHI. For a weak source, the percentage and density of patches have positive impacts on LST. For a strong sink, the percentage, density, and degree of aggregation of patches have negative impacts on LST. The effects of edge density and patch shape complexity vary spatially with the fragmentation of a strong sink. Similarly, the impacts of a weak sink are mainly exerted via the characteristics of percent, density, and shape complexity of patches. Copyright © 2017 Elsevier B.V. All rights reserved.

Thermal island destabilization and the Greenwald limit

DOE PAGES

White, R. B.; Gates, D. A.; Brennan, D. P.

2015-02-24

Magnetic reconnection is ubiquitous in the magnetosphere, the solar corona, and in toroidal fusion research discharges. A magnetic island saturates at a width which produces a minimum in the magnetic energy of the configuration is evident in a fusion device. At saturation, the modified current density profile, a function of the flux in the island, is essentially flat, the growth rate proportional to the difference in the current at the O-point and the X-point. Furthermore, modification of the current density profile in the island interior causes a change in the island stability and additional growth or contraction of the saturatedmore » island. Because field lines in an island are isolated from the outside plasma, an island can heat or cool preferentially depending on the balance of Ohmic heating and radiation loss in the interior, changing the resistivity and hence the current in the island. A simple model of island destabilization due to radiation cooling of the island is constructed, and the effect of modification of the current within an island is calculated. In addition destabilization effect is described, and it is shown that a small imbalance of heating can lead to exponential growth of the island. A destabilized magnetic island near the plasma edge can lead to plasma loss, and because the radiation is proportional to plasma density and charge, this effect can cause an impurity dependent density limit.« less

Thermal island destabilization and the Greenwald limit

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, R. B.; Gates, D. A.; Brennan, D. P.

Magnetic reconnection is ubiquitous in the magnetosphere, the solar corona, and in toroidal fusion research discharges. A magnetic island saturates at a width which produces a minimum in the magnetic energy of the configuration is evident in a fusion device. At saturation, the modified current density profile, a function of the flux in the island, is essentially flat, the growth rate proportional to the difference in the current at the O-point and the X-point. Furthermore, modification of the current density profile in the island interior causes a change in the island stability and additional growth or contraction of the saturatedmore » island. Because field lines in an island are isolated from the outside plasma, an island can heat or cool preferentially depending on the balance of Ohmic heating and radiation loss in the interior, changing the resistivity and hence the current in the island. A simple model of island destabilization due to radiation cooling of the island is constructed, and the effect of modification of the current within an island is calculated. In addition destabilization effect is described, and it is shown that a small imbalance of heating can lead to exponential growth of the island. A destabilized magnetic island near the plasma edge can lead to plasma loss, and because the radiation is proportional to plasma density and charge, this effect can cause an impurity dependent density limit.« less

Thermal island destabilization and the Greenwald limit

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, R. B.; Gates, D. A.; Brennan, D. P.

Magnetic reconnection is ubiquitous in the magnetosphere, the solar corona, and in toroidal fusion research discharges. In a fusion device, a magnetic island saturates at a width which produces a minimum in the magnetic energy of the configuration. At saturation, the modified current density profile, a function of the flux in the island, is essentially flat, the growth rate proportional to the difference in the current at the O-point and the X-point. Further modification of the current density profile in the island interior causes a change in the island stability and additional growth or contraction of the saturated island. Becausemore » field lines in an island are isolated from the outside plasma, an island can heat or cool preferentially depending on the balance of Ohmic heating and radiation loss in the interior, changing the resistivity and hence the current in the island. A simple model of island destabilization due to radiation cooling of the island is constructed, and the effect of modification of the current within an island is calculated. An additional destabilization effect is described, and it is shown that a small imbalance of heating can lead to exponential growth of the island. A destabilized magnetic island near the plasma edge can lead to plasma loss, and because the radiation is proportional to plasma density and charge, this effect can cause an impurity dependent density limit.« less

Effectiveness of Different Urban Heat Island Mitigation Methods and Their Regional Impacts

NASA Astrophysics Data System (ADS)

Zhang, N.

2017-12-01

Cool roofs and green roofs are two popular methods to mitigate urban heat island and improve urban climate. The effectiveness of different urban heat island mitigation strategies in the summer of 2013 in the Yangtze River Delta, China is investigated using the WRF (Weather Research and Forecasting) model coupled with a physically based urban canopy model. The modifications to the roof surface changed the urban surface radiation balance and then modified the local surface energy budget. Both cool roofs and green roofs led to lower surface skin temperature and near-surface air temperature. Increasing the roof albedo to 0.5 caused a similar effectiveness as covering 25% of urban roofs with vegetation; increasing roof albedo to 0.7 caused a similar near-surface air temperature decrease as 75% green roof coverage. The near-surface relative humidity increased in both cool roof and green roof experiments because of the combination of the impacts of increases in specific humidity and decreases in air temperature. The regional impacts of cool roofs and green roofs were evaluated using the regional effect index. The regional effect could be found in both near-surface air temperature and surface specific/relative humidity when the percentage of roofs covered with high albedo materials or green roofs reached a higher fraction (greater than 50%). The changes in the vertical profiles of temperature cause a more stable atmospheric boundary layer over the urban area; at the same time, the crossover phenomena occurred above the boundary layer due to the decrease in vertical wind speed.

Energy Savings Calculations for Heat Island Reduction Strategies in Baton Rouge, Sacramento and Salt Lake City

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konopacki, S.; Akbari, H.

2000-03-01

In 1997, the US Environmental Protection Agency (EPA) established the ''Heat Island Reduction Initiative'', to quantify the potential benefits of Heat Island Reduction (HIR) strategies (i.e., shade trees, reflective roofs, reflective pavements and urban vegetation) to reduce cooling energy use in buildings, lower the ambient air temperature and improve urban air quality in cities, and reduce CO2 emissions from power plants. Under this initiative, the Urban Heat Island Pilot Project (UHIPP) was created with the objective to investigate the potential of HIR strategies in residential and commercial buildings in three initial UHIPP cities: Baton Rouge, Sacramento and Salt Lake City.more » This paper summarizes our efforts to calculate the annual energy savings, peak power avoidance and annual C02 reduction of HIR strategies in the three initial cities. In this analysis, we focused on three building types that offer most savings potential: single-family residence, office and retail store. Each building type was characterized in detail by old or new construction and with a gas furnace or an electric heat pump. We defined prototypical building characteristics for each building type and simulated the impact of HIR strategies on building cooling and heating energy use and peak power demand using the DOE-2.IE model. Our simulations included the impact of (1) strategically-placed shade trees near buildings [direct effect], (2) use of high-albedo roofing material on building [direct effect], (3) combined strategies I and 2 [direct effect], (4) urban reforestation with high-albedo pavements and building surfaces [indirect effect] and (5) combined strategies 1, 2 and 4 [direct and indirect effects]. We then estimated the total roof area of air-conditioned buildings in each city using readily obtainable data to calculate the metropolitan-wide impact of HIR strategies. The results show, that in Baton Rouge, potential annual energy savings of $15M could be realized by rate

Application of spatially gridded temperature and land cover data sets for urban heat island analysis

USGS Publications Warehouse

Gallo, Kevin; Xian, George Z.

2014-01-01

Two gridded data sets that included (1) daily mean temperatures from 2006 through 2011 and (2) satellite-derived impervious surface area, were combined for a spatial analysis of the urban heat-island effect within the Dallas-Ft. Worth Texas region. The primary advantage of using these combined datasets included the capability to designate each 1 × 1 km grid cell of available temperature data as urban or rural based on the level of impervious surface area within the grid cell. Generally, the observed differences in urban and rural temperature increased as the impervious surface area thresholds used to define an urban grid cell were increased. This result, however, was also dependent on the size of the sample area included in the analysis. As the spatial extent of the sample area increased and included a greater number of rural defined grid cells, the observed urban and rural differences in temperature also increased. A cursory comparison of the spatially gridded temperature observations with observations from climate stations suggest that the number and location of stations included in an urban heat island analysis requires consideration to assure representative samples of each (urban and rural) environment are included in the analysis.

Acquisition and Processing of High Resolution Hyperspectral Imageries for the 3d Mapping of Urban Heat Islands and Microparticles of Montreal

NASA Astrophysics Data System (ADS)

Mongeau, R.; Baudouin, Y.; Cavayas, F.

2017-10-01

Ville de Montreal wanted to develop a system to identify heat islands and microparticles at the urban scale and to study their formation. UQAM and UdeM universities have joined their expertise under the framework "Observatoire Spatial Urbain" to create a representative geospatial database of thermal and atmospheric parameters collected during the summer months. They innovated in the development of a methodology for processing high resolution hyperspectral images (1-2 m). In partnership with Ville de Montreal, they integrated 3D geospatial data (topography, transportation and meteorology) in the process. The 3D mapping of intraurban heat islands as well as air micro-particles makes it possible, initially, to identify the problematic situations for future civil protection interventions during extreme heat. Moreover, it will be used as a reference for the Ville de Montreal to establish a strategy for public domain tree planting and in the analysis of urban development projects.

The role of one large greenspace in mitigating London's nocturnal urban heat island.

PubMed

Doick, Kieron J; Peace, Andrew; Hutchings, Tony R

2014-09-15

The term urban heat island (UHI) describes a phenomenon where cities are on average warmer than the surrounding rural area. Trees and greenspaces are recognised for their strong potential to regulate urban air temperatures and combat the UHI. Empirical data is required in the UK to inform predictions on cooling by urban greenspaces and guide planning to maximise cooling of urban populations. We describe a 5-month study to measure the temperature profile of one of central London's large greenspaces and also in an adjacent street to determine the extent to which the greenspace reduced night-time UHI intensity. Statistical modelling displayed an exponential decay in the extent of cooling with increased distance from the greenspace. The extent of cooling ranged from an estimated 20 m on some nights to 440 m on other nights. The mean temperature reduction over these distances was 1.1 °C in the summer months, with a maximum of 4 °C cooling observed on some nights. Results suggest that calculation of London's UHI using Met Stations close to urban greenspace can underestimate 'urban' heat island intensity due to the cooling effect of the greenspace and values could be in the region of 45% higher. Our results lend support to claims that urban greenspace is an important component of UHI mitigation strategies. Lack of certainty over the variables that govern the extent of the greenspace cooling influence indicates that the multifaceted roles of trees and greenspaces in the UK's urban environment merit further consideration. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Urban Heat Islands (UHI) and the influence of city parks within the urban environment.

NASA Astrophysics Data System (ADS)

Garcia, W.; Shandas, V.; Voelkel, J.; Espinoza, D.

2016-12-01

Urban Heat Islands (UHI) and the influence of city parks within the urban environment.As cities grow outward and their populations increase the Urban Heat Island (UHI) phenomena becomes an ever more important topic to reducing environmental stressors. When UHI combines with human sensitivities such as pre-existing health conditions, and other vulnerabilities, finding an effective way to cool our cities is a matter of life and death. One way to cool an area is to introduce vegetation; which is abundant is in city parks. This study measures the cooling effect and temperature gradient of city parks; characterizing the relationship between the cooling effects within parks and surrounding neighborhoods. Past studies of the UHI are largely based on satellite images and, more recently, car traverses across that describe the ambient temperatures. The present project aims to understand the effects of parks on the UHI by asking two research questions: (1) how do the physical characteristics and designs of city parks impact the variation in ambient temperatures? And (2) what effect does the park have on cooling the surrounding neighborhoods? We address these questions by using a bicycle mounted with a temperature probe, and a series of geospatial analytics. The bicycle collects temperature data every one second, and the traverse intervals are an hour long to prevent normal fluctuations of daily temperature. Preliminary analysis shows that there is a temperature gradient within the parks (Figure 1). Further, the average temperature of the urban park could cool the surrounding area by upwards of 2°C, depending on the physical characteristics of then park and neighborhood. Our results suggest that the role of smaller parks and their design can reduce heat stress particularly among the vulnerable populations. These results can help urban planners make informed decisions when developing future city infrastructure.

Contributions to urban heat island on the local neighborhood scale

NASA Astrophysics Data System (ADS)

Hertel, Daniel; Schlink, Uwe

2017-04-01

Already today around half of the global population is living in urban regions and recent studies expect a further increase until mid-21st century. Therefore, especially in the context of climate change, an increasing amount of urban inhabitants are affected by urban climate and air quality. One special characteristic of urban climate is the urban heat island (UHI) effect, where urbanized regions are warmer than the rural surroundings. With respect to climate change and the growing urbanization it is obvious that the UHI effect will tend to be intensified. To keep our cities worth living, it is necessary to think about adaptation and mitigation strategies which refer to both, climate protection as well as utilization of chances resulting from climate changes. One step to a more precisely adaptation, particularly on the neighborhood scale, is an improved understanding of the magnitude of bio geophysical processes (e.g.: radiation balance, convection efficiency, evapotranspiration, storage heat, anthropogenic heat etc.), which contribute to the urban warming. Considering that UHI can be expressed as temperature difference ΔT between urban and rural areas, we can interpret these processes as how they would change temperature, because of energy redistribution, from a rural area to an urbanized region. Up to now on the local scale there is a knowledge gap about these processes. The mentioned processes are parts of a surface energy balance (based on the work of Zhao et al., 2014). That means they refer to the surface UHI effect and not to the canopy layer UHI effect. Assuming that the urban region is a volume with the top at the height of the canopy layer, we can approximately identify the surface UHI effect as the canopy layer UHI effect since the information comes from both the surface and the atmosphere inside. This assumption is not valid for Zhao's approach because they analyzed whole cities and could neglect such processes within the volume. This contribution

The Urban Heat Island Impact in Consideration of Spatial Pattern of Urban Landscape and Structure

NASA Astrophysics Data System (ADS)

Kim, J.; Lee, D. K.; Jeong, W.; Sung, S.; Park, J.

2015-12-01

Preceding study has established a clear relationship between land surface temperature and area of land covers. However, only few studies have specifically examined the effects of spatial patterns of land covers and urban structure. To examine how much the local climate is affected by the spatial pattern in highly urbanized city, we investigated the correlation between land surface temperature and spatial patterns of land covers. In the analysis of correlation, we categorized urban structure to four different land uses: Apartment residential area, low rise residential area, industrial area and central business district. Through this study, we aims to examine the types of residential structure and land cover pattern for reducing urban heat island and sustainable development. Based on land surface temperature, we investigated the phenomenon of urban heat island through using the data of remote sensing. This study focused on Daegu in Korea. This city, one of the hottest city in Korea has basin form. We used high-resolution land cover data and land surface temperature by using Landsat8 satellite image to examine 100 randomly selected sample sites of 884.15km2 (1)In each land use, we quantified several landscape-levels and class-level landscape metrics for the sample study sites. (2)In addition, we measured the land surface temperature in 3 year hot summer seasons (July to September). Then, we investigated the pattern of land surface temperature for each land use through Ecognition package. (3)We deducted the Pearson correlation coefficients between land surface temperature and each landscape metrics. (4)We analyzed the variance among the four land uses. (5)Using linear regression, we determined land surface temperature model for each land use. (6)Through this analysis, we aims to examine the best pattern of land cover and artificial structure for reducing urban heat island effect in highly urbanized city. The results of linear regression showed that proportional land

Characterising the influence of atmospheric mixing state on Urban Heat Island Intensity using Radon-222

NASA Astrophysics Data System (ADS)

Chambers, Scott D.; Podstawczyńska, Agnieszka; Williams, Alastair G.; Pawlak, Włodzimierz

2016-12-01

Characterisation of the effects of varying atmospheric mixing states (stability) in urban climate studies has historically been hampered by problems associated with the complexity of the urban environment, representativity of measurement techniques, and the logistical and financial burdens of maintaining multiple long-term comprehensive measurement sites. These shortcomings, together with a lack of a consistent measurement approach, have limited our ability to understand the physical processes contributing to the urban heat island effect. In this study, we analyse 4 years of continuous hourly near-surface meteorological and atmospheric radon data from an urban-rural site pair in central Poland. A recently-developed radon-based stability classification technique, previously developed for urban pollution characterisation, is employed to characterise the Urban Heat Island Intensity (UHII) and other climatic factors over the full diurnal cycle by season and atmospheric mixing state. By characterising the UHII over a range of atmospheric mixing states in a statistically robust way, this technique provides an effective tool for assessing the efficacy of mitigation measures for urban climate effects in a consistent way over timescales of years to decades. The consistency of approach, ease of application, and unprecedented clarity of findings, provide a strong argument for atmospheric radon observations to be included as part of the 'standard measurement suite' for urban climate monitoring networks for non-coastal cities.

Assessing the Urban Heat Island Effect Across Biomes in the Continental USA Using Landsat and MODIS

NASA Technical Reports Server (NTRS)

Imhoff, Marc L.; Bounoua, L.; Zhang, Ping; Wolfe, Robert

2011-01-01

Impervious surface area (ISA) from the Landsat TM and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for 38 of the most populous cities in the continental United States. Development intensity zones based on %ISA are defined across urban gradients and used to stratify sampling of LST and NDVI. We find that ecological context significantly influences the amplitude of summer daytime UHI (urban - rural temperature difference) with the largest 8 C (average) for cities built in mixed forest biomes. For all cities ISA is the primary driver for increase in temperature explaining 70% of the total variance. Annually, urban areas are warmer than the non-urban fringe by 2.9 C, except in biomes with arid and semiarid climates. The average amplitude of the UHI is asymmetric with a 4.3 C difference in summer and 1.3 C in winter. In desert environments, UHI's point to a possible heat sink effect. Results show that the urban heat island amplitude increases with city size and is seasonally asymmetric for a large number of cities across most biomes. The implications are that for urban areas developed within forested ecosystems the summertime UHI can be quite high relative to the wintertime UHI suggesting that the residential energy consumption required for summer cooling is likely to increase with urban growth within those biomes.

Experimental urban heat island research of Norilsk city in northern Russia in the polar night

NASA Astrophysics Data System (ADS)

Varentsov, Mikhail; Konstantinov, Pavel; Repina, Irina; Samsonov, Timofey; Baklanov, Alexander

2014-05-01

Growing socioeconomic activity in Arctic zone and prospective of planning and building new settlements and cities in this region requires better understanding of the urban-caused microclimatic features and their behavior in the conditions of arctic and sub-arctic climate. The most important of these features is well-known urban heat island (UHI) effect, because in high latitudes it could mitigate severe climatic conditions within urban areas and provide the economy of fuel for house heating. The UHI effect is quietly good investigated and described for the cities in low and moderate latitudes (Oke, 1987), but there is significant lack of knowledge about UHI of the cities over the Polar Circle and especially about its behavior during the polar night, while anthropogenic heat is the only source of energy to form heat island. In this study, we consider the results of experimental research of the UHI of Norilsk - the second biggest city over the Polar Circle, which were obtained during the expedition of Russian Geographic Society in December 2013, practically around the middle of the polar night. Field measurements in Norilsk included installation of three automatic weather stations (AWS) and the net of small temperature sensors (iButton) in the city and surrounding landscape and also car-based temperature sounding of the city with AWS. The influence of the relief and stratification was filtered by using the data of MTP-5 microwave temperature profiler. Analysis of the collected data showed the existence of significant UHI with the difference between city center and surrounding landscape up to 6 °C. The dependence of UHI power and shape on the synoptic conditions were analyzed for several typical synoptic situations, which were observed during the expedition, and the negative correlation of the UHI power with air temperature was determined. The reported study was supported by Russian Geographic Society, research projects No. 69/2013-H7 and 27/2013-H3. References: 1

The summer urban heat island of Bucharest (Romania) as retrieved from satellite imagery

NASA Astrophysics Data System (ADS)

Cheval, Sorin; Dumitrescu, Alexandru

2014-05-01

The summer Urban Heat Island (UHI) of the city of Bucharest (Romania) has been investigated in terms of its shape, intensity, extension, and links to land cover. The study integrates land surface temperature (LST) data retrieved by the MODIS sensors aboard the Terra and Aqua NASA satellites, and SEVIRI sensors on board of the geostationary platform MSG, along 2000-2012. Based on the Rodionov Regime Shift Index, the significant changing points in the land surface temperature values along transverse profiles crossing the city's centre were considered as UHI's limits. The study shows that the intensity calculated as the difference between the LST within the UHI limits and several surrounding buffers is an objective and flexible tool for describing the average thermal state of the urban-rural transition. The method secures the weight of comparing the UHI's intensity of different urban areas. There are little variations from one month to another, but UHI's shapes and intensities under clear-sky conditions are very specific to nighttime (more regular and 2-3°C less in the 7-km width buffer), and daytime (more twisted and more steep temperature decrease). For both cases, strong relationships with the land cover can be assumed. The nighttime UHI's geometry is more regular, and the intensity lower than the day situation, while the land cover exerts a strong influence on the Bucharest LST. After all, the study promotes an objective manner to delimitate and quantify the UHI based on satellite imagery. The study was performed within the STAR project 92/2013 (Urban Heat Island Monitoring under Present and Future Climate - UCLIMESA).

Urban heat island research from 1991 to 2015: a bibliometric analysis

NASA Astrophysics Data System (ADS)

Huang, Qunfang; Lu, Yuqi

2018-02-01

A bibliometric analysis based on the Science Citation Index-Expanded (SCI-Expanded) database from the Web of Science was performed to review urban heat island (UHI) research from 1991 to 2015 and statistically assess its developments, trends, and directions. In total, 1822 papers published in 352 journals over the past 25 years were analyzed for scientific output; citations; subject categories; major journals; outstanding keywords; and leading countries, institutions, authors, and research collaborations. The number of UHI-related publications has continuously increased since 1991. Meteorology atmospheric sciences, environmental sciences, and construction building technology were the three most frequent subject categories. Building and Environment, International Journal of Climatology, and Theoretical and Applied Climatology were the three most popular publishing journals. The USA and China were the two leading countries in UHI research, contributing 49.56% of the total articles. Chinese Academy of Science, Arizona State University, and China Meteorological Administration published the most UHI articles. Weng QH and Santamouris M were the two most prolific authors. Author keywords were classified into four major groups: (1) research methods and indicators, e.g., remote sensing, field measurement, and models; (2) generation factors, e.g., impervious urban surfaces, urban geometry, waste heat, vegetation, and pollutants; (3) environmental effects, e.g., urban climate, heat wave, ecology, and pollution; and (4) mitigation and adaption strategies, e.g., roof technology cooling, reflective cooling, vegetation cooling, and urban geometry cooling. A comparative analysis of popular issues revealed that UHI determination (intensity, heat source, supporting techniques) remains the central topic, whereas UHI impacts and mitigation strategies are becoming the popular issues that will receive increasing scientific attention in the future. Modeling will continue to be the

Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City.

PubMed

Dang, Tran Ngoc; Van, Doan Quang; Kusaka, Hiroyuki; Seposo, Xerxes T; Honda, Yasushi

2018-04-01

To quantify heat-related deaths in Ho Chi Minh City, Vietnam, caused by the urban heat island (UHI) and explore factors that may alleviate the impact of UHIs. We estimated district-specific meteorological conditions from 2010 to 2013 using the dynamic downscaling model and calculated the attributable fraction and number of mortalities resulting from the total, extreme, and mild heat in each district. The difference in attributable fraction of total heat between the central and outer districts was classified as the attributable fraction resulting from the UHI. The association among attributable fraction, attributable number with a green space, population density, and budget revenue of each district was then explored. The temperature-mortality relationship between the central and outer areas was almost identical. The attributable fraction resulting from the UHI was 0.42%, which was contributed by the difference in temperature distribution between the 2 areas. Every 1-square-kilometer increase in green space per 1000 people can prevent 7.4 deaths caused by heat. Green space can alleviate the impacts of UHIs, although future studies conducting a heath economic evaluation of tree planting are warranted.

Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City

PubMed Central

Van, Doan Quang; Kusaka, Hiroyuki; Seposo, Xerxes T.; Honda, Yasushi

2018-01-01

Objectives. To quantify heat-related deaths in Ho Chi Minh City, Vietnam, caused by the urban heat island (UHI) and explore factors that may alleviate the impact of UHIs. Methods. We estimated district-specific meteorological conditions from 2010 to 2013 using the dynamic downscaling model and calculated the attributable fraction and number of mortalities resulting from the total, extreme, and mild heat in each district. The difference in attributable fraction of total heat between the central and outer districts was classified as the attributable fraction resulting from the UHI. The association among attributable fraction, attributable number with a green space, population density, and budget revenue of each district was then explored. Results. The temperature–mortality relationship between the central and outer areas was almost identical. The attributable fraction resulting from the UHI was 0.42%, which was contributed by the difference in temperature distribution between the 2 areas. Every 1-square-kilometer increase in green space per 1000 people can prevent 7.4 deaths caused by heat. Conclusions. Green space can alleviate the impacts of UHIs, although future studies conducting a heath economic evaluation of tree planting are warranted. PMID:29072938

Land Use and Land Cover Change, Urban Heat Island Phenomenon, and Health Implications: A Remote Sensing Approach

NASA Technical Reports Server (NTRS)

Lo, C. P.; Quattrochi, Dale A.

2003-01-01

Land use and land cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973,1979,1983,1987,1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119% between 1973 and 1997. These land use and land cover changes have drastically altered the land surface characteristics. An analysis of Landsat images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect and an increase in ground level ozone production to such an extent, that Atlanta has violated EPA's ozone level standard in recent years. The urban heat island initiated precipitation events that were identified between 1996 and 2000 tended to occur near high-density urban areas but outside the I-285 loop that traverses around the Central Business District, i.e. not in the inner city area, but some in close proximity to the highways. The health implications were investigated by comparing the spatial patterns of volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, with those of rates of cardiovascular and chronic lower respiratory diseases. A clear core-periphery pattern was revealed for both VOC and NOx emissions, but the spatial pattern was more random in the cases of rates of cardiovascular and chronic lower respiratory diseases. Clearly, factors other than ozone pollution were involved in explaining the rates of these diseases. Further research is therefore needed to understand the health geography and its relationship to land use and land cover change as well as urban heat island effect. This paper illustrates the usefulness of a remote sensing approach for this purpose.

Positive effects of vegetation: urban heat island and green roofs.

PubMed

Susca, T; Gaffin, S R; Dell'osso, G R

2011-01-01

This paper attempts to evaluate the positive effects of vegetation with a multi-scale approach: an urban and a building scale. Monitoring the urban heat island in four areas of New York City, we have found an average of 2 °C difference of temperatures between the most and the least vegetated areas, ascribable to the substitution of vegetation with man-made building materials. At micro-scale, we have assessed the effect of surface albedo on climate through the use of a climatological model. Then, using the CO(2) equivalents as indicators of the impact on climate, we have compared the surface albedo, and the construction, replacement and use phase of a black, a white and a green roof. By our analyses, we found that both the white and the green roofs are less impactive than the black one; with the thermal resistance, the biological activity of plants and the surface albedo playing a crucial role. Copyright © 2011 Elsevier Ltd. All rights reserved.

Heat islands over Mumbai as revealed by autorecorded thermograph data

NASA Astrophysics Data System (ADS)

Srivastava, A. K.; Voogt, James; Kshirsagar, S. R.; Srivastava, Kavita

2016-02-01

This study examined hourly temperature data of two locations of Mumbai metropolitan city. One data point (Coloba, Mumbai) is in centre of the city and the other one (Santacruz, Mumbai) is at the airport. The study finds that there were many occasions when night-time hourly temperatures over the city centre were considerably higher than that of the airport, even though temperature at the time of sunset at both the places was nearly same. In this study, the occasions, when hourly night-time temperature over city was more than that of the airport by objectively defined threshold value (3.0 ∘C in this study) for most of the hours in the night, were termed as heat island events. Analysis of the study reveals that these events are mostly confined to November-February months. The study also found that frequency of such events has doubled in recent two decades in comparison to the earlier two decades.

The influence of urban heat islands and socioeconomic factors on the spatial distribution of Aedes aegypti larval habitats.

PubMed

De Azevedo, Thiago S; Bourke, Brian Patrick; Piovezan, Rafael; Sallum, Maria Anice M

2018-05-08

We addressed the potential associations among the temporal and spatial distribution of larval habitats of Aedes (Stegomyia) aegypti, the presence of urban heat islands and socioeconomic factors. Data on larval habitats were collected in Santa Bárbara d'Oeste, São Paulo, Brazil, from 2004 to 2006, and spatial and temporal variations were analysed using a wavelet-based approach. We quantified urban heat islands by calculating surface temperatures using the results of wavelet analyses and grey level transformation from Thematic Mapper images (Landsat 5). Ae. aegypti larval habitats were geo-referenced corresponding to the wavelet analyses to test the potential association between geographical distribution of habitats and surface temperature. In an inhomogeneous spatial point process, we estimated the frequency of occurrence of larval habitats in relation to temperature. The São Paulo State Social Vulnerability Index in the municipality of Santa Barbára d'Oeste was used to test the potential association between presence of larval habitats and social vulnerability. We found abundant Ae. aegypti larval habitats in areas of higher surface temperature and social vulnerability and fewer larval habitats in areas with lower surface temperature and social vulnerability.

Spatio-Temporal Variability of Urban Heat Island and Urban Mobility

NASA Astrophysics Data System (ADS)

Kar, B.; Omitaomu, O.

2017-12-01

A 2016 report by the U.S. Census stated that while the rural areas cover 97% of the U.S. landmass, these areas house only 19.7% of the nation's population. Given that the U.S. coastal counties are home to more than 50% of the U.S. population, these urban areas are clustered along the coast that is susceptible to sea level rise induced impacts. In light of increasing climate variability and extreme events, it is pertinent to understand the Urban Heat Island (UHI) effect that results from increasing population density and mobility in the urban areas, and that contributes to increased energy consumption and temperature as well as unmitigated flooding events. For example, in Illinois, warmer summers contribute to heavy precipitation that overwhelms the region's drainage capacity. This study focuses on understanding the spatio-temporal variability of the relationship between population density and mobility distribution, and creation of UHI due to temperature change in selected cities across the U.S. This knowledge will help us understand the role of UHI in energy-water nexus in urban areas, specifically, energy consumption.

The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures

PubMed Central

Barron-Gafford, Greg A.; Minor, Rebecca L.; Allen, Nathan A.; Cronin, Alex D.; Brooks, Adria E.; Pavao-Zuckerman, Mitchell A.

2016-01-01

While photovoltaic (PV) renewable energy production has surged, concerns remain about whether or not PV power plants induce a “heat island” (PVHI) effect, much like the increase in ambient temperatures relative to wildlands generates an Urban Heat Island effect in cities. Transitions to PV plants alter the way that incoming energy is reflected back to the atmosphere or absorbed, stored, and reradiated because PV plants change the albedo, vegetation, and structure of the terrain. Prior work on the PVHI has been mostly theoretical or based upon simulated models. Furthermore, past empirical work has been limited in scope to a single biome. Because there are still large uncertainties surrounding the potential for a PHVI effect, we examined the PVHI empirically with experiments that spanned three biomes. We found temperatures over a PV plant were regularly 3–4 °C warmer than wildlands at night, which is in direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures. Deducing the underlying cause and scale of the PVHI effect and identifying mitigation strategies are key in supporting decision-making regarding PV development, particularly in semiarid landscapes, which are among the most likely for large-scale PV installations. PMID:27733772

Self-regulated oscillation of transport and topology of magnetic islands in toroidal plasmas

DOE PAGES

Ida, K.; Kobayashi, T.; Evans, T. E.; ...

2015-11-04

The coupling between the transport and magnetic topology is an important issue because the structure of magnetic islands, embedded in a toroidal equilibrium field, depends on the nature of the transport at the edge of the islands. Measurements of modulated heat pulse propagation in the DIII-D tokamak have revealed the existence of self-regulated oscillations in the radial energy transport into magnetic islands that are indicative of bifurcations in the island structure and transport near the q = 2 surface. Large amplitude heat pulses are seen in one state followed by small amplitude pulses later in the discharge resulting in amore » repeating cycle of island states. These two states are interpreted as a bifurcation of magnetic island with high and low heat pulse accessibility. In conclusion, this report describes the discovery of a bifurcation in the coupled dynamics between the transport and topology of magnetic islands in tokamak plasmas.« less

Remote Sensing of the Urban Heat Island Effect Across Biomes in the Continental USA

NASA Technical Reports Server (NTRS)

Imhoff, Marc L.; Zhang, Ping; Wolfe, Robert E.; Bounoua, Lahouari

2010-01-01

Impervious surface area (ISA) from the Landsat TM-based NLCD 2001 dataset and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for 38 of the most populous cities in the continental United States. Development intensity zones based on %ISA are defined for each urban area emanating outward from the urban core to the nonurban rural areas nearby and used to stratify sampling for land surface temperatures and NDVI. Sampling is further constrained by biome and elevation to insure objective intercomparisons between zones and between cities in different biomes permitting the definition of hierarchically ordered zones that are consistent across urban areas in different ecological setting and across scales. We find that ecological context significantly influences the amplitude of summer daytime UHI (urban-rural temperature difference) the largest (8 C average) observed for cities built in biomes dominated by temperate broadleaf and mixed forest. For all cities combined, ISA is the primary driver for increase in temperature explaining 70% of the total variance in LST. On a yearly average, urban areas are substantially warmer than the non-urban fringe by 2.9 C, except for urban areas in biomes with arid and semiarid climates. The average amplitude of the UHI is remarkably asymmetric with a 4.3 C temperature difference in summer and only 1.3 C in winter. In desert environments, the LST's response to ISA presents an uncharacteristic "U-shaped" horizontal gradient decreasing from the urban core to the outskirts of the city and then increasing again in the suburban to the rural zones. UHI's calculated for these cities point to a possible heat sink effect. These observational results show that the urban heat island amplitude both increases with city size and is seasonally

Mitigating the surface urban heat island: Mechanism study and sensitivity analysis

NASA Astrophysics Data System (ADS)

Meng, Chunlei

2017-08-01

In a surface urban heat island (SUHI), the urban land surface temperature (LST) is usually higher than the temperature of the surrounding rural areas due to human activities and surface characteristics. Because a SUHI has many adverse impacts on urban environment and human health, SUHI mitigation strategies are very important. This paper investigates the mechanism of a SUHI based on the basic physical laws that control the formation of a SUHI; five mitigation strategies are proposed, namely: sprinkling and watering; paving a pervious surface; reducing the anthropogenic heat (AH) release; using a "white roof"; increasing the fractional vegetation cover or leaf area index (LAI). To quantify the effect of these mitigation strategies, 26 sets of experiments are designed and implemented by running the integrated urban land model (IUM). The results of the sensitivity analysis indicate that sprinkling and watering is an effective measure for mitigating a SUHI for an entire day. Decreasing the AH release is also useful for both night- and daytime SUHI mitigation; however, the cooling extent is proportional to the diurnal cycle of AH. Increasing the albedo can reduce the LST in the daytime, especially when the solar radiation is significant; the cooling extent is approximately proportional to the diurnal cycle of the net radiation. Increasing the pervious surface percentage can mitigate the SUHI especially in the daytime. Increasing the fractional vegetation cover can mitigate the SUHI in the daytime but may aggravate the SUHI at night.

Assessment of urban heat Island for Craiova from satellite-based LST

NASA Astrophysics Data System (ADS)

Udristioiu, Mihaela Tinca; Velea, Liliana; Bojariu, Roxana; Sararu, Silviu Constantin

2017-12-01

The urban heat island is defined as an excess of heating in urban areas compared with surrounding rural zones which is illustrated by higher surface and air temperatures in the inner part of the cities. The aim of this study is to identify the UHI effect for Craiova - the largest city in the South-Western part of Romania - and to assess its intensity during summer. To this end, MODIS Land surface temperature (LST) for day and night for summer months (June, July, August), in the interval 2002-2017, as well as yearly Land Cover Type (LCT) data also from MODIS were employed. Furthermore, measurements of air and soil temperature from meteorological station Craiova, available from the National Meteorological Administration database, were used to investigate their relation with LST. The analysis shows that in the urban area of Craiova the long-term summer mean LST is about 4 °C (2 °C), higher than in the rural area during daytime (nighttime). During high temperatures episodes, the mean daytime LST reaches 45-47 °C in the city, while the difference from the rural surrounding area is of 2-3 °C. A high correlation (0.77-0.83) is found between LST and air temperature for all land-use types in the area considered. Both LST and 2m-air temperature time-series manifest an increasing linear tendency over the period considered, being more pronounced during the day.

Observing the Vertical Dimensions of Singapore's Urban Heat Island

NASA Astrophysics Data System (ADS)

Chow, W. T. L.; Ho, D. X. Q.

2015-12-01

In numerous cities, measurements of urban warmth in most urban heat island (UHI) studies are generally constrained towards surface or near-surface (<2 m above ground) levels across horizontal variations in land use and land cover. However, there has been hitherto limited attention towards the measurement of vertical temperature profiles extending from the urban surface through to the urban boundary layer. Knowledge of these profiles, through how they vary over different local urban morphologies, and develop with respect to synoptic meteorological conditions, are important towards several aspects of UHI research; these include validating modelling urban canopy lapse rate profiles or estimating the growth of urban plumes. In this study, we utilised temperature sensors attached onto remote controlled aerial quadcopter platforms to measure urban temperature and humidity profiles in Singapore, which is a rapidly urbanizing major tropical metropolis. These profiles were measured from the surface to ~100 m above ground level, a height which includes all of the urban canopy and parts of the urban boundary layer. Initial results indicate significant variations in stability measured over different land uses (e.g. urban park, high-rise residential, commercial); these profiles are also temporally dynamic, depending on the time of day and larger-scale weather conditions.

Modeling of Urban Heat Island at Global Scale

NASA Astrophysics Data System (ADS)

KC, B.; Ruth, M.

2015-12-01

Urban Heat Island (UHI) is the temperature difference between urban and its rural background temperature. At the local level, the choice of building materials and urban geometry are vital in determining the UHI magnitude of a city. At the city scale, economic growth, population, climate, and land use dynamics are the main drivers behind changes in UHIs. The main objective of this paper is to provide a comprehensive assessment of UHI based on these "macro variables" at regional and global scale. We based our analysis on published research for Europe, North America, and Asia, reporting data for 83 cities across the globe with unique climatic, economic, and environmental conditions. Exploratory data analysis including Pearson correlation was performed to explore the relationship between UHI and PM2.5 (particulate matter with aerodynamic diameter ≤5 microns), PM10 (particulate matter with aerodynamic diameter ≤10 microns), vegetation per capita, built area, Gross Domestic Product (GDP), population density and population. Additionally, dummy variables were used to capture potential influences of climate types (based on Koppen classifications) and the ways by which UHI was measured. We developed three linear regression models, one for each of the three continents (Asia, Europe, and North America) and one model for all the cities across these continents. This study provides a unique perspective for predicting UHI magnitudes at large scales based on economic activity and pollution levels of a city, which has important implications in urban planning.

Data use investigations for applications Explorer Mission A (Heat Capacity Mapping Mission): HCMM's role in studies of the urban heat island, Great Lakes thermal phenomena and radiometric calibration of satellite data. [Buffalo, Syracuse, and Rochester New York and Lake Ontario

NASA Technical Reports Server (NTRS)

Schott, J. R. (Principal Investigator); Schimminger, E. W.

1981-01-01

The utility of data from NASA'a heat capacity mapping mission satellite for studies of the urban heat island, thermal phenomena in large lakes and radiometric calibration of satellite sensors was assessed. The data were found to be of significant value in all cases. Using HCMM data, the existence and microstructure of the heat island can be observed and associated with land cover within the urban complex. The formation and development of the thermal bar in the Great Lakes can be observed and quantitatively mapped using HCMM data. In addition, the thermal patterns observed can be associated with water quality variations observed both from other remote sensing platforms and in situ. The imaging radiometer on-board the HCMM satellite is shown to be calibratible to within about 1.1 C of actual surface temperatures. These findings, as well as the analytical procedures used in studying the HCMM data, are included.

The urban heat island in the city of Poznań as derived from Landsat 5 TM

NASA Astrophysics Data System (ADS)

Majkowska, Agnieszka; Kolendowicz, Leszek; Półrolniczak, Marek; Hauke, Jan; Czernecki, Bartosz

2017-05-01

To study urban heat island (UHI), Landsat 5 TM data and in situ measurements of air temperature from nine points in Poznań (Poland) for the period June 2008-May 2013 were used. Based on data from measurement points located in different types of land use, the surface urban heat island (SUHI) maps were created. All available and quality-controlled Landsat 5 TM images from 15 unique days were used to obtain the characteristics of land surface temperature (LST) and UHI intensity. In addition, spatial analysis of UHI was conducted on the basis of Corine Land Cover 2006 dataset. In situ measurements at a height of 2 m above ground level show that the UHI is a common occurrence in Poznań with a mean annual intensity of 1.0 °C. The UHI intensity is greater during the warm half of the year. Moreover, results based on the remote sensing data and the Corine Land Cover 2006 indicate that the highest value of the mean LST anomalies (3.4 °C) is attained by the continuous urban fabric, while the lowest value occurs within the broad-leaved forests (-3.1 °C). To re-count from LST to the air temperature at a height of 2 m above ground level ( T agl), linear and non-linear regression models were created. For both models, coefficients of determination equal about 0.80, with slightly higher value for the non-linear approach, which was applied to estimate the T agl spatial variability over the city of Poznań.

Heat stress control in the TMI-2 (Three Mile Island Unit 2) defueling and decontamination activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schork, J.S.; Parfitt, B.A.

During the initial stages of the Three Mile Island Unit 2 (TMI-2) defueling and decontamination activities for the reactor building, it was realized that the high levels of loose radioactive contamination would require the use of extensive protective clothing by entry personnel. While there was no doubt that layered protective clothing protects workers from becoming contaminated, it was recognized that these same layers of clothing would impose a very significant heat stress burden. To prevent the potentially serious consequences of a severe reaction to heat stress by workers in the hostile environment of the TMI-2 reactor building and yet maintainmore » the reasonable work productivity necessary to perform the recovery adequately, an effective program of controlling worker exposure to heat stress had to be developed. Body-cooling devices produce a flow of cool air, which is introduced close to the skin to remove body heat through convection and increased sweat evaporation. The cooling effect produced by the Vortex tube successfully protected the workers from heat stress, however, there were several logistical and operational problems that hindered extensive use of these devices. The last type of cooling garment examined was the frozen water garment (FWG) developed by Elizier Kamon at the Pennsylvania State University as part of an Electric Power Research Institute research grant. Personal protection, i.e., body cooling, engineering controls, and administrative controls, have been implemented successfully.« less

Transport properties of interacting magnetic islands in tokamak plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gianakon, T.A.; Callen, J.D.; Hegna, C.C.

1993-10-01

This paper explores the equilibrium and transient transport properties of a mixed magnetic topology model for tokamak equilibria. The magnetic topology is composed of a discrete set of mostly non-overlapping magnetic islands centered on the low-order rational surfaces. Transport across the island regions is fast due to parallel transport along the stochastic magnetic field lines about the separatrix of each island. Transport between island regions is assumed to be slow due to a low residual cross-field transport. In equilibrium, such a model leads to: a nonlinear dependence of the heat flux on the pressure gradient; a power balance diffusion coefficientmore » which increases from core to edge; and profile resiliency. Transiently, such a model also exhibits a heat pulse diffusion coefficient larger than the power balance diffusion coefficient.« less

Urban weather data and building models for the inclusion of the urban heat island effect in building performance simulation.

PubMed

Palme, M; Inostroza, L; Villacreses, G; Lobato, A; Carrasco, C

2017-10-01

This data article presents files supporting calculation for urban heat island (UHI) inclusion in building performance simulation (BPS). Methodology is used in the research article "From urban climate to energy consumption. Enhancing building performance simulation by including the urban heat island effect" (Palme et al., 2017) [1]. In this research, a Geographical Information System (GIS) study is done in order to statistically represent the most important urban scenarios of four South-American cities (Guayaquil, Lima, Antofagasta and Valparaíso). Then, a Principal Component Analysis (PCA) is done to obtain reference Urban Tissues Categories (UTC) to be used in urban weather simulation. The urban weather files are generated by using the Urban Weather Generator (UWG) software (version 4.1 beta). Finally, BPS is run out with the Transient System Simulation (TRNSYS) software (version 17). In this data paper, four sets of data are presented: 1) PCA data (excel) to explain how to group different urban samples in representative UTC; 2) UWG data (text) to reproduce the Urban Weather Generation for the UTC used in the four cities (4 UTC in Lima, Guayaquil, Antofagasta and 5 UTC in Valparaíso); 3) weather data (text) with the resulting rural and urban weather; 4) BPS models (text) data containing the TRNSYS models (four building models).

The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete.

PubMed

Mohajerani, Abbas; Bakaric, Jason; Jeffrey-Bailey, Tristan

2017-07-15

The Urban Heat Island (UHI) is a phenomenon that affects many millions of people worldwide. The higher temperatures experienced in urban areas compared to the surrounding countryside has enormous consequences for the health and wellbeing of people living in cities. The increased use of manmade materials and increased anthropogenic heat production are the main causes of the UHI. This has led to the understanding that increased urbanisation is the primary cause of the urban heat island. The UHI effect also leads to increased energy needs that further contribute to the heating of our urban landscape, and the associated environmental and public health consequences. Pavements and roofs dominate the urban surface exposed to solar irradiation. This review article outlines the contribution that pavements make to the UHI effect and analyses localized and citywide mitigation strategies against the UHI. Asphalt Concrete (AC) is one of the most common pavement surfacing materials and is a significant contributor to the UHI. Densely graded AC has low albedo and high volumetric heat capacity, which results in surface temperatures reaching upwards of 60 °C on hot summer days. Cooling the surface of a pavement by utilizing cool pavements has been a consistent theme in recent literature. Cool pavements can be reflective or evaporative. However, the urban geometry and local atmospheric conditions should dictate whether or not these mitigation strategies should be used. Otherwise both of these pavements can actually increase the UHI effect. Increasing the prevalence of green spaces through the installation of street trees, city parks and rooftop gardens has consistently demonstrated a reduction in the UHI effect. Green spaces also increase the cooling effect derived from water and wind sources. This literature review demonstrates that UHI mitigation techniques are best used in combination with each other. As a result of the study, it was concluded that the current mitigation

A validated methodology for the prediction of heating and cooling energy demand for buildings within the Urban Heat Island: Case-study of London

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolokotroni, Maria; Bhuiyan, Saiful; Davies, Michael

2010-12-15

This paper describes a method for predicting air temperatures within the Urban Heat Island at discreet locations based on input data from one meteorological station for the time the prediction is required and historic measured air temperatures within the city. It uses London as a case-study to describe the method and its applications. The prediction model is based on Artificial Neural Network (ANN) modelling and it is termed the London Site Specific Air Temperature (LSSAT) predictor. The temporal and spatial validity of the model was tested using data measured 8 years later from the original dataset; it was found thatmore » site specific hourly air temperature prediction provides acceptable accuracy and improves considerably for average monthly values. It thus is a very reliable tool for use as part of the process of predicting heating and cooling loads for urban buildings. This is illustrated by the computation of Heating Degree Days (HDD) and Cooling Degree Hours (CDH) for a West-East Transect within London. The described method could be used for any city for which historic hourly air temperatures are available for a number of locations; for example air pollution measuring sites, common in many cities, typically measure air temperature on an hourly basis. (author)« less

An effective public health program to reduce urban heat islands in Québec, Canada.

PubMed

Beaudoin, Mélanie; Gosselin, Pierre

2016-09-01

In 2005, the Government of the Province of Québec, Canada, adopted the Climate Change Action Plan for 2006 - 2012. The Institut national de santé publique du Québec (National Institute of Public Health of Québec), charged with implementing the health adaptation component of the Plan, worked to mitigate urban heat islands (UHI) by funding and evaluating 40 pilot projects. These projects explored different methods of fighting UHIs by greening cities in a participative and mobilizing approach led mainly by non-governmental organizations and municipalities. An assessment of temperatures before and after implementing various methods demonstrated that some actions enabled significant gains of coolness and more efficiently mitigated heat (reduction of concrete/asphalt surfaces, increasing vegetation, etc.). An assessment of quality of life showed that projects were positively received by users, especially by those living in vulnerable situations. A lifecycle analysis showed that from the environmental perspective, UHI mitigation measures that do not require fertilization or maintenance are preferable. Finally, communication efforts that raise awareness of UHI and mitigation are of significant importance to program success.

Utilising green and bluespace to mitigate urban heat island intensity.

PubMed

Gunawardena, K R; Wells, M J; Kershaw, T

2017-04-15

It has long been recognised that cities exhibit their own microclimate and are typically warmer than the surrounding rural areas. This 'mesoscale' influence is known as the urban heat island (UHI) effect and results largely from modification of surface properties leading to greater absorption of solar radiation, reduced convective cooling and lower water evaporation rates. Cities typically contain less vegetation and bodies of water than rural areas, and existing green and bluespace is often under threat from increasing population densities. This paper presents a meta-analysis of the key ways in which green and bluespace affect both urban canopy- and boundary-layer temperatures, examined from the perspectives of city-planning, urban climatology and climate science. The analysis suggests that the evapotranspiration-based cooling influence of both green and bluespace is primarily relevant for urban canopy-layer conditions, and that tree-dominated greenspace offers the greatest heat stress relief when it is most needed. However, the magnitude and transport of cooling experienced depends on size, spread, and geometry of greenspaces, with some solitary large parks found to offer minimal boundary-layer cooling. Contribution to cooling at the scale of the urban boundary-layer climate is attributed mainly to greenspace increasing surface roughness and thereby improving convection efficiency rather than evaporation. Although bluespace cooling and transport during the day can be substantial, nocturnal warming is highlighted as likely when conditions are most oppressive. However, when both features are employed together they can offer many synergistic ecosystem benefits including cooling. The ways in which green and bluespace infrastructure is applied in future urban growth strategies, particularly in countries expected to experience rapid urbanisation, warrants greater consideration in urban planning policy to mitigate the adverse effects of the UHI and enhance climate

Relationship between Surface Urban Heat Island intensity and sensible heat flux retrieved from meteorological parameters observed by road weather stations in urban area

NASA Astrophysics Data System (ADS)

Gawuć, Lech

2017-04-01

Urban Heat Island (UHI) is a direct consequence of altered energy balance in urban areas (Oke 1982). There has been a significant effort put into an understanding of air temperature variability in urban areas and underlying mechanisms (Arnfield 2003, Grimmond 2006, Stewart 2011, Barlow 2014). However, studies that are concerned on surface temperature are less frequent. Therefore, Voogt & Oke (2003) proposed term "Surface Urban Heat Island (SUHI)", which is analogical to UHI and it is defined as a difference in land surface temperature (LST) between urban and rural areas. SUHI is a phenomenon that is not only concerned with high spatial variability, but also with high temporal variability (Weng and Fu 2014). In spite of the fact that satellite remote sensing techniques give a full spatial pattern over a vast area, such measurements are strictly limited to cloudless conditions during a satellite overpass (Sobrino et al., 2012). This significantly reduces the availability and applicability of satellite LST observations, especially over areas and seasons with high cloudiness occurrence. Also, the surface temperature is influenced by synoptic conditions (e.g., wind and humidity) (Gawuc & Struzewska 2016). Hence, utilising single observations is not sufficient to obtain a full image of spatiotemporal variability of urban LST and SUHI intensity (Gawuc & Struzewska 2016). One of the possible solutions would be a utilisation of time-series of LST data, which could be useful to monitor the UHI growth of individual cities and thus, to reveal the impact of urbanisation on local climate (Tran et al., 2006). The relationship between UHI and synoptic conditions have been summarised by Arnfield (2003). However, similar analyses conducted for urban LST and SUHI are lacking. We will present analyses of the relationship between time series of remotely-sensed LST and SUHI intensity and in-situ meteorological observations collected by road weather stations network, namely: road surface

Natural Ventilation: A Mitigation Strategy to Reduce Overheating In Buildings under Urban Heat Island Effect in South American Cities

NASA Astrophysics Data System (ADS)

Palme, Massimo; Carrasco, Claudio; Ángel Gálvez, Miguel; Inostroza, Luis

2017-10-01

Urban heat island effect often produces an increase of overheating sensation inside of buildings. To evacuate this heat, the current use of air conditioning increases the energy consumption of buildings. As a good alternative, natural ventilation is one of the best strategies to obtain indoor comfort conditions, even in summer season, if buildings and urban designs are appropriated. In this work, the overheating risk of a small house is evaluated in four South American cities: Guayaquil, Lima, Antofagasta and Valparaíso, with and without considering the UHI effect. Then, natural ventilation is assessed in order to understand the capability of this passive strategy to assure comfort inside the house. Results show that an important portion of the indoor heat can be evacuated, however the temperature rising (especially during the night) due to UHI can generate a saturation effect if appropriate technical solutions, like the increase in the air speed that can be obtained with good urban design, are not considered.

Rectification of the Diurnal Cycle and the Impact of Islands on the Tropical Climate

NASA Astrophysics Data System (ADS)

Cronin, T. W.; Emanuel, K.

2012-12-01

Tropical islands are observed to be rainier than nearby ocean areas, and rainfall over the islands of the Maritime Continent plays an important role in the atmospheric general circulation. Convective heating over tropical islands is also strongly modulated by the diurnal cycle of solar insolation and surface enthalpy fluxes, and convective parameterizations in general circulation models are known to reproduce the phase and amplitude of the observed diurnal cycle of convection rather poorly. Connecting these ideas suggests that poor representation of the diurnal cycle of convection and precipitation over tropical islands in climate models may be a significant source of model biases. Here, we explore how a highly idealized island, which differs only in heat capacity from the surrounding ocean, could rectify the diurnal cycle and impact the tropical climate, especially the spatial distribution of rainfall. We perform simulations of radiative-convective equilibrium with the System for Atmospheric Modeling cloud-system-resolving model, with interactive surface temperature and a varied surface heat capacity. For the case of relatively small-scale simulations, where a shallow (~5 cm) slab-ocean "swamp island" surface is embedded in a deeper (~1 m) slab-ocean domain, the precipitation rate over the island is more than double the domain average value, with island rainfall occurring primarily in a strong regular convective event each afternoon. In addition to this island precipitation enhancement, the upper troposphere also warms with the inclusion of a low- heat capacity island. We discuss two radiative mechanisms that contribute to both island precipitation enhancement and free tropospheric warming, by producing a top-of-atmosphere radiative surplus over the island. The first radiative mechanism is a clear-sky effect, related to nonlinearities in the surface energy budget, and differences in how surface energy balance is achieved over surfaces of different heat capacities

Urban heat island impacts on plant phenology: intra-urban variability and response to land cover

NASA Astrophysics Data System (ADS)

Zipper, Samuel C.; Schatz, Jason; Singh, Aditya; Kucharik, Christopher J.; Townsend, Philip A.; Loheide, Steven P., II

2016-05-01

Despite documented intra-urban heterogeneity in the urban heat island (UHI) effect, little is known about spatial or temporal variability in plant response to the UHI. Using an automated temperature sensor network in conjunction with Landsat-derived remotely sensed estimates of start/end of the growing season, we investigate the impacts of the UHI on plant phenology in the city of Madison WI (USA) for the 2012-2014 growing seasons. Median urban growing season length (GSL) estimated from temperature sensors is ˜5 d longer than surrounding rural areas, and UHI impacts on GSL are relatively consistent from year-to-year. Parks within urban areas experience a subdued expression of GSL lengthening resulting from interactions between the UHI and a park cool island effect. Across all growing seasons, impervious cover in the area surrounding each temperature sensor explains >50% of observed variability in phenology. Comparisons between long-term estimates of annual mean phenological timing, derived from remote sensing, and temperature-based estimates of individual growing seasons show no relationship at the individual sensor level. The magnitude of disagreement between temperature-based and remotely sensed phenology is a function of impervious and grass cover surrounding the sensor, suggesting that realized GSL is controlled by both local land cover and micrometeorological conditions.

Influences of land cover types, meteorological conditions, anthropogenic heat and urban area on surface urban heat island in the Yangtze River Delta Urban Agglomeration.

PubMed

Du, Hongyu; Wang, Duoduo; Wang, Yuanyuan; Zhao, Xiaolei; Qin, Fei; Jiang, Hong; Cai, Yongli

2016-11-15

Urban heat islands (UHIs) reflect the localized impact of human activities on thermal fields. In this study, we assessed the surface UHI and its relationship with types of land, meteorological conditions, anthropogenic heat sources and urban areas in the Yangtze River Delta Urban Agglomeration (YRDUA) with the aid of remote sensing data, statistical data and meteorological data. The results showed that the UHI intensity in YRDUA was the strongest (0.84°C) in summer, followed by 0.81°C in autumn, 0.78°C in spring and 0.53°C in winter. The daytime UHI intensity is 0.98°C, which is higher than the nighttime UHI intensity of 0.50°C. Then, the relationship between the UHI intensity and several factors such as meteorological conditions, anthropogenic heat sources and the urban area were analysed. The results indicated that there was an insignificant correlation between population density and the UHI intensity. Energy consumption, average temperature and urban area had a significant positive correlation with UHI intensity. However, the average wind speed and average precipitation were significantly negatively correlated with UHI intensity. This study provides insight into the regional climate characteristics and a scientific basis for city layout. Copyright © 2016 Elsevier B.V. All rights reserved.

A Review on Mitigation Technologies for Controlling Urban Heat Island Effect in Housing and Settlement Areas

NASA Astrophysics Data System (ADS)

Andoni, Heri; Wonorahardjo, Surjamanto

2018-05-01

Urban Heat Island (UHI) has many harm impacts to urban and human life, the examples are increased building and energy consumption, increased air pollutants emissions, compromised human comfort and health, and many more. Despite UHI phenomenon and those impacts has been realized long enough by the experts along with development of major cities in the world, but its mitigation technology has not been well developed. This paper discusses few mitigation technologies for UHI phenomenon that have been developed by experts. Some mitigation technologies such as double skin façade, shading strategies, and many more are discussed in this study, include the strengths and the weaknesses of each strategy. The focus of the study is mainly on the potential of building skin engineering in which thermal conductivity, infrared emissivity, and specific heat factors. The selected case discussed are buildings made of heavy weight materials. The result in this study reveals a potential map where thermal insulation is one potential strategy to reduce the intensity of UHI through the reduction of heat emissions of heavy building materials components. By this study, improvement of the urban life in its relation to UHI are expected to occur, especially in housing and settlements area.

Observed and Simulated Urban Heat Island and Urban Cool Island in Las Vegas

NASA Astrophysics Data System (ADS)

Sauceda, Daniel O.

This research investigates the urban climate of Las Vegas and establishes long-term trends relative to the regional climate in an attempt to identify climate disturbances strictly related to urban growth. An experimental surface station network (DRI-UHI) of low-cost surface temperature (T2m) and relative humidity (RH) sensors were designed to cover under-sampled low-intensity residential urban areas, as well as complement the in-city and surrounding rural areas. In addition to the analysis of the surface station data, high-resolution gridded data products (GDPs) from Daymet (1km) and PRISM (800 m) and results from numerical simulations were used to further characterize the Las Vegas climate trends. The Weather Research and Forecasting (WRF) model was coupled with three different models: the Noah Land Surface Model (LSM) and a single- and multi-layer urban canopy model (UCM) to assess the urban related climate disturbances; as well as the model sensitivity and ability to characterize diurnal variability and rural/urban thermal contrasts. The simulations consisted of 1 km grid size for five, one month-long hindcast simulations during November of 2012: (i) using the Noah LSM without UCM treatment, (ii) same as (i) with a single-layer UCM (UCM1), (iii) same as (i) with a multi-layer UCM (UCM2), (iv) removing the City of Las Vegas (NC) and replacing it with predominant land cover (shrub), and (v) same as (ii) with increasing the albedo of rooftops from 0.20 to 0.65 as a potential adaptation scenario known as "white roofing". T2m long-term trends showed a regional warming of minimum temperatures (Tmin) and negligible trends in maximum temperatures (Tmax ). By isolating the regional temperature trends, an observed urban heat island (UHI) of ~1.63°C was identified as well as a daytime urban cool island (UCI) of ~0.15°C. GDPs agree with temperature trends but tend to underpredict UHI intensity by ~1.05°C. The WRF-UCM showed strong correlations with observed T2m (0

Energy flux parametrization as an opportunity to get Urban Heat Island insights: The case of Athens, Greece (Thermopolis 2009 Campaign).

PubMed

Loupa, G; Rapsomanikis, S; Trepekli, A; Kourtidis, K

2016-01-15

Energy flux parameterization was effected for the city of Athens, Greece, by utilizing two approaches, the Local-Scale Urban Meteorological Parameterization Scheme (LUMPS) and the Bulk Approach (BA). In situ acquired data are used to validate the algorithms of these schemes and derive coefficients applicable to the study area. Model results from these corrected algorithms are compared with literature results for coefficients applicable to other cities and their varying construction materials. Asphalt and concrete surfaces, canyons and anthropogenic heat releases were found to be the key characteristics of the city center that sustain the elevated surface and air temperatures, under hot, sunny and dry weather, during the Mediterranean summer. A relationship between storage heat flux plus anthropogenic energy flux and temperatures (surface and lower atmosphere) is presented, that results in understanding of the interplay between temperatures, anthropogenic energy releases and the city characteristics under the Urban Heat Island conditions.

Monitoring Urban Heat Island Through Google Earth Engine: Potentialities and Difficulties in Different Cities of the United States

NASA Astrophysics Data System (ADS)

Ravanelli, R.; Nascetti, A.; Cirigliano, R. V.; Di Rico, C.; Monti, P.; Crespi, M.

2018-04-01

The aim of this work is to exploit the large-scale analysis capabilities of the innovative Google Earth Engine platform in order to investigate the temporal variations of the Urban Heat Island phenomenon as a whole. A intuitive methodology implementing a largescale correlation analysis between the Land Surface Temperature and Land Cover alterations was thus developed.The results obtained for the Phoenix MA are promising and show how the urbanization heavily affects the magnitude of the UHI effects with significant increases in LST. The proposed methodology is therefore able to efficiently monitor the UHI phenomenon.

Energy savings for heat-island reduction strategies in Chicago and Houston (including updates for Baton Rouge, Sacramento, and Salt Lake City)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konopacki, S.; Akbari, H.

2002-02-28

In 1997, the U.S. Environmental Protection Agency (EPA) established the ''Heat Island Reduction Initiative'' to quantify the potential benefits of Heat-Island Reduction (HIR) strategies (i.e., shade trees, reflective roofs, reflective pavements and urban vegetation) to reduce cooling-energy use in buildings, lower the ambient air temperature and improve urban air quality in cities, and reduce CO2 emissions from power plants. Under this initiative, the Urban Heat Island Pilot Project (UHIPP) was created with the objective of investigating the potential of HIR strategies in residential and commercial buildings in three initial UHIPP cities: Baton Rouge, LA; Sacramento, CA; and Salt Lake City,more » UT. Later two other cities, Chicago, IL and Houston, TX were added to the UHIPP. In an earlier report we summarized our efforts to calculate the annual energy savings, peak power avoidance, and annual CO2 reduction obtainable from the introduction of HIR strategies in the initial three cities. This report summarizes the results of our study for Chicago and Houston. In this analysis, we focused on three building types that offer the highest potential savings: single-family residence, office and retail store. Each building type was characterized in detail by vintage and system type (i.e., old and new building constructions, and gas and electric heat). We used the prototypical building characteristics developed earlier for each building type and simulated the impact of HIR strategies on building cooling- and heating-energy use and peak power demand using the DOE-2.1E model. Our simulations included the impact of (1) strategically-placed shade trees near buildings [direct effect], (2) use of high-albedo roofing material on the building [direct effect], (3) urban reforestation with high-albedo pavements and building surfaces [indirect effect] and (4) combined strategies 1, 2, and 3 [direct and indirect effects]. We then estimated the total roof area of air

The Three Mile Island Disaster.

ERIC Educational Resources Information Center

Crosby, Emeral

1980-01-01

For the past decade, education has been experiencing meltdown, explosions, radiation leaks, heat pollution, and management crises, just like the Three Mile Island disaster. This article offers suggestions on how to deal with these problems. (Author/LD)

Spatio-temporal variability of urban heat islands in local climate zones of Delhi-NCR

NASA Astrophysics Data System (ADS)

Budhiraja, Bakul; Pathak, Prasad; Agrawal, Girish

2017-10-01

Land use change is at the nexus of human territory expansion and urbanization. Human intrusion disturbs the natural heat energy balance of the area, although a new equilibrium of energy flux is attained but with greater diurnal range and adversely affecting the geo/physical variables. Modification in the trend of these variables causes a phenomenon known as Urban Heat Island (UHI) i.e. a dome of heat is formed around the city which has 7-10 °C high temperature than the nearby rural area at night. The study focuses on Surface UHI conventionally studied using thermal band of the remotely sensed satellite images. Land Surface Temperature (LST) is determined for the year 2015 using Landsat 8 for Delhi National Capital Region (NCR). This region was chosen because it is the biggest urban agglomeration in India, many satellite cities are coming in periphery and it has temperate climate. Quantification of UHI is predictably done using UHI intensity that is the difference between representative Urban and rural temperature. Recently the definition of urban and rural has been questioned because of various kinds of configurations of urban spaces across the globe. Delhi NCR urban configurations vary spatially- thus one UHI intensity does not give a deep understanding of the micro-climate. Advancement was made recently to standardize UHI intensity by dividing city into Local Climate Zones (LCZ), comes with 17 broad categories. LCZ map of Delhi NCR has been acquired from World Urban Database. The seasonality in LST across LCZ has been determined along with identifying warmest and coolest LCZ.

A new structure of permeable pavement for mitigating urban heat island.

PubMed

Liu, Yong; Li, Tian; Peng, Hangyu

2018-09-01

The urban heat island (UHI) effect has been a great threat to human habitation, and how to mitigate this problem has been a global concern over decades. This paper addresses the cooling effect of a novel permeable pavement called evaporation-enhancing permeable pavement, which has capillary columns in aggregate and a liner at the bottom. To explore the efficiency of mitigating the UHI, bench-scale permeable pavement units with capillary columns were developed and compared with conventional permeable pavement. Criteria of capillary capacities of the column, evaporation rates, and surface temperature of the pavements were monitored under simulated rainfall and Shanghai local weather conditions. Results show the capillary column was important in increasing evaporation by lifting water from the bottom to the surface, and the evaporation-enhancing permeable pavement was cooler than a conventional permeable pavement by as much as 9.4°C during the experimental period. Moreover, the cooling effect of the former pavement could persist more than seven days under the condition of no further rainfall. Statistical analysis result reveals that evaporation-enhancing permeable pavement can mitigate the UHI effect significantly more than a conventional permeable pavement. Copyright © 2018 Elsevier B.V. All rights reserved.

The urban heat island of a city in an arid zone: the case of Eilat, Israel

NASA Astrophysics Data System (ADS)

Sofer, M.; Potchter, O.

2006-05-01

This study presents the results of a preliminary research that was conducted in the city of Eilat, located in an extreme hot and arid zone on the northern coast of the Red Sea. The purpose was to analyse the characteristics of the local urban heat island (UHI). Diurnal pre-dawn and early-afternoon measurements were taken in winter and summer weather conditions on three separate occasions for two consecutive years. The results show the development of a moderate UHI located around the most intensive area of human activity; the city business centre and dense hotel belt. The UHI is more significant at midday during the summer period, while early morning inversions in winter have a weakening effect on the UHI intensity. It was found that the topography and wind regime have a dominant effect on the location and intensity of the UHI, while the sea has a very marginal effect. Due to the UHI influences on the spatial distribution of the heat stress in the city, it is suggested that further applied UHI research should be focused on the summer period.

Multiscale interaction between a large scale magnetic island and small scale turbulence

NASA Astrophysics Data System (ADS)

Choi, M. J.; Kim, J.; Kwon, J.-M.; Park, H. K.; In, Y.; Lee, W.; Lee, K. D.; Yun, G. S.; Lee, J.; Kim, M.; Ko, W.-H.; Lee, J. H.; Park, Y. S.; Na, Y.-S.; Luhmann, N. C., Jr.; Park, B. H.

2017-12-01

Multiscale interaction between the magnetic island and turbulence has been demonstrated through simultaneous two-dimensional measurements of turbulence and temperature and flow profiles. The magnetic island and turbulence can mutually interact via coupling between the electron temperature (T e ) gradient, the T e turbulence, and the poloidal flow. The T e gradient altered by the magnetic island steepens outside and flattens inside the island. The T e turbulence can appear in increased T e gradient regions. The combined effects of the T e gradient and the poloidal flow shear determines the two-dimensional distribution of the T e turbulence. When the poloidal vortex flow forms, it can maintain the steepest T e gradient and the magnetic island acts more like an electron heat transport barrier. Interestingly, when the T e gradient, the T e turbulence, and the vortex flow shear increase beyond critical levels, the magnetic island turns into a fast electron heat transport channel, which directly leads to the minor disruption.

Effects of the large-scale atmospheric circulation on the onset and strength of urban heat islands: a case study

NASA Astrophysics Data System (ADS)

Targino, Admir Créso; Krecl, Patricia; Coraiola, Guilherme Conor

2014-07-01

Air temperature was monitored at 13 sites across the urban perimeter of a Brazilian midsize city in winter 2011. In this study, we show that the urban heat island (UHI) develops only at night and under certain weather conditions, and its intensity depends not only on the site's land cover but also on the meteorological setting. The urban heat island intensity was largest (6.6 °C) under lingering high-pressure conditions, milder (3.0 °C) under cold anticyclones and almost vanished (1.0 °C) during the passage of cold fronts. The cooling rates were calculated to monitor the growth and decay of the UHI over each specific synoptic setting. Over four contiguous days under the effect of a lingering high-pressure event, we observed that the onset of cooling was always at about 2 h before sunset. The reference site attained mean cooling rate of -2.6 °C h-1 at sunset, whilst the maximum urban rate was -1.2 °C h-1. Under a 3-day cold anticyclone episode, cooling also started about 2 h before sunset, and the difference between maximum rural (-2.0 °C h-1) and urban (-1.0 °C h-1) cooling rates diminished. Under cold-front conditions, the cooling rate was homogeneous for all sites and swang about zero throughout the day. The air temperature has a memory effect under lingering high-pressure conditions which intensified the UHI, in addition to the larger heat storage in the urban area. Cold anticyclone conditions promoted the development of the UHI; however, the cold air pool and relatively light winds smoothed out its intensity. Under the influence of cold fronts, the urban fabric had little effect on the city's air temperature field, and the UHI was imperceptible.

Estimates of horizontal fluxes of oxygen, heat, and salt in western Long Island Sound

NASA Astrophysics Data System (ADS)

McCardell, Grant; O'Donnell, James

2014-10-01

The dissolved oxygen (DO) concentration in the bottom waters of western Long Island Sound decreases to hypoxic levels between April and July. Since the rate of decline of DO is considerably less than measured respiration, there must be significant vertical transport of DO from oxygen richer waters near the surface and/or horizontal transport from the central Sound. Simple model budgets with either of these sources are able to provide predictions of the seasonal rate of decline that are consistent with the observed values. Although prior budget estimates indicated that vertical fluxes were a significant portion of the resupply of DO, these were not able to discount the possible importance of horizontal fluxes, nor have there been any measurements of horizontal fluxes in this region. We present an analysis of time series of moored conductivity, temperature, DO, and current observations in the hypoxic area of Long Island Sound during the summers of 2005 and 2006. We estimate the near-bottom along-channel flux divergences of salt, heat, and DO as 0.11 ± 0.08 g kg-1 d-1, -5 ± 6 W m-3, and 4 ± 6 μM d-1, respectively. Since this horizontal DO transport is only 25% of the magnitude of the mean rate of respiration, we conclude that vertical transport by mixing forms the bulk of the physical resupply of DO to the hypoxic zone of the western Sound.

The Impact of Urban Growth and Climate Change on Heat Stress in an Australian City

NASA Astrophysics Data System (ADS)

Chapman, S.; Mcalpine, C. A.; Thatcher, M. J.; Salazar, A.; Watson, J. R.

2017-12-01

Over half of the world's population lives in urban areas. Most people will therefore be exposed to climate change in an urban environment. One of the climate risks facing urban residents is heat stress, which can lead to illness and death. Urban residents are at increased risk of heat stress due to the urban heat island effect. The urban heat island is a modification of the urban environment and increases temperatures on average by 2°C, though the increase can be much higher, up to 8°C when wind speeds and cloud cover are low. The urban heat island is also expected to increase in the future due to urban growth and intensification, further exacerbating urban heat stress. Climate change alters the urban heat island due to changes in weather (wind speed and cloudiness) and evapotranspiration. Future urban heat stress will therefore be affected by urban growth and climate change. The aim of this study was to examine the impact of urban growth and climate change on the urban heat island and heat stress in Brisbane, Australia. We used CCAM, the conformal cubic atmospheric model developed by the CSIRO, to examine temperatures in Brisbane using scenarios of urban growth and climate change. We downscaled the urban climate using CCAM, based on bias corrected Sea Surface Temperatures from the ACCESS1.0 projection of future climate. We used Representative Concentration Pathway (RCP) 8.5 for the periods 1990 - 2000, 2049 - 2060 and 2089 - 2090 with current land use and an urban growth scenario. The present day climatology was verified using weather station data from the Australian Bureau of Meteorology. We compared the urban heat island of the present day with the urban heat island with climate change to determine if climate change altered the heat island. We also calculated heat stress using wet-bulb globe temperature and apparent temperature for the climate change and base case scenarios. We found the urban growth scenario increased present day temperatures by 0.5°C in the

Magnetic Roots and the Driving of Extended Coronal Heating

NASA Technical Reports Server (NTRS)

Porter, Jason G.; Falconer, D. A.; Moore, Ronald L.; Harvey, Karen L.; Rabin, Douglas M.; Shimizu, T.

1998-01-01

We report results from a continuation of a previous study, in which we found large bright coronal loops within active regions and extending from active regions that have one end rooted near an island of included magnetic polarity that is a site of enhanced coronal heating and microflares. This suggested that magnetic activity such as microflaring results in enhanced heating in both the compact core field around the island and in the large loops extending from it. We might expect that the intensity variations due to enhanced heating in the compact and extended structures would be correlated. However, although some ex- tended loops do respond to the largest events taking place in the core fields near their feet, they do not show a clear response to most smaller individual events nor to the overall envelope of coronal heating activity in the core fields at their feet as determined from longer-term observations. Thus, while it is clear that the extended loops' heating is being driven from their ends at the magnetic islands, much of this heating is apparently by some form of footpoint activity that is not strongly coupled to the heating in the footpoint core fields. One possibility is that the remote heating in the extended loops is driven by reconnection at the magnetic null over the island, and that this reconnection is driven mainly by core-field activity that produces little coronal heating within the core field itself, perhaps in the manner of the numerical simulations by Karpen, Antiochos, and DeVore.

Assessing the effect of wind speed/direction changes on urban heat island intensity of Istanbul.

NASA Astrophysics Data System (ADS)

Perim Temizoz, Huriye; Unal, Yurdanur S.

2017-04-01

Assessing the effect of wind speed/direction changes on urban heat island intensity of Istanbul. Perim Temizöz, Deniz H. Diren, Cemre Yürük and Yurdanur S. Ünal Istanbul Technical University, Department of Meteorological Engineering, Maslak, Istanbul, Turkey City or metropolitan areas are significantly warmer than the outlying rural areas since the urban fabrics and artificial surfaces which have different radiative, thermal and aerodynamic features alter the surface energy balance, interact with the regional circulation and introduce anthropogenic sensible heat and moisture into the atmosphere. The temperature contrast between urban and rural areas is most prominent during nighttime since heat is absorbed by day and emitted by night. The intensity of the urban heat island (UHI) vary considerably depending on the prevailent meteorological conditions and the characteristics of the region. Even though urban areas cover a small fraction of Earth, their climate has greater impact on the world's population. Over half of the world population lives in the cities and it is expected to rise within the coming decades. Today almost one fifth of the Turkey's population resides in Istanbul with the percentage expected to increase due to the greater job opportunities compared to the other cities. Its population has been increased from 2 millions to 14 millions since 1960s. Eventually, the city has been expanded tremendously within the last half century, shifting the landscape from vegetation to built up areas. The observations of the last fifty years over Istanbul show that the UHI is most pronounced during summer season. The seasonal temperature differences between urban and suburban sites reach up to 3 K and roughly haft degree increase in UHI intensity is observed after 2000. In this study, we explore the possible range of heat load and distribution over Istanbul for different prevailing wind conditions by using the non-hydrostatic MUKLIMO3 model developed by DWD

Key Parameters for Urban Heat Island Assessment in A Mediterranean Context: A Sensitivity Analysis Using the Urban Weather Generator Model

NASA Astrophysics Data System (ADS)

Salvati, Agnese; Palme, Massimo; Inostroza, Luis

2017-10-01

Although Urban Heat Island (UHI) is a fundamental effect modifying the urban climate, being widely studied, the relative weight of the parameters involved in its generation is still not clear. This paper investigates the hierarchy of importance of eight parameters responsible for UHI intensity in the Mediterranean context. Sensitivity analyses have been carried out using the Urban Weather Generator model, considering the range of variability of: 1) city radius, 2) urban morphology, 3) tree coverage, 4) anthropogenic heat from vehicles, 5) building’s cooling set point, 6) heat released to canyon from HVAC systems, 7) wall construction properties and 8) albedo of vertical and horizontal surfaces. Results show a clear hierarchy of significance among the considered parameters; the urban morphology is the most important variable, causing a relative change up to 120% of the annual average UHI intensity in the Mediterranean context. The impact of anthropogenic sources of heat such as cooling systems and vehicles is also significant. These results suggest that urban morphology parameters can be used as descriptors of the climatic performance of different urban areas, easing the work of urban planners and designers in understanding a complex physical phenomenon, such as the UHI.

Study of the Relationships between the Spatial Extent of Surface Urban Heat Islands and Urban Characteristic Factors Based on Landsat ETM+ Data

PubMed Central

Zhang, Jinqu; Wang, Yunpeng

2008-01-01

Ten cities with different population and urban sizes located in the Pearl River Delta, Guangdong Province, P.R. China were selected to study the relationships between the spatial extent of surface urban heat islands (SUHI) and five urban characteristic factors such as urban size, development area, water proportion, mean NDVI (Normalized Vegetation Index) and population density, etc. The spatial extent of SUHI was quantified by using the hot island area (HIA). All the cities are almost at the same latitude, showing similar climate and solar radiation, the influence of which could thus be eliminated during our computation and comparative study. The land surface temperatures (LST) were retrieved from the data of Landsat 7 Enhanced Thematic Mapper Plus (ETM+) band 6 using a mono-window algorithm. A variance-segmenting method was proposed to compute HIA for each city from the retrieved LST. Factors like urban size, development area and water proportion were extracted directly from the classification images of the same ETM+ data and the population density factor is from the official census. Correlation and regression analyses were performed to study the relationships between the HIA and the related factors, and the results show that HIA is highly correlated to urban size (r=0.95), population density (r=0.97) and development area (r=0.83) in this area. It was also proved that a weak negative correlation existed between HIA and both mean NDVI and water proportion for each city. Linear functions between HIA and its related factors were established, respectively. The HIA can reflect the spatial extent and magnitude of the surface urban heat island effect, and can be used as reference in the urban planning. PMID:27873939

Application of High-Resolution Thermal Infrared Remote Sensing and GIS to Assess the Urban Heat Island Effect

NASA Technical Reports Server (NTRS)

Lo, C. P.; Quattrochi, D. A.; Luvall, J. C.

1997-01-01

Day and night airborne thermal infrared image data at 5 m spatial resolution acquired with the 15-channel (0.45 micron - 12.2 micron) 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 (9.6 micron - 10.2 micron) data with the best noise-equivalent temperature change (NEAT) 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: 0.60-0.63 micron) and reflected infrared (channel number 6: 0.76-0.90 micron) 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 center of the city, and favors 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.

The relationship between built-up areas and the spatial development of the mean maximum urban heat island in Debrecen, Hungary

NASA Astrophysics Data System (ADS)

Bottyán, Zsolt; Kircsi, Andrea; Szegedi, Sándor; Unger, János

2005-03-01

The climate of built-up regions differs significantly from rural regions and the most important modifying effect of urbanization on local climate is the urban temperature excess, otherwise called the urban heat island (UHI).This study examines the influence of built-up areas on the near-surface air temperature field in the case of the medium-sized city of Debrecen, Hungary. Mobile measurements were used under different weather conditions between March 2002 and March 2003. Efforts concentrated on the determination of the spatial distribution of mean maximum UHI intensity with special regard to land-use features such as built-up ratio and its areal extensions.In both (heating and non-heating) seasons the spatial distribution of the UHI intensity field showed a basically concentric shape with local anomalies. The mean maximum UHI intensity reaches more than 2.0 °C (heating season) and 2.5 °C (non-heating season) in the centre of the city. We established the relationship between the above-mentioned land-use parameters and mean maximum UHI intensity by means of multiple linear regression analysis. As the measured and predicted mean maximum UHI intensity patterns show, there is an obvious connection between the spatial distribution of urban thermal excess and the land-use parameters examined, so these parameters play a significant role in the development of the strong UHI intensity field over the city.

A study of urban heat island and its association with particulate matter during winter months over Delhi.

PubMed

Pandey, Puneeta; Kumar, Dinesh; Prakash, Amit; Masih, Jamson; Singh, Manoj; Kumar, Surendra; Jain, Vinod Kumar; Kumar, Krishan

2012-01-01

Day and night time thermal mapping of Delhi has been done with MODIS satellite data for the months of November and December for years 2007, 2008, 2009 and 2010. The study reveals the formation of day time "cool island" over central parts of Delhi which are found to be cooler by a maximum of 4-6 °C than the surrounding rural areas. During the night time, however, the central parts of Delhi are found to be warmer by a maximum of 4-7 °C or even more than the surrounding rural areas thus confirming the formation of nocturnal urban heat island over Delhi. Measurements of solar spectral irradiance over Delhi reveal significantly lower values as compared to a rural site located south-west of Delhi, during the low wind conditions in the months of November and December. Analysis of average monthly temporal data of surface wind speed and particulate matter concentration over Delhi reveals a strong anti-correlation between wind speed and particulate matter concentration. High values of particulate matter during low wind conditions seem to favor the so called "cool island" over Delhi. Analysis of radiosonde data of 975 hPa and 850 hPa temperatures over Delhi during November and December from 1973 to 2010 reveals a warming trend at the 850 hPa level and an overall declining trend of ∆T between 975 hPa temperatures and 850 hPa temperatures, thus indicating a weakening of vertical thermal gradients over Delhi during these months. The study suggests that urban areas behave more like moderators of diurnal temperature variation in low wind conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

Urban heat island investigations in Arctic cities of northwestern Russia

NASA Astrophysics Data System (ADS)

Shumilov, Oleg I.; Kasatkina, Elena A.; Kanatjev, Alexander G.

2017-12-01

Urban microclimate peculiarities in two Arctic cities in northwestern Russia—Kirovsk (67.62°N, 33.67°E) and Apatity (67.57°N, 33.38°E)—were investigated by using mobile temperature records. The experiment was carried out in and around Apatity and Kirovsk in February 2014 and December 2016. The DS18B20 digital thermometer was installed on the roof of a car (height: approximately 1.2 m) to measure and record temperature variations automatically. In addition to the digital thermometer, the car was also equipped with an onboard global positioning system, allowing every temperature measurement to be referenced with an altitude and a latitude/longitude position. The possibility of urban heat island formation in these polar cities, above the Arctic Circle, was studied. Our analysis indicated that on 11 February 2014, the temperature varied in accordance with the background environmental lapse rate (-0.0045°C m-1), and nearly corresponded to it (-0.0165°C m-1) on 12 February 2014. On 6 December 2016, a strong local temperature inversion with a positive value of 0.032°C m-1 was detected, seemingly caused by the formation of a cold air pool in the valley near Kirovsk. It was found that the temperature variations within and outside these cities are strongly influenced by local topographic effects and the physical conditions of the atmospheric boundary layer.

The Effect of Tree Spacing and Size in Urban Areas: Strategies for Mitigating High Temperature in Urban Heat Islands

NASA Astrophysics Data System (ADS)

Berry, R.; Shandas, V.; Makido, Y.

2017-12-01

Many cities are unintentionally designed to be heat sinks, which absorb the sun's short-wave radiation and reemit as long-wave radiation. Long time reorganization of this `urban heat island' (UHI) phenomena has led researchers and city planners into developing strategies for reducing ambient temperatures through urban design. Specifically, greening areas have proven to reduce the temperature in UHI's, including strategies such as green streets, green facades, and green roofs have been implemented. Among the scientific community there is promoted study of how myriad greening strategies can reduce temperature, relatively limited work has focused on the distribution, density, and quantity of tree campaigns. This paper examines how the spacing and size of trees reduce temperatures differently. A major focus of the paper is to understand how to lower the temperature through tree planting, and provide recommendations to cities that are attempting to solve their own urban heat island issues. Because different cities have different room for planting greenery, we examined which strategies are more efficient given an area constraint. Areas that have less available room might not be able to plant a high density of trees. We compared the different experimental groups varying in density and size of trees against the control to see the effect the trees had. Through calibration with local weather stations, we used a micrometeorology program (ENVI-Met) to model and simulate the different experimental models and how they affect the temperature. The results suggest that some urban designs can reduce ambient temperatures by over 7 0C, and the inclusion of large form trees have the greatest contribution, by reducing temperatures over 15 0C. The results suggest that using specific strategies that combine placement of specific tree configurations with alternative distribution of urban development patterns can help to solve the current challenges of UHI's, and thereby support management

A study of the Merritt Island, Florida sea breeze flow regimes and their effect on surface heat and moisture fluxes

NASA Technical Reports Server (NTRS)

Rubes, M. T.; Cooper, H. J.; Smith, E. A.

1993-01-01

Data collected during the Convective and Precipitation/Electrification Experiment were analyzed as part of an investigation of the sea breeze in the vicinity of Merritt Island, Florida. Analysis of near-surface divergence fields shows that the classical 24-hour oscillation in divergence over the island due to the direct sea breeze circulation is frequently disrupted and exhibits two distinct modes: the classical sea breeze pattern and deviations from that pattern. A comparison of clear day surface energy fluxes with fluxes on other days indicates that changes in magnitudes were dominated by the presence or absence of clouds. Non-classical sea breeze days tended to lose more available energy in the morning than classical sea breeze days due to earlier development of small cumulus over the island. A composite storm of surface winds, surface energy fluxes, rainfall, and satellite visible data was constructed. A spectral transmittance over the visible wavelengths for the cloud cover resulting from the composite storm was calculated. It is shown that pre-storm transmittances of 0.8 fall to values near 0.1 as the downdraft moves directly over the site. It is also found that under post-composite storm conditions of continuous clear sky days, 3.5 days are required to evaporate back into the atmosphere the latent heat energy lost to the surface by rainfall.

Combating the Urban Heat Island Effect: Results from a Long-Term Monitoring Study on Urban Green, White, and Black Roofs in New York City

NASA Astrophysics Data System (ADS)

Gaffin, S. R.; Kong, A. Y.; Hartung, E.; Hsu, B.; Roditi, A.; Rosenzweig, C.

2011-12-01

Urban heat island mitigation strategies include increasing urban vegetation and increasing the albedo of impervious surfaces. Vegetated "green" roofs can provide benefits to stormwater management, water quality, energy cost efficiency, and biodiversity in cities, but the body of research on green roofs in the US is not large and cities in the US have been slow to adopt green roofs. On the other hand, "high-albedo" white roofs have been applied more widely through projects such as New York City Cool Roofs. There are several major issues (e.g., albedo decline, product differences, and long-term temperature controls) about green and white roof performance versus typical black roofs with respect to urban heat island mitigation that have yet to be fully addressed. Here, we present data from an on-going, long-term study in New York City in which pilot, urban albedo enhancement and vegetation effects have been monitored at the building-scale since 2007. Although the urban heat island effect can be detected throughout the year, our objective for this paper was to compare green roof vegetation with those of the high-albedo roofs for their ability to reduce the electricity demand for cooling in the summer. Using energy balance methodology across our sites (three), we found that green and white roof membrane temperature peaks are on average 60°F (33°C) and 30° F (17°C), respectively, cooler than black roof temperature peaks, and that these alternative surfaces significantly reduce thermal stress to roof membranes. Interestingly, we found that industrial white membranes [thermoplastic polyolefin (TPO) and ethylene propylene diene monomer (EPDM)] stay cleaner longer, thereby, maintaining the high-albedo benefits longer than the painted roofs, which tend to lose their albedo properties rapidly. Results thus far suggest that more long-term research comparing the albedo and cooling benefits of green and white roofs to black roofs is necessary to understand temporal changes to

Effect of urbanization activities towards the formation of urban heat island in Cameron Highlands, Malaysia

NASA Astrophysics Data System (ADS)

Ibrahim, M. H.; Latiff, N. A. A.; Ismail, K.; Isa, N. K. M.

2018-04-01

This study carried out to study the effect of urbanization activities towards the formation of Urban Heat Islands (UHI) in Cameron Highlands (CH).The aim of this study is to identify the formation of UHI in CH following the urbanization activities. This study also involved two main data that are primary through field survey and secondary data from collection data. In addition, this study was used qualitative and quantitative method. The data was taken two times a day, at a day and night between the hours of 12:00 to 14:00 and 19:00 to 21:00. Data in this study analyzed by using correlation analysis and analysis of Geographic Information Systems (GIS) which known as interpolation. Result found the formation of UHI in CH was concentrated at city centre namely in Pekan Tanah Rata. From the whole average value, city centre was recorded the highest reading of temperatures which is 30.5°C, while reading of temperature for subtown and suburban was recorded 28.6°C and 23.8°C. Average of humidity in CH during the day was recorded as highest reading in the suburban area namely Tringkap Bee Farm (station 11) which is 58.4%. Then, average of humidity in CH at night was recorded highest reading in the suburban area namely Habu Mini Market 91 (station 9) which the value is 83.2%. The reading of wind speed in CH during the day recorded the highest reading day at the suburban namely Tringkap Bee Farm (station 11) which the value is 2.3 m/s. While, following the reading of wind speed in CH at night, suburban namely Habu Mini Market 91(station 9) was recorded the highest reading which is 0.8 m/s. The Intensity of Urban Heat Island in CH during the day was recorded 2.8°C, while at night intensity of UHI was recorded 1.4°C. Overall, the urbanization activities in CH had caused the formation of UHI. Therefore, measures of legislation such as protect forest from development by control the urbanization activities need to be implemented so that the formation of UHI can be reduced and

Effects of latent heat in various cloud microphysics processes on autumn rainstorms with different intensities on Hainan Island, China

NASA Astrophysics Data System (ADS)

Li, Jiangnan; Wu, Kailu; Li, Fangzhou; Chen, Youlong; Huang, Yanbin; Feng, YeRong

2017-06-01

In this study, we used the Weather Research and Forecasting (WRF) and WRF-3DVAR models to perform a series of simulations of two autumn rainstorms on Hainan Island. The results of neighborhood fractions and Hanssen skill scoring (FSS, HSS) methods show that the control experiments reproduced well two heavy rainfall episodes. Effects of latent heat in various cloud microphysical processes are different at distinct intensities or stages of precipitation. In the absence of any heating effect of deposition, precipitation weakened. The greater was the precipitation, the more significant was the weakening effect. Ascending movement at upper troposphere could be weakened or descending movement at lower troposphere enhanced. With decreases in the strength of precipitation, cloud ice, snow, graupel, and rainwater, increases in latent heat lessened. With weak precipitation, at upper troposphere the rainwater content increased and snow and ice content decreased, whereas at middle troposphere, the ice, snow, and graupel contents increased. Latent heating increased at middle and lower troposphere and decreased at upper troposphere. The absence of any heating effect of freezing had little effect on precipitation. By removing the evaporative cooling of cloud water, the interactions between vertical movement and cloud microphysical processes resulted in a weakening of strong precipitation and an intensification of weak precipitation. However, in the preliminary stages of these two precipitation events, snow, graupel, cloud ice, and rainwater all increased, and precipitation was enhanced in both. In the later stages, strong precipitation systems weakened and weak precipitation systems strengthened. Latent heating first increased and then dropped in strong precipitation systems, whereas they continuously increased in weak precipitation systems.

Spatially Analyzing the Inequity of the Hong Kong Urban Heat Island by Socio-Demographic Characteristics

PubMed Central

Wong, Man Sing; Peng, Fen; Zou, Bin; Shi, Wen Zhong; Wilson, Gaines J.

2016-01-01

Recent studies have suggested that some disadvantaged socio-demographic groups face serious environmental-related inequities in Hong Kong due to the rising ambient urban temperatures. Identifying heat-vulnerable groups and locating areas of Surface Urban Heat Island (SUHI) inequities is thus important for prioritizing interventions to mitigate death/illness rates from heat. This study addresses this problem by integrating methods of remote sensing retrieval, logistic regression modelling, and spatial autocorrelation. In this process, the SUHI effect was first estimated from the Land Surface Temperature (LST) derived from a Landsat image. With the scale assimilated to the SUHI and socio-demographic data, a logistic regression model was consequently adopted to ascertain their relationships based on Hong Kong Tertiary Planning Units (TPUs). Lastly, inequity “hotspots” were derived using spatial autocorrelation methods. Results show that disadvantaged socio-demographic groups were significantly more prone to be exposed to an intense SUHI effect: over half of 287 TPUs characterized by age groups of 60+ years, secondary and matriculation education attainment, widowed, divorced and separated, low and middle incomes, and certain occupation groups of workers, have significant Odds Ratios (ORs) larger than 1.2. It can be concluded that a clustering analysis stratified by age, income, educational attainment, marital status, and occupation is an effective way to detect the inequity hotspots of SUHI exposure. Additionally, inequities explored using income, marital status and occupation factors were more significant than the age and educational attainment in these areas. The derived maps and model can be further analyzed in urban/city planning, in order to mitigate the physical and social causes of the SUHI effect. PMID:26985899

Spatially Analyzing the Inequity of the Hong Kong Urban Heat Island by Socio-Demographic Characteristics.

PubMed

Wong, Man Sing; Peng, Fen; Zou, Bin; Shi, Wen Zhong; Wilson, Gaines J

2016-03-12

Recent studies have suggested that some disadvantaged socio-demographic groups face serious environmental-related inequities in Hong Kong due to the rising ambient urban temperatures. Identifying heat-vulnerable groups and locating areas of Surface Urban Heat Island (SUHI) inequities is thus important for prioritizing interventions to mitigate death/illness rates from heat. This study addresses this problem by integrating methods of remote sensing retrieval, logistic regression modelling, and spatial autocorrelation. In this process, the SUHI effect was first estimated from the Land Surface Temperature (LST) derived from a Landsat image. With the scale assimilated to the SUHI and socio-demographic data, a logistic regression model was consequently adopted to ascertain their relationships based on Hong Kong Tertiary Planning Units (TPUs). Lastly, inequity "hotspots" were derived using spatial autocorrelation methods. Results show that disadvantaged socio-demographic groups were significantly more prone to be exposed to an intense SUHI effect: over half of 287 TPUs characterized by age groups of 60+ years, secondary and matriculation education attainment, widowed, divorced and separated, low and middle incomes, and certain occupation groups of workers, have significant Odds Ratios (ORs) larger than 1.2. It can be concluded that a clustering analysis stratified by age, income, educational attainment, marital status, and occupation is an effective way to detect the inequity hotspots of SUHI exposure. Additionally, inequities explored using income, marital status and occupation factors were more significant than the age and educational attainment in these areas. The derived maps and model can be further analyzed in urban/city planning, in order to mitigate the physical and social causes of the SUHI effect.

The use of reflective and permeable pavements as a potential practice for heat island mitigation and stormwater management

NASA Astrophysics Data System (ADS)

Li, H.; Harvey, J. T.; Holland, T. J.; Kayhanian, M.

2013-03-01

To help address the built environmental issues of both heat island and stormwater runoff, strategies that make pavements cooler and permeable have been investigated through measurements and modeling of a set of pavement test sections. The investigation included the hydraulic and thermal performance of the pavements. The permeability results showed that permeable interlocking concrete pavers have the highest permeability (or infiltration rate, ˜0.5 cm s-1). The two permeable asphalt pavements showed the lowest permeability, but still had an infiltration rate of ˜0.1 cm s-1, which is adequate to drain rainwater without generating surface runoff during most typical rain events in central California. An increase in albedo can significantly reduce the daytime high surface temperature in summer. Permeable pavements under wet conditions could give lower surface temperatures than impermeable pavements. The cooling effect highly depends on the availability of moisture near the surface layer and the evaporation rate. The peak cooling effect of watering for the test sections was approximately 15-35 °C on the pavement surface temperature in the early afternoon during summer in central California. The evaporative cooling effect on the pavement surface temperature at 4:00 pm on the third day (25 h after watering) was still 2-7 °C lower compared to that on the second day, without considering the higher air temperature on the third day. A separate and related simulation study performed by UCPRC showed that full depth permeable pavements, if designed properly, can carry both light-duty traffic and certain heavy-duty vehicles while retaining the runoff volume captured from an average California storm event. These preliminarily results indicated the technical feasibility of combined reflective and permeable pavements for addressing the built environment issues related to both heat island mitigation and stormwater runoff management.

Isolation of thermotolerant Vermamoeba vermiformis strains from water sources in Lanzarote Island, Canary Islands, Spain.

PubMed

Reyes-Batlle, María; Wagner, Carolina; Zamora-Herrera, Jonadab; Vargas-Mesa, Alejandro; Sifaoui, Ines; González, Ana C; López-Arencibia, Atteneri; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

2016-09-01

In this study, twenty water samples were collected in the island of Lanzarote, Canary Islands, Spain in order to check for the presence of V. vermiformis strains in these samples. Water samples were cultured on 2% Non-Nutrient Agar (NNA) plates covered with a thin layer of heat killed E. coli and checked daily for the presence of Vermamoeba. After a week, V. vermiformis amoebae were observed in 2 of the 20 processed samples (10%) incubated at room temperature and 37°C. Molecular characterization was carried out by amplifying the 18S rDNA gene and DNA sequencing in order to confirm the identity of the isolated amoebic strains. To the best of our knowledge, this is the first report on the presence of FLA in environmental sources in Lanzarote Island and the first report of Vermamoeba vermiformis in water sources in this island. Furthermore, the two strains isolated in this study were collected in recreational areas with close contact with humans and thus awareness should be raised.

The Conundrum of Impacts of Climate Change on Urbanization and the Urban Heat Island Effect

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.

2011-01-01

The twenty-first century is the first urban century according to the United Nations Development Program. The focus on cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In 2000, approximately 3 billion people representing about 40% of the global population resided in urban areas. The United Nations estimates that by 2025, 60% of the world s population will live in urban areas. As a consequence, the number of megacities (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand the spatial growth of urban areas and what the impacts are on the environment. Moreover, there is a critical need to assess how under global climate change, cities will affect the local, regional, and even global climate. As urban areas increase in size, it is anticipated there will be a concomitant growth of the Urban Heat Island effect (UHI), and the attributes that are related to its spatial and temporal dynamics. Therefore, how climate change, including the dynamics of the UHI, will affect the urban environment, must be explored to help mitigate potential impacts on the environment (e.g., air quality, heat stress, vectorborne disease) and on human health and well being, to develop adaptation schemes to cope with these impacts.

Roles of Urban Tree Canopy and Buildings in Urban Heat Island Effects: Parameterization and Preliminary Results

NASA Technical Reports Server (NTRS)

Loughner, Christopher P.; Allen, Dale J.; Zhang, Da-Lin; Pickering, Kenneth E.; Dickerson, Russell R.; Landry, Laura

2012-01-01

Urban heat island (UHI) effects can strengthen heat waves and air pollution episodes. In this study, the dampening impact of urban trees on the UHI during an extreme heat wave in the Washington, D.C., and Baltimore, Maryland, metropolitan area is examined by incorporating trees, soil, and grass into the coupled Weather Research and Forecasting model and an urban canopy model (WRF-UCM). By parameterizing the effects of these natural surfaces alongside roadways and buildings, the modified WRF-UCM is used to investigate how urban trees, soil, and grass dampen the UHI. The modified model was run with 50% tree cover over urban roads and a 10% decrease in the width of urban streets to make space for soil and grass alongside the roads and buildings. Results show that, averaged over all urban areas, the added vegetation decreases surface air temperature in urban street canyons by 4.1 K and road-surface and building-wall temperatures by 15.4 and 8.9 K, respectively, as a result of tree shading and evapotranspiration. These temperature changes propagate downwind and alter the temperature gradient associated with the Chesapeake Bay breeze and, therefore, alter the strength of the bay breeze. The impact of building height on the UHI shows that decreasing commercial building heights by 8 m and residential building heights by 2.5 m results in up to 0.4-K higher daytime surface and near-surface air temperatures because of less building shading and up to 1.2-K lower nighttime temperatures because of less longwave radiative trapping in urban street canyons.

Suburban heat island effect in groundwater energy utilisation in Nordic climate - case study

NASA Astrophysics Data System (ADS)

Arola, Teppo

2017-04-01

We present the preliminary results from the initial thermogeological characterization of Finland's first-ever planned large-scale aquifer thermal energy storage (ATES) facility. The site is located in the Asko area (Lahti), at a latitude of 60°59'N. In particular, emphasis is put on the results from an aquifer's pumping test performed in July / August 2016 to investigate the potential implication of suburban heat island (SUHI) effect to ATES system on the naturally cold groundwater area. The site has been under geological investigation since July 2015. At a regional scale, the groundwater's natural temperature is about 5.8- 6°C. However, preliminary measurements during the investigations revealed that local groundwater temperature ranged between 7.5 to 8.7 °C in Asko area. The highest temperature was observed underneath buildings, suggesting that higher-than-average temperature is most likely influenced due to anthropogenic heat flux into the ground. The pumping test was performed for 39 days, of which 28 days with groundwater withdrawal and 11 days of heads recovery. The pumped volumes range from 350 to 540 m3/d leading the total volume of 10400 m3 of groundwater. Groundwater temperatures were continuously measured from pumping test well and two observation piezometers during the entire test. The results indicated that aquifer's temperature remained nearly constant being between 7.4 to 7.9 °C during the test period. Heat pulses with temperature variation of 0.1 to 0.3 °C were observed in the pumping well and nearest monitoring well (19 meters from pumping well) during the pumping test and recovery phase. We estimate that the pulses were due to rapidly changed groundwater flowing conditions and pulse indicate "new groundwater" flow to the well. Overall, the preliminary test suggests that groundwater temperature are expected to remain elevated during the ATES system operation. Elevated temperature due the SUHI effect increases groundwater heating potential

Effect of heating on the suppression of tearing modes in tokamaks.

PubMed

Classen, I G J; Westerhof, E; Domier, C W; Donné, A J H; Jaspers, R J E; Luhmann, N C; Park, H K; van de Pol, M J; Spakman, G W; Jakubowski, M W

2007-01-19

The suppression of (neoclassical) tearing modes is of great importance for the success of future fusion reactors like ITER. Electron cyclotron waves can suppress islands, both by driving noninductive current in the island region and by heating the island, causing a perturbation to the Ohmic plasma current. This Letter reports on experiments on the TEXTOR tokamak, investigating the effect of heating, which is usually neglected. The unique set of tools available on TEXTOR, notably the dynamic ergodic divertor to create islands with a fully known driving term, and the electron cyclotron emission imaging diagnostic to provide detailed 2D electron temperature information, enables a detailed study of the suppression process and a comparison with theory.

Airborne infrared video radiometry as a low-cost tool for remote sensing of the environment, two mapping examples from Israel of urban heat islands and mineralogical site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ben-Dor, E.; Saaroni, H.; Ochana, D.

1996-10-01

In this study we examined the capability of a laboratory infrared video camera for use in remote sensing of the environment. The instrument used, INFRAMETRICS 760, was mounted onboard a Bell 206 helicopter. Under the flight conditions examined, the radiometer proved itself to be very stable and produced high-quality thermal images in a real-time mode. We studied two different environmental aspects, as follows: (1) Urban heat island of the most dense city in Israel, Tel-Aviv- and (2) lithological distribution of a well-known mineralogical site in Israel, Makhtesh Ramon. The radiometer used in both studies was able to produce a temperaturemore » presentation, rather than a gray scale from an altitude of 7,000 and 10,000 feet and at 70 knots air speed. The instrument produced a high-quality set of data in terms of signal-to-noise, stability, temperature accuracy and spatial resolution. In the Tel-Aviv case, the results showed that the urban heat island of the city can be depicted in a very high spatial and thermal resolutions domain and that a significant correlation exists between ground objects and the surrounding air temperature values. Based on the flight results, we could generated an isotherm map of the city that, for the first time, located the urban heat island of the city both in meso- and microscales. In the case of Makhtesh Ramon, we found that under field conditions, the radiometer, coupled with a VIS-CCD camera can provide significant ATI parameters of typical rocks that characterize tile study area. Although more study is planned and suggested based on the current data, it was concluded that the airborne thermal video radiometry, is a promising, inexpensive tool for monitoring the environment on a real-time basis. 10 refs., 5 figs., 1 tab.« less

Numerical simulations of heat transfer considering hydraulic discontinuity for an enhanced geothermal system development in Seokmo Island, Korea

NASA Astrophysics Data System (ADS)

Shin, J.; Kim, K.; Hyun, Y.; Lee, K.; Lee, T.

2011-12-01

The construction of the first geothermal plant in Korea is under planning in Seokmo Island, where a few artesian wells showing relatively high water temperature of around 70 degrees were discovered lately. Geologic structure in this region is characterized by the fractured granite. Numerical simulations for the temperature evolution in a fractured geothermal reservoir in Seokmo Island under the supposed injection-extraction operating conditions were carried out using TOUGH2. A MINC model including a hydraulic discontinuity in Seokmo Island region, which reflected the analysis from several geophysical explorations and drilled rock core, was generated. Supposing the N05°E, NW83° fracture zone containing the pumping range, the numerical simulation results show that temperature of the extracted geothermal water decreases after 15 years of operation, which decreases the overall efficiency of the expected geothermal plant. This is because the colder water from the injection well, which is 400 m apart, begins to flow into the more permeable fracture zone from the 15th year, resulting in a decrease in temperature near the pumping well. Temperature distribution calculated from the simulation also shows a rise of relatively hot geothermal water along the fracture plane. All of the results are different from the non-fracture MINC model, which shows a low temperature contour in concentric circle shape around the injection well and relatively consistent extracting temperature. This demonstrates that the distribution and the structure of fracture system influence the major mass and heat flow mechanisms in geologic medium. Therefore, an intensive geologic investigation for the fractures including their structure, permeability and connecting relation is important. Acknowledgement This study was financially supported by KIGAM, KETEP and BK21.

Urban Heat Island Effect on the Energy Consumption of Institutional Buildings in Rome

NASA Astrophysics Data System (ADS)

Calice, Claudia; Clemente, Carola; Salvati, Agnese; Palme, Massimo; Inostroza, Luis

2017-10-01

The urban heat island (UHI) effect is constantly increasing the energy consumption of buildings, especially in summer periods. The energy gap between the estimated energy performance - often simulated without considering UHI - and the real operational consumption is especially relevant for institutional buildings, where the cooling needs are in general higher than in other kind of buildings, due to more internal gains (people, appliances) and different architectural design (more transparent façades and light walls). This paper presents a calculation of the energy penalty due to UHI in two institutional buildings in Rome. Urban Weather Generator (UWG) is used to generate a modified weather file, taking into account the UHI phenomenon. Then, two building performance simulations are done for each case: the first simulation uses a standard weather file and the second uses the modified one. Results shows how is it necessary to re-develop mitigation strategies and a new energy retrofit approach, in order to include urbanization ad UHI effect, especially in this kind of buildings, characterized by very poor conditions of comfort during summer, taking into account users and occupant-driven demand.

Solar cooling system performance, Frenchman's Reef Hotel, Virgin Islands

NASA Astrophysics Data System (ADS)

Harber, H.

1981-09-01

The operational and thermal performance of a variety of solar systems are described. The Solar Cooling System was installed in a hotel at St. Thomas, U. S. Virgin Islands. The system consists of the evacuated glass tube collectors, two 2500 gallon tanks, pumps, computerized controller, a large solar optimized industrial sized lithium bromide absorption chiller, and associated plumbing. Solar heated water is pumped through the system to the designed public areas such as lobby, lounges, restaurant and hallways. Auxiliary heat is provided by steam and a heat exchanger to supplement the solar heat.

Solar cooling system performance, Frenchman's Reef Hotel, Virgin Islands

NASA Technical Reports Server (NTRS)

Harber, H.

1981-01-01

The operational and thermal performance of a variety of solar systems are described. The Solar Cooling System was installed in a hotel at St. Thomas, U. S. Virgin Islands. The system consists of the evacuated glass tube collectors, two 2500 gallon tanks, pumps, computerized controller, a large solar optimized industrial sized lithium bromide absorption chiller, and associated plumbing. Solar heated water is pumped through the system to the designed public areas such as lobby, lounges, restaurant and hallways. Auxiliary heat is provided by steam and a heat exchanger to supplement the solar heat.

An Assessment of Magnetic Conditions for Strong Coronal Heating in Solar Active Regions by Comparing Observed Loops with Computed Potential Field Lines

NASA Technical Reports Server (NTRS)

Gary, G. A.; Moore, R. L.; Porter, J. G.; Falconer, D. A.

1999-01-01

We report further results on the magnetic origins of coronal heating found from registering coronal images with photospheric vector magnetograms. For two complementary active regions, we use computed potential field lines to examine the global non-potentiality of bright extended coronal loops and the three-dimensional structure of the magnetic field at their feet, and assess the role of these magnetic conditions in the strong coronal heating in these loops. The two active regions are complementary, in that one is globally potential and the other is globally nonpotential, while each is predominantly bipolar, and each has an island of included polarity in its trailing polarity domain. We find the following: (1) The brightest main-arch loops of the globally potential active region are brighter than the brightest main- arch loops of the globally strongly nonpotential active region. (2) In each active region, only a few of the mainarch magnetic loops are strongly heated, and these are all rooted near the island. (3) The end of each main-arch bright loop apparently bifurcates above the island, so that it embraces the island and the magnetic null above the island. (4) At any one time, there are other main-arch magnetic loops that embrace the island in the same manner as do the bright loops but that are not selected for strong coronal heating. (5) There is continual microflaring in sheared core fields around the island, but the main-arch bright loops show little response to these microflares. From these observational and modeling results we draw the following conclusions: (1) The heating of the main-arch bright loops arises mainly from conditions at the island end of these loops and not from their global non-potentiality. (2) There is, at most, only a loose coupling between the coronal heating in the bright loops of the main arch and the coronal heating in the sheared core fields at their feet, although in both the heating is driven by conditions/events in and around the

Threat of attacks of Ixodes ricinus ticks (Ixodida: Ixodidae) and Lyme borreliosis within urban heat islands in south-western Poland.

PubMed

Buczek, Alicja; Ciura, Dariusz; Bartosik, Katarzyna; Zając, Zbigniew; Kulisz, Joanna

2014-12-11

The increased incidence of Lyme disease in Europe necessitates permanent monitoring of the occurrence and activity of its vector. Therefore, in this study, we have investigated the presence and seasonal activity of Ixodes ricinus ticks in various habitats of a large industrial region in south-western Poland in correlation with environmental factors present in urban heat islands. Additionally, the risk of borreliosis in this part of Poland has been assessed. The investigations were carried out at two-week intervals between April and October 2001 and 2002. Ticks were collected from four localities in Upper Silesia, i.e. in a city park (CH), on the outskirts of two large cities (KO, MI), and in a forest (KL). We analysed the impact of temperature and humidity measured during the collection period in the I. ricinus habitats, the climatic conditions prevailing in the study area, and the degree of environmental contamination on the abundance and activity of these ticks in the respective sites. The degree of borreliosis risk in the region was determined on the basis of the results of research on the prevalence of Borrelia burgdorferi s.l. in ticks and reports from sanitary-epidemiological stations. In total, 2061 I. ricinus ticks, including 606 nymphs and 1455 adults, were collected in the study area. The number and activity of the ticks varied during the collection in the different sites. In the urban locality CH, tick abundance was the lowest (455 throughout the investigation period), and the seasonal activity of females was unimodal and persisted for as long as 4 months. In the suburban localities KO and MI, tick abundance was higher (485 and 481 specimens, respectively) and the activity of females was unimodal. The highest abundance (640 ticks) and a bimodal pattern of female activity were reported from the forest locality KL. In all the localities, the activity of nymphs was unimodal. Humidity was found to be a factor influencing I. ricinus abundance and activity

The Need for High Spatial Resolution Multispectral Thermal Remote Sensing Data In Urban Heat Island Research

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Luvall, Jeffrey C.

2006-01-01

Although the study of the Urban Heat Island (UHI) effect dates back to the early 1800's when Luke Howard discovered London s heat island, it has only been with the advent of thermal remote sensing systems that the extent, characteristics, and impacts of the UHI have become to be understood. Analysis of the UHI effect is important because above all, this phenomenon can directly influence the health and welfare of urban residents. For example, in 1995, over 700 people died in Chicago due to heat-related causes. UHI s are characterized by increased temperature in comparison to rural areas and mortality rates during a heat wave increase exponentially with the maximum temperature, an effect that is exacerbated by the UHI. Aside from the direct impacts of the UHI on temperature, UHI s can produce secondary effects on local meteorology, including altering local wind patterns, increased development of clouds and fog, and increasing rates of precipitation either over, or downwind, of cities. Because of the extreme heterogeneity of the urban surface, in combination with the sprawl associated with urban growth, thermal infrared (TIR) remote sensing data have become of significant importance in understanding how land cover and land use characteristics affect the development and intensification of the UHI. TIR satellite data have been used extensively to analyze the surface temperature regimes of cities to help observe and measure the impacts of surface temperatures across the urban landscape. However, the spatial scales at which satellite TIR data are collected are for the most part, coarse, with the finest readily available TIR data collected by the Landsat ETM+ sensor at 60m spatial resolution. For many years, we have collected high spatial resolution (10m) data using an airborne multispectral TIR sensor over a number of cities across the United States. These high resolution data have been used to develop an understanding of how discrete surfaces across the urban environment

Improving Heat Health Resilience through Urban Infrastructure Planning and Design

EPA Pesticide Factsheets

Public health and environmental agencies can reduce the heat island effect, increase resilience to extreme heat events, and help each other further their respective missions. Listen to this webinar to learn how.

Modulated heat pulse propagation and partial transport barriers in chaotic magnetic fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castillo-Negrete, Diego del; Blazevski, Daniel

2016-04-15

Direct numerical simulations of the time dependent parallel heat transport equation modeling heat pulses driven by power modulation in three-dimensional chaotic magnetic fields are presented. The numerical method is based on the Fourier formulation of a Lagrangian-Green's function method that provides an accurate and efficient technique for the solution of the parallel heat transport equation in the presence of harmonic power modulation. The numerical results presented provide conclusive evidence that even in the absence of magnetic flux surfaces, chaotic magnetic field configurations with intermediate levels of stochasticity exhibit transport barriers to modulated heat pulse propagation. In particular, high-order islands andmore » remnants of destroyed flux surfaces (Cantori) act as partial barriers that slow down or even stop the propagation of heat waves at places where the magnetic field connection length exhibits a strong gradient. Results on modulated heat pulse propagation in fully stochastic fields and across magnetic islands are also presented. In qualitative agreement with recent experiments in large helical device and DIII-D, it is shown that the elliptic (O) and hyperbolic (X) points of magnetic islands have a direct impact on the spatio-temporal dependence of the amplitude of modulated heat pulses.« less

Mechanisms driving variability in the ocean forcing of Pine Island Glacier

PubMed Central

Webber, Benjamin G. M.; Heywood, Karen J.; Stevens, David P.; Dutrieux, Pierre; Abrahamsen, E. Povl; Jenkins, Adrian; Jacobs, Stanley S.; Ha, Ho Kyung; Lee, Sang Hoon; Kim, Tae Wan

2017-01-01

Pine Island Glacier (PIG) terminates in a rapidly melting ice shelf, and ocean circulation and temperature are implicated in the retreat and growing contribution to sea level rise of PIG and nearby glaciers. However, the variability of the ocean forcing of PIG has been poorly constrained due to a lack of multi-year observations. Here we show, using a unique record close to the Pine Island Ice Shelf (PIIS), that there is considerable oceanic variability at seasonal and interannual timescales, including a pronounced cold period from October 2011 to May 2013. This variability can be largely explained by two processes: cumulative ocean surface heat fluxes and sea ice formation close to PIIS; and interannual reversals in ocean currents and associated heat transport within Pine Island Bay, driven by a combination of local and remote forcing. Local atmospheric forcing therefore plays an important role in driving oceanic variability close to PIIS. PMID:28211473

The Atlanta Urban Heat Island Mitigation and Air Quality Modeling Project: How High-Resoution Remote Sensing Data Can Improve Air Quality Models

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Estes, Maurice G., Jr.; Crosson, William L.; Khan, Maudood N.

2006-01-01

The Atlanta Urban Heat Island and Air Quality Project had its genesis in Project ATLANTA (ATlanta Land use Analysis: Temperature and Air quality) that began in 1996. Project ATLANTA examined how high-spatial resolution thermal remote sensing data could be used to derive better measurements of the Urban Heat Island effect over Atlanta. We have explored how these thermal remote sensing, as well as other imaged datasets, can be used to better characterize the urban landscape for improved air quality modeling over the Atlanta area. For the air quality modeling project, the National Land Cover Dataset and the local scale Landpro99 dataset at 30m spatial resolutions have been used to derive land use/land cover characteristics for input into the MM5 mesoscale meteorological model that is one of the foundations for the Community Multiscale Air Quality (CMAQ) model to assess how these data can improve output from CMAQ. Additionally, land use changes to 2030 have been predicted using a Spatial Growth Model (SGM). SGM simulates growth around a region using population, employment and travel demand forecasts. Air quality modeling simulations were conducted using both current and future land cover. Meteorological modeling simulations indicate a 0.5 C increase in daily maximum air temperatures by 2030. Air quality modeling simulations show substantial differences in relative contributions of individual atmospheric pollutant constituents as a result of land cover change. Enhanced boundary layer mixing over the city tends to offset the increase in ozone concentration expected due to higher surface temperatures as a result of urbanization.

Spatial Analysis of Post-Hurricane Katrina Thermal Pattern and Intensity in Greater New Orleans: Implications for Urban Heat Island Phenomenon

NASA Astrophysics Data System (ADS)

Lief, Aram Parrish

In 2005, Hurricane Katrina's diverse impacts on the Greater New Orleans area included damaged and destroyed trees, and other despoiled vegetation, which also increased the exposure of artificial and bare surfaces, known factors that contribute to the climatic phenomenon known as the urban heat island (UHI). This is an investigation of UHI in the aftermath of Hurricane Katrina, which entails the analysis of pre and post-hurricane Katrina thermal imagery of the study area, including changes to surface heat patterns and vegetative cover. Imagery from Landsat TM was used to show changes to the pattern and intensity of the UHI effect, caused by an extreme weather event. Using remote sensing visualization methods, in situ data, and local knowledge, the author found there was a measurable change in the pattern and intensity of the New Orleans UHI effect, as well as concomitant changes to vegetative land cover. This finding may be relevant for urban planners and citizens, especially in the context of recovery from a large-scale disaster of a coastal city, regarding future weather events, and other natural and human impacts.

Modeling of the Urban Heat Island (UHI) using WRF - Assessment of adaptation and mitigation strategies for the city of Stuttgart.

NASA Astrophysics Data System (ADS)

Fallmann, Joachim; Suppan, Peter; Emeis, Stefan

2013-04-01

Cities are warmer than their surroundings (called urban heat island, UHI). UHI influence urban atmospheric circulation, air quality, and ecological conditions. UHI leads to upward motion and compensating near-surface inflow from the surroundings which import rural trace substances. Chemical and aerosol formation processes are modified due to increased temperature, reduced humidity and modified urban-rural trace substance mixtures. UHIs produce enhanced heat stress for humans, animals and plants, less water availability and modified air quality. Growing cities and Climate Change will aggravate the UHI and its effects and urgently require adaptation and mitigation strategies. Prior to this, UHI properties must be assessed by surface observations, ground- and satellite-based vertical remote sensing and numerical modelling. The Weather Research and Forecasting Model (WRF) is an instrument to simulate and assess this phenomenon based on boundary conditions from observations and global climate models. Three urbanization schemes are available with WRF, which are tested during this study for different weather conditions in central Europe and will be enhanced if necessary. High resolution land use maps are used for this modeling effort. In situ measurements and Landsat thermal images are employed for validation of the results. The study will focus on the city of Stuttgart located in the south western part of Germany that is situated in a caldera-like orographic feature. This municipality has a long tradition in urban climate research and thus is well equipped with climatologic measurement stations. By using Geographical Information Systems (GIS), it is possible to simulate several scenarios for different surface properties. By increasing the albedo of roof and wall layers in the urban canopy model or by replacing urban land use by natural vegetation, simple urban planning strategies can be tested and the effect on urban heat island formation and air quality can be

Hypothesis: Urbanization and exposure to urban heat islands contribute to increasing prevalence of kidney stones.

PubMed

Goldfarb, David S; Hirsch, Jacqueline

2015-12-01

The prevalence of kidney stones is increasing worldwide. Various etiologies may in part explain this observation including increased prevalence of diabetes, obesity and the metabolic syndrome, increased dietary protein and salt content, and decreased dietary dairy products. We hypothesize an additional and novel potential contributor to increasing kidney stone prevalence: migration to urban settings, or urbanization, and resultant exposure of the population to the higher temperatures of urban heat islands (UHIs). Both urbanization and exposure to UHIs are worldwide, continuous trends. Because the difference in temperature between rural and urban settings is greater than the increase in temperature caused by global warming, the potential effect of urbanization on stone prevalence may be of greater magnitude. However, demonstration of a convincing link between urbanization and kidney stones is confounded by many variables simultaneously affected by migration to cities, such as changes in occupation, income, and diet. No data have yet been published supporting this proposed association. We explore the plausibility and limitations of this possible etiology of increasing kidney stone prevalence. Published by Elsevier Ltd.

Investigation of writing error in staggered heated-dot magnetic recording systems

NASA Astrophysics Data System (ADS)

Tipcharoen, W.; Warisarn, C.; Tongsomporn, D.; Karns, D.; Kovintavewat, P.

2017-05-01

To achieve an ultra-high storage capacity, heated-dot magnetic recording (HDMR) has been proposed, which heats a bit-patterned medium before recording data. Generally, an error during the HDMR writing process comes from several sources; however, we only investigate the effects of staggered island arrangement, island size fluctuation caused by imperfect fabrication, and main pole position fluctuation. Simulation results demonstrate that a writing error can be minimized by using a staggered array (hexagonal lattice) instead of a square array. Under the effect of main pole position fluctuation, the writing error is higher than the system without main pole position fluctuation. Finally, we found that the error percentage can drop below 10% when the island size is 8.5 nm and the standard deviation of the island size is 1 nm in the absence of main pole jitter.

Effects of the Urban Heat Island on Aerosol pH

NASA Astrophysics Data System (ADS)

Battaglia, M., Jr.; Douglas, S.; Hennigan, C. J.

2017-12-01

The urban heat island (UHI) is a widely observed phenomenon whereby urban environments have higher temperature (T) and lower relative humidity (RH) than surrounding suburban and rural areas. Both of these factors affect the partitioning of semi-volatile species found in the atmosphere, such as nitric acid and ammonia. These species are inherently tied to aerosol pH, which is a key parameter driving some atmospheric chemical processes and environmental effects of aerosols. In this study, we characterized the effect of the UHI on aerosol pH in Baltimore, MD and Chicago, IL. These cities were selected based on differences in climatology, source influences, and atmospheric composition. Meteorological and atmospheric composition data from the urban centers and surrounding rural locations were used as inputs to the ISORROPIA-II aerosol thermodynamic model to compute gas/particle partitioning, aerosol liquid water content, and aerosol pH. Dramatic differences in aerosol liquid water (ALW) content were found in both cities and were attributable to the T and RH differences (UHI effect). The urban-rural differences in ALW result in urban aerosol pH that is systematically lower (more acidic) than rural aerosol pH for identical atmospheric composition. The UHI in Baltimore is most intense during the summer and at night, with differences of up to 1 pH unit predicted during these times. Similarly, the UHI in Chicago is most intense during the summer and at night; however, the atmospheric composition in Chicago shows a mediating effect, with differences of up to 0.65 pH units predicted during these times. These results are likely to have broad implications for chemistry occurring in and around urban atmospheres globally, although the magnitude of the effect may differ based on the UHI characteristic of each urban environment.

The Urban Tree as a Tool to Mitigate the Urban Heat Island in Mexico City: A Simple Phenomenological Model.

PubMed

Ballinas, Mónica; Barradas, Víctor L

2016-01-01

The urban heat island (UHI) is mainly a nocturnal phenomenon, but it also appears during the day in Mexico City. The UHI may affect human thermal comfort, which can influence human productivity and morbidity in the spring/summer period. A simple phenomenological model based on the energy balance was developed to generate theoretical support of UHI mitigation in Mexico City focused on the latent heat flux change by increasing tree coverage to reduce sensible heat flux and air temperature. Half-hourly data of the urban energy balance components were generated in a typical residential/commercial neighborhood of Mexico City and then parameterized using easily measured variables (air temperature, humidity, pressure, and visibility). Canopy conductance was estimated every hour in four tree species, and transpiration was estimated using sap flow technique and parameterized by the envelope function method. Averaged values of net radiation, energy storage, and sensible and latent heat flux were around 449, 224, 153, and 72 W m, respectively. Daily tree transpiration ranged from 3.64 to 4.35 Ld. To reduce air temperature by 1°C in the studied area, 63 large would be required per hectare, whereas to reduce the air temperature by 2°C only 24 large trees would be required. This study suggests increasing tree canopy cover in the city cannot mitigate UHI adequately but requires choosing the most appropriate tree species to solve this problem. It is imperative to include these types of studies in tree selection and urban development planning to adequately mitigate UHI. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Urban Heat Wave Hazard Assessment

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Jedlovec, Gary; Meyer, Paul J.; LaFontaine, Frank J.; Crane, Dakota L.

2016-01-01

Heat waves are the largest cause of environment-related deaths globally. On average, over 6,000 people in the United States alone are hospitalized each summer due to excessive heat. Key elements leading to these disasters are elevated humidity and the urban heat island effect, which act together to increase apparent temperature and amplify the effects of a heat wave. Urban demographics and socioeconomic factors also play a role in determining individual risk. Currently, advisories of impending heat waves are often too generalized, with limited or no spatial variability over urban regions. This frequently contributes to a lack of specific response on behalf of the population. A goal of this project is to develop a product that has the potential to provide more specific heat wave guidance invoking greater awareness and action.

Characterizing Urban Heat Islands of Global Settlements Using MODIS and Nighttime Lights Products

NASA Technical Reports Server (NTRS)

Zhang, Ping; Imhoff, Marc L.; Wolfe, Robert E.; Bounoua, Lahouari

2010-01-01

Impervious surface area (ISA) from the National Geophysical Data Center (NGDC) and land surface temperature (LST) from the Moderate Resolution Imaging Spectroradiometer (MODIS) averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) signature on LST amplitude and its relationship with development intensity, size, and ecological setting for more than 3000 urban settlements globally. Development intensity zones based on fractional ISA are defined for each urban area emanating outward from the urban core to the nearby nonurban rural areas and used to stratify sampling for LST. Sampling is further constrained by biome type and elevation data to ensure objective intercomparisons between zones and between cities in different biomes. We find that the ecological context and settlement size significantly influence the amplitude of summer daytime UHI. Globally, an average of 3.8 C UHI is found in cities built in biomes dominated by forests; 1.9 C UHI in cities embedded in grass shrubs biomes; and only a weak UHI or sometimes an urban heat sink (UHS) in cities in arid and semi-arid biomes. Overall, the amplitude of the UHI is negatively correlated (R = -0.66) with the difference in vegetation density between urban and rural zones represented by the MODIS normalized difference vegetation index (NDVI). Globally averaged, the daytime UHI amplitude for all settlements is 2.6 C in summer and 1.4 C in winter. Globally, the average summer daytime UHI is 4.7 C for settlements larger than 500 square kilometers compared with 2.5 C for settlements smaller than 50 square kilometers and larger than 10 square kilometers. The stratification of cities by size indicates that the aggregated amount of ISA is the primary driver of UHI amplitude, with variations between ecological contexts and latitudinal zones. More than 60% of the total LST variance is explained by ISA for urban settlements within forests at mid to high latitudes. This

Characterizing Urban Heat Islands of Global Settlements Using MODIS and Nighttime Lights Products

NASA Technical Reports Server (NTRS)

Zhang, Ping; Imhoff, Marc L.; Wolfe, Robert E.; Bounoua, Lahouari

2010-01-01

Impervious surface area (ISA) from the National Geophysical Data Center (NGDC) and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) signature on LST amplitude and its relationship to development intensity, size, and ecological setting for more than 3000 urban settlements over the globe. Development intensity zones based on fractional ISA are defined for each urban area emanating outward from the urban core to the nearby non-urban rural areas and used to stratify sampling for LST. Sampling is further constrained by biome type and elevation data to insure objective inter-comparisons between zones and between cities in different biomes. We find that the ecological context and settlement size significantly influence the amplitude of summer daytime UHI. Globally, an average of 3.8 C UHI is found in cities built in biomes dominated by forests; 1.9 C UHI in cities embedded in grass/shrub biomes, and only a weak UHI or sometimes an Urban Heat Sink (UHS) in cities in and and semi-arid biomes. Overall, the amplitude of the UHI is negatively correlated (R = -0.66) to the difference in vegetation density between urban and rural zones represented by MODIS Normalized Difference Vegetation Index (NDVI). Globally averaged, the daytime UHI amplitude for all settlement is 2.6 C in summer and 1.4 C in winter. Globally, the average summer daytime UHI is 4.7 C for settlements larger than 500 square kilometers, compared to 2.5 C for settlements smaller than 50 square kilometers and larger than 10 square kilometers. The stratification of cities by size indicates that the aggregated amount of ISA is the primary driver of UHI amplitude with variations between ecological contexts and latitudinal zones. More than 60% of the total LST variances is explained by ISA for urban settlements within forests at mid-to-high latitudes. This percentage will increase to more than 80% when only USA

Climate change and heat waves in Paris and London metropolitan areas

NASA Astrophysics Data System (ADS)

Dousset, B.

2010-12-01

Summer warming trends in Western and Central Europe and in Mediterranean regions are increasing the incidence, intensity, and duration of heat waves. Those extreme events are especially deadly in large cities, owing to high population densities, surface characteristics, heat island effects, anthropogenic heat and pollutants. In August 2003, a persistent anticyclone over Western Europe generated a heat wave of exceptional strength and duration with an estimated death toll of 70,000, including 4678 in the Paris region. A series of NOAA-AVHRR satellite thermal images over the Paris and London metropolitan areas, were used to analyze Land Surface Temperature (LST) and its related mortality. In the Paris region, LSTs were merged with land use and cover data to identify risk areas, and thermal indicators were produced at the addresses of ~ 500 elderly people to assess diurnal heat exposure. Results indicate: (i) contrasting night time and daytime heat island patterns related to land use and surface characteristics; (ii) the relation between night-time heat islands and heat waves intensity; (iii) the impact of elevated minimal temperatures on excess mortality, with a 0.5 °C increase doubling the risk of death, (in the temperature range of the heatwave); iv) the correlation between the spatial distribution of highest night-time LSTs and that of highest mortality ratios; and v) the significant impact of urban parks in the partitioning between latent and sensible surface heat fluxes, despite a prior warm and dry spring. Near-real time satellite monitoring of heat waves in urban areas improve our understanding of the LST processes and spatial variability, and of the related heat stress and mortality. These observations provide criteria for warning systems, contingency policies and planning, and climate adaptation and mitigation strategies.

A Global Characterization of Urban Heat Islands

NASA Astrophysics Data System (ADS)

Chakraborty, T.; Lee, X.

2017-12-01

The urban heat island (UHI) effect refers to the higher temperatures in urban areas, and it is one of the most well-known consequences of urbanization on local climate. In the present study, we define a new simplified urban-boundary (SUB) algorithm to quantify the daytime and nighttime surface UHIs on a global scale based on 16 years of MODIS Land Surface Temperature (LST) data. The results from the algorithm are validated against previous studies and used to determine the diurnal, monthly, and long-term variation in the surface UHI for over 9000 urban clusters situated in the different Koppen-Geiger climate zones,namely equatorial, arid, warm temperate, snow, and polar. Thus, the variability of the surface UHI for each climate class is determined using a consistent methodology for the first time. The 16-year mean global daytime surface UHI is 0.71 ± 0.93 °C at 1030 LT and 1.00 ± 1.17 °C at 1330 LT, while the nighttime surface UHI is 0.51 ± 0.50 °C at 2230 LT and 0.42 ± 0.52 °C at 0130 LT. This is in good agreement with the results from previous studies, which have looked at the UHI for multiple cities. Summer surface UHI is larger than winter surface UHI across all climate zones. The annual daytime surface UHI is highest in the polar urban clusters (1.77 ± 1.61 °C), followed by snow (1.39 ± 1.17 °C), equatorial (1.21 ± 1.32 °C), warm temperate (1.02 ± 0.98 °C), and arid (0.18 ± 1.27 °C). Urban clusters in the arid climate are found to show different diurnal and seasonal patterns, with higher nighttime surface UHI (0.65 ± 0.58 °C) and two seasonal peaks during the year. The diurnal variation in surface UHI is highest in the polar zone (1.16 °C) and lowest in the arid zone (0.57 °C). The inter-seasonality is also highest in the polar Zone (2.20 °C) and lowest in the arid zone (0.80 °C). Finally, we investigate the change in the surface UHI in more than a decade (2001 to 2013 for MODIS TERRA and 2003 to 2013 for MODIS AQUA) and find a gradual

Different Patterns of the Urban Heat Island Intensity from Cluster Analysis

NASA Astrophysics Data System (ADS)

Silva, F. B.; Longo, K.

2014-12-01

This study analyzes the different variability patterns of the Urban Heat Island intensity (UHII) in the Metropolitan Area of Rio de Janeiro (MARJ), one of the largest urban agglomerations in Brazil. The UHII is defined as the difference in the surface air temperature between the urban/suburban and rural/vegetated areas. To choose one or more stations that represent those areas we used the technique of cluster analysis on the air temperature observations from 14 surface weather stations in the MARJ. The cluster analysis aims to classify objects based on their characteristics, gathering similar groups. The results show homogeneity patterns between air temperature observations, with 6 homogeneous groups being defined. Among those groups, one might be a natural choice for the representative urban area (Central station); one corresponds to suburban area (Afonsos station); and another group referred as rural area is compound of three stations (Ecologia, Santa Cruz and Xerém) that are located in vegetated regions. The arithmetic mean of temperature from the three rural stations is taken to represent the rural station temperature. The UHII is determined from these homogeneous groups. The first UHII is estimated from urban and rural temperature areas (Case 1), whilst the second UHII is obtained from suburban and rural temperature areas (Case 2). In Case 1, the maximum UHII occurs in two periods, one in the early morning and the other at night, while the minimum UHII occurs in the afternoon. In Case 2, the maximum UHII is observed during afternoon/night and the minimum during dawn/early morning. This study demonstrates that the stations choice reflects different UHII patterns, evidencing that distinct behaviors of this phenomenon can be identified.

Dynamic analysis and ecological evaluation of urban heat islands in Raipur city, India

NASA Astrophysics Data System (ADS)

Guha, Subhanil; Govil, Himanshu; Mukherjee, Sandip

2017-07-01

Spatial-temporal distribution of the urban heat islands (UHI) and their changes over Raipur city have been analyzed using multitemporal Landsat satellite data from 1995 to 2016. Land surface temperature (LST) was retrieved through a mono-window algorithm. Some selected land use/land cover (LU-LC) indices were analyzed with LST using linear regression. The urban thermal field variance index (UTFVI) was applied to measure the thermal comfort level of the city. Results show that during the observed period, the study area experienced a gradual increasing rate in mean LST (>1% per annum). The UHI developed especially along the north-western industrial area and south-eastern bare land of the city. A difference in mean LST between UHI and non-UHI for different time periods (2.6°C in 1995, 2.85°C in 2006, 3.42°C in 2009, and 3.63°C in 2016) reflects the continuous warming status of the city. The LST map also shows the existence of a few urban hot spots near the industrial areas, metal roofs, and high density transport parking lots, which are more abundant in the north-western part of the city. The UTFVI map associated with UHI indicates that the inner parts of the city are ecologically more comfortable than the outer peripheries.

Air-Quality and Climate Coupling in High Resolution for Urban Heat Island Study

NASA Astrophysics Data System (ADS)

Halenka, T.; Huszar, P.; Belda, M.

2012-04-01

Recent studies show considerable effect of atmospheric chemistry and aerosols on climate on regional and local scale. For the purpose of qualifying and quantifying the magnitude of climate forcing due to atmospheric chemistry/aerosols on regional scale and climate change effects on air-quality the regional climate model RegCM and chemistry/aerosol model CAMx was coupled. Climate change impacts on air-quality have been studied in high resolution of 10km with interactive two-way coupling of the effects of air-quality on climate. The experiments with the couple were performed for EC FP7 project MEGAPOLI assessing the impact of the megacities and industrialized areas on climate. New experiments in high resolution are prepared andsimulated for Urban Heat Island studies within the OP Central Europe Project UHI. Meteorological fields generated by RCM drive CAMx transport, chemistry and a dry/wet deposition. A preprocessor utility was developed for transforming RegCM provided fields to CAMx input fields and format. There is critical issue of the emission inventories available for 10km resolution including the urban hot-spots, TNO emissions are adopted for the experiments. Sensitivity tests switching on/off urban areas emissions are analysed as well. The results for year 2005 are presented and discussed, interactive coupling is compared to study the potential of possible impact of urban air-pollution to the urban area climate.

Modulated heat pulse propagation and partial transport barriers in chaotic magnetic fields

DOE PAGES

del-Castillo-Negrete, Diego; Blazevski, Daniel

2016-04-01

Direct numerical simulations of the time dependent parallel heat transport equation modeling heat pulses driven by power modulation in 3-dimensional chaotic magnetic fields are presented. The numerical method is based on the Fourier formulation of a Lagrangian-Green's function method that provides an accurate and efficient technique for the solution of the parallel heat transport equation in the presence of harmonic power modulation. The numerical results presented provide conclusive evidence that even in the absence of magnetic flux surfaces, chaotic magnetic field configurations with intermediate levels of stochasticity exhibit transport barriers to modulated heat pulse propagation. In particular, high-order islands and remnants of destroyed flux surfaces (Cantori) act as partial barriers that slow down or even stop the propagation of heat waves at places where the magnetic field connection length exhibits a strong gradient. The key parameter ismore » $$\\gamma=\\sqrt{\\omega/2 \\chi_\\parallel}$$ that determines the length scale, $$1/\\gamma$$, of the heat wave penetration along the magnetic field line. For large perturbation frequencies, $$\\omega \\gg 1$$, or small parallel thermal conductivities, $$\\chi_\\parallel \\ll 1$$, parallel heat transport is strongly damped and the magnetic field partial barriers act as robust barriers where the heat wave amplitude vanishes and its phase speed slows down to a halt. On the other hand, in the limit of small $$\\gamma$$, parallel heat transport is largely unimpeded, global transport is observed and the radial amplitude and phase speed of the heat wave remain finite. Results on modulated heat pulse propagation in fully stochastic fields and across magnetic islands are also presented. In qualitative agreement with recent experiments in LHD and DIII-D, it is shown that the elliptic (O) and hyperbolic (X) points of magnetic islands have a direct impact on the spatio-temporal dependence of the amplitude and the time delay

Practical issues for using solar-reflective materials to mitigate urban heat islands

NASA Astrophysics Data System (ADS)

Bretz, Sarah; Akbari, Hashem; Rosenfeld, Arthur

Solar-reflective or high-albedo, alternatives to traditionally absorptive urban surfaces such as rooftops and roadways can reduce cooling energy use and improve urban air quality at almost no cost. This paper presents information to support programs that mitigate urban heat islands with solar-reflective surfaces: estimates of the achievable increase in albedo for a variety of surfaces, issues related to the selection of materials and costs and benefits of using them. As an example, we present data for Sacramento, California. In Sacramento, we estimate that 20% of the 96 square mile area is dark roofing and 10% is dark pavement. Based on the change in albedo that is achievable for these surfaces, the overall albedo of Sacramento could be increased by 18%, a change that would produce significant energy savings and increase comfort within the city. Roofing market data indicate which roofing materials should be targeted for incentive programs. In 1995, asphalt shingle was used for over 65% of residential roofing area in the U.S. and 6% of commercial. Built-up roofing was used for about 5% of residential roofing and about 30% of commercial roofing. Single-ply membranes covered about 9% of the residential roofing area and over 30% of the commercial area. White, solar-reflective alternatives are presently available for these roofing materials but a low- first-cost, solar-reflective alternative to asphalt shingles is needed to capture the sloped-roof market. Since incoming solar radiation has a large non-visible component, solar-reflective materials can also be produced in a variety of colors.

Modeling reduction of the Urban Heat Island effect to counter-act the effects of climate change in densely built-up areas

NASA Astrophysics Data System (ADS)

Andre, Konrad; Zuvela-Aloise, Maja; Lettmayer, Gudrun; Schwaiger, Hannes Peter; Kaltenegger, Ingrid; Bird, David Neil; Woess-Gallasch, Susanne

2017-04-01

The phenomenon of Urban Heat Islands (UHIs) observed in cities, caused by changes in energy balance due to the structural development of the city as well as by sealed surfaces and a lack of vegetation, is expected to strengthen in the future and will further contribute to heat stress, creating an increased need for energy for cooling and ventilation as well as lowering human comfort. Due to a changing climate, rising heat stress, pronounced by an increased intensity or frequency of heat waves, could have far reaching implications for major Austrian cities in the near future. Simultaneous to this expected increasing of the already existing UHI-effect, it is observable, that continuous densification of the core parts of cities is being intensified through implemented traditional urban planning measures. This is particular relevant for high densely populated districts of the city. Several possible counteractions how to address this challenge are already known, partly investigated in urban modeling studies on the effects of modifying the reflective properties of buildings and urban areas for the city of Vienna. On this experience, within the Austrian FFG and KLIEN Smart Cities project JACKY COOL CHECK (Project Nr. 855554), a wide set of measures to reduce heat stress, consisting of e.g. unsealed surfaces, green areas, green roofs, improve reflective properties of different surfaces etc., for the densely built-up residential and business district of Jakomini in the city of Graz/Styria is investigated, to gain decisive data pointing out the peculiarities of UHIs and the potential cooling effects of these target measures for this local specific area. These results serving as a basis for the selection of sustainable measures that will be implemented, in coordination with local stakeholders and considering their interests.

Mass coral bleaching due to unprecedented marine heatwave in Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands).

PubMed

Couch, Courtney S; Burns, John H R; Liu, Gang; Steward, Kanoelani; Gutlay, Tiffany Nicole; Kenyon, Jean; Eakin, C Mark; Kosaki, Randall K

2017-01-01

2014 marked the sixth and most widespread mass bleaching event reported in the Northwestern Hawaiian Islands, home to the Papahānaumokuākea Marine National Monument (PMNM), the world's second largest marine reserve. This event was associated with an unusual basin-scale warming in the North Pacific Ocean, with an unprecedented peak intensity of around 20°C-weeks of cumulative heat stress at Lisianksi Island. In situ bleaching surveys and satellite data were used to evaluate the relative importance of potential drivers of bleaching patterns in 2014, assess the subsequent morality and its effects on coral communities and 3D complexity, test for signs of regional acclimation, and investigate long-term change in heat stress in PMNM. Surveys conducted at four island/atoll (French Frigate Shoals, Lisianski Island, Pearl and Hermes Atoll, and Midway Atoll) showed that in 2014, percent bleaching varied considerably between islands/atolls and habitats (back reef/fore reef and depth), and was up to 91% in shallow habitats at Lisianski. The percent bleaching during the 2014 event was best explained by a combination of duration of heat stress measured by Coral Reef Watch's satellite Degree Heating Week, relative community susceptibility (bleaching susceptibility score of each taxon * the taxon's abundance relative to the total number of colonies), depth and region. Mean coral cover at permanent Lisianski monitoring sites decreased by 68% due to severe losses of Montipora dilatata complex, resulting in rapid reductions in habitat complexity. Spatial distribution of the 2014 bleaching was significantly different from the 2002 and 2004 bleaching events likely due to a combination of differences in heat stress and local acclimatization. Historical satellite data demonstrated heat stress in 2014 was unlike any previous event and that the exposure of corals to the bleaching-level heat stress has increased significantly in the northern PMNM since 1982, highlighting the increasing

Mass coral bleaching due to unprecedented marine heatwave in Papahānaumokuākea Marine National Monument (Northwestern Hawaiian Islands)

PubMed Central

Couch, Courtney S.; Burns, John H. R.; Liu, Gang; Steward, Kanoelani; Gutlay, Tiffany Nicole; Kenyon, Jean; Eakin, C. Mark; Kosaki, Randall K.

2017-01-01

2014 marked the sixth and most widespread mass bleaching event reported in the Northwestern Hawaiian Islands, home to the Papahānaumokuākea Marine National Monument (PMNM), the world’s second largest marine reserve. This event was associated with an unusual basin-scale warming in the North Pacific Ocean, with an unprecedented peak intensity of around 20°C-weeks of cumulative heat stress at Lisianksi Island. In situ bleaching surveys and satellite data were used to evaluate the relative importance of potential drivers of bleaching patterns in 2014, assess the subsequent morality and its effects on coral communities and 3D complexity, test for signs of regional acclimation, and investigate long-term change in heat stress in PMNM. Surveys conducted at four island/atoll (French Frigate Shoals, Lisianski Island, Pearl and Hermes Atoll, and Midway Atoll) showed that in 2014, percent bleaching varied considerably between islands/atolls and habitats (back reef/fore reef and depth), and was up to 91% in shallow habitats at Lisianski. The percent bleaching during the 2014 event was best explained by a combination of duration of heat stress measured by Coral Reef Watch’s satellite Degree Heating Week, relative community susceptibility (bleaching susceptibility score of each taxon * the taxon’s abundance relative to the total number of colonies), depth and region. Mean coral cover at permanent Lisianski monitoring sites decreased by 68% due to severe losses of Montipora dilatata complex, resulting in rapid reductions in habitat complexity. Spatial distribution of the 2014 bleaching was significantly different from the 2002 and 2004 bleaching events likely due to a combination of differences in heat stress and local acclimatization. Historical satellite data demonstrated heat stress in 2014 was unlike any previous event and that the exposure of corals to the bleaching-level heat stress has increased significantly in the northern PMNM since 1982, highlighting the

Turbulent circulation above the surface heat source in stably stratified atmosphere

NASA Astrophysics Data System (ADS)

Kurbatskii, A. F.; Kurbatskaya, L. I.

2016-10-01

The 3-level RANS approach for simulating a turbulent circulation over the heat island in a stably stratified environment under nearly calm conditions is formulated. The turbulent kinetic energy its spectral consumption (dissipation) and the dispersion of turbulent fluctuations of temperature are found from differential equations, thus the correct modeling of transport processes in the interface layer with the counter-gradient heat flux is assured. The three-parameter turbulence RANS approach minimizes difficulties in simulating the turbulent transport in a stably stratified environment and reduces efforts needed for the numerical implementation of the 3-level RANS approach. Numerical simulation of the turbulent structure of the penetrative convection over the heat island under conditions of stably stratified atmosphere demonstrates that the three-equation model is able to predict the thermal circulation induced by the heat island. The temperature distribution, root-mean-square fluctuations of the turbulent velocity and temperature fields and spectral turbulent kinetic energy flux are in good agreement with the experimental data. The model describes such thin physical effects, as a crossing of vertical profiles of temperature of a thermal plume with the formation of the negative buoyancy area testifying to development of the dome-shaped form at the top part of a plume in the form of "hat".

Trend Assessment of Spatio-Temporal Change of Tehran Heat Island Using Satellite Images

NASA Astrophysics Data System (ADS)

Saradjian, M. R.; Sherafati, Sh.

2015-12-01

Numerous investigations on Urban Heat Island (UHI) show that land cover change is the main factor of increasing Land Surface Temperature (LST) in urban areas, especially conversion of vegetation and bare soil to concrete, asphalt and other man-made structures. On the other hand, other human activities like those which cause to burning fossil fuels, that increase the amount of carbon dioxide, may raise temperature in global scale in comparison with small scales (urban areas). In this study, multiple satellite images with different spatial and temporal resolutions have been used to determine Land Surface Temperature (LST) variability in Tehran metropolitan area. High temporal resolution of AVHRR images have been used as the main data source when investigating temperature variability in the urban area. The analysis shows that UHI appears more significant at afternoon and night hours. But the urban class temperature is almost equal to its surrounding vegetation and bare soil classes at around noon. It also reveals that there is no specific difference in UHI intense during the days throughout the year. However, it can be concluded that in the process of city expansion in years, UHI has been grown both spatially and in magnitude. In order to locate land-cover types and relate them to LST, Thematic Mapper (TM) images have been exploited. The influence of elevation on the LST has also been studied, using digital elevation model derived from SRTM database.

An approach to analyzing the intensity of the daytime surface urban heat island effect at a local scale.

PubMed

Xu, Shenlai

2009-04-01

A landscape index LI is proposed to evaluate the intensity of the daytime surface urban heat island (SUHI) effect at a local scale. Three aspects of this landscape index are crucial: the source landscape, the sink landscape, and the contribution of source and sink landscapes to the intensity of the SUHI. Source and sink landscape types are identified using the thermo-band of Landsat 7 with a spatial resolution of 60 m, along with appropriate threshold values for the Normalized Difference Vegetation Index, Modified Normalized Difference Water Index, and Normalized Difference Built-up Index. The landscape index was defined as the ratio of the contributions of the source and sink landscapes to the intensity of the SUHI. The intensity of the daytime SUHI is assessed with the help of the landscape index. Our analysis indicates the landscape index can be used to evaluate and compare the intensity of the daytime SUHI for different areas.

Modification of the Atmospheric Boundary Layer by a Small Island: Observations from Nauru

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Stuart; Hacker, Jorg M.; Cole, Jason N.

2007-03-01

Nauru, a small island in the tropical pacific, generates plumes of clouds that may grow to several hundred km length. This study uses observations to examine the mesoscale disturbance of the marine atmospheric boundary layer by the island that produces these cloud streets. Observations of the surface layer were made from two ships in the vicinity of Nauru and from instruments on the island. The structure of the atmospheric boundary layer over the island was investigated using aircraft flights. Cloud production over Nauru was examined using remote sensing instruments. During the day the island surface layer was warmer than themore » marine surface layer and wind speed was lower than over the ocean. Surface heating forced the growth of a thermal internal boundary layer, above which a street of cumulus clouds formed. The production of clouds resulted in reduced downwelling shortwave irradiance at the island surface. A plume of warm-dry air was observed over the island which extended 15 – 20 km downwind.« less

New York City Impact on Regional Heat Wave

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz, Luis E.; Schoonen, Martin

Abstract Extreme heat events are projected to increase in magnitude and frequency throughout this century due to increasing global temperatures, making it critically important to acquire improved understanding of their genesis and interactions with large cities. This study presents an application of the factor separation method to assess combined impacts of a synoptic scale heat wave, urban land cover, and urban energy and momentum fluxes on temperatures and winds over New York City via use of high resolution simulations (1 km grid spacing) with an urbanized WRF model. Results showed that, while the heat wave had the largest contribution tomore » temperatures (> 8°C), urban surface factors matched it in highly urbanized areas. Surface factors matched this in highly urbanized areas during night and early morning hours, with contributions up to 5°C, when calm land breeze conditions result in a strong urban heat island. Positive interactions between all factors during morning and nighttime indicate urban heat island amplification of up to 4°C during the heat wave. Midtown Manhattan vertical cross-sections, where urban canopies are most dense, showed a change in the sign (from positive to negative) of the contribution of the urban fluxes between night and day below 500 m, possibly due to radiation blocking and increased thermal storage by buildings as well as frictional effects opposing the incoming warm air.« less

New York City Impact on Regional Heat Wave

DOE PAGES

Ortiz, Luis E.; Schoonen, Martin

2018-04-01

Abstract Extreme heat events are projected to increase in magnitude and frequency throughout this century due to increasing global temperatures, making it critically important to acquire improved understanding of their genesis and interactions with large cities. This study presents an application of the factor separation method to assess combined impacts of a synoptic scale heat wave, urban land cover, and urban energy and momentum fluxes on temperatures and winds over New York City via use of high resolution simulations (1 km grid spacing) with an urbanized WRF model. Results showed that, while the heat wave had the largest contribution tomore » temperatures (> 8°C), urban surface factors matched it in highly urbanized areas. Surface factors matched this in highly urbanized areas during night and early morning hours, with contributions up to 5°C, when calm land breeze conditions result in a strong urban heat island. Positive interactions between all factors during morning and nighttime indicate urban heat island amplification of up to 4°C during the heat wave. Midtown Manhattan vertical cross-sections, where urban canopies are most dense, showed a change in the sign (from positive to negative) of the contribution of the urban fluxes between night and day below 500 m, possibly due to radiation blocking and increased thermal storage by buildings as well as frictional effects opposing the incoming warm air.« less

A heat-flow reconnaissance of southeastern Alaska.

USGS Publications Warehouse

Sass, J.H.; Lawver, L.A.; Munroe, R.J.

1985-01-01

Heat flow was measured at nine sites in crystalline and sedimentary rocks of SE Alaska. Seven of the sites, located between 115 and 155 km landward of the Queen Charlotte-Fairweather transform fault, have heat flows significantly higher than the mean in the coastal provinces between Cape Mendocino and the Queen Charlotte Islands, and lower than the mean for 81 values within 100 km of the San Andreas transform fault, even further S. There is no evidence for heat sources that might be associated with late Cainozoic thermal events.-P.Br.

An Evidence-Based Review of Impacts, Strategies and Tools to Mitigate Urban Heat Islands

PubMed Central

Leal Filho, Walter; Echevarria Icaza, Leyre; Emanche, Victoria Omeche; Quasem Al-Amin, Abul

2017-01-01

The impacts of climate changes on cities, which are home to over half of the world’s population, are already being felt. In many cases, the intensive speed with which urban centres have been growing means that little attention has been paid to the role played by climatic factors in maintaining quality of life. Among the negative consequences of rapid city growth is the expansion of the problems posed by urban heat islands (UHIs), defined as areas in a city that are much warmer than other sites, especially in comparison with rural areas. This paper analyses the consistency of the UHI-related literature in three stages: first it outlines its characteristics and impacts in a wide variety of cities around the world, which poses pressures to public health in many different countries. Then it introduces strategies which may be employed in order to reduce its effects, and finally it analyses available tools to systematize the initial high level assessment of the phenomenon for multidisciplinary teams involved in the urban planning process. The analysis of literature on the characteristics, impacts, strategies and digital tools to assess on the UHI, reveals the wide variety of parameters, methods, tools and strategies analysed and suggested in the different studies, which does not always allow to compare or standardize the diagnosis or solutions. PMID:29257100

Calculating Pressure-Driven Current Near Magnetic Islands for 3D MHD Equilibria

NASA Astrophysics Data System (ADS)

Radhakrishnan, Dhanush; Reiman, Allan

2016-10-01

In general, 3D MHD equilibria in toroidal plasmas do not result in nested pressure surfaces. Instead, islands and chaotic regions appear in the equilibrium. Near small magnetic islands, the pressure varies within the flux surfaces, which has a significant effect on the pressure-driven current, introducing singularities. Previously, the MHD equilibrium current near a magnetic island was calculated, including the effect of ``stellarator symmetry,'' wherein the singular components of the pressure-driven current vanish [A. H. Reiman, Phys. Plasmas 23, 072502 (2016)]. Here we first solve for pressure in a cylindrical plasma from the heat diffusion equation, after adding a helical perturbation. We then numerically calculate the corresponding Pfirsch-Schluter current. At the small island limit, we compare the pressure-driven current with the previously calculated solution, and far from the island, we recover the solution for nested flux surfaces. Lastly, we compute the current for a toroidal plasma for symmetric and non-symmetric geometries.

Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs

PubMed Central

Edmondson, J. L.; Stott, I.; Davies, Z. G.; Gaston, K. J.; Leake, J. R.

2016-01-01

Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health. PMID:27641002

Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs.

PubMed

Edmondson, J L; Stott, I; Davies, Z G; Gaston, K J; Leake, J R

2016-09-19

Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health.

Soil surface temperatures reveal moderation of the urban heat island effect by trees and shrubs

NASA Astrophysics Data System (ADS)

Edmondson, J. L.; Stott, I.; Davies, Z. G.; Gaston, K. J.; Leake, J. R.

2016-09-01

Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-sized UK city we buried temperature loggers at the surface of greenspace soils at 100 sites, stratified by proximity to city centre, vegetation cover and land-use. Mean daily soil surface temperature over 11 months increased by 0.6 °C over the 5 km from the city outskirts to the centre. Trees and shrubs in non-domestic greenspace reduced mean maximum daily soil surface temperatures in the summer by 5.7 °C compared to herbaceous vegetation, but tended to maintain slightly higher temperatures in winter. Trees in domestic gardens, which tend to be smaller, were less effective at reducing summer soil surface temperatures. Our findings reveal that the UHI effects soil temperatures at a city-wide scale, and that in their moderating urban soil surface temperature extremes, trees and shrubs may help to reduce the adverse impacts of urbanization on microclimate, soil processes and human health.

Shifting the urban heat island clock in a megacity: a case study of Hong Kong

NASA Astrophysics Data System (ADS)

Chen, Xuan; Jeong, Su-Jong

2018-01-01

With increasing levels of urbanization in the near future, understanding the impact of urbanization on urban heat islands (UHIs) is critical to adapting to regional climate and environmental changes. However, our understanding of the UHI effect relies mainly on its intensity or magnitude. The present study evaluates the impact of urbanization on UHI duration changes by comparing three stations with different rates of urbanization, including highly developed and developing urban areas throughout Hong Kong, from 1990-2015. Results show that the 26 year average UHI intensity in highly urbanized regions is much higher than that in developing areas, and the 26 year average of UHI duration is similar. Over the past 25 years, however, UHI duration has increased only in developing urban areas, from 13.59-17.47 hours. Both earlier UHI starting and later UHI ending times concurrently contribute to the UHI effect being experienced for a longer duration. The differences in UHI duration change between the two areas are supported by population and by night light changes from space. Increasing night light, which suggests enhancements in the economic infrastructure, occurred only in the developing urban areas. Our results suggest that changes in UHI duration should be included in an assessment of regional climate change as well as in urban planning in a megacity.

Functional Analysis of Genes Comprising the Locus of Heat Resistance in Escherichia coli

PubMed Central

Mercer, Ryan; Nguyen, Oanh; Ou, Qixing; McMullen, Lynn

2017-01-01

ABSTRACT The locus of heat resistance (LHR) is a 15- to 19-kb genomic island conferring exceptional heat resistance to organisms in the family Enterobacteriaceae, including pathogenic strains of Salmonella enterica and Escherichia coli. The complement of LHR-comprising genes that is necessary for heat resistance and the stress-induced or growth-phase-induced expression of LHR-comprising genes are unknown. This study determined the contribution of the seven LHR-comprising genes yfdX1GI, yfdX2, hdeDGI, orf11, trxGI, kefB, and psiEGI by comparing the heat resistances of E. coli strains harboring plasmid-encoded derivatives of the different LHRs in these genes. (Genes carry a subscript “GI” [genomic island] if an ortholog of the same gene is present in genomes of E. coli.) LHR-encoded heat shock proteins sHSP20, ClpKGI, and sHSPGI are not sufficient for the heat resistance phenotype; YfdX1, YfdX2, and HdeD are necessary to complement the LHR heat shock proteins and to impart a high level of resistance. Deletion of trxGI, kefB, and psiEGI from plasmid-encoded copies of the LHR did not significantly affect heat resistance. The effect of the growth phase and the NaCl concentration on expression from the putative LHR promoter p2 was determined by quantitative reverse transcription-PCR and by a plasmid-encoded p2:GFP promoter fusion. The expression levels of exponential- and stationary-phase E. coli cells were not significantly different, but the addition of 1% NaCl significantly increased LHR expression. Remarkably, LHR expression in E. coli was dependent on a chromosomal copy of evgA. In conclusion, this study improved our understanding of the genes required for exceptional heat resistance in E. coli and factors that increase their expression in food. IMPORTANCE The locus of heat resistance (LHR) is a genomic island conferring exceptional heat resistance to several foodborne pathogens. The exceptional level of heat resistance provided by the LHR questions the control

Using Cool Roofs to Reduce Energy Use, Greenhouse Gas Emissions, and Urban Heat-island Effects: Findings from an India Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akbari, Hashem; Xu, Tengfang; Taha, Haider

cooling energy in India. Meteorological simulations in this study indicated that a reduction of 2C in air temperature in the Hyderabad area would be likely if a combination of increased surface albedo and vegetative cover are used as urban heat-island control strategies. In addition, air-temperature reductions on the order of 2.5-3.5C could be achieved if moderate and aggressive heat-island mitigation measures are adopted, respectively. A large-scale deployment of mitigation measures can bring additional indirect benefit to the urban area. For example, cooling outside air can improve the efficiency of cooling systems, reduce smog and greenhouse gas (GHG) emissions, and indirectly reduce pollution from power plants - all improving environmental health quality. This study has demonstrated the effectiveness of cool-roof technology as one of the urban heat-island control strategies for the Indian industrial and scientific communities and has provided an estimate of the national energy savings potential of cool roofs in India. These outcomes can be used for developing cool-roof building standards and related policies in India. Additional field studies, built upon the successes and lessons learned from this project, may be helpful to further confirm the scale of potential energy savings from the application of cooler roofs in various regions of India. In the future, a more rigorous meteorological simulation using urbanized (meso-urban) meteorological models should be conducted, which may produce a more accurate estimate of the air-temperature reductions for the entire urban area.« less

Urban heat island effect: A systematic review of spatio-temporal factors, data, methods, and mitigation measures

NASA Astrophysics Data System (ADS)

Deilami, Kaveh; Kamruzzaman, Md.; Liu, Yan

2018-05-01

Despite research on urban heat island (UHI) effect has increased exponentially over the last few decades, a systematic review of factors contributing to UHI effect has scarcely been reported in the literature. This paper provides a systematic and overarching review of different spatial and temporal factors affecting the UHI effect. UHI is a phenomenon when urban areas experience a higher temperature than their surrounding non-urban areas and is considered as a critical factor contributing to global warming, heat related mortalities, and unpredictable climatic changes. Therefore, there is a pressing need to identify the spatio-temporal factors that contribute to (or mitigate) the UHI effect in order to develop a thorough understanding of their causal mechanism so that these are addressed through urban planning policies. This paper systematically identified 75 eligible studies on UHI effect and reviews the nature and type of satellite images used, the techniques applied to classify land cover/use changes, the models to assess the link between spatio-temporal factors and UHI effect, and the effects of these factors on UHI. The review results show that: a) 54% of the studies used Landsat TM images for modelling the UHI effect followed by Landsat ETM (34%), and MODIS (28%); b) land cover indices (46%), followed by supervised classification (17%) were the dominant methods to derive land cover/use changes associated with UHI effect; c) ordinary least square regression is the most commonly applied method (68%) to investigate the link between different spatio-temporal factors and the UHI effect followed by comparative analysis (33%); and d) the most common factors affecting the UHI effect as reported in the reviewed studies, include vegetation cover (44%), season (33%), built-up area (28%), day/night (25%), population density (14%), water body (12%) together with others. This research discusses the findings in policy terms and provides directions for future research.

Urban heat island effect on cicada densities in metropolitan Seoul.

PubMed

Nguyen, Hoa Q; Andersen, Desiree K; Kim, Yuseob; Jang, Yikweon

2018-01-01

Urban heat island (UHI) effect, the ubiquitous consequence of urbanization, is considered to play a major role in population expansion of numerous insects. Cryptotympana atrata and Hyalessa fuscata are the most abundant cicada species in the Korean Peninsula, where their population densities are higher in urban than in rural areas. We predicted a positive relationship between the UHI intensities and population densities of these two cicada species in metropolitan Seoul. To test this prediction, enumeration surveys of cicada exuviae densities were conducted in 36 localities located within and in the vicinity of metropolitan Seoul. Samples were collected in two consecutive periods from July to August 2015. The abundance of each species was estimated by two resource-weighted densities, one based on the total geographic area, and the other on the total number of trees. Multiple linear regression analyses were performed to identify factors critical for the prevalence of cicada species in the urban habitat. C. atrata and H. fuscata were major constituents of cicada species composition collected across all localities. Minimum temperature and sampling period were significant factors contributing to the variation in densities of both species, whereas other environmental factors related to urbanization were not significant. More cicada exuviae were collected in the second rather than in the first samplings, which matched the phenological pattern of cicadas in metropolitan Seoul. Cicada population densities increased measurably with the increase in temperature. Age of residential complex also exhibited a significantly positive correlation to H. fuscata densities, but not to C. atrata densities. Effects of temperature on cicada densities have been discerned from other environmental factors, as cicada densities increased measurably in tandem with elevated temperature. Several mechanisms may contribute to the abundance of cicadas in urban environments, such as higher fecundity

Seasonality of the urban heat island effect: patterns and drivers

NASA Astrophysics Data System (ADS)

Schatz, J.; Kucharik, C. J.

2014-12-01

We conducted a rigorous analysis of the drivers of seasonality in the urban heat island (UHI) effect. Many studies report annual cycles in UHI intensity and have attributed those patterns to various hypotheses, including seasonal trends in wind and clouds, prevalence of anti-cyclonic conditions, soil moisture, and day length. But to our knowledge, those hypotheses have never been tested, leaving a substantial gap in our basic understanding of the urban climate. We tested these and other hypotheses using two years of continuous temperature measurements from an array of 150 sensors in and around Madison, Wisconsin USA, an urban area of 407,000 surrounded by lakes and a rural landscape of agriculture, forests, wetlands, and grasslands. This is one of the best replicated urban climate arrays ever deployed, which allowed us to characterize the UHI in rich spatial and temporal detail and rigorously assess the biophysical and synoptic drivers of its seasonal variation. UHI intensities were typically highest in summer and lowest in winter. Seasonal trends in wind speed and cloud cover generally tracked annual trends in UHI intensity, with the clearer, calmer conditions conducive to stronger UHIs more common in summer. This is consistent with the hypothesis that seasonal trends in wind, clouds, and anti-cyclonic conditions drive UHI seasonality. However, clear, calm summer nights still had higher UHI intensities than clear, calm winter nights, indicating that some background factor shifted baseline UHI intensities throughout the year. We found that regional vegetation and snow cover conditions set distinct seasonal baselines for UHI intensity, with nighttime intensities averaging 4°C in summer and 1°C in winter. Synoptic and biophysical factors that vary on shorter time scales (e.g. wind, clouds, soil moisture, relative humidity) modified daily UHI intensity around those baselines by 1-3°C but were not the primary drivers of UHI seasonality, contrary to the most common

Ober's Island: The Mallard Ober's Island, One of the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Ober's Island: The Mallard - Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

Island Formation: Constructing a Coral Island

ERIC Educational Resources Information Center

Austin, Heather; Edd, Amelia

2009-01-01

The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

Effects of Green Space and Land Use/Land Cover on Urban Heat Island in a Subtropical Mega-city in China

NASA Astrophysics Data System (ADS)

Qiu, G. Y.; Li, X.; Li, H.; Guo, Q.

2014-12-01

With the quick expansion of urban in size and population, its urban heat island intensity (UHII, expressed as the temperature difference between urban and rural areas) increased rapidly. However, very few studies could quantitatively reveal the effects of green space and land use/land cover (LULC) on urban thermal environment because of lacking of the detailed measurement. This study focuses on quantifying the effects of green space and LULC on urban Heat Island (UHI) in Shenzhen, a mega subtropical city in China. Extensive measurements (air temperature and humidity) were made by mobile traverse method in a transect of 8 km in length, where a variety of LULC types were included. Measurements were carried out at 2 hours interval for 2 years (totally repeated for 7011 times). According to LULC types, we selected 5 different LULC types for studying, including water body, village in the city, shopping center (commercial area), urban green space (well-vegetated area) and suburb (forest). The main conclusions are obtained as follows: (1) The temperature difference between the 5 different urban landscapes is obvious, i.e. shopping center > village in the city > urban water body > urban green space > suburb; (2) Air temperature and UHII decreases linearly with the increase of green space in urban; (3) Green space and water body in urban have obvious effects to reduce the air temperature by evapotranspiration. Compared to the commercial areas, urban water body can relieve the IUHI by 0.9℃, while the urban green space can relieve the IUHI by 1.57℃. The cooling effect of the urban green space is better than that of the urban water body; (4) Periodic activity of human being has obvious effects on urban air temperature. The UHII on Saturday and Sunday are higher than that from Monday to Friday, respectively higher for 0.65, 0.57, 0.26 and 0.21℃. Thursday and Friday have the minimum air temperature and UHII. These results indicate that increase in urban evapotranspiration

Habitat and environment of islands: primary and supplemental island sets

USGS Publications Warehouse

Matalas, Nicholas C.; Grossling, Bernardo F.

2002-01-01

The original intent of the study was to develop a first-order synopsis of island hydrology with an integrated geologic basis on a global scale. As the study progressed, the aim was broadened to provide a framework for subsequent assessments on large regional or global scales of island resources and impacts on those resources that are derived from global changes. Fundamental to the study was the development of a comprehensive framework?a wide range of parameters that describe a set of 'saltwater' islands sufficiently large to Characterize the spatial distribution of the world?s islands; Account for all major archipelagos; Account for almost all oceanically isolated islands, and Account collectively for a very large proportion of the total area of the world?s islands whereby additional islands would only marginally contribute to the representativeness and accountability of the island set. The comprehensive framework, which is referred to as the ?Primary Island Set,? is built on 122 parameters that describe 1,000 islands. To complement the investigations based on the Primary Island Set, two supplemental island sets, Set A?Other Islands (not in the Primary Island Set) and Set B?Lagoonal Atolls, are included in the study. The Primary Island Set, together with the Supplemental Island Sets A and B, provides a framework that can be used in various scientific disciplines for their island-based studies on broad regional or global scales. The study uses an informal, coherent, geophysical organization of the islands that belong to the three island sets. The organization is in the form of a global island chain, which is a particular sequential ordering of the islands referred to as the 'Alisida.' The Alisida was developed through a trial-and-error procedure by seeking to strike a balance between 'minimizing the length of the global chain' and 'maximizing the chain?s geophysical coherence.' The fact that an objective function cannot be minimized and maximized simultaneously

Quality and sensitivity of high-resolution numerical simulation of urban heat islands

NASA Astrophysics Data System (ADS)

Li, Dan; Bou-Zeid, Elie

2014-05-01

High-resolution numerical simulations of the urban heat island (UHI) effect with the widely-used Weather Research and Forecasting (WRF) model are assessed. Both the sensitivity of the results to the simulation setup, and the quality of the simulated fields as representations of the real world, are investigated. Results indicate that the WRF-simulated surface temperatures are more sensitive to the planetary boundary layer (PBL) scheme choice during nighttime, and more sensitive to the surface thermal roughness length parameterization during daytime. The urban surface temperatures simulated by WRF are also highly sensitive to the urban canopy model (UCM) used. The implementation in this study of an improved UCM (the Princeton UCM or PUCM) that allows the simulation of heterogeneous urban facets and of key hydrological processes, together with the so-called CZ09 parameterization for the thermal roughness length, significantly reduce the bias (<1.5 °C) in the surface temperature fields as compared to satellite observations during daytime. The boundary layer potential temperature profiles are captured by WRF reasonable well at both urban and rural sites; the biases in these profiles relative to aircraft-mounted senor measurements are on the order of 1.5 °C. Changing UCMs and PBL schemes does not alter the performance of WRF in reproducing bulk boundary layer temperature profiles significantly. The results illustrate the wide range of urban environmental conditions that various configurations of WRF can produce, and the significant biases that should be assessed before inferences are made based on WRF outputs. The optimal set-up of WRF-PUCM developed in this paper also paves the way for a confident exploration of the city-scale impacts of UHI mitigation strategies in the companion paper (Li et al 2014).

Functional Analysis of Genes Comprising the Locus of Heat Resistance in Escherichia coli.

PubMed

Mercer, Ryan; Nguyen, Oanh; Ou, Qixing; McMullen, Lynn; Gänzle, Michael G

2017-10-15

The locus of heat resistance (LHR) is a 15- to 19-kb genomic island conferring exceptional heat resistance to organisms in the family Enterobacteriaceae , including pathogenic strains of Salmonella enterica and Escherichia coli The complement of LHR-comprising genes that is necessary for heat resistance and the stress-induced or growth-phase-induced expression of LHR-comprising genes are unknown. This study determined the contribution of the seven LHR-comprising genes yfdX1 GI , yfdX2 , hdeD GI , orf11 , trx GI , kefB , and psiE GI by comparing the heat resistances of E. coli strains harboring plasmid-encoded derivatives of the different LHRs in these genes. (Genes carry a subscript "GI" [genomic island] if an ortholog of the same gene is present in genomes of E. coli ) LHR-encoded heat shock proteins sHSP20, ClpK GI , and sHSP GI are not sufficient for the heat resistance phenotype; YfdX1, YfdX2, and HdeD are necessary to complement the LHR heat shock proteins and to impart a high level of resistance. Deletion of trx GI , kefB , and psiE GI from plasmid-encoded copies of the LHR did not significantly affect heat resistance. The effect of the growth phase and the NaCl concentration on expression from the putative LHR promoter p2 was determined by quantitative reverse transcription-PCR and by a plasmid-encoded p2:GFP promoter fusion. The expression levels of exponential- and stationary-phase E. coli cells were not significantly different, but the addition of 1% NaCl significantly increased LHR expression. Remarkably, LHR expression in E. coli was dependent on a chromosomal copy of evgA In conclusion, this study improved our understanding of the genes required for exceptional heat resistance in E. coli and factors that increase their expression in food. IMPORTANCE The locus of heat resistance (LHR) is a genomic island conferring exceptional heat resistance to several foodborne pathogens. The exceptional level of heat resistance provided by the LHR questions the

Investigating the vertical dimension of Singapore's urban heat island through quadcopter platforms: an pilot study

NASA Astrophysics Data System (ADS)

Chow, Winston; Ho, Dawn

2016-04-01

In numerous cities, measurements of urban warmth in most urban heat island (UHI) studies are generally constrained towards surface or near-surface (<2 m above surface level) levels across horizontal variations in land use and land cover. However, there has been hitherto limited attention towards the measurement of vertical temperature profiles extending from the urban surface, urban canopy layer through to the urban boundary layer. Knowledge of these profiles, through (a.) how they vary over different local urban morphologies, and (b.) develop with respect to synoptic meteorological conditions, are important towards several aspects of UHI research; these include validating modelling urban canopy lapse rate profiles or estimating the growth of urban plumes. In this novel study, we utilised temperature sensor-loggers attached onto remote controlled aerial quadcopter platforms to measure urban temperature profiles up to 100 m above ground level in Singapore, which is a rapidly urbanizing major tropical metropolis. Three different land use/land cover categories were sampled; a high-rise residential estate, a university campus, and an urban park/green-space. Sorties were flown repeatedly at four different times - sunrise, noon, sunset and midnight. Initial results indicate significant variations in intra-site stability and inversion development between the urban canopy and boundary layers. These profiles are also temporally dynamic, depending on the time of day and larger-scale weather conditions.

Aleutian Islands

NASA Image and Video Library

2014-05-21

Remote, rugged and extraordinarily beautiful, Alaska’s Aleutian Islands are best known for wildlife reserves, military bases, fishing, furs and fog. The sprawling volcanic archipelago was brought into the spotlight by the Russian-supported expedition of Alexey Chirikov and Vitus Bering in 1741, and soon became controlled by the Russian-American Fur Company. In 1867 the United States purchased Alaska, including the Aleutian Islands, from Russia. By 1900 the port in Unalaska was well established as a shipping port for Alaska gold. The archipelago sweeps about 1,200 miles (1,800 km) from the tip of the Alaskan Peninsula to Attu, the most westward island. Four major island groups hold 14 large islands, about 55 smaller islands, and a large number of islets, adding up to roughly 150 islands/islets in total. This chain separates the Bering Sea (north) from the Pacific Ocean (south) and the islands are connected by the Marine Highway Ferry – at least as far as Unalaska. For the most remote islands, such as birding paradise of Attu, the western-most Aleutian Island, travel becomes trickier and relies primarily on custom charter. The Moderate Resolution Imaging Spectroradiometer (MODIS) flew over the region and captured this spectacular true-color image of the eastern Aleutian Islands on May 15, 2014. In this image, the Alaskan Peninsula protrudes from the mainland and sweeps to the southwest. The first set of islands are called the Fox Island group. Unalaska Island is part of this group and can be identified, with some imagination, as an island formed in the shape of a flying cherub, with two arms (peninsulas) outstretched towards the northeast, seemingly reaching for the round “balls” of Akutan and Akun Islands. The smallest islands in the west of the image belong to the group known as the Islands of Four Mountains. The Aleutians continue far to the west of this image. Fog surrounds the Aleutians, stretching from just off the southwestern Alaska mainland to the

Tenarife Island, Canary Island Archipelago, Atlantic Ocean

NASA Technical Reports Server (NTRS)

1991-01-01

Tenarife Island is one of the most volcanically active of the Canary Island archipelago, Atlantic Ocean, just off the NW coast of Africa, (28.5N, 16.5W). The old central caldera, nearly filled in by successive volcanic activity culminating in two stratocones. From those two peaks, a line of smaller cinder cones extend to the point of the island. Extensive gullies dissect the west side of the island and some forests still remain on the east side.

Tenarife Island, Canary Island Archipelago, Atlantic Ocean

NASA Image and Video Library

1991-08-11

Tenarife Island is one of the most volcanically active of the Canary Island archipelago, Atlantic Ocean, just off the NW coast of Africa, (28.5N, 16.5W). The old central caldera, nearly filled in by successive volcanic activity culminating in two stratocones. From those two peaks, a line of smaller cinder cones extend to the point of the island. Extensive gullies dissect the west side of the island and some forests still remain on the east side.

Spatial regression models of park and land-use impacts on the urban heat island in central Beijing.

PubMed

Dai, Zhaoxin; Guldmann, Jean-Michel; Hu, Yunfeng

2018-06-01

Understanding the relationship between urban land structure and land surface temperatures (LST) is important for mitigating the urban heat island (UHI). This paper explores this relationship within central Beijing, an area located within the 2nd Ring Road. The urban variables include the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Build-up Index (NDBI), the area of building footprints, the area of main roads, the area of water bodies and a gravity index for parks that account for both park size and distance. The data are captured over 8 grids of square cells (30 m, 60 m, 90 m, 120 m, 150 m, 180 m, 210 m, 240 m). The research involves: (1) estimating land surface temperatures using Landsat 8 satellite imagery, (2) building the database of urban variables, and (3) conducting regression analyses. The results show that (1) all the variables impact surface temperatures, (2) spatial regressions are necessary to capture neighboring effects, and (3) higher-order polynomial functions are more suitable for capturing the effects of NDVI and NDBI. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessing the relationship between surface urban heat islands and landscape patterns across climatic zones in China.

PubMed

Yang, Qiquan; Huang, Xin; Li, Jiayi

2017-08-24

The urban heat island (UHI) effect exerts a great influence on the Earth's environment and human health and has been the subject of considerable attention. Landscape patterns are among the most important factors relevant to surface UHIs (SUHIs); however, the relationship between SUHIs and landscape patterns is poorly understood over large areas. In this study, the surface UHI intensity (SUHII) is defined as the temperature difference between urban and suburban areas, and the landscape patterns are quantified by the urban-suburban differences in several typical landscape metrics (ΔLMs). Temperature and land-cover classification datasets based on satellite observations were applied to analyze the relationship between SUHII and ΔLMs in 332 cities/city agglomerations distributed in different climatic zones of China. The results indicate that SUHII and its correlations with ΔLMs are profoundly influenced by seasonal, diurnal, and climatic factors. The impacts of different land-cover types on SUHIs are different, and the landscape patterns of the built-up and vegetation (including forest, grassland, and cultivated land) classes have the most significant effects on SUHIs. The results of this study will help us to gain a deeper understanding of the relationship between the SUHI effect and landscape patterns.

Effects of Land Use/Cover Changes and Urban Forest Configuration on Urban Heat Islands in a Loess Hilly Region: Case Study Based on Yan'an City, China.

PubMed

Zhang, Xinping; Wang, Dexiang; Hao, Hongke; Zhang, Fangfang; Hu, Youning

2017-07-26

In this study Yan'an City, a typical hilly valley city, was considered as the study area in order to explain the relationships between the surface urban heat island (SUHI) and land use/land cover (LULC) types, the landscape pattern metrics of LULC types and land surface temperature (LST) and remote sensing indexes were retrieved from Landsat data during 1990-2015, and to find factors contributed to the green space cool island intensity (GSCI) through field measurements of 34 green spaces. The results showed that during 1990-2015, because of local anthropogenic activities, SUHI was mainly located in lower vegetation cover areas. There was a significant suburban-urban gradient in the average LST, as well as its heterogeneity and fluctuations. Six landscape metrics comprising the fractal dimension index, percentage of landscape, aggregation index, division index, Shannon's diversity index, and expansion intensity of the classified LST spatiotemporal changes were paralleled to LULC changes, especially for construction land, during the past 25 years. In the urban area, an index-based built-up index was the key positive factor for explaining LST increases, whereas the normalized difference vegetation index and modified normalized difference water index were crucial factors for explaining LST decreases during the study periods. In terms of the heat mitigation performance of green spaces, mixed forest was better than pure forest, and the urban forest configuration had positive effects on GSCI. The results of this study provide insights into the importance of species choice and the spatial design of green spaces for cooling the environment.

Effects of Land Use/Cover Changes and Urban Forest Configuration on Urban Heat Islands in a Loess Hilly Region: Case Study Based on Yan’an City, China

PubMed Central

Zhang, Xinping; Hao, Hongke; Zhang, Fangfang; Hu, Youning

2017-01-01

In this study Yan’an City, a typical hilly valley city, was considered as the study area in order to explain the relationships between the surface urban heat island (SUHI) and land use/land cover (LULC) types, the landscape pattern metrics of LULC types and land surface temperature (LST) and remote sensing indexes were retrieved from Landsat data during 1990–2015, and to find factors contributed to the green space cool island intensity (GSCI) through field measurements of 34 green spaces. The results showed that during 1990–2015, because of local anthropogenic activities, SUHI was mainly located in lower vegetation cover areas. There was a significant suburban-urban gradient in the average LST, as well as its heterogeneity and fluctuations. Six landscape metrics comprising the fractal dimension index, percentage of landscape, aggregation index, division index, Shannon’s diversity index, and expansion intensity of the classified LST spatiotemporal changes were paralleled to LULC changes, especially for construction land, during the past 25 years. In the urban area, an index-based built-up index was the key positive factor for explaining LST increases, whereas the normalized difference vegetation index and modified normalized difference water index were crucial factors for explaining LST decreases during the study periods. In terms of the heat mitigation performance of green spaces, mixed forest was better than pure forest, and the urban forest configuration had positive effects on GSCI. The results of this study provide insights into the importance of species choice and the spatial design of green spaces for cooling the environment. PMID:28933770

Interannual variations in surface urban heat island intensity and associated drivers in China.

PubMed

Yao, Rui; Wang, Lunche; Huang, Xin; Zhang, Wenwen; Li, Junli; Niu, Zigeng

2018-09-15

The spatial, diurnal and seasonal variations of surface urban heat islands (SUHIs) have been investigated in many places, but we still have limited understanding of the interannual variations of SUHIs and associated drivers. In this study, the interannual variations in SUHI intensity (SUHII, derived from MODIS land surface temperature (LST) data (8-day composites of twice-daily observations), urban LST minus rural) and their relationships with climate variability and urbanization were analyzed in 31 cities in China for the period 2001-2015. Significant increasing trends of SUHII were observed in 71.0%, 58.1%, 25.8% and 54.8% the cities in summer days (SDs), summer nights (SNs), winter days (WDs) and winter nights (WNs), respectively. Pearson's correlation analyses were first performed from a temporal perspective, which were different from a spatial perspective as previous studies. The results showed that the SUHII in SDs and WDs was negatively correlated with the background LST and mean air temperature in most of the cities. The nighttime SUHII in most cities was negatively and positively correlated with total precipitation and total sunshine duration, respectively. Average wind speed has little effect on SUHII. Decreasing vegetation and increased population were the main factors that contributed to the increased SUHII in SDs and SNs, while albedo only influenced the SUHII in WDs. In addition, Pearson's correlation analyses across cities showed that cities with higher decreasing rates of vegetation exhibited higher increasing rates of the SUHII in SDs and WDs. Cities with larger population growth rates do not necessarily have higher increasing rates of SUHII. Copyright © 2018 Elsevier Ltd. All rights reserved.

Canary Islands

NASA Technical Reports Server (NTRS)

1992-01-01

This easterly looking view shows the seven major volcanic islands of the Canary Island chain (28.0N, 16.5W) and offers a unique view of the islands that have become a frequent vacation spot for Europeans. The northwest coastline of Africa, (Morocco and Western Sahara), is visible in the background. Frequently, these islands create an impact on local weather (cloud formations) and ocean currents (island wakes) as seen in this photo.

Communicating the Connection between Climate Change and Heat Health

EPA Pesticide Factsheets

Explore how public health and environmental professionals can effectively communicate and leverage the connections among climate change, the heat island effect, and public health to raise awareness among the public and to promote progress on these issues.

High Spatial Resolution Thermal Infrared Remote Sensing Data for Analysis of the Atlanta, Georgia, Urban Heat Island Effect and Its Impacts on the Environment

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.

2007-01-01

The twenty-first century is the first "urban century" according to the United Nations Development Program. The focus of cities reflects awareness of the growing percentage of the world's population that lives in urban areas. In environmental terms, cities are the original producers of many of the global problems related to waste disposal, air and water pollution, and associated environmental and ecological challenges. Expansion of cities, both in population and areal extent, is a relentless process. In 2000, approximately 3 billion people representing about 40% of the global population, resided in urban areas. Urban population will continue to rise substantially over the next several decades according to UN estimates, and most of this growth will Occur in developing countries. The UN estimates that by 2025, 60% of the world's population will live in urban areas. As a consequence, the number of"megacities" (those cities with populations of 10 million inhabitants or more) will increase by 100 by 2025. Thus, there is a critical need to understand urban areas and what their impacts are on environmental, ecological and hydrologic resources, as well as on the local, regional, and even global climate. One of the more egregious side effects of urbanization is the increase in surface and air temperatures that lead to deterioration in air quality. In the United States, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency in 1997, nearly 300 counties in 34 states will not meet these new air quality standards for ground level ozone. Mitigation of the urban heat island (UHI) effect is actively being evaluated as a possible way to reduce ground ozone levels in cities and assist states in improving air quality. Foremost in the analysis of how the UHI affects air quality and other environmental factors is the use of remote sensing technology and data to characterize urban land covers in sufficient detail to quantifiably measure

Island-Trapped Waves, Internal Waves, and Island Circulation

DTIC Science & Technology

2014-09-30

from the government of Palau to allow us to deliver some water and food to the officers. Governor Patris of Hatohobei State and the Coral Reef ...Island-trapped waves , internal waves , and island circulation T. M. Shaun Johnston Scripps Institution of Oceanography University of California...large islands (Godfrey, 1989; Firing et al., 1999); • Westward propagating eddies and/or Rossby waves encounter large islands and produce boundary

Eco-geomorphic processes that maintain a small coral reef island: Ballast Island in the Ryukyu Islands, Japan

NASA Astrophysics Data System (ADS)

Kayanne, Hajime; Aoki, Kenji; Suzuki, Takuya; Hongo, Chuki; Yamano, Hiroya; Ide, Yoichi; Iwatsuka, Yuudai; Takahashi, Kenya; Katayama, Hiroyuki; Sekimoto, Tsunehiro; Isobe, Masahiko

2016-10-01

Landform changes in Ballast Island, a small coral reef island in the Ryukyu Islands, were investigated by remote sensing analysis and a field survey. The area of the island almost doubled after a mass coral bleaching event in 1998. Coral branches generated by the mass mortality and broken by waves were delivered and stocked on a reef flat and accumulated to expand the area of the island. In 2012 high waves generated by typhoons also changed the island's topography. Overall, the island moved in the downdrift direction of the higher waves. Waves impacting both sides of the island piled up a large volume of coral gravels above the high-tide level. Eco-geomorphic processes, including a supply of calcareous materials from the corals on the same reef especially during stormy wave conditions, were key factors in maintaining the dynamic topographic features of this small coral reef island.

Galapagos Islands

NASA Technical Reports Server (NTRS)

2002-01-01

This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

The oceanic islands - Azores. [geological, geophysical and geochemical features

NASA Technical Reports Server (NTRS)

Ridley, W. I.; Watkins, N. D.; Macfarlane, D. J.

1974-01-01

A presentation is made of the known geological, geophysical, and geochemical data on the Azores. The regional setting of the islands is described; under the geological heading, surface geology and petrochemistry are discussed; and paleomagnetism, marine magnetic surveys, gravity, seismology, and heat flow are treated in the geophysics category. A model for the origin of the Azores is constructed on the basis of these observations.

Ober's Island, One of the Review Islands on Rainy Lake, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Ober's Island, One of the Review Islands on Rainy Lake, bounded on the south by The Hawk Island and on the north by The Crow Island. These islands are located seven miles east of Ranier, Minnesota, three miles west of Voyageur National Park, and one mile south of the international border of the United States of America and Canada. The legal description of Mallard Island is Lot 6, Section 19, T-17-N, R-22-W, Koochiching County, Minnesota, Ranier, Koochiching County, MN

Multidecadal shoreline changes of atoll islands in the Marshall Islands

NASA Astrophysics Data System (ADS)

Ford, M.

2012-12-01

Atoll islands are considered highly vulnerable to the impacts of continued sea level rise. One of the most commonly predicted outcomes of continued sea level rise is widespread and chronic shoreline erosion. Despite the widespread implications of predicted erosion, the decadal scale changes of atoll island shorelines are poorly resolved. The Marshall Islands is one of only four countries where the majority of inhabited land is comprised of reef and atoll islands. Consisting of 29 atolls and 5 mid-ocean reef islands, the Marshall Islands are considered highly vulnerable to the impacts of sea level rise. A detailed analysis of shoreline change on over 300 islands on 10 atolls was undertaken using historic aerial photos (1945-1978) and modern high resolution satellite imagery (2004-2012). Results highlight the complex and dynamic nature of atoll islands, with significant shifts in shoreline position observed over the period of analysis. Results suggest shoreline accretion is the dominant mode of change on the islands studied, often associated with a net increase in vegetated island area. However, considerable inter- and intra-atoll variability exists with regards to shoreline stability. Findings are discussed with respect to island morphodynamics and potential hazard mitigation and planning responses within atoll settings.

The extent and intensity of the urban heat island in Iași city, Romania

NASA Astrophysics Data System (ADS)

Sfîcă, Lucian; Ichim, Pavel; Apostol, Liviu; Ursu, Adrian

2017-10-01

The study underlines the characteristics of the urban heat island of Iași (Iași's UHI) on the basis of 3 years of air temperature measurements obtained by fixed-point observations. We focus on the identification of UHI development and intensity as it is expressed by the temperature differences between the city centre and the rural surroundings. Annual, seasonal and daily characteristics of Iaşi's UHI are investigated at the level of the classical weather observation. In brief, an intensity of 0.8 °C of UHI and a spatial extension which corresponds to the densely built area of the city were delineated. The Iaşi UHI is stronger during summer calm nights—when the inner city is warmer with 2.5-3 °C than the surroundings—and is weaker during windy spring days. The specific features of Iași's UHI bear a profound connection to the specificity of the urban structure, the high atmospheric stability in the region and the local topography. Also, the effects of Iași's UHI upon some environmental aspects are presented as study cases. For instance, under the direct influence of UHI, we have observed that in the city centre, the apricot tree blossoms earlier (with up to 4 days) and the depth of the snow cover is significantly lower (with up to 10 cm for a rural snow depth of 30 cm) than in the surrounding areas.

The Impact of Temporal Aggregation of Land Surface Temperature Data for Urban Heat Island Monitoring

NASA Astrophysics Data System (ADS)

Hu, L.; Brunsell, N. A.

2012-12-01

Temporally composited remote sensing products are widely used in monitoring the urban heat island (UHI). In order to quantify the impact of temporal aggregation for assessing the UHI, we examined MODIS land surface temperature (LST) products for 11 years focusing on Houston, Texas and its surroundings. By using the daily LST from 2000 to 2010, the urban and rural daily LST were presented for the 8-day period and annual comparisons for both day and night. Statistics based on the rural-urban LST differences show that the 8-day composite mean UHI effects are generally more intensive than that calculated by daily UHI images. Moreover, the seasonal pattern shows that the summer daytime UHI has the largest magnitude and variation while nighttime UHI magnitudes are much smaller and less variable. Regression analyses enhance the results showing an apparently higher UHI derived from 8-day composite dataset. The summer mean UHI maps were compared, indicating a land cover related pattern. We introduced yearly MODIS land cover type product to explore the spatial differences caused by temporal aggression of LST product. The mean bias caused by land cover types are calculated about 0.5 ~ 0.7K during the daytime, and less than 0.1K at night. The potential causes of the higher UHI are discussed. The analysis shows that the land-atmosphere interactions, which result in the regional cloud formation, are the primary reason.

Foundation Investigation for Ground Based Radar Project-Kwajalein Island, Marshall Islands

DTIC Science & Technology

1990-04-01

iL_ COPY MISCELLANEOUS PAPER GL-90-5 i iFOUNDATION INVESTIGATION FOR GROUND BASED RADAR PROJECT--KWAJALEIN ISLAND, MARSHALL ISLANDS by Donald E...C!assification) Foundatioa Investigation for Ground Based Radar Project -- Kwajalein Island, Marshall Islands 12. PERSONAL AUTHOR(S) Yule, Donald E...investigation for the Ground Based Radar Project -- Kwajalein Island, Marshall Islands , are presented.- eophysical tests comprised of surface refrac- tion

[Urban heat island intensity and its grading in Liaoning Province of Northeast China].

PubMed

Li, Li-Guang; Wang, Hong-Bo; Jia, Qing-Yu; Lü, Guo-Hong; Wang, Xiao-Ying; Zhang, Yu-Shu; Ai, Jing-Feng

2012-05-01

According to the recorded air temperature data and their continuity of each weather station, the location of each weather station, the numbers of and the distances among the weather stations, and the records on the weather stations migration, several weather stations in Liaoning Province were selected as the urban and rural representative stations to study the characteristics of urban heat island (UHI) intensity in the province. Based on the annual and monthly air temperature data of the representative stations, the ranges and amplitudes of the UHI intensity were analyzed, and the grades of the UHI intensity were classified. The Tieling station, Dalian station, Anshan station, Chaoyang station, Dandong station, and Jinzhou station and the 18 stations including Tai' an station were selected as the representative urban and rural weather stations, respectively. In 1980-2009, the changes of the annual UHI intensity in the 6 representative cities differed. The annual UHI intensity in Tieling was in a decreasing trend, while that in the other five cities was in an increasing trend. The UHI intensity was strong in Tieling but weak in Dalian. The changes of the monthly UHI intensity in the 6 representative cities also differed. The distribution of the monthly UHI intensity in Dandong, Jinzhou and Tieling took a "U" shape, with the maximum and minimum appeared in January and in May-August, respectively, indicating that the monthly UHI intensity was strong in winter and weak in summer. The ranges of the annual and monthly UHI intensity in the 6 cities were 0.57-2.15 degrees C and -0.70-4.60 degrees C, and the ranges of 0.5-2.0 degrees C accounted for 97.8% and 72.3%, respectively. The UHI intensity in the province could be classified into 4 grades, i. e., weak, strong, stronger and strongest.

Examples of cooler reflective streets for urban heat-island mitigation : Portland cement concrete and chip seals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomerantz, M.; Akbari, H.; Chang, S.-C.

Part of the urban heat island effect can be attributed to dark pavements that are commonly used on streets and parking lots. In this paper we consider two light colored, hence cooler, alternative paving materials that are in actual use in cities today. These are Portland cement concrete (PCC) pavements and chip seals. We report measurements of the albedos of some PCC and chip sealed pavements in the San Francisco Bay Area. The albedos of the PCC pavements ranged from about 0.18 to 0.35. The temperatures of some PCC pavements are also measured and calculated. We then consider how themore » albedos of the constituent materials of the PCC (stone, sand and cement) contribute to the albedos of the resulting finished concrete. The albedos of a set of chip sealed pavements in San Jose, CA, were measured and correlated with the times of their placement. It is found that the albedos decrease with age (and use) but remain higher than that of standard asphalt concrete (AC) for about five years. After t hat, the albedos of the chip seals are about 0.12, similar to aged AC. The fact that many PCC pavements have albedos at least twice as high as aged AC suggests that it is possible to have pavement albedos that remain high for many years.« less

Kerguelen Islands

NASA Image and Video Library

2014-05-27

This image from NASA Terra spacecraft shows the Kerguelen Islands also known as the Desolation Islands, which are part of the French Southern and Antarctic lands. The islands are among the most isolated places on Earth.

Streams in the urban heat island: spatial and temporal variability in temperature

USGS Publications Warehouse

Somers, Kayleigh A.; Bernhardt, Emily S.; Grace, James B.; Hassett, Brooke A.; Sudduth, Elizabeth B.; Wang, Siyi; Urban, Dean L.

2013-01-01

Streams draining urban heat islands tend to be hotter than rural and forested streams at baseflow because of warmer urban air and ground temperatures, paved surfaces, and decreased riparian canopy. Urban infrastructure efficiently routes runoff over hot impervious surfaces and through storm drains directly into streams and can lead to rapid, dramatic increases in temperature. Thermal regimes affect habitat quality and biogeochemical processes, and changes can be lethal if temperatures exceed upper tolerance limits of aquatic fauna. In summer 2009, we collected continuous (10-min interval) temperature data in 60 streams spanning a range of development intensity in the Piedmont of North Carolina, USA. The 5 most urbanized streams averaged 21.1°C at baseflow, compared to 19.5°C in the 5 most forested streams. Temperatures in urban streams rose as much as 4°C during a small regional storm, whereas the same storm led to extremely small to no changes in temperature in forested streams. Over a kilometer of stream length, baseflow temperature varied by as much as 10°C in an urban stream and as little as 2°C in a forested stream. We used structural equation modeling to explore how reach- and catchment-scale attributes interact to explain maximum temperatures and magnitudes of storm-flow temperature surges. The best predictive model of baseflow temperatures (R2  =  0.461) included moderately strong pathways directly (extent of development and road density) and indirectly, as mediated by reach-scale factors (canopy closure and stream width), from catchment-scale factors. The strongest influence on storm-flow temperature surges appeared to be % development in the catchment. Reach-scale factors, such as the extent of riparian forest and stream width, had little mitigating influence (R2  =  0.448). Stream temperature is an essential, but overlooked, aspect of the urban stream syndrome and is affected by reach-scale habitat variables, catchment-scale urbanization

Three-Dimensional City Determinants of the Urban Heat Island: A Statistical Approach

NASA Astrophysics Data System (ADS)

Chun, Bum Seok

There is no doubt that the Urban Heat Island (UHI) is a mounting problem in built-up environments, due to the energy retention by the surface materials of dense buildings, leading to increased temperatures, air pollution, and energy consumption. Much of the earlier research on the UHI has used two-dimensional (2-D) information, such as land uses and the distribution of vegetation. In the case of homogeneous land uses, it is possible to predict surface temperatures with reasonable accuracy with 2-D information. However, three-dimensional (3-D) information is necessary to analyze more complex sites, including dense building clusters. Recent research on the UHI has started to consider multi-dimensional models. The purpose of this research is to explore the urban determinants of the UHI, using 2-D/3-D urban information with statistical modeling. The research includes the following stages: (a) estimating urban temperature, using satellite images, (b) developing a 3-D city model by LiDAR data, (c) generating geometric parameters with regard to 2-/3-D geospatial information, and (d) conducting different statistical analyses: OLS and spatial regressions. The research area is part of the City of Columbus, Ohio. To effectively and systematically analyze the UHI, hierarchical grid scales (480m, 240m, 120m, 60m, and 30m) are proposed, together with linear and the log-linear regression models. The non-linear OLS models with Log(AST) as dependent variable have the highest R2 among all the OLS-estimated models. However, both SAR and GSM models are estimated for the 480m, 240m, 120m, and 60m grids to reduce their spatial dependency. Most GSM models have R2s higher than 0.9, except for the 240m grid. Overall, the urban characteristics having high impacts in all grids are embodied in solar radiation, 3-D open space, greenery, and water streams. These results demonstrate that it is possible to mitigate the UHI, providing guidelines for policies aiming to reduce the UHI.

Landscapes of Santa Rosa Island, Channel Islands National Park, California

USGS Publications Warehouse

Schumann, R. Randall; Minor, Scott A.; Muhs, Daniel R.; Pigati, Jeffery S.

2014-01-01

Santa Rosa Island (SRI) is the second-largest of the California Channel Islands. It is one of 4 east–west aligned islands forming the northern Channel Islands chain, and one of the 5 islands in Channel Islands National Park. The landforms, and collections of landforms called landscapes, of Santa Rosa Island have been created by tectonic uplift and faulting, rising and falling sea level, landslides, erosion and deposition, floods, and droughts. Landscape features, and areas delineating groups of related features on Santa Rosa Island, are mapped, classified, and described in this paper. Notable landscapes on the island include beaches, coastal plains formed on marine terraces, sand dunes, and sand sheets. In this study, the inland physiography has been classified into 4 areas based on relief and degree of fluvial dissection. Most of the larger streams on the island occupy broad valleys that have been filled with alluvium and later incised to form steep- to vertical-walled arroyos, or barrancas, leaving a relict floodplain above the present channel. A better understanding of the processes and mechanisms that created these landscapes enhances visitors’ enjoyment of their surroundings and contributes to improving land and resource management strategies in order to optimize and balance the multiple goals of conservation, preservation, restoration, and visitor experience.

Arctic ice islands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.

1988-01-01

The development of offshore oil and gas resources in the Arctic waters of Alaska requires offshore structures which successfully resist the lateral forces due to moving, drifting ice. Ice islands are floating, a tabular icebergs, up to 60 meters thick, of solid ice throughout their thickness. The ice islands are thus regarded as the strongest ice features in the Arctic; fixed offshore structures which can directly withstand the impact of ice islands are possible but in some locations may be so expensive as to make oilfield development uneconomic. The resolution of the ice island problem requires two research steps: (1)more » calculation of the probability of interaction between an ice island and an offshore structure in a given region; and (2) if the probability if sufficiently large, then the study of possible interactions between ice island and structure, to discover mitigative measures to deal with the moving ice island. The ice island research conducted during the 1983-1988 interval, which is summarized in this report, was concerned with the first step. Monte Carlo simulations of ice island generation and movement suggest that ice island lifetimes range from 0 to 70 years, and that 85% of the lifetimes are less then 35 years. The simulation shows a mean value of 18 ice islands present at any time in the Arctic Ocean, with a 90% probability of less than 30 ice islands. At this time, approximately 34 ice islands are known, from observations, to exist in the Arctic Ocean, not including the 10-meter thick class of ice islands. Return interval plots from the simulation show that coastal zones of the Beaufort and Chukchi Seas, already leased for oil development, have ice island recurrences of 10 to 100 years. This implies that the ice island hazard must be considered thoroughly, and appropriate safety measures adopted, when offshore oil production plans are formulated for the Alaskan Arctic offshore. 132 refs., 161 figs., 17 tabs.« less

Perspective View of Umnak Island, Aleutian Islands, Alaska #2

NASA Image and Video Library

2001-11-04

This image is a perspective view acquired by NASA Airborne Synthetic Aperture Radar AIRSAR in 2001, is of Umnak Island, one of Alaska Aleutian Islands. The active Okmok volcano appears in the center of the island.

Perspective View of Umnak Island, Aleutian Islands, Alaska #1

NASA Image and Video Library

2001-11-04

This image is a perspective view acquired by NASA Airborne Synthetic Aperture Radar AIRSAR in 2001, is of Umnak Island, one of Alaska Aleutian Islands. The active Okmok volcano appears in the center of the island.

Ancient ice islands in salt lakes of the Central Andes

USGS Publications Warehouse

Hurlbert, S.H.; Chang, Cecily C.Y.

1984-01-01

Massive blocks of freshwater ice and frozen sediments protrude from shallow, saline lakes in the Andes of southwestern Bolivia and northeastern Chile. These ice islands range up to 1.5 kilometers long, stand up to 7 meters above the water surface, and may extend out tens of meters and more beneath the unfrozen lake sediments. The upper surfaces of the islands are covered with dry white sediments, mostly aragonite or calcite. The ice blocks may have formed by freezing of the fresh pore water of lake sediments during the "little ice age." The largest blocks are melting rapidly because of possibly recent increases in geothermal heat flux through the lake bottom and undercutting by warm saline lake water during the summer.

Historical Temperature Variability Affects Coral Response to Heat Stress

PubMed Central

Carilli, Jessica; Donner, Simon D.; Hartmann, Aaron C.

2012-01-01

Coral bleaching is the breakdown of symbiosis between coral animal hosts and their dinoflagellate algae symbionts in response to environmental stress. On large spatial scales, heat stress is the most common factor causing bleaching, which is predicted to increase in frequency and severity as the climate warms. There is evidence that the temperature threshold at which bleaching occurs varies with local environmental conditions and background climate conditions. We investigated the influence of past temperature variability on coral susceptibility to bleaching, using the natural gradient in peak temperature variability in the Gilbert Islands, Republic of Kiribati. The spatial pattern in skeletal growth rates and partial mortality scars found in massive Porites sp. across the central and northern islands suggests that corals subject to larger year-to-year fluctuations in maximum ocean temperature were more resistant to a 2004 warm-water event. In addition, a subsequent 2009 warm event had a disproportionately larger impact on those corals from the island with lower historical heat stress, as indicated by lower concentrations of triacylglycerol, a lipid utilized for energy, as well as thinner tissue in those corals. This study indicates that coral reefs in locations with more frequent warm events may be more resilient to future warming, and protection measures may be more effective in these regions. PMID:22479626

Characterization Urban Heat Island Effect and Modelling of Secondary Pollutant Formations at Urban Hotspots

NASA Astrophysics Data System (ADS)

Undi, G. S. N. V. K. S. N. S.

2017-12-01

More than 60 percent of the world population is living the urban zones by 2020. This socio of economic transformations will bring considerable changes to the ambient atmosphere. More than 70 percent of the air pollutants in the urban hotspots are from vehicular emissions. in the urban hotspots. In the urban hotspots, the meteorological and dispersion conditions will have different characteristics than in surrounding rural areas. Reactive pollutants transformations are drastically influenced by the local meteorological conditions. The complexity of urban structure alters the pollutants dispersion in the hotspots. This relationship between urban meteorology and air pollution is an important aspect of consideration. In the atmosphere, drastic changes have been noticed from micro to regional and global scales. However, the characteristics of air pollutant emissions vary with time and space, favorable dispersion conditions transport them from local to regional scale. In the present study, the impact of land cover change on Urban Heat Island effect (UHI) has been characterized by considering the three different zones with varying land use patterns. An attempt has been made to estimate the impact of UHI on secondary pollutants (O3) transformations. Envi-Met model has been used to characterize the UHI intensity for the selected zones. Meteorological and air quality measurements were carried out at the selected locations. The diurnal variations of Ozone (O3) concentration for three zones are correlated with the UHI intensity. And the monitoring and model results of O3 concentrations are in good agreement. It is observed from the obtained model results that the metrological parameters influence on local air quality is significant in urban zones.

Urbanization-induced urban heat island and aerosol effects on climate extremes in the Yangtze River Delta region of China

NASA Astrophysics Data System (ADS)

Zhong, Shi; Qian, Yun; Zhao, Chun; Leung, Ruby; Wang, Hailong; Yang, Ben; Fan, Jiwen; Yan, Huiping; Yang, Xiu-Qun; Liu, Dongqing

2017-04-01

The WRF-Chem model coupled with a single-layer urban canopy model (UCM) is integrated for 5 years at convection-permitting scale to investigate the individual and combined impacts of urbanization-induced changes in land cover and pollutant emissions on regional climate in the Yangtze River Delta (YRD) region in eastern China. Simulations with the urbanization effects reasonably reproduced the observed features of temperature and precipitation in the YRD region. Urbanization over the YRD induces an urban heat island (UHI) effect, which increases the surface temperature by 0.53 °C in summer and increases the annual heat wave days at a rate of 3.7 d yr-1 in the major megacities in the YRD, accompanied by intensified heat stress. In winter, the near-surface air temperature increases by approximately 0.7 °C over commercial areas in the cities but decreases in the surrounding areas. Radiative effects of aerosols tend to cool the surface air by reducing net shortwave radiation at the surface. Compared to the more localized UHI effect, aerosol effects on solar radiation and temperature influence a much larger area, especially downwind of the city cluster in the YRD. Results also show that the UHI increases the frequency of extreme summer precipitation by strengthening the convergence and updrafts over urbanized areas in the afternoon, which favor the development of deep convection. In contrast, the radiative forcing of aerosols results in a surface cooling and upper-atmospheric heating, which enhances atmospheric stability and suppresses convection. The combined effects of the UHI and aerosols on precipitation depend on synoptic conditions. Two rainfall events under two typical but different synoptic weather patterns are further analyzed. It is shown that the impact of urban land cover and aerosols on precipitation is not only determined by their influence on local convergence but also modulated by large-scale weather systems. For the case with a strong synoptic forcing

Urbanization-induced urban heat island and aerosol effects on climate extremes in the Yangtze River Delta region of China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Shi; Qian, Yun; Zhao, Chun

The WRF-Chem model coupled with a single-layer urban canopy model (UCM) is integrated for 5 years at convection-permitting scale to investigate the individual and combined impacts of urbanization-induced changes in land cover and pollutant emissions on regional climate in the Yangtze River Delta (YRD) region in eastern China. Simulations with the urbanization effects reasonably reproduced the observed features of temperature and precipitation in the YRD region. Urbanization over the YRD induces an urban heat island (UHI) effect, which increases the surface temperature by 0.53 °C in summer and increases the annual heat wave days at a rate of 3.7 d yr −1 in themore » major megacities in the YRD, accompanied by intensified heat stress. In winter, the near-surface air temperature increases by approximately 0.7 °C over commercial areas in the cities but decreases in the surrounding areas. Radiative effects of aerosols tend to cool the surface air by reducing net shortwave radiation at the surface. Compared to the more localized UHI effect, aerosol effects on solar radiation and temperature influence a much larger area, especially downwind of the city cluster in the YRD. Results also show that the UHI increases the frequency of extreme summer precipitation by strengthening the convergence and updrafts over urbanized areas in the afternoon, which favor the development of deep convection. In contrast, the radiative forcing of aerosols results in a surface cooling and upper-atmospheric heating, which enhances atmospheric stability and suppresses convection. The combined effects of the UHI and aerosols on precipitation depend on synoptic conditions. Two rainfall events under two typical but different synoptic weather patterns are further analyzed. It is shown that the impact of urban land cover and aerosols on precipitation is not only determined by their influence on local convergence but also modulated by large-scale weather systems. For the case with a

Urbanization-induced urban heat island and aerosol effects on climate extremes in the Yangtze River Delta region of China

DOE PAGES

Zhong, Shi; Qian, Yun; Zhao, Chun; ...

2017-04-27

The WRF-Chem model coupled with a single-layer urban canopy model (UCM) is integrated for 5 years at convection-permitting scale to investigate the individual and combined impacts of urbanization-induced changes in land cover and pollutant emissions on regional climate in the Yangtze River Delta (YRD) region in eastern China. Simulations with the urbanization effects reasonably reproduced the observed features of temperature and precipitation in the YRD region. Urbanization over the YRD induces an urban heat island (UHI) effect, which increases the surface temperature by 0.53 °C in summer and increases the annual heat wave days at a rate of 3.7 d yr −1 in themore » major megacities in the YRD, accompanied by intensified heat stress. In winter, the near-surface air temperature increases by approximately 0.7 °C over commercial areas in the cities but decreases in the surrounding areas. Radiative effects of aerosols tend to cool the surface air by reducing net shortwave radiation at the surface. Compared to the more localized UHI effect, aerosol effects on solar radiation and temperature influence a much larger area, especially downwind of the city cluster in the YRD. Results also show that the UHI increases the frequency of extreme summer precipitation by strengthening the convergence and updrafts over urbanized areas in the afternoon, which favor the development of deep convection. In contrast, the radiative forcing of aerosols results in a surface cooling and upper-atmospheric heating, which enhances atmospheric stability and suppresses convection. The combined effects of the UHI and aerosols on precipitation depend on synoptic conditions. Two rainfall events under two typical but different synoptic weather patterns are further analyzed. It is shown that the impact of urban land cover and aerosols on precipitation is not only determined by their influence on local convergence but also modulated by large-scale weather systems. For the case with a

Assessment of Groundwater Resources of Dauphin Island and its Connection to Urban Sprawl and Economic Growth

NASA Astrophysics Data System (ADS)

Petty, K. S.

2009-12-01

Dauphin Island is a barrier island about 28 miles south of Mobile, Alabama. The island relies heavily on the shallow aquifer underlying the barrier island. Worldwide, the largest volume of water used for human consumption and use comes from groundwater resources. On barrier islands such as Dauphin Island, the proportion of water used by humans coming from groundwater resources is even higher. Additionally, tourism is very important to the economy of Dauphin Island, and the hotels and tourist attractions rely on groundwater. Because of the large influx of people there are peaks in water demand during tourist season. The goal of this project is to quantify the impacts of urban growth on the aquifer and provide an estimate for sustainable withdrawal rates. The project will be carried out in two main phases. In the first phase a water resource assessment and analysis will be conducted using the SEAWAT model. SEAWAT simulates three-dimensional variable-density ground-water flow coupled with multi-species solute and heat transport. In the second phase the calibrated groundwater model for the island will be used to perform a scenario analysis which would help link groundwater availability with urban sprawl. In this paper we will describe the research methodology and procedures that will be used in the project.

Validation of a Fast-Response Urban Micrometeorological Model to Assess the Performance of Urban Heat Island Mitigation Strategies

NASA Astrophysics Data System (ADS)

Nadeau, D.; Girard, P.; Overby, M.; Pardyjak, E.; Stoll, R., II; Willemsen, P.; Bailey, B.; Parlange, M. B.

2015-12-01

Urban heat islands (UHI) are a real threat in many cities worldwide and mitigation measures have become a central component of urban planning strategies. Even within a city, causes of UHI vary from one neighborhood to another, mostly due the spatial variability in surface thermal properties, building geometry, anthropogenic heat flux releases and vegetation cover. As a result, the performance of UHI mitigation measures also varies in space. Hence, there is a need to develop a tool to quantify the efficiency of UHI mitigation measures at the neighborhood scale. The objective of this ongoing study is to validate the fast-response micrometeorological model QUIC EnvSim (QES). This model can provide all information required for UHI studies with a fine spatial resolution (up to 0.5m) and short computation time. QES combines QUIC, a CFD-based wind solver and dispersion model, and EnvSim, composed of a radiation model, a land-surface model and a turbulent transport model. Here, high-resolution (1 m) simulations are run over a subset of the École Polytechnique Fédérale de Lausanne (EPFL) campus including complex buildings, various surfaces properties and vegetation. For nearly five months in 2006-07, a dense network of meteorological observations (92 weather stations over 0.1 km2) was deployed over the campus and these unique data are used here as a validation dataset. We present validation results for different test cases (e.g., sunny vs cloudy days, different incoming wind speeds and directions) and explore the effect of a few UHI mitigation strategies on the spatial distribution of near-surface air temperatures. Preliminary results suggest that QES may be a valuable tool in decision-making regarding adaptation of urban planning to UHI.

A microbiological survey of Montserrat Island hydrothermal biotopes.

PubMed

Atkinson, T; Cairns, S; Cowan, D A; Danson, M J; Hough, D W; Johnson, D B; Norris, P R; Raven, N; Robinson, C; Robson, R; Sharp, R J

2000-10-01

In March 1996, a survey of hydrothermal sites on the island of Montserrat was carried out. Six sites (Galway's Soufrière. Gages Upper and Lower Soufrières, Hot Water Pond, Hot River, and Tar River Soufrière) were mapped and sampled for chemical, ATP, and microbial analyses. The hydrothermal Soufrière sites on the slopes of the active Chances Peak volcano exhibited temperatures up to almost 100 degrees C and were generally either mildly acidic at pH 5-7 or strongly acidic at pH 1.5-3, but with some hot streams and pools of low redox potential at pH 7-8. Hot Water Pond sites, comprising a series of heated pools near the western shoreline of the island. were neutral and saline, consistent with subsurface heating of entrained seawater. Biological activity shown by ATP analyses was greatest in near-neutral pH samples and generally decreased as acidity increased. A variety of heterotrophic and chemolithotrophic thermophilic organisms were isolated or observed in enrichment cultures. Most of the bacteria that were obtained in pure culture were familiar acidophiles and neutrophiles, but novel, iron-oxidizing species of Sulfobacillus were revealed. These species included the first mesophilic iron-oxidizing Sulfobacillus strains to be isolated and a strain with a higher maximum growth temperature (65 degrees C) than the previously described moderately thermophilic Sulfobacillus species.

RICO Graduate Student Research Flight: The Island Tail Objective

NASA Astrophysics Data System (ADS)

Small, J. D.; Anderson-Bereznicki, S. D.; Medeiros, B.; Nuijens, L.; Henry, C. K.; O'Donnell, D. M.; Morales, F.; Shen, H.

2005-12-01

addressed with data collected on the island tail include: 1) Are these clouds forced by a heated island effect or another dynamical mechanism? 2) Do islands serve merely as source regions of aerosol which act as nucleation sites? 3) Where in the island tail does rain develop, if at all? A description of the unique learning experience and the educational and scientific benefits of the graduate student research flight island tail objective are outlined and discussed.

75 FR 51098 - Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, Island, San Juan...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-18

..., Washington Maritime National Wildlife Refuge Complex, 715 Holgerson Drive, Sequim, WA 98382. FOR FURTHER...] Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, Island, San Juan, Skagit, and Whatcom Counties, WA AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of availability: draft...

Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama

USGS Publications Warehouse

Hansen, Mark; Sallenger, Asbury H.

2007-01-01

Breaching of barrier islands can adversely impact society by severing infrastructure, destroying private properties, and altering water quality in back bays and estuaries. This study provides a scheme that assesses the relative vulnerability of a barrier island to breach during storms. Dauphin Island, Alabama was selected for this study because it has a well documented history of island breaches and extensive geological and geomorphic data. To assess the vulnerability of the island, we defined several variables contributing to the risk of breaching: island geology, breaching history, and island topography and geomorphology. These variables were combined to form a breaching index (BI) value for cross island computational bins, each bin every 50 m in the alongshore direction. Results suggest the eastern section of Dauphin Island has the lowest risk of breaching with the remaining portion of the island having a moderate to high risk of breaching. Two reaches in the western section of the island were found to be particularly vulnerable due primarily to their minimal cross-sectional dimensions.

78 FR 48668 - PSEG Long Island LLC, Long Island Electric Utility Servco LLC, Long Island Power Authority, Long...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-09

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Docket No. EL13-81-000] PSEG Long Island LLC, Long Island Electric Utility Servco LLC, Long Island Power Authority, Long Island Lighting Company; Notice of Petition for Declaratory Order Take notice that on August 1, 2013, pursuant to Rule 207 of the Federal Energy Regulatory...

A Numerical Study of the Urban Heat Island in the Coastal Tropical City of San Juan, Puerto Rico: Model Validation and Impacts of LCLU Changes

NASA Technical Reports Server (NTRS)

Comarazamy, Daniel E.; Gonzalez, Jorge E.; Luvall, Jeff; Rickman, Douglas L.

2007-01-01

Urban sprawls in tropical locations are rapidly accelerating and it is more evident in islands where a large percentage of the population resides along the coasts. This paper focuses on the analysis of the impacts of land use and land cover for urbanization in the tropical coastal city of San Juan, in the tropical island of Puerto Rico. A mesoscale numerical model, the Regional Atmospheric Modeling System (RAMS), is used to study specific characteristics and patterns of the urban heat island in the San Juan Metropolitan Area (SJMA), the most noticeable urban core of the Caribbean. The research present in this paper makes use of the observations obtained during the airborne San Juan Atlas Mission in two ways. First, surface and rawinsonde data are used to validate the atmospheric model yielding satisfactory results. Second, airborne remote sensing information is used to update the model's surface characteristics to obtain a detailed configuration of the SJMA in order to perform the LCLU changes impact analysis. This analysis showed that the presence of San Juan has an impact reflected in higher air temperatures over the area occupied by the city, with positive values of up to 2.5 C, for the simulations that have specified urban LCLU indexes in the bottom boundary. One interesting result of the impact analysis was the finding of a precipitation disturbance shown as a difference in total accumulated rainfall between simulation with the city and with a potential natural vegetation induced by the presence of the urban area. Model results indicate that the urban-induced cloud formation and precipitation development occur mainly downwind of the city, including the accumulated precipitation. This spatial pattern can be explained by the presence of a-larger urbanized area in the southwest sector of the city, and of the approaching northeasterly trade winds.

Christmas Island, Line Island Group, Pacific Ocean

NASA Technical Reports Server (NTRS)

1990-01-01

Christmas Island (2.0N,158.0W), mid central Pacific Ocean, is considered to be the largest atoll in the world, about 25 km in diameter, and is part of the Line Island Group, a northwest-southeast trending chain of volcanic islands on some of the oldest ocean crust in the Pacific. The lagoon is nearly filled with reef growth leaving only a narrow entrance from the sea and large cocoanut groves are found along the fringes of the lagoon.

Akpatok Island

NASA Image and Video Library

2017-12-08

January 1st, 2001: Description: Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. Source: Landsat 7 To learn more about the Landsat satellite go to: landsat.gsfc.nasa.gov/

Hawaiian Island Archipelago

NASA Image and Video Library

1985-06-24

The entire Hawaiian Island Archipelago (21.5N, 158.0W) is seen in this single view. The islands are a favorite international resort and tourist attraction drawing visitors from all over the world to enjoy the tropical climate, year round beaches and lush island flora. Being volcanic in origin, the islands' offer a rugged landscape and on the big island of Hawaii, there is still an occasional volcanic eruption of lava flows and steam vents.

33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Island. (d) A line drawn from the microwave antenna tower on Edisto Beach charted in approximate position..., SC to Hilton Head Island, SC. (a) A line drawn from the easternmost tip of Folley Island to the... Island. (b) A straight line drawn from the seaward tangent of Folly Island through Folly River Daybeacon...

33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Island. (d) A line drawn from the microwave antenna tower on Edisto Beach charted in approximate position..., SC to Hilton Head Island, SC. (a) A line drawn from the easternmost tip of Folley Island to the... Island. (b) A straight line drawn from the seaward tangent of Folly Island through Folly River Daybeacon...

São Paulo urban heat islands have a higher incidence of dengue than other urban areas.

PubMed

Araujo, Ricardo Vieira; Albertini, Marcos Roberto; Costa-da-Silva, André Luis; Suesdek, Lincoln; Franceschi, Nathália Cristina Soares; Bastos, Nancy Marçal; Katz, Gizelda; Cardoso, Vivian Ailt; Castro, Bronislawa Ciotek; Capurro, Margareth Lara; Allegro, Vera Lúcia Anacleto Cardoso

2015-01-01

Urban heat islands are characterized by high land surface temperature, low humidity, and poor vegetation, and considered to favor the transmission of the mosquito-borne dengue fever that is transmitted by the Aedes aegypti mosquito. We analyzed the recorded dengue incidence in Sao Paulo city, Brazil, in 2010-2011, in terms of multiple environmental and socioeconomic variables. Geographical information systems, thermal remote sensing images, and census data were used to classify city areas according to land surface temperature, vegetation cover, population density, socioeconomic status, and housing standards. Of the 7415 dengue cases, a majority (93.1%) mapped to areas with land surface temperature >28°C. The dengue incidence rate (cases per 100,000 inhabitants) was low (3.2 cases) in high vegetation cover areas, but high (72.3 cases) in low vegetation cover areas where the land surface temperature was 29±2°C. Interestingly, a multiple cluster analysis phenogram showed more dengue cases clustered in areas of land surface temperature >32°C, than in areas characterized as low socioeconomic zones, high population density areas, or slum-like areas. In laboratory experiments, A. aegypti mosquito larval development, blood feeding, and oviposition associated positively with temperatures of 28-32°C, indicating these temperatures to be favorable for dengue transmission. Thus, among all the variables studied, dengue incidence was most affected by the temperature. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Tybee Island 255° true across Tybee Inlet to the shore of Little Tybee Island south of the entrance to... Island to the seaward tangent of Bradley Point on Ossabaw Island. (d) A north-south line (longitude 81°8...-south line (longitude 81°10.6′ W.) drawn from the southernmost extremity of St. Catherines Island to...

33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Tybee Island 255° true across Tybee Inlet to the shore of Little Tybee Island south of the entrance to... Island to the seaward tangent of Bradley Point on Ossabaw Island. (d) A north-south line (longitude 81°8...-south line (longitude 81°10.6′ W.) drawn from the southernmost extremity of St. Catherines Island to...

46 CFR 7.80 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Tybee Island south of the entrance to Buck Hammock Creek. (b) A line drawn from the southernmost... 46 Shipping 1 2011-10-01 2011-10-01 false Tybee Island, GA to St. Simons Island, GA. 7.80 Section... BOUNDARY LINES Atlantic Coast § 7.80 Tybee Island, GA to St. Simons Island, GA. (a) A line drawn from the...

33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Tybee Island 255° true across Tybee Inlet to the shore of Little Tybee Island south of the entrance to... Island to the seaward tangent of Bradley Point on Ossabaw Island. (d) A north-south line (longitude 81°08...-south line (longitude 81°10.6′ W.) drawn from the southernmost extremity of St. Catherines Island to...

46 CFR 7.80 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Tybee Island south of the entrance to Buck Hammock Creek. (b) A line drawn from the southernmost... 46 Shipping 1 2012-10-01 2012-10-01 false Tybee Island, GA to St. Simons Island, GA. 7.80 Section... BOUNDARY LINES Atlantic Coast § 7.80 Tybee Island, GA to St. Simons Island, GA. (a) A line drawn from the...

46 CFR 7.80 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Tybee Island south of the entrance to Buck Hammock Creek. (b) A line drawn from the southernmost... 46 Shipping 1 2014-10-01 2014-10-01 false Tybee Island, GA to St. Simons Island, GA. 7.80 Section... BOUNDARY LINES Atlantic Coast § 7.80 Tybee Island, GA to St. Simons Island, GA. (a) A line drawn from the...

46 CFR 7.80 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Tybee Island south of the entrance to Buck Hammock Creek. (b) A line drawn from the southernmost... 46 Shipping 1 2013-10-01 2013-10-01 false Tybee Island, GA to St. Simons Island, GA. 7.80 Section... BOUNDARY LINES Atlantic Coast § 7.80 Tybee Island, GA to St. Simons Island, GA. (a) A line drawn from the...

33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Tybee Island 255° true across Tybee Inlet to the shore of Little Tybee Island south of the entrance to... Island to the seaward tangent of Bradley Point on Ossabaw Island. (d) A north-south line (longitude 81°08...-south line (longitude 81°10.6′ W.) drawn from the southernmost extremity of St. Catherines Island to...

Hawaiian Island Archipelago

NASA Technical Reports Server (NTRS)

1988-01-01

In this view of the entire Hawaiian Island Archipelago (21.0N, 157.0W), the islands perturb the prevailing northeastewrly winds producing extensive cloud wakes in the lee of the islands. The atmospheric haze within the wake is a result of the near continuous eruptions of Kilauea volcano on the southeast coast of the big island of Hawaii.

Akpatok Island

NASA Technical Reports Server (NTRS)

2002-01-01

Akpatok Island lies in Ungava Bay in northern Quebec, Canada. Accessible only by air, Akpatok Island rises out of the water as sheer cliffs that soar 500 to 800 feet (150 to 243 m) above the sea surface. The island is an important sanctuary for cliff-nesting seabirds. Numerous ice floes around the island attract walrus and whales, making Akpatok a traditional hunting ground for native Inuit people. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on January 22, 2001. Image provided by the USGS EROS Data Center Satellite Systems Branch

Implementation of the Montreal heat response plan during the 2010 heat wave.

PubMed

Price, Karine; Perron, Stéphane; King, Norman

2013-02-11

The objective of this paper is to describe Montreal's heat response plan and its application during the July 2010 heat wave. The Montreal heat response plan is designed to ensure the surveillance of weather and health indicators during the summer season and to coordinate actions to be undertaken during this period to reduce morbidity and mortality due to heat, particularly when weather thresholds are reached or an increase in health indicators is observed. It was developed to coordinate and apply intervention measures on the Island of Montreal and has been in effect since 2004. In the beginning of July 2010, Montreal experienced a heat wave that lasted 5 days. During this period, health indicators such as total mortality, prehospital emergency transports, calls to the health information line and hospital admissions were monitored by the Montreal public health surveillance system. The decision to implement emergency interventions and actions performed by regional and local public health and municipal partners (intervention level) was made following attainment of a predetermined weather threshold and increases in health indicators. The significant increase in daily observed mortality from all causes and in particular people dying at home or in the community prompted the Director of public health to conduct a chart review of all people deceased from July 5 to July 11, 2010 to determine cause of death and underlying health conditions. During the heat wave, there were 304 reported deaths from all causes in Montreal residents, of which 106 were probably or possibly heat-related. Major underlying health conditions in heat-related deaths included cardiovascular problems and mental health illness. Furthermore, in the case of people with mental illness who died during the heat wave, the chart review revealed that many were contacted 24 hours prior to their death by health care professionals, family members, neighbours or friends. Following the 2010 heat wave, the Montreal

Reshaping the Built Environment to Reduce Environmental and Public Health Impacts of Summertime Heat

NASA Astrophysics Data System (ADS)

Rosenthal, J. E.; Bakewell, K.

2005-12-01

Many American cities are experiencing two types of warming trends in their local climate that due to global environmental change, and that due to local environmental change. Over the next five decades, urban areas within temperate regions may warm disproportionately compared to tropical and subtropical zones according to the IPCC Special Report on The Regional Impacts of Climate Change, and the frequency of very hot days in these climates is expected to approximately double for an increase of 2-3°C in the average summer temperature. As well, due to urbanized land-cover, air temperatures in cities can register 2 to 10 degrees F higher than in surrounding rural areas, resulting in a hotter environment, higher energy demand, and accelerated smog formation due to the urban heat island effect. Our previous research analyzed the temperature differences over time between NY Central Park (NYCP) station and 23 metropolitan regional weather stations classified according to distance and level of urbanization, and showed a heat island effect existing in NYC, with mean temperatures in the NYCP Station generally higher than the surrounding stations, ranging from 1.20 C to 3.02 C. A difference of at least 1 C already existed at the beginning of the 20th century between the mean temperature in NYC and its surrounding rural areas, and this difference increased over the twentieth century. Summertime heat can create heat stress and other health consequences for urban residents. In cities around the world, summer heat can lead to elevated mortality and morbidity rates, especially during extreme events. The epidemiological literature has identified factors in the built environment and demographic characteristics that can increase the risk of heat-related mortality. The elderly and people with pre-existing illnesses are especially vulnerable; also, being bedridden, living alone, and having poor access to public transportation or air-conditioned places. During the Chicago 1995 heat wave

Satellite data based approach for the estimation of anthropogenic heat flux over urban areas

NASA Astrophysics Data System (ADS)

Nitis, Theodoros; Tsegas, George; Moussiopoulos, Nicolas; Gounaridis, Dimitrios; Bliziotis, Dimitrios

2017-09-01

Anthropogenic effects in urban areas influence the thermal conditions in the environment and cause an increase of the atmospheric temperature. The cities are sources of heat and pollution, affecting the thermal structure of the atmosphere above them which results to the urban heat island effect. In order to analyze the urban heat island mechanism, it is important to estimate the anthropogenic heat flux which has a considerable impact on the urban energy budget. The anthropogenic heat flux is the result of man-made activities (i.e. traffic, industrial processes, heating/cooling) and thermal releases from the human body. Many studies have underlined the importance of the Anthropogenic Heat Flux to the calculation of the urban energy budget and subsequently, the estimation of mesoscale meteorological fields over urban areas. Therefore, spatially disaggregated anthropogenic heat flux data, at local and city scales, are of major importance for mesoscale meteorological models. The main objectives of the present work are to improve the quality of such data used as input for mesoscale meteorological models simulations and to enhance the application potential of GIS and remote sensing in the fields of climatology and meteorology. For this reason, the Urban Energy Budget concept is proposed as the foundation for an accurate determination of the anthropogenic heat discharge as a residual term in the surface energy balance. The methodology is applied to the cities of Athens and Paris using the Landsat ETM+ remote sensing data. The results will help to improve our knowledge on Anthropogenic Heat Flux, while the potential for further improvement of the methodology is also discussed.

Diomede Islands, Bering Straight

NASA Technical Reports Server (NTRS)

2008-01-01

The Diomede Islands consisting of the western island Big Diomede (also known as Imaqliq, Nunarbuk or Ratmanov Island), and the eastern island Little Diomede (also known as Krusenstern Island or Inaliq), are two rocky islands located in the middle of the Bering Strait between Russia and Alaska. The islands are separated by an international border and the International Date Line which is approximately 1.5 km from each island; you can look from Alaska into tomorrow in Russia. At the closest land approach between the United States, which controls Little Diomede, and Russia, which controls Big Diomede, they are 3 km apart. Little Diomede Island constitutes the Alaskan City of Diomede, while Big Diomede Island is Russia's easternmost point. The first European to reach the islands was the Russian explorer Semyon Dezhnev in 1648. The text of the 1867 treaty finalizing the sale of Alaska uses the islands to designate the border between the two nations.

The image was acquired July 8, 2000, covers an area of 13.5 x 10.8 km, and is located at 65.8 degrees north latitude, 169 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Energy conservation measures for the Charles E. Shea Senior High School, Pawtucket, Rhode Island. Public service report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-07-01

A thermographic audit of a Pawtucket, Rhode Island high school is reported. Conducted with the aid of an infrared camera system, this thermographic study located heat losses not evident to the naked eye. Heat losses were documented and the thermograms analyzed to obtain complete knowledge of the location of all heat losses from the building complex. Each thermogram showed one or more types of heat loss together with the specific section of the building where it occurred. Priorities were assigned to various retrofit processes and a thermographic inspection conducted after retrofitting to confirm its efficacy. The study comprised an analysismore » and recommendations of heat loss and heating system appraisals plus an analysis of roof moisture inspection. Numerous thermograms illustrate the report.« less

The urban heat island of a tropical coastal city: the case of Muscat, Oman

NASA Astrophysics Data System (ADS)

Charabi, Yassine

2010-05-01

preliminary research. The T(u-r) from the mobile measurements show that in the early morning (7 hours after the sunset), the average urban heat island intensity over the year is 3.7°C, which is 0.8°C stronger than the average urban heat intensity calculated from the fixed meteorological stations. The warmest sites of measurements are usually encountered in the canyon streets of the old districts of Muscat. The range between those warmest sites and the coldest one was 5.3°C.

Soil CO2 emissions as a proxy for heat and mass flow assessment, Taupō Volcanic Zone, New Zealand

USGS Publications Warehouse

Bloomberg, S.; Werner, Cynthia A.; Rissmann, C.F.; Mazot, A.; Horton, Travis B.; Gravley, D; Kennedy, B.; Oze, C

2014-01-01

The quantification of heat and mass flow between deep reservoirs and the surface is important for understanding magmatic and hydrothermal systems. Here, we use high-resolution measurement of carbon dioxide flux (φCO2) and heat flow at the surface to characterize the mass (CO2 and steam) and heat released to the atmosphere from two magma-hydrothermal systems. Our soil gas and heat flow surveys at Rotokawa and White Island in the Taupō Volcanic Zone, New Zealand, include over 3000 direct measurements of φCO2 and soil temperature and 60 carbon isotopic values on soil gases. Carbon dioxide flux was separated into background and magmatic/hydrothermal populations based on the measured values and isotopic characterization. Total CO2 emission rates (ΣCO2) of 441 ± 84 t d−1 and 124 ± 18 t d−1were calculated for Rotokawa (2.9 km2) and for the crater floor at White Island (0.3 km2), respectively. The total CO2 emissions differ from previously published values by +386 t d−1 at Rotokawa and +25 t d−1 at White Island, demonstrating that earlier research underestimated emissions by 700% (Rotokawa) and 25% (White Island). These differences suggest that soil CO2 emissions facilitate more robust estimates of the thermal energy and mass flux in geothermal systems than traditional approaches. Combining the magmatic/hydrothermal-sourced CO2 emission (constrained using stable isotopes) with reservoir H2O:CO2mass ratios and the enthalpy of evaporation, the surface expression of thermal energy release for the Rotokawa hydrothermal system (226 MWt) is 10 times greater than the White Island crater floor (22.5 MWt).

Effect of a Stepped Si(100) Surface on the Nucleation Process of Ge Islands

NASA Astrophysics Data System (ADS)

Yesin, M. Yu.; Nikiforov, A. I.; Timofeev, V. A.; Mashanov, V. I.; Tuktamyshev, A. R.; Loshkarev, I. D.; Pchelyakov, O. P.

2018-03-01

Nucleation of Ge islands on a stepped Si(100) surface is studied. It is shown by diffraction of fast electrons that at a temperature of 600°C, constant flux of Si, and deposition rate of 0.652 Å/s, a series of the 1×2 superstructure reflections completely disappears, if the Si (100) substrate deviated by an angle of 0.35° to the (111) face is preliminarily heated to 1000°C. The disappearance of the 1×2 superstructure reflexes is due to the transition from the surface with monoatomic steps to that with diatomic ones. Investigations of the Ge islands' growth were carried out on the Si(100) surface preliminarily annealed at temperatures of 800 and 1000°C. It is shown that the islands tend to nucleate at the step edges.

Norfolk Island, Australia

NASA Image and Video Library

2015-05-13

Situated 1670 km northeast of Sydney, Norfolk Island is an Australian Territory. It was permanently settled in 1856 by Pitcairn Islanders who were descendants of Tahitians and HMS Bounty mutineers. In 1979 Norfolk was granted limited self-government: the island elects a government that runs most of the island's affairs. In March, a local council replaced the local government, and the island was given closer financial ties to Australia. The image was acquired November 12, 2009, covers an area of 9 x 11 km, and is located at 29 degrees south, 168 degrees east. http://photojournal.jpl.nasa.gov/catalog/PIA19463

Hydrologic data for Block Island, Rhode Island

USGS Publications Warehouse

Burns, Emily

1993-01-01

This report was compiled as part of a study to assess the hydrogeology and the quality and quantity of fresh ground water on Block Island, Rhode Island. Hydrologic data were collected on Block Island during 1988-91. The data are pre- sented in illustrations and tables. Data collec- ted include precipitation, surfae-water, ground- water, lithologic, and well-construction and dis- charge information. Precipitation data include total monthly precipitation values from 11 rain gages and water-quality analyses of 14 precipi- tation samples from one station. Surface-water data include water-level measurements at 12 ponds, water-quality data for five ponds, and field specific-conductance measurements at 56 surface- water sites (streams, ponds, and springs). Ground- water data include water-level measurements at 159 wells, water-quality data at 150 wells, and field specific-conductance data at 52 wells. Lithologic logs for 375 wells and test borings, and construc- tion and location data for 570 wells, springs, and test borings are included. In addition, the data set contains data on water quality of water samples, collected by the Rhode Island Department of Health during 1976-91, from Fresh and Sands Ponds and from wells at the Block Island Water Company well field north of Sands Pond.

Inverter Anti-Islanding with Advanced Grid Support in Single- and Multi-Inverter Islands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoke, Andy

As PV and other DER systems are connected to the grid at increased penetration levels, island detection may become more challenging for two reasons: 1. In islands containing many DERs, active inverter-based anti-islanding methods may have more difficulty detecting islands because each individual inverter's efforts to detect the island may be interfered with by the other inverters in the island. 2. The increasing numbers of DERs are leading to new requirements that DERs ride through grid disturbances and even actively try to regulate grid voltage and frequency back towards nominal operating conditions. These new grid support requirements may directly ormore » indirectly interfere with anti-islanding controls. This report describes a series of tests designed to examine the impacts of both grid support functions and multi-inverter islands on anti-islanding effectiveness.« less

Applications of HCMM satellite data to the study of urban heating patterns

NASA Technical Reports Server (NTRS)

Carlson, T. N. (Principal Investigator)

1980-01-01

A research summary is presented and is divided into two major areas, one developmental and the other basic science. In the first three sub-categories are discussed: image processing techniques, especially the method whereby surface temperature image are converted to images of surface energy budget, moisture availability and thermal inertia; model development; and model verification. Basic science includes the use of a method to further the understanding of the urban heat island and anthropogenic modification of the surface heating, evaporation over vegetated surfaces, and the effect of surface heat flux on plume spread.

Island wake produced by Antipodes Islands south of New Zealand

NASA Image and Video Library

1973-12-16

SL4-137-3655 (16 Dec. 1973) --- An island wake produced by the Antipodes Islands in the ocean current south of New Zealand is seen in this photograph taken from the Skylab space station in Earth orbit. A Skylab 4 crewmen took the picture with a hand-held 70mm Hasselblad camera. The bow wave pattern is quite evident and can be used to determine the current speed from the angle of the bow wave if the propagation speed of the surface wave is known. Also, evident is the darker band extending downstream from the island tens of miles. This is the actual wake of the island. The existence of water color differences from within to outside a turbulent island wake may indicate a temperature difference, with cooler water being stirred to the surface in the wake. This temperature difference could be used to drive a thermo-electric type generator to reduce small islands' dependence on imported oil for power generation. Photo credit: NASA

Ogasawara Islands, Japan

NASA Image and Video Library

2012-11-12

This image, acquired by NASA Terra spacecraft, is of the volcanic Ogasawara Islands. The islands were listed as a UNESCO World Heritage site, in recognition of an outstanding example of ongoing evolutionary processes in oceanic island ecosystems.

78 FR 63860 - Amendment of Class D Airspace; Kwajalein Island, Marshall Islands, RMI

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-25

...This action amends the Kwajalein Island Class D airspace description by amending the geographic coordinates for Bucholz Army Airfield (AAF), Kwajalein Island, Marshall Islands, RMI. The Bucholz AAF geographic coordinates information was updated in the Kwajalein Island Class E airspace descriptions in 2011, but was inadvertently overlooked in the Kwajalein Island Class D airspace description. This action ensures the safety of aircraft operating in the Kwajalein Island airspace area. This is an administrative action and does not affect the operating requirements of the airspace.

Canary Island Archipelago

NASA Technical Reports Server (NTRS)

1989-01-01

This nearly vertical view of the Canary Archipelago (28.5N, 16.5W) shows five of the seven islands: Grand Canary, Tenerife, Gomera, Hierro and La Palma. The largest island in view is Tenerife. Island cloud wakes evident in this photo are the result of southerly winds giving rise to cloud banks on the lee side especially on Tenerife which has the highest volcanic peaks. Island water wakes and internal waves are also evident but not as apparent.

Falkland Islands, UK

NASA Technical Reports Server (NTRS)

1991-01-01

This view of the Falkland Islands (52.0S, 58.5W) was taken with a dual camera mount. Compare this scene with STS048-109-043 to analyze the unique properties of each film type. Seldom seen cloud free, the Falkland Islands lie off the southern coast of Argentina. The cold Falklands Ocean Current keeps the islands chilly, ideal for sheep herding and fishing, the two main industries. Colonies of seals and penguins also thrive on the islands.

Geothermal surveys in the oceanic volcanic island of Mauritius

NASA Astrophysics Data System (ADS)

Verdoya, Massimo; Chiozzi, Paolo; Pasqua, Claudio

2017-04-01

Oceanic island chains are generally characterised by young volcanic systems that are predominately composed of basaltic lavas and related magmatic products. Although hot springs are occasionally present, the pervasive, massive, recent outpourings of basaltic lavas are the primary manifestation of the existence of geothermal resources. These islands may have, in principle, significant potential for the exploitation of geothermal energy. In this paper, we present results of recent investigations aimed at the evaluation of geothermal resources of the island of Mauritius, that is the emerging portion of a huge submarine, aseismic, volcanic plateau extending in the SW part of the Indian Ocean. The plateau is related to a long-lived hotspot track, whose present-day expression is the active volcano of La Réunion Island, located about 200 km SW of Mauritius. The island does not show at present any volcanic activity, but magmatism is quite recent as it dates from 7.8 to 0.03 Myr. Geochemical data from water samples collected from boreholes do not indicate the presence of mature water, i.e. circulating in high-temperature geothermal reservoirs, and argue for short-term water-rock interaction in shallow hydrogeological circuits. However, this cannot rule out that a deep magmatic heat source, hydraulically insulated from shallow aquifers, may occur. To evaluate the geothermal gradient, a 270-m-deep hole was thus drilled in the island central portion, in which the most recent volcanic activity (0.03 Myr) took place. Temperature-depth profiles, recorded after complete thermal equilibration, revealed a thermal gradient of 40 mK/m. Attempts of extracting additional thermal information were also made by measuring the temperature in a 170-m-deep deep water hole, no longer used. The results were consistent with the gradient hole, i.e. pointing to a weak or null deep-seated thermal anomaly beneath Mauritius and low geothermal potential. The deep thermal process (mantle plume) invoked

33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tybee Island, GA to St. Simons..., GA to St. Simons Island, GA. (a) A line drawn from the southernmost extremity of Savannah Beach on....4′ W.) drawn from the southernmost extremity of Ossabaw Island to St. Catherines Island. (e) A north...

Non-native megaherbivores: the case for novel function to manage plant invasions on islands

PubMed Central

Hansen, Dennis M.

2015-01-01

There is a heated debate about whether all non-native species are ‘guilty until proven innocent’, or whether some should be accepted or even welcomed. Further fanning the flames, I here present a case where introductions of carefully vetted, non-native species could provide a net conservation benefit. On many islands, native megaherbivores (flightless birds, tortoises) recently went extinct. Here, rewilding with carefully selected non-native species as ecological replacements is increasingly considered a solution, reinstating a herbivory regime that largely benefits the native flora. Based on these efforts, I suggest that restoration practitioners working on islands without a history of native megaherbivores that are threatened by invasive plants should consider introducing a non-native island megaherbivore, and that large and giant tortoises are ideal candidates. Such tortoises would be equally useful on islands where eradication of invasive mammals has led to increased problems with invasive plants, or on islands that never had introduced mammalian herbivores, but where invasive plants are a problem. My proposal may seem radical, but the reversibility of using giant tortoises means that nothing is lost from trying, and that indeed much is to be gained. As an easily regulated adaptive management tool, it represents an innovative, hypothesis-driven ‘innocent until proven guilty’ approach. PMID:26194166

Energy Transition Initiative: Island Energy Snapshot - U.S. Virgin Islands (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2015-03-01

This profile provides a snapshot of the energy landscape of the U.S. Virgin Islands (USVI) - St. Thomas, St. John, and St. Croix. The Virgin Islands archipelago makes up the northern portion of the Lesser Antilles and the western island group of the Leeward Islands, forming the border between the Atlantic Ocean and the Caribbean Sea.

Contextual view of Treasure Island from Yerba Buena Island, showing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Contextual view of Treasure Island from Yerba Buena Island, showing Palace of Fine and Decorative Arts (Building 3), far right, Hall of Transportation (Building 2), middle, and The Administration Building (Building 1), far left, Port of Trade Winds is in foreground, camera facing northwest - Golden Gate International Exposition, Treasure Island, San Francisco, San Francisco County, CA

Withdrawal of ground water and pond water on Long Island from 1904 to 1949

USGS Publications Warehouse

Lusczynski, Norbert J.

1950-01-01

For more than 50 years the highly productive and readily replenishable water-bearing sands and gravels on Long Island -- capable of yielding an average of at least 1,000 million gallons a day -- and also some surface streams and ponds have been utilized on a large scale of public water supply and industrial, agricultural and domestic uses. During the drought months of 1949, when many surface and groundwater supplied were being depleted at an alarming rate in many localities in the Northeast, the abundant water resources of Long Island provided sufficient water for public water supply for a large number of private companies and municipalities, as well as for large emergency drafts by the City of New York. In addition they kept industrial concerns from curtailing production, saved millions of dollars of potato, cauliflower, and other Long Island crops, and even furnished, during the summer heat, comfort cooling and theatergoers.

Vegetation Monitoring by Remote Sensing Technology for Uninhabited Islands of the Xisha Islands

NASA Astrophysics Data System (ADS)

Li, L.; Guo, Y.; Wu, X.

2018-04-01

The Xisha islands are tropical coral islands in the south sea of China, with special ecological environment. As far away from the inland, they are more sensitive to climate change than inland, and are looked as the window to reflect global environment changes. Since Sansha city established, some of islands were developed. The uninhabited islands are decreasing. To discover the changes of uninhabited islands become more impending. In order to find out the natural status of uninhabited islands, monitoring four years vegetation change of 2002, 2010, 2013 and 2016. In addition, monitoring the typical uninhabited island and sandbar vegetation by making the most of existed high resolution remote sensing data, nine years from 2002 to 2013 and six months in 2012. The results show that the sandbars are in stable growth stage, especially after 2010, the vegetation start appeared. Meanwhile, analysis the vegetation variation of the uninhabited islands and sandbars.

The status of island scrub oak (Quercus pacifica on Catalina Island, California

Treesearch

Denise A. Knapp

2002-01-01

The island scrub oak is characterized by a shrubby (to 2 meters) or arborescent (to 5 meters or taller) growth form. It is the dominant species of the scrub oak chaparral community on Catalina Island, which occupies approximately 25 percent of the 76 square-mile island, primarily on north-facing slopes. The Santa Catalina Island Conservancy, which owns and manages 88...

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Folly Island, SC to Hilton Head Island, SC. 7.70 Section... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...′ W. (Port Royal Sound Lighted Whistle Buoy “2PR”); thence to the easternmost extremity of Hilton Head...

Spatio-Temporal Analysis of Urban Heat Island and Urban Metabolism by Satellite Imagery over the Phoenix Metropolitan Area

NASA Astrophysics Data System (ADS)

Zhao, Q.; Zhan, S.; Kuai, X.; Zhan, Q.

2015-12-01

The goal of this research is to combine DMSP-OLS nighttime light data with Landsat imagery and use spatio-temporal analysis methods to evaluate the relationships between urbanization processes and temperature variation in Phoenix metropolitan area. The urbanization process is a combination of both land use change within the existing urban environment as well as urban sprawl that enlarges the urban area through the transformation of rural areas to urban structures. These transformations modify the overall urban climate environment, resulting in higher nighttime temperatures in urban areas compared to the surrounding rural environment. This is a well-known and well-studied phenomenon referred to as the urban heat island effect (UHI). What is unknown is the direct relationship between the urbanization process and the mechanisms of the UHI. To better understand this interaction, this research focuses on using nighttime light satellite imagery to delineate and detect urban extent changes and utilizing existing land use/land cover map or newly classified imagery from Landsat to analyze the internal urban land use variations. These data are combined with summer and winter land surface temperature data extracted from Landsat. We developed a time series of these combined data for Phoenix, AZ from 1992 to 2013 to analyze the relationships among land use change, land surface temperature and urban growth.

Habitat islands and the equilibrium theory of island biogeography: testing some predictions

USGS Publications Warehouse

Brown, M.; Dinsmore, J.J.

1988-01-01

Species-area data from a study of marsh birds are used to test five predictions generated by the equilibrium theory of island biogeography. Three predictions are supported: we found a significant species-area relationship, a non-zero level of turnover, and a variance-mean ratio of 0.5. One prediction is rejected: the extinction rates were not greater on small islands. The results of one test are equivocal: the number of species on each island was not always the same. As Gilbert (1980) suggests, a strong species-area relationship alone does not validate the theory. The avian communities we studied were on habitat islands, not true islands, and underwent complete extinction annually. Thus caution must be used before applying the theory to these and other habitat islands.

Real-Time Thermal Mapping for Heat & Cool Archipelagos of Bengaluru, India

NASA Astrophysics Data System (ADS)

Gopinath, Rajesh; Banerjee, Aditya; Sachin, S.; Tiwari, Prakhar; Wilson, Sunny

2017-12-01

Blessed with a salubrious climate, the city of Bengaluru over the past few decades has constantly witnessed thermal discomfort owing to several Urban Heat islands that have mushroomed within the city. The subsequent increase in builtup area, consequent loss of productive agricultural lands/green zones, encroachment of surface water bodies coupled with the ill-preparedness of decision makers to handle the demand for land have invariably crumbled the natural micro-climate of the city. In this present research, an attempt has been made to detect the distribution of Urban Heat Islands in Bengaluru City by conducting real-time survey at 100 observatories marked across the entire urban & rural locations; with thermohygrometers as per the W.M.O. guidelines. The study confirmed the violation of the Human Thermal Comfort Range in 9, 83, 98, 99, 98 and 80 observatories for the monitoring at 6 AM, 9 AM, 12 PM, 3 PM, 6 PM and 9 PM respectively.

Determining Heat Waves from Observations and COSMO-CLM Simulations in Istanbul

NASA Astrophysics Data System (ADS)

Yuruk, Cemre; Unal, Yurdanur; Irem Bilgen, Simge; Topcu, Sema; Mentes, Sibel

2016-04-01

km resolution between 1970 and 2005 and the verifications of the heat waves are carried out in terms of the intensity, duration and spatial extent. It is found that urban heat island increases the frequency of hot-days at the urbanized areas of Istanbul. This work is supported by TUBITAK project, number 114Y047. Keywords: Heat waves, Istanbul, local climate, COSMO-CLM, urban heat island

50 CFR Appendix E to Part 622 - Caribbean Island/Island Group Management Areas

Code of Federal Regulations, 2013 CFR

2013-10-01

..., AND SOUTH ATLANTIC Pt. 622, App. E Appendix E to Part 622—Caribbean Island/Island Group Management... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Caribbean Island/Island Group Management... St. Thomas/St. John island group to Point C C 18°13′59.0606″ 65°05′33.058″ D 18°01′16.9636″ 64°57′38...

Maintenance of biodiversity on islands.

PubMed

Chisholm, Ryan A; Fung, Tak; Chimalakonda, Deepthi; O'Dwyer, James P

2016-04-27

MacArthur and Wilson's theory of island biogeography predicts that island species richness should increase with island area. This prediction generally holds among large islands, but among small islands species richness often varies independently of island area, producing the so-called 'small-island effect' and an overall biphasic species-area relationship (SAR). Here, we develop a unified theory that explains the biphasic island SAR. Our theory's key postulate is that as island area increases, the total number of immigrants increases faster than niche diversity. A parsimonious mechanistic model approximating these processes reproduces a biphasic SAR and provides excellent fits to 100 archipelago datasets. In the light of our theory, the biphasic island SAR can be interpreted as arising from a transition from a niche-structured regime on small islands to a colonization-extinction balance regime on large islands. The first regime is characteristic of classic deterministic niche theories; the second regime is characteristic of stochastic theories including the theory of island biogeography and neutral theory. The data furthermore confirm our theory's key prediction that the transition between the two SAR regimes should occur at smaller areas, where immigration is stronger (i.e. for taxa that are better dispersers and for archipelagos that are less isolated). © 2016 The Author(s).

A comprehensive approach for the simulation of the Urban Heat Island effect with the WRF/SLUCM modeling system: The case of Athens (Greece)

NASA Astrophysics Data System (ADS)

Giannaros, Christos; Nenes, Athanasios; Giannaros, Theodore M.; Kourtidis, Konstantinos; Melas, Dimitrios

2018-03-01

This study presents a comprehensive modeling approach for simulating the spatiotemporal distribution of urban air temperatures with a modeling system that includes the Weather Research and Forecasting (WRF) model and the Single-Layer Urban Canopy Model (SLUCM) with a modified treatment of the impervious surface temperature. The model was applied to simulate a 3-day summer heat wave event over the city of Athens, Greece. The simulation, using default SLUCM parameters, is capable of capturing the observed diurnal variation of urban temperatures and the Urban Heat Island (UHI) in the greater Athens Area (GAA), albeit with systematic biases that are prominent during nighttime hours. These biases are particularly evident over low-intensity residential areas, and they are associated with the surface and urban canopy properties representing the urban environment. A series of sensitivity simulations unravels the importance of the sub-grid urban fraction parameter, surface albedo, and street canyon geometry in the overall causation and development of the UHI effect. The sensitivities are then used to determine optimal values of the street canyon geometry, which reproduces the observed temperatures throughout the simulation domain. The optimal parameters, apart from considerably improving model performance (reductions in mean temperature bias from 0.30 °C to 1.58 °C), are also consistent with actual city building characteristics - which gives confidence that the model set-up is robust, and can be used to study the UHI in the GAA in the anticipated warmer conditions in the future.

A study on dynamic heat assisted magnetization reversal mechanisms under insufficient reversal field conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Y. J.; Yang, H. Z.; Leong, S. H.

2014-10-20

We report an experimental study on the dynamic thermomagnetic (TM) reversal mechanisms at around Curie temperature (Tc) for isolated 60 nm pitch single-domain [Co/Pd] islands heated by a 1.5 μm spot size laser pulse under an applied magnetic reversal field (Hr). Magnetic force microscopy (MFM) observations with high resolution MFM tips clearly showed randomly trapped non-switched islands within the laser irradiated spot after dynamic TM reversal process with insufficient Hr strength. This observation provides direct experimental evidence by MFM of a large magnetization switching variation due to increased thermal fluctuation/agitation over magnetization energy at the elevated temperature of around Tc. The averagemore » percentage of non-switched islands/magnetization was further found to be inversely proportional to the applied reversal field Hr for incomplete magnetization reversal when Hr is less than 13% of the island coercivity (Hc), showing an increased switching field distribution (SFD) at elevated temperature of around Tc (where main contributions to SFD broadening are from Tc distribution and stronger thermal fluctuations). Our experimental study and results provide better understanding and insight on practical heat assisted magnetic recording (HAMR) process and recording performance, including HAMR writing magnetization dynamics induced SFD as well as associated DC saturation noise that limits areal density, as were previously observed and investigated by theoretical simulations.« less

Reunion Island Volcano Erupts

NASA Technical Reports Server (NTRS)

2002-01-01

On January 16, 2002, lava that had begun flowing on January 5 from the Piton de la Fournaise volcano on the French island of Reunion abruptly decreased, marking the end of the volcano's most recent eruption. These false color MODIS images of Reunion, located off the southeastern coast of Madagascar in the Indian Ocean, were captured on the last day of the eruption (top) and two days later (bottom). The volcano itself is located on the southeast side of the island and is dark brown compared to the surrounding green vegetation. Beneath clouds (light blue) and smoke, MODIS detected the hot lava pouring down the volcano's flanks into the Indian Ocean. The heat, detected by MODIS at 2.1 um, has been colored red in the January 16 image, and is absent from the lower image, taken two days later on January 18, suggesting the lava had cooled considerably even in that short time. Earthquake activity on the northeast flank continued even after the eruption had stopped, but by January 21 had dropped to a sufficiently low enough level that the 24-hour surveillance by the local observatory was suspended. Reunion is essentially all volcano, with the northwest portion of the island built on the remains of an extinct volcano, and the southeast half built on the basaltic shield of 8,630-foot Piton de la Fournaise. A basaltic shield volcano is one with a broad, gentle slope built by the eruption of fluid basalt lava. Basalt lava flows easily across the ground remaining hot and fluid for long distances, and so they often result in enormous, low-angle cones. The Piton de la Fournaise is one of Earth's most active volcanoes, erupting over 150 times in the last few hundred years, and it has been the subject of NASA research because of its likeness to the volcanoes of Mars. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

Modeling Catastrophic Barrier Island Dynamics

NASA Astrophysics Data System (ADS)

Whitley, J. W.; McNamara, D.

2012-12-01

Barrier islands, thin strips of sand lying parallel to the mainland coastline, along the U.S. Atlantic and Gulf Coasts appear to have maintained their form for thousands of years in the face of rising sea level. The mechanisms that allow barrier islands to remain robust are transport of sediment from the ocean side of barriers to the top and backside during storms, termed island overwash, and the growth and alongshore propagation of tidal deltas near barrier island inlets. Dynamically these processes provide the necessary feedbacks to maintain a barrier island in an attractor that withstands rising sea level within a phase space of barrier island geometrical characteristics. Current barrier island configurations along the Atlantic and Gulf coasts exist among a wide range of storm climate and underlying geologic conditions and therefore the environment that forces overwash and tidal delta dynamics varies considerably. It has been suggested that barrier islands in certain locations such as those between Avon and Buxton (losing 76% of island width since 1852) and Chandeleur islands (losing 85% of its surface area since 2005) along the Atlantic and Gulf coasts, respectively, may be subject to a catastrophic shift in barrier island attractor states - more numerous inlets cutting barriers in some locations and the complete disappearance of barrier islands in other locations. In contrast to common models for barrier islands that neglect storm dynamics and often only consider cross-shore response, we use an alongshore extended model for barrier island dynamics including beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms to explore the response of barrier islands to a wide range of environmental forcing. Results will be presented that show how barrier island attractor states are altered with variations in the rate of sea level rise, storminess, and underlying geology. We will

Effects of urban form on the urban heat island effect based on spatial regression model.

PubMed

Yin, Chaohui; Yuan, Man; Lu, Youpeng; Huang, Yaping; Liu, Yanfang

2018-09-01

The urban heat island (UHI) effect is becoming more of a concern with the accelerated process of urbanization. However, few studies have examined the effect of urban form on land surface temperature (LST) especially from an urban planning perspective. This paper used spatial regression model to investigate the effects of both land use composition and urban form on LST in Wuhan City, China, based on the regulatory planning management unit. Landsat ETM+ image data was used to estimate LST. Land use composition was calculated by impervious surface area proportion, vegetated area proportion, and water proportion, while urban form indicators included sky view factor (SVF), building density, and floor area ratio (FAR). We first tested for spatial autocorrelation of urban LST, which confirmed that a traditional regression method would be invalid. A spatial error model (SEM) was chosen because its parameters were better than a spatial lag model (SLM). The results showed that urban form metrics should be the focus for mitigation efforts of UHI effects. In addition, analysis of the relationship between urban form and UHI effect based on the regulatory planning management unit was helpful for promoting corresponding UHI effect mitigation rules in practice. Finally, the spatial regression model was recommended to be an appropriate method for dealing with problems related to the urban thermal environment. Results suggested that the impact of urbanization on the UHI effect can be mitigated not only by balancing various land use types, but also by optimizing urban form, which is even more effective. This research expands the scientific understanding of effects of urban form on UHI by explicitly analyzing indicators closely related to urban detailed planning at the level of regulatory planning management unit. In addition, it may provide important insights and effective regulation measures for urban planners to mitigate future UHI effects. Copyright © 2018 Elsevier B.V. All

Spatiotemporal trends of urban heat island effect along the urban development intensity gradient in China.

PubMed

Zhou, Decheng; Zhang, Liangxia; Hao, Lu; Sun, Ge; Liu, Yongqiang; Zhu, Chao

2016-02-15

Urban heat island (UHI) represents a major anthropogenic modification to the Earth system and its relationship with urban development is poorly understood at a regional scale. Using Aqua MODIS data and Landsat TM/ETM+ images, we examined the spatiotemporal trends of the UHI effect (ΔT, relative to the rural reference) along the urban development intensity (UDI) gradient in 32 major Chinese cities from 2003 to 2012. We found that the daytime and nighttime ΔT increased significantly (p<0.05, mostly in linear form) along a rising UDI for 27 and 30 out of 32 cities, respectively. More rapid increases were observed in the southeastern and northwestern parts of China in the day and night, respectively. Moreover, the ΔT trends differed greatly by season and during daytime in particular. The ΔT increased more rapidly in summer than in winter during the day and the reverse occurred at night for most cities. Inter-annually, the ΔT increased significantly in about one-third of the cities during both the day and night times from 2003 to 2012, especially in suburban areas (0.25

46 CFR 7.80 - Tybee Island, GA to St. Simons Island, GA.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Tybee Island, GA to St. Simons Island, GA. 7.80 Section... BOUNDARY LINES Atlantic Coast § 7.80 Tybee Island, GA to St. Simons Island, GA. (a) A line drawn from the...′ N. longitude 81°02.3′ W. (St. Catherines Sound Buoy “St. C.”); thence to latitude 31°31.2′ N...

Time series decomposition of remotely sensed land surface temperature and investigation of trends and seasonal variations in surface urban heat islands

NASA Astrophysics Data System (ADS)

Quan, Jinling; Zhan, Wenfeng; Chen, Yunhao; Wang, Mengjie; Wang, Jinfei

2016-03-01

Previous time series methods have difficulties in simultaneous characterization of seasonal, gradual, and abrupt changes of remotely sensed land surface temperature (LST). This study proposed a model to decompose LST time series into trend, seasonal, and noise components. The trend component indicates long-term climate change and land development and is described as a piecewise linear function with iterative breakpoint detection. The seasonal component illustrates annual insolation variations and is modeled as a sinusoidal function on the detrended data. This model is able to separate the seasonal variation in LST from the long-term (including gradual and abrupt) change. Model application to nighttime Moderate Resolution Imaging Spectroradiometer (MODIS)/LST time series during 2000-2012 over Beijing yielded an overall root-mean-square error of 1.62 K between the combination of the decomposed trend and seasonal components and the actual MODIS/LSTs. LST decreased (~ -0.086 K/yr, p < 0.1) in 53% of the study area, whereas it increased with breakpoints in 2009 (~0.084 K/yr before and ~0.245 K/yr after 2009) between the fifth and sixth ring roads. The decreasing trend was stronger over croplands than over urban lands (p < 0.05), resulting in an increasing trend in surface urban heat island intensity (SUHII, 0.022 ± 0.006 K/yr). This was mainly attributed to the trends in urban-rural differences in rainfall and albedo. The SUHII demonstrated a concave seasonal variation primarily due to the seasonal variations of urban-rural differences in temperature cooling rate (related to canyon structure, vegetation, and soil moisture) and surface heat dissipation (affected by humidity and wind).

Green or blue spaces? Assessment of the effectiveness and costs to mitigate the urban heat island in a Latin American city

NASA Astrophysics Data System (ADS)

Targino, Admir Créso; Coraiola, Guilherme Conor; Krecl, Patricia

2018-06-01

We measured air temperature at 14 sites with different land cover composition within the urban canopy layer of a mid-sized Brazilian city. The intensity (ΔT) of the urban heat island (UHI) was calculated using data collected above a lake and at an urban park as references. We investigated the spatio-temporal variability of ΔT during four contiguous days with varying weather. The first day was overcast and rainy, giving rise to a moderate UHI. The second day was sunny, which caused the diurnal ΔT fields to become heterogeneous, due to larger heating rates at sites with more man-made surfaces compared to natural surfaces. A high-pressure system observed on the last days brought cloudless skies, causing smaller ΔT during the day and greater at night. We hypothesise that the effect was due to the reduction of cooling via evapotranspiration caused by closing of the stomata as the soil dried out, which reduced the daytime temperature differences among the sites. The night-time effect was caused by stronger radiative cooling due to clear skies. The temperature within the park was always lower than over the lake, confirming that urban forestry is a more effective mechanism to combat the UHI. Introducing a park would be about sevenfold cheaper than building a city pond. Hence, green spaces are not only more efficient to combat the UHI but it is also a cheaper strategy compared to blue spaces. Moreover, vegetation delivers other benefits, such as removal of air pollutants, attenuation of urban noise, improvement of city aesthetic and their use as recreational spaces.

Bardsey Island, Wales

NASA Image and Video Library

2016-12-01

Lying 3 km off the Llyn peninsula of Wales, the Bardsey Island is known as the Island of 20,000 saints. While today's permanent population numbers only four, the island was once an important religious site, with a 6th century monastery. It is the legendary burial site of King Arthur. Another legend holds that anyone who died on the island would not go to hell. The image was acquired April 4, 2006, covers an area of 6 by 10 km, and is located at 52.7 degrees north, 4.8 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA21182

Remote Sensing of the Urban Heat Island Effect: Assessment of Risks to Human Health and Development of Mitigation Strategies for Sustainable Cities

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Luvall, Jeffrey C.; Rickman, Douglas L.; Estes, Maurice G., Jr.; Laymon, Charles A.; Crosson, William; Howell, Burgess F.; Gillani, Noor V.; Arnold, James E. (Technical Monitor)

2001-01-01

The growth of cities, both in population and in areal extent, appears as an inexorable process. Urbanization continues at a rapid rate, and it is estimated that by the year 2025, 80% of the world's population will live in cities. One of the more egregious side effects of urbanization is the deterioration in air quality as a result of increased vehicular traffic, industrialization and related activities. In the United States alone, under the more stringent air quality guidelines established by the U.S. Environmental Protection Agency (EPA) in 1997, nearly 300 counties in 34 states will not meet the new air quality standards for ground level ozone. The mitigation of one the physical/environmental characteristics of urbanization known as the urban heat island (UHI) effect, is now being looked at more closely as a possible way to bring down ground level ozone levels in cities and assist states in improving air quality. The UHI results from the replacement of "natural" land covers (e.g., trees, grass) with urban land surface types, such as pavement and buildings. Heat stored in these surfaces is released into the air and results in a "dome" of elevated air temperatures that presides over cities. The effect of this dome of elevated air temperatures is known as the UHI, which is most prevalent about 2-3 hours after sunset on days with intense solar radiation and calm winds. Given the local and regional impacts of the UHI, there are significant potential affects on human health, particularly as related to heat stress and ozone on body temperature regulation and on the cardiovascular and respiratory systems. In this study we are using airborne and satellite remote sensing data to analyze how differences in the urban landscape influence or drive the development of the UHI over four U.S. cities. Additionally, we are assessing what the potential impact is on risks to human health, and developing mitigation strategies to make urban areas more environmentally sustainable.

Floating stones off El Hierro, Canary Islands: xenoliths of pre-island sedimentary origin in the early products of the October 2011 eruption

NASA Astrophysics Data System (ADS)

Troll, V. R.; Klügel, A.; Longpré, M.-A.; Burchardt, S.; Deegan, F. M.; Carracedo, J. C.; Wiesmaier, S.; Kueppers, U.; Dahren, B.; Blythe, L. S.; Hansteen, T. H.; Freda, C.; Budd, D. A.; Jolis, E. M.; Jonsson, E.; Meade, F. C.; Harris, C.; Berg, S. E.; Mancini, L.; Polacci, M.; Pedroza, K.

2012-03-01

A submarine eruption started off the south coast of El Hierro, Canary Islands, on 10 October 2011 and continues at the time of this writing (February 2012). In the first days of the event, peculiar eruption products were found floating on the sea surface, drifting for long distances from the eruption site. These specimens, which have in the meantime been termed "restingolites" (after the close-by village of La Restinga), appeared as black volcanic "bombs" that exhibit cores of white and porous pumice-like material. Since their brief appearance, the nature and origin of these "floating stones" has been vigorously debated among researchers, with important implications for the interpretation of the hazard potential of the ongoing eruption. The "restingolites" have been proposed to be either (i) juvenile high-silica magma (e.g. rhyolite), (ii) remelted magmatic material (trachyte), (iii) altered volcanic rock, or (iv) reheated hyaloclastites or zeolite from the submarine slopes of El Hierro. Here, we provide evidence that supports yet a different conclusion. We have analysed the textures and compositions of representative "restingolites" and compared the results to previous work on similar rocks found in the Canary Islands. Based on their high-silica content, the lack of igneous trace element signatures, the presence of remnant quartz crystals, jasper fragments and carbonate as well as wollastonite (derived from thermal overprint of carbonate) and their relatively high oxygen isotope values, we conclude that "restingolites" are in fact xenoliths from pre-island sedimentary layers that were picked up and heated by the ascending magma, causing them to partially melt and vesiculate. As they are closely resembling pumice in appearance, but are xenolithic in origin, we refer to these rocks as "xeno-pumice". The El Hierro xeno-pumices hence represent messengers from depth that help us to understand the interaction between ascending magma and crustal lithologies beneath the

Coastal management strategy for small island: ecotourism potency development in Karimata Island, West Kalimantan

NASA Astrophysics Data System (ADS)

Rudiastuti, A. W.; Munawaroh; Setyawan, I. E.; Pramono, G. H.

2018-04-01

Sustainable coastal management is playing an important role in coastal resources conservation, particularly on small islands. Karimata archipelago has unique characteristics and great potential to be developed as a tourism object, one of which is Karimata Island as the largest island and also reserve area. The concept of ecotourism focuses on the ecology conservation, economic benefits, and social life. Ecotourism aims to build sustainable tourism that provides economically viable and social benefits to the community. This study aims to develop coastal management strategy based on ecotourism at Karimata Island. Spatial approaching through coastal type was done. Qualitative descriptive analysis and SWOT are used to develop sustainable management strategies for the coast of Karimata Island, where the opportunities and challenges to the development of coastal ecotourism Karimata Island also included. If this potential is optimally utilized, it can be relied as an economic opportunity for local communities. Structurally shaped coast, marine depositional coast and coast build by organism are several of coastal types found at Karimata Island. Coastal ecosystems inhabited Karimata Island are mangroves, coral reefs, and macro-algae. Karimata Island have not been optimally utilized for tourist destinations. The biggest obstacle encountered is the accessibility from Kalimantan or other island at Karimata islands. Several problems related to the utilization of coastal resources were found such as mangrove and coral reef damage, also regulation that less supportive. The results of this study are expected to provide an overview of solutions for the development of coastal tourism potentials in Karimata Island.

Mesospheric heating due to intense tropospheric convection

NASA Technical Reports Server (NTRS)

Taylor, L. L.

1979-01-01

A series of rocket measurements made twice daily at Wallops Island, Va., revealed a rapid heating of the mesosphere on the order of 10 K on days when thunderstorms or squall lines were in the area. This heating is explained as the result of frictional dissipation of vertically propagating internal gravity waves generated by intense tropospheric convection. Ray-tracing theory is used to determine the spectrum of gravity wave groups that actually reach mesospheric heights. This knowledge is used in an equation describing the spectral energy density of a penetrative convective element to calculate the fraction of the total energy initially available to excite those waves that do reach the level of heating. This value, converted into a vertical velocity, is used as the lower boundary condition for a multilayer model used to determine the detailed structure of the vertically propagating waves. The amount of frictional dissipation produced by the waves is calculated from the solutions of the frictionless model by use of a vertically varying eddy viscosity coefficient. The heating produced by the dissipation is then calculated from the thermodynamic equation.

Canary Islands

NASA Image and Video Library

2012-01-03

NASA image acquired December 21, 2011 The rugged landscape of the Canary Islands stood out in sharp contrast to the smooth blue waters of the Atlantic Ocean and the flat tan land of northwestern Africa on December 21, 2011, when the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite captured this true-color image. The Canary Islands are a group of seven large islands and several smaller islets, all volcanic in origin. The eastern edge of the chain lies only 100 kilometers from the coasts of Morocco and Western Sahara, and the chain stretches for about 500 kilometers across the Atlantic. All the islands are mountainous, and Tenerife, the central island in this image is home to Pico de Teinde, the highest peak, which rises 12,198 feet (3,718 meters) above sea level. From east to west, the islands are named Lanzarote, Fuerteventura, Gran Canaria, Tenerife, La Gomera, La Palmera and El Hierro. A bright swirl of peacock blue marks the ocean south of El Hierro, a stain on the sea from an ongoing eruption of a volcano under the waters. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Surface Heat Balance Analysis of Tainan City on March 6, 2001 Using ASTER and Formosat-2 Data

PubMed Central

Kato, Soushi; Yamaguchi, Yasushi; Liu, Cheng-Chien; Sun, Chen-Yi

2008-01-01

The urban heat island phenomenon occurs as a mixed result of anthropogenic heat discharge, decreased vegetation, and increased artificial impervious surfaces. To clarify the contribution of each factor to the urban heat island, it is necessary to evaluate the surface heat balance. Satellite remote sensing data of Tainan City, Taiwan, obtained from Terra ASTER and Formosat-2 were used to estimate surface heat balance in this study. ASTER data is suitable for analyzing heat balance because of the wide spectral range. We used Formosat-2 multispectral data to classify the land surface, which was used to interpolate some surface parameters for estimating heat fluxes. Because of the high spatial resolution of the Formosat-2 image, more roads, open spaces and small vegetation areas could be distinguished from buildings in urban areas; however, misclassifications of land cover in such areas using ASTER data would overestimate the sensible heat flux. On the other hand, the small vegetated areas detected from the Formosat-2 image slightly increased the estimation of latent heat flux. As a result, the storage heat flux derived from Formosat-2 is higher than that derived from ASTER data in most areas. From these results, we can conclude that the higher resolution land coverage map increases accuracy of the heat balance analysis. Storage heat flux occupies about 60 to 80% of the net radiation in most of the artificial surface areas in spite of their usages. Because of the homogeneity of the building roof materials, there is no contrast between the storage heat flux in business and residential areas. In sparsely vegetated urban areas, more heat is stored and latent heat is smaller than that in the forested suburbs. This result implies that density of vegetation has a significant influence in decreasing temperatures. PMID:27873856

Effect of magnetic islands on the localization of kinetic Alfvén wave

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rai, Rajesh Kumar, E-mail: rajanraj.rai7@gmail.com; Sharma, Swati, E-mail: swati.sharma704@gmail.com; Yadav, Nitin

2015-12-15

Recent studies have revealed an intimate link between magnetic reconnection and turbulence. Observations show that kinetic Alfvén waves (KAWs) play a very crucial role in magnetic reconnection and have been a topic of interest from decades in the context of turbulence and particle heating. In the present paper, we study the role that KAW plays in the formation of coherent structures/current sheets when KAW is propagating in the pre-existing fully developed chain of magnetic islands. We derived the dynamical equation of KAW in the presence of chain of magnetic islands and solved it using numerical simulations well as analytic tools.more » Due to pre-existing chain of magnetic islands, KAW splits into coherent structures and the scale size of these structures along transverse directions (with respect to background magnetic field) comes out to be either less than or greater than ion gyro radius. Therefore, the present work may be the first step towards understanding how magnetic reconnection generated islands may affect the KAW localization and eventually contribute to magnetic turbulence. In this way the present approach may be helpful to understand the interplay between magnetic reconnection and turbulence in ion diffusion region.« less

Disturbed island ecology.

PubMed

Whittaker, R J

1995-10-01

The natural occurrence of significant disturbances to the operation of insular ecosystems has tended to be downplayed in the development of island ecological theory. Despite the importance of events such as Hurricane Hugo, which in 1989 affected islands in the Caribbean, islands that are disturbed tend to be viewed as deviants from the `true path' described by equilibrium models. However, particularly with organisms of long generation times, it is questionable whether such models are applicable. This may be as important for wildlife managers to take account of as for theorists. Disturbance regime should be incorporated into island ecological models alongside other ecological factors structuring colonization patterns and turnover.

Islander: A database of precisely mapped genomic islands in tRNA and tmRNA genes

DOE PAGES

Hudson, Corey M.; Lau, Britney Y.; Williams, Kelly P.

2014-11-05

Genomic islands are mobile DNAs that are major agents of bacterial and archaeal evolution. Integration into prokaryotic chromosomes usually occurs site-specifically at tRNA or tmRNA gene (together, tDNA) targets, catalyzed by tyrosine integrases. This splits the target gene, yet sequences within the island restore the disrupted gene; the regenerated target and its displaced fragment precisely mark the endpoints of the island. We applied this principle to search for islands in genomic DNA sequences. Our algorithm identifies tDNAs, finds fragments of those tDNAs in the same replicon and removes unlikely candidate islands through a series of filters. A search for islandsmore » in 2168 whole prokaryotic genomes produced 3919 candidates. The website Islander (recently moved to http://bioinformatics.sandia.gov/islander/) presents these precisely mapped candidate islands, the gene content and the island sequence. The algorithm further insists that each island encode an integrase, and attachment site sequence identity is carefully noted; therefore, the database also serves in the study of integrase site-specificity and its evolution.« less

Geochemical investigation of the hydrothermal system on Akutan Island, Alaska, July 2012

USGS Publications Warehouse

Bergfeld, D.; Lewicki, Jennifer L.; Evans, William C.; Hunt, Andrew G.; Revesz, Kinga; Huebner, Mark

2014-01-01

We have studied the geochemistry of the hot springs on Akutan Island in detail for the first time since the early 1980s. Springs in four discrete groups (A-D) along Hot Springs Creek showed generally higher temperatures and substantially higher Na, Ca, and Cl concentrations than previously reported, and total hot-spring discharge has also increased markedly. The springs now account for a heat output of ~29 MW, about an order of magnitude more than in 1981. Gas samples from the hot springs and from a fumarolic area on the flank of Akutan Volcano show high 3He/4He ratios (>6.4 RA) after correction for air contamination and reveal a common magmatic heat source. Hot-spring gases are unusually rich in N2, Ar, and CH4, suggesting that the water has boiled and lost CO2 during upflow beneath the flank fumarole field. Gas geothermometry calculations applied to the flank fumarole field implies temperatures of 200–240 °C for the reservoir, and Na-K-Ca geothermometry implies temperatures near 180 °C for the outflow waters that feed the hot springs. The results of our study confirm the existence of a substantial geothermal resource on the island.

46 CFR 7.85 - St. Simons Island, GA to Little Talbot Island, FL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false St. Simons Island, GA to Little Talbot Island, FL. 7.85... BOUNDARY LINES Atlantic Coast § 7.85 St. Simons Island, GA to Little Talbot Island, FL. (a) A line drawn from latitude 31°04.1′ N. longitude 81°16.7′ W. (St. Simons Lighted Whistle Buoy “ST S”) to latitude 30...

Impact of urbanization-related land use land cover changes and urban morphology changes on the urban heat island phenomenon.

PubMed

Zhou, Xuefan; Chen, Hong

2018-04-24

Urban growth and development caused by urbanization influence the urban heat island (UHI) phenomenon. With the rapid development of urbanization, China's major cities are facing more serious climate change problems, especially the UHI phenomenon. Proper planning and urban design of compact cities may improve the ventilation of street canyons and change the heat balance in the urban canopy and thus mitigate the UHI phenomenon. The aim of this study is to evaluate and discuss the mitigation of UHI with different types of land-use and land-cover (LUCC), as well as different development patterns for compact cities. To this end, we applied the weather research and forecasting model (WRF) with urban canopy model (WRF/UCM) in this study. To evaluate the impact of LUCC changes on the UHI, we set 2 cases based on land use and land cover statistical data from 1965 and 2008 of Wuhan. Also, to evaluate the impact of urban morphology changes on the UHI, we designed 2 hypothetical cases based on 2 different urban developing patterns, one is high rise case and another is high density case, to simulate the impact of urban morphology on the UHI. As for the results of this study, with different LUCC of 1965 and 2008, UHI intensity of Wuhan increased by 0.2 °C-0.4 °C in average. Moreover, the critical wind speed which can mitigate UHI of case 1965 is much lower than case 2008. With different urban morphology, the high-rise case may lead to lower UHI intensity at the pedestrian level due to the shading effects of high-rise buildings. However, the critical value of wind speed in the high-rise case was almost 1.5-2 times greater than that of the high-density case, which illustrates the reduced possibility of mitigating the UHI phenomenon for high-rise buildings in Wuhan City. Copyright © 2018 Elsevier B.V. All rights reserved.

The urban forest and ecosystem services: impact on urban water, heat, and pollution cycles at the tree, street, and city scale

Treesearch

S. J. Livesley; E. G. McPherson; C. Calfapietra

2016-01-01

Many environmental challenges are exacerbated within the urban landscape, such as stormwater runoff and flood risk, chemical and particulate pollution of urban air, soil and water, the urban heat island, and summer heat waves. Urban trees, and the urban forest as a whole, can be managed to have an impact on the urban water, heat, carbon and pollution cycles. However,...

Heron Island, Australia

NASA Technical Reports Server (NTRS)

2002-01-01

Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging

Belcher Islands, Canada

NASA Technical Reports Server (NTRS)

2008-01-01

The Belcher Islands are an archipelago in Hudson Bay in Canada, belonging to the territory of Nunavit. The hamlet of Sanikiluaq is on the north coast of Flaherty Island. Over 1500 islands make up the archipelago. The folded sedimentary and volcanic rocks making up the islands are Proterozoic in age between 0.5 and 2.5 billion years old.

The image mosaic was acquired 18 September 2006, covers an area of 45.7 x 113.3 km, and is located near 56.1 degrees north latitude, 79.4 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Formation and adjustment of typhoon-impacted reef islands interpreted from remote imagery: Nadikdik Atoll, Marshall Islands

NASA Astrophysics Data System (ADS)

Ford, Murray R.; Kench, Paul S.

2014-06-01

In 1905, a devastating typhoon hit Nadikdik Atoll (5°54‧ N and 172°09‧ E) in the southern Marshall Islands. Evidence suggests that large sections of reef islands on Nadikdik were overwashed and destroyed. Comparison of aerial photographs taken in 1945 and modern satellite imagery provides a unique record of the geomorphic adjustment of islands after the typhoon. Between 1945 and 2010 the vegetated area of islands on Nadikdik grew from 0.74 to 0.90 km2. Observed changes to Nadikdik reef islands manifested through a range of styles and were largely accretionary. Of note, the formation of a new island was tracked from an embryonic deposit to a fully vegetated and stable island over a 61 year period. Similarly, a number of previously discrete islands have agglomerated and formed a single larger island. These changes were rapid and indicate that reef island formation can occur quickly. Evidence suggests that despite the typhoon occurring over a century ago the geomorphic adjustment of islands is still on-going.

33 CFR 80.720 - St. Simons Island, GA to Amelia Island, FL.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false St. Simons Island, GA to Amelia... SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Seventh District § 80.720 St. Simons Island, GA to Amelia Island, FL. (a) A line drawn from St. Simons Light to the northernmost tank on...

Island of Timor, Indonesia

NASA Image and Video Library

1989-11-27

This almost totally cloud free, photo of the island of Timor, Indonesia (9.0S, 125.0E) illustrates the volcanic origin of the over 1500 islands of Indonesia. Close examination of the photo reveals several eroded volcanoes on the Island of Timor and several of the adjacent islands. The linear alignment of the volcanoes, as seen from space, indicates the edges of the tectonic plates of the Earth's crust where volcanic activity is most common.

Bimodal volcanism in northeast Puerto Rico and the Virgin Islands (Greater Antilles Island Arc): Genetic links with Cretaceous subduction of the mid-Atlantic ridge Caribbean spur

NASA Astrophysics Data System (ADS)

Jolly, Wayne T.; Lidiak, Edward G.; Dickin, Alan P.

2008-07-01

perpendicular subduction of the Caribbean spur of the mid-Atlantic Ridge, which was located approximately midway between North and South America until Campanian times. Within this hypothetical setting the centrally positioned Virgin Islands terrain remained approximately fixed above the subducting ridge as the Antilles arc platform swept northeastward into the slot between the Americas. Accordingly, heat flow in the Virgin Islands was elevated throughout the Cretaceous, giving rise to widespread crustal melting, whereas the subducted sediment flux was limited. Conversely, toward the west in central Puerto Rico, which was consistently more remote from the subducting ridge, heat flow was relatively low and produced limited crustal melting, while the sediment flux was comparatively elevated.

11. VIEW NORTH, WOODLYNNE AVENUE ISLAND FROM 130 SOUTH ISLAND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. VIEW NORTH, WOODLYNNE AVENUE ISLAND FROM 130 SOUTH ISLAND - White Horse Pike Rond Point, Intersection of Crescent Boulevard (U.S. Route 130), White Horse Pike (U.S. Route 30), & Clay Avenue, Collingswood, Camden County, NJ

33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Edisto River Entrance to the shore of Botany Bay Island. (d) A line drawn from the microwave antenna..., SC to Hilton Head Island, SC. (a) A straight line drawn from the seaward tangent of Folly Island through across Stono River to the shoreline of Sandy Point. (b) A straight line drawn from the seaward...

33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Edisto River Entrance to the shore of Botany Bay Island. (d) A line drawn from the microwave antenna..., SC to Hilton Head Island, SC. (a) A straight line drawn from the seaward tangent of Folly Island through across Stono River to the shoreline of Sandy Point. (b) A straight line drawn from the seaward...

77 FR 51473 - Safety Zone; Bostock 50th Anniversary Fireworks, Long Island Sound; Manursing Island, NY

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-24

... 1625-AA00 Safety Zone; Bostock 50th Anniversary Fireworks, Long Island Sound; Manursing Island, NY... zone on the navigable waters of Long Island Sound in the vicinity of Manursing Island, NY for a... of Long Island Sound before, during, and immediately after the fireworks event. DATES: This rule is...

Polycrystalline silicon thin-film transistors fabricated by Joule-heating-induced crystallization

NASA Astrophysics Data System (ADS)

Hong, Won-Eui; Ro, Jae-Sang

2015-01-01

Joule-heating-induced crystallization (JIC) of amorphous silicon (a-Si) films is carried out by applying an electric pulse to a conductive layer located beneath or above the films. Crystallization occurs across the whole substrate surface within few tens of microseconds. Arc instability, however, is observed during crystallization, and is attributed to dielectric breakdown in the conductor/insulator/transformed polycrystalline silicon (poly-Si) sandwich structures at high temperatures during electrical pulsing for crystallization. In this study, we devised a method for the crystallization of a-Si films while preventing arc generation; this method consisted of pre-patterning an a-Si active layer into islands and then depositing a gate oxide and gate electrode. Electric pulsing was then applied to the gate electrode formed using a Mo layer. The Mo layer was used as a Joule-heat source for the crystallization of pre-patterned active islands of a-Si films. JIC-processed poly-Si thin-film transistors (TFTs) were fabricated successfully, and the proposed method was found to be compatible with the standard processing of coplanar top-gate poly-Si TFTs.

Using EnviroAtlas to Identify Locations for Urban Heat Island Abatement

EPA Science Inventory

For the metropolitan region of Portland, Oregon, this use case demonstrates how city planners could use EnviroAtlas data with a map of the UHI to identify areas that might benefit from heat mitigation through additional street trees. Street trees are one option, and other solutio...

Bryophytes from Simeonof Island in the Shumagin Islands, southwestern Alaska

USGS Publications Warehouse

Schofield, W.B.; Talbot, S. S.; Talbot, S.L.

2004-01-01

Simeonof Island is located south of the Alaska Peninsula in the hyperoceanic sector of the middle boreal subzone. We examined the bryoflora of Simeonof Island to determine species composition in an area where no previous collections had been reported. This field study was conducted in sites selected to represent the spectrum of environmental variation within Simeonof Island. Data were analyzed using published reports to compare bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 271 bryophytes were identified: 202 mosses and 69 liverworts. The annotated list of species for Simeonof Island expands the known range for many species and fills distribution gaps within Hulte??n's Western Pacific Coast district. Maps and notes on the distribution of 14 significant distribution records are presented. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Simeonof Island primarily includes taxa of boreal (55%), temperate (20%), arctic (10%), and cosmopolitan (8%) distribution; 6% of the moss flora are western North America endemics. A description of the bryophytes present in the vegetation and habitat types is provided as is a quantitative analysis of the most frequently occurring bryophytes in crowberry heath.

Quantifying coastal connectivity of coral spawn and larvae around Ryukyu Islands in the East China Sea

NASA Astrophysics Data System (ADS)

Odani, S.; Uchiyama, Y.; Kashima, M.; Kamidaira, Y.; Mitarai, S.

2016-12-01

Ryukyu Islands in the East China Sea are in a subtropical climate, hosting desirable environment for abundant coral ecosystem. Okinawa Main Island is the most densely populated island among them with tremendous tourist attractions including enchanting coral reefs and beaches. Kamidaira et al. (2016) suggested that the Kuroshio warm water maintains warmer water temperature favorable to corals around the island due mainly to intermittent eddy heat transport. It is presumed that the Kuroshio and associated eddy mixing also promote the transport and dispersal of coral spawn and larvae across the islands, whereas the area has suffered from coral breeching in the recent decades. Therefore, for optimal preservation and protection of the coral habitats around Ryukyu Island, we conduct a double nested high-resolution synoptic ocean modeling using ROMS with grid spacing down to 1 km coupled with an offline Lagrangian particle tracking model to investigate dispersal of coral spawn and larvae released from about 20 major islands and lagoons. Based on the model outcome, we quantify connectivity using Lagrangian probability density functions (PDFs) of the Lagrangian particles (e.g., Mitarai et al., 2009) among Ryukyu Islands. We then focus on the larval dispersal released from Sekisei Lagoon in Yaeyama Islands close to Taiwan, where we have carried out a series of in-situ surface drifter measurement. To compare the observation with the model, 160 source and sink patches with a diameter of 3 km are defined around Sekisei Lagoon and Okinawa Main Island for quantification of the detailed connectivity between them. The advection time is assumed for no more than 3 weeks to represent the lifespan of coral spawn and larvae. A PDF analysis suggests that the particles mostly remain near the released areas with predominant clockwise circulation around the lagoon, while approximately less than 5 % of particles are trapped and transported northeastward in long distance by the Kuroshio. The

Canary Islands

NASA Image and Video Library

2013-12-30

On December 10, 2013 the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite flew across the central Atlantic Ocean and captured a true-color image of the Canary Islands. Lying off of the coast of Western Sahara and Morocco, the islands were created by successive submarine volcanic eruptions which raised the ocean floor vertically until some of land rose above sea level. The oldest islands lie in the east and the youngest in the west. From east to west, the major islands seen in this image are: Lanzarote, Fuerteventura, Gran Canaria, Tenerife, La Gomera, La Palmera and El Hierro. While the creation of the islands began in the Late Cretaceous Period (70 – 80 million years ago), active volcanic activity continues. In 2011, a spectacular submarine eruption occurred just off the shore of El Hierro. The volcano became quiet again, but very recently increasing earthquakes and changing height of El Hierro suggested the volcano may again be entering an active eruptive phase. On December 27 the island’s volcano monitoring agency had raised the volcanic eruption risk for El Hierro to “yellow” – a code that means increasing activity but no eruption imminent. That afternoon a magnitude 5.1 earthquake struck offshore at El Hierro. The epicenter was 9 miles (15 km) deep, and it was one of the largest quakes ever recorded at the island. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HEATING MECHANISMS IN THE LOW SOLAR ATMOSPHERE THROUGH MAGNETIC RECONNECTION IN CURRENT SHEETS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ni, Lei; Lin, Jun; Roussev, Ilia I.

2016-12-01

We simulate several magnetic reconnection processes in the low solar chromosphere/photosphere; the radiation cooling, heat conduction and ambipolar diffusion are all included. Our numerical results indicate that both the high temperature (≳8 × 10{sup 4} K) and low temperature (∼10{sup 4} K) magnetic reconnection events can happen in the low solar atmosphere (100–600 km above the solar surface). The plasma β controlled by plasma density and magnetic fields is one important factor to decide how much the plasma can be heated up. The low temperature event is formed in a high β magnetic reconnection process, Joule heating is the mainmore » mechanism to heat plasma and the maximum temperature increase is only several thousand Kelvin. The high temperature explosions can be generated in a low β magnetic reconnection process, slow and fast-mode shocks attached at the edges of the well developed plasmoids are the main physical mechanisms to heat the plasma from several thousand Kelvin to over 8 × 10{sup 4} K. Gravity in the low chromosphere can strongly hinder the plasmoid instability and the formation of slow-mode shocks in a vertical current sheet. Only small secondary islands are formed; these islands, however, are not as well developed as those in the horizontal current sheets. This work can be applied to understand the heating mechanism in the low solar atmosphere and could possibly be extended to explain the formation of common low temperature Ellerman bombs (∼10{sup 4} K) and the high temperature Interface Region Imaging Spectrograph (IRIS) bombs (≳8 × 10{sup 4}) in the future.« less

Surface energy exchanges over contrasting vegetation types on a subtropical sand island

NASA Astrophysics Data System (ADS)

Gray, Michael; McGowan, Hamish; Lowry, Andrew; Guyot, Adrien

2017-04-01

The surface energy balance of subtropical coastal vegetation communities has thus far received little attention. Here we present a multi-year observational data set using the eddy covariance method to quantify for the first time the surface energy balance over three contrasting vegetation types on a subtropical sand island in eastern Australia: a periodically inundated sedge swamp, an exotic pine plantation and a coastal heath. Maximum daily sensible heat flux varied between sites but was typically > 280 Wm-2 in the coastal heath and pine plantation but no more than 250 Wm-2 in the swamp when dry and < 110 Wm-2 when inundated. Maximum daily latent heat flux was up to 300 Wm-2 in the coastal heath and pine, but in the swamp it was up to 250 Wm-2 when dry and 209 Wm-2 when inundated. On seasonal timescales, the coastal heath and swamp were both found to be dominated by latent heat flux, with Bowen ratio (β) < 1, whereas the pine plantation typically exhibited β > 1. The partitioning of energy, as represented by β, is similar to a variety of Australian ecosystems, and a range of coastal vegetation types in other latitudes, but differs from other tropical or subtropical locations which have strongly seasonal rainfall patterns and therefore a switch from β > 1 before rainfall to β < 1 afterwards. The energy fluxes over the three vegetation types responded to seasonal changes in background meteorology with the most important influences being net radiation, absolute humidity, and rainfall. The main factor differentiating the sites was soil water content, with the remnant coastal heath and swamp having ready access to water but the exotic pine plantation having much drier soils. Should the current balance between remnant vegetation and the pine plantation undergo changes there would be a corresponding shift in the surface energy balance of the island as a whole, and altered plant water use may lead to reduced water table depth, important because the groundwater of the

Cyclic Explosivity in High Elevation Phreatomagmatic Eruptions at Ocean Island Volcanoes: Implications for Aquifer Pressurization and Volcano Flank Destabilization.

NASA Astrophysics Data System (ADS)

Tarff, R.; Day, S. J.; Downes, H.; Seghedi, I.

2015-12-01

Groundwater heating and pressurization of aquifers trapped between dikes in ocean island volcanoes has been proposed as a mechanism for destabilizing and triggering large-volume flank collapses. Previous modelling has indicated that heat transfer from sustained magma flow through dikes during eruption has the potential to produce destabilizing levels of pressure on time scales of 4 to 400 days, if the aquifers remain confined. Here we revisit this proposal from a different perspective. We examine evidence for pressure variations in dike-confined aquifers during eruptions at high elevation vents on ocean island volcanoes. Initially magmatic, these eruptions change to mostly small-volume explosive phreatomagmatic activity. A recent example is the 1949 eruption on La Palma, Canary Islands. Some such eruptions involve sequences of larger-volume explosive phases or cycles, including production of voluminous low-temperature, pyroclastic density currents (PDC). Here we present and interpret data from the Cova de Paul crater eruption (Santo Antao, Cape Verde Islands). The phreatomagmatic part of this eruption formed two cycles, each culminating with eruption of PDCs. Compositional and textural variations in the products of both cycles indicate that the diatreme fill began as coarse-grained and permeable which allowed gas to escape. During the eruption, the fill evolved to a finer grained, poorly sorted, less permeable material, in which pore fluid pressures built up to produce violent explosive phases. This implies that aquifers adjacent to the feeder intrusion were not simply depressurized at the onset of phreatomagmatic explosivity but experienced fluctuations in pressure throughout the eruption as the vent repeatedly choked and emptied. In combination with fluctuations in magma supply rate, driving of aquifer pressurization by cyclical vent choking will further complicate the prediction of flank destabilization during comparable eruptions on ocean island volcanoes.

78 FR 35135 - Special Local Regulation; Kelley's Island Swim, Lake Erie; Kelley's Island, Lakeside, OH

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-12

...-AA08 Special Local Regulation; Kelley's Island Swim, Lake Erie; Kelley's Island, Lakeside, OH AGENCY... vessel movement in portions of Lake Erie during the annual Kelley's Island Swim from. This special local... special local regulations listed in 33 CFR 100.921 Special Local Regulation; Kelley's Island Swim, Lake...

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2011 CFR

2011-10-01

...′ N. longitude 80°12.7′ W. (c) A line drawn from the microwave antenna tower on Edisto Beach charted... 80°26.5′ W. (d) A line drawn from the abandoned lighthouse on Hunting Island in approximate position... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2014 CFR

2014-10-01

...′ N. longitude 80°12.7′ W. (c) A line drawn from the microwave antenna tower on Edisto Beach charted... 80°26.5′ W. (d) A line drawn from the abandoned lighthouse on Hunting Island in approximate position... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2012 CFR

2012-10-01

...′ N. longitude 80°12.7′ W. (c) A line drawn from the microwave antenna tower on Edisto Beach charted... 80°26.5′ W. (d) A line drawn from the abandoned lighthouse on Hunting Island in approximate position... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2013 CFR

2013-10-01

...′ N. longitude 80°12.7′ W. (c) A line drawn from the microwave antenna tower on Edisto Beach charted... 80°26.5′ W. (d) A line drawn from the abandoned lighthouse on Hunting Island in approximate position... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...

Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment

NASA Astrophysics Data System (ADS)

Viner, Brian J.; Arritt, Raymond W.; Westgate, Mark E.

2017-08-01

Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua'i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near the island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni'ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. They demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.

Spatial temporal analysis of urban heat hazard in Tangerang City

NASA Astrophysics Data System (ADS)

Wibowo, Adi; Kuswantoro; Ardiansyah; Rustanto, Andry; Putut Ash Shidiq, Iqbal

2016-11-01

Urban heat is a natural phenomenon which might caused by human activities. The human activities were represented by various types of land-use such as urban and non-urban area. The aim of this study is to identify the urban heat behavior in Tangerang City as it might threats the urban environment. This study used three types of remote sensing data namely, Landsat TM, Landsat ETM+ and Landsat OLI-TIRS, to capture the urban heat behavior and to analysis the urban heat signature of Tangerang City in 2001, 2012, 2013, 2014, 2015 and 2016. The result showed that urban heat signature change dynamically each month based on the sun radiation. The urban heat island covered only small part of Tangerang City in 2001, but it was significantly increased and reached 50% of the area in 2012. Based on the result on urban heat signature, the threshold for threatening condition is 30 oC which recognized from land surface temperature (LST). The effective temperature (ET) index explains that condition as warm, uncomfortable, increase stress due to sweating and blood flow and may causing cardiovascular disorder.

Observations of Urban Heat Island Mitigation in California Coastal Cities due to a Sea Breeze Induced Coastal-Cooling ``REVERSE-REACTION'' to Global Warming

NASA Astrophysics Data System (ADS)

Bornstein, R. D.; Lebassi, B.; Gonzalez, J.

2010-12-01

The study evaluated long-term (1948-2005) air temperatures at over 300 urban and rural sites in California (CA) during summer (June-August, JJA). The aggregate CA results showed asymmetric warming, as daily min temperatures increased faster than daily max temperatures. The spatial distributions of daily max temperatures in the heavily urbanized South Coast and San Francisco Bay Area air basins, however, exhibited a complex pattern, with cooling at low-elevation (mainly urban) coastal-areas and warming at (mainly rural) inland areas. Previous studies have suggested that cooling summer max temperatures in CA were due to increased irrigation, coastal upwelling, or cloud cover. The current hypothesis, however, is that this temperature pattern arises from a “reverse-reaction” to greenhouse gas (GHG) induced global-warming. In this hypothesis, the global warming of inland areas resulted in an increased (cooling) sea breeze activity in coastal areas. That daytime summer coastal cooling was seen in coastal urban areas implies that urban heat island (UHI) warming was weaker than the reverse-reaction sea breeze cooling; if there was no UHI effect, then the cooling would have been even stronger. Analysis of daytime summer max temperatures at four adjacent pairs of urban and rural sites near the inland cooling-warming boundary, however, showed that the rural sites experienced cooling, while the urban sites showed warming due to UHI development. The rate of heat island growth was estimated as the sum of each urban warming rate and the absolute magnitude of the concurrent adjacent rural cooling rate. Values ranged from 0.12 to 0.55 K decade-1, and were proportional to changes in urban population and urban extent. As Sacramento, Modesto, Stockton, and San José have grown in aerial extent (21 to 59%) and population (40 to 118%), part of the observed increased JJA max values could be due to increased daytime UHI-intensity. Without UHI effects, the currently observed JJA SFBA

Hawaiian Island Archipelago

NASA Image and Video Library

1988-10-03

STS026-43-082 (29 Sept. - 3 Oct. 1988) --- This 70mm northerly oriented frame over the Pacific Ocean features the Hawaiian Islands chain. The islands perturb the prevailing northeasterly winds producing extensive cloud wakes in the lee of the islands. Photo experts feel that atmospheric haze in the Hawaii wake is probably a result of the continuing eruptions of Kilauea volcano on the southeast coast. From the lower right corner in a diagonal directed upward to the north are the islands of Nihau, Kauai, Oahu, Molokai, Lanai, Maui, Kahoolawe, and Hawaii. This photo was shown during the post-flight press conference on October 11, 1988 by the STS-26 astronauts, who at one time during the flight wore Hawaiian attire to pay tribute to the working staff of the Hawaii tracking station.

U.S. Virgin Islands Analysis Brief

EIA Publications

2016-01-01

The U.S. Virgin Islands (USVI), part of the Leeward Islands of the Lesser Antilles, is a U.S. territory located in the Caribbean Sea, about 600 miles southeast of Miami, Florida.1 The USVI has a total area of 134 square miles, about twice the size of Washington, DC. The islands are hilly and forested, with limited arable areas, and most food is imported.2 The largest island is St. Croix. It lies about 40 miles south of the three other inhabited islands: St. John, St. Thomas, and Water Island. Those islands are located between the Commonwealth of Puerto Rico on the west and the British Virgin Islands on the east.

Typologi of Island City in Indonesia

NASA Astrophysics Data System (ADS)

Maulana, Alvaryan; Benita, Tania

2017-07-01

As an archipelagic country, Indonesia consist of thousands of island. Some of them are big enough to contain growth and become the center of settlement and activity in Indonesia. However, growth and habitation are not only mushrooming in main island. Several small island also experience growth and become densely population places and simply become a city within island. This study aims to identify island city in Indonesia and creating the typology of the island city. This study is using exploratory approach and heavily rely on statistical figure of every single autonomous region as data sources. Eventually, this study found twelve (12) island cities in Indonesia, and three distinctive typology of island cities.

Molecular epidemiology and phylogenetic distribution of the Escherichia coli pks genomic island.

PubMed

Johnson, James R; Johnston, Brian; Kuskowski, Michael A; Nougayrede, Jean-Philippe; Oswald, Eric

2008-12-01

Epidemiological and phylogenetic associations of the pks genomic island of extraintestinal pathogenic Escherichia coli (ExPEC), which encodes the genotoxin colibactin, are incompletely defined. clbB and clbN (as markers for the 5' and 3' regions of the pks island, respectively), clbA and clbQ (as supplemental pks island markers), and 12 other putative ExPEC virulence genes were newly sought by PCR among 131 published E. coli isolates from hospitalized veterans (62 blood isolates and 69 fecal isolates). Blood and fecal isolates and clbB-positive and -negative isolates were compared for 66 newly and previously assessed traits. Among the 14 newly sought traits, clbB and clbN (colibactin polyketide synthesis system), hra (heat-resistant agglutinin), and vat (vacuolating toxin) were significantly associated with bacteremia. clbB and clbN identified a subset within phylogenetic group B2 with extremely high virulence scores and a high proportion of blood isolates. However, by multivariable analysis, other traits were more predictive of blood source than clbB and clbN were; indeed, among the newly sought traits, only pic significantly predicted bacteremia (negative association). By correspondence analysis, clbB and clbN were closely associated with group B2 and multiple B2-associated traits; by principal coordinate analysis, clbB and clbN partitioned the data set better than did blood versus fecal source. Thus, the pks island was significantly associated with bacteremia, multiple ExPEC-associated virulence genes, and group B2, and within group B2, it identified an especially high-virulence subset. This extends previous work regarding the pks island and supports investigation of the colibactin system as a potential therapeutic target.

Coastal Erosion in a Coral Reef Island, Taiping Island, South China Sea

NASA Astrophysics Data System (ADS)

Su, S.; Ma, G.; Liang, M.; Chu, J.

2011-12-01

Reef flats surrounding islands are known to dissipate much offshore wave energy, and thereby protect beaches from erosion. Taiping Island, the largest coral reef islands of the Spratly Islands in the South China Sea, has been observed the shorelines erosion on the southwest coast over past decades. It is recognized that wave and current processes across coral reefs affect reef-island development and morphology. A number of studies suggest effects of climate changes, sea-level rise and storm-intensity increase, determine the magnitude of wave energy on the reef platform and will likely intensify the erosion. The topographical change in the local region, the southwest reef flat was dredged a channel for navigation, may be a significant factor in influencing current characteristics. Numerical modeling is used to describe both hydrodynamics and sediment dynamics because there are no field measurements available around the reef flat. Field observations off the island conducted in August 2004 and November 2005 provides offshore wave characteristics of the predominant wind seasons. Numerical simulations perform the spatial and temporal variation of waves and current patterns and coastal erosion potential on the reef platform.

33 CFR 165.152 - Coast Guard Station Fire Island, Long Island, New York-safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Coast Guard Station Fire Island, Long Island, New York-safety zone. 165.152 Section 165.152 Navigation and Navigable Waters COAST GUARD... § 165.152 Coast Guard Station Fire Island, Long Island, New York—safety zone. (a) Location. The...

Island biogeography of the Anthropocene.

PubMed

Helmus, Matthew R; Mahler, D Luke; Losos, Jonathan B

2014-09-25

For centuries, biogeographers have examined the factors that produce patterns of biodiversity across regions. The study of islands has proved particularly fruitful and has led to the theory that geographic area and isolation influence species colonization, extinction and speciation such that larger islands have more species and isolated islands have fewer species (that is, positive species-area and negative species-isolation relationships). However, experimental tests of this theory have been limited, owing to the difficulty in experimental manipulation of islands at the scales at which speciation and long-distance colonization are relevant. Here we have used the human-aided transport of exotic anole lizards among Caribbean islands as such a test at an appropriate scale. In accord with theory, as anole colonizations have increased, islands impoverished in native species have gained the most exotic species, the past influence of speciation on island biogeography has been obscured, and the species-area relationship has strengthened while the species-isolation relationship has weakened. Moreover, anole biogeography increasingly reflects anthropogenic rather than geographic processes. Unlike the island biogeography of the past that was determined by geographic area and isolation, in the Anthropocene--an epoch proposed for the present time interval--island biogeography is dominated by the economic isolation of human populations.

Barrier island habitat map and vegetation survey—Dauphin Island, Alabama, 2015

USGS Publications Warehouse

Enwright, Nicholas M.; Borchert, Sinéad M.; Day, Richard H.; Feher, Laura C.; Osland, Michael J.; Wang, Lei; Wang, Hongqing

2017-08-04

Barrier islands are dynamic environments due to their position at the land-sea interface. Storms, waves, tides, currents, and relative sea-level rise are powerful forces that shape barrier island geomorphology and habitats (for example, beach, dune, marsh, and forest). Hurricane Katrina in 2005 and the Deep Water Horizon oil spill in 2010 are two major events that have affected habitats and natural resources on Dauphin Island, Alabama. The latter event prompted a collaborative effort between the U.S. Geological Survey, the U.S. Army Corps of Engineers, and the State of Alabama funded by the National Fish and Wildlife Foundation to investigate viable, sustainable restoration options that protect and restore the natural resources of Dauphin Island, Alabama.In order to understand the feasibility and sustainability of various restoration scenarios, it is important to understand current conditions on Dauphin Island. To further this understanding, a detailed 19-class habitat map for Dauphin Island was produced from 1-foot aerial infrared photography collected on December 4, 2015, and lidar data collected in January 2015. We also conducted a ground survey of habitat types, vegetation community structure, and elevations in November and December 2015. These products provide baseline data regarding the ecological and general geomorphological attributes of the area, which can be compared with observations from other dates for tracking changes over time.

33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Morris Island, SC to Hilton Head..., SC to Hilton Head Island, SC. (a) A line drawn from the easternmost tip of Folley Island to the... easternmost extremity of Hilton Head at latitude 32°13.0′ N. longitude 80°40.1′ W. [CGD 77-118a, 42 FR 35784...

Assessment of land surface temperature and heat fluxes over Delhi using remote sensing data.

PubMed

Chakraborty, Surya Deb; Kant, Yogesh; Mitra, Debashis

2015-01-15

Surface energy processes has an essential role in urban weather, climate and hydrosphere cycles, as well in urban heat redistribution. The research was undertaken to analyze the potential of Landsat and MODIS data in retrieving biophysical parameters in estimating land surface temperature & heat fluxes diurnally in summer and winter seasons of years 2000 and 2010 and understanding its effect on anthropogenic heat disturbance over Delhi and surrounding region. Results show that during years 2000-2010, settlement and industrial area increased from 5.66 to 11.74% and 4.92 to 11.87% respectively which in turn has direct effect on land surface temperature (LST) and heat fluxes including anthropogenic heat flux. Based on the energy balance model for land surface, a method to estimate the increase in anthropogenic heat flux (Has) has been proposed. The settlement and industrial areas has higher amounts of energy consumed and has high values of Has in all seasons. The comparison of satellite derived LST with that of field measured values show that Landsat estimated values are in close agreement within error of ±2 °C than MODIS with an error of ±3 °C. It was observed that, during 2000 and 2010, the average change in surface temperature using Landsat over settlement & industrial areas of both seasons is 1.4 °C & for MODIS data is 3.7 °C. The seasonal average change in anthropogenic heat flux (Has) estimated using Landsat & MODIS is up by around 38 W/m(2) and 62 W/m(2) respectively while higher change is observed over settlement and concrete structures. The study reveals that the dynamic range of Has values has increased in the 10 year period due to the strong anthropogenic influence over the area. The study showed that anthropogenic heat flux is an indicator of the strength of urban heat island effect, and can be used to quantify the magnitude of the urban heat island effect. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessing Vulnerability to Urban Heat: A Study of Disproportionate Heat Exposure and Access to Refuge by Socio-Demographic Status in Portland, Oregon

PubMed Central

Hellman, Dana; Sakuma, Ryu; Shandas, Vivek

2018-01-01

Extreme urban heat is a powerful environmental stressor which poses a significant threat to human health and well-being. Exacerbated by the urban heat island phenomenon, heat events are expected to become more intense and frequent as climate change progresses, though we have limited understanding of the impact of such events on vulnerable populations at a neighborhood or census block group level. Focusing on the City of Portland, Oregon, this study aimed to determine which socio-demographic populations experience disproportionate exposure to extreme heat, as well as the level of access to refuge in the form of public cooling centers or residential central air conditioning. During a 2014 heat wave, temperature data were recorded using a vehicle-traverse collection method, then extrapolated to determine average temperature at the census block group level. Socio-demographic factors including income, race, education, age, and English speaking ability were tested using statistical assessments to identify significant relationships with heat exposure and access to refuge from extreme heat. Results indicate that groups with limited adaptive capacity, including those in poverty and non-white populations, are at higher risk for heat exposure, suggesting an emerging concern of environmental justice as it relates to climate change. The paper concludes by emphasizing the importance of cultural sensitivity and inclusion, in combination with effectively distributing cooling centers in areas where the greatest burden befalls vulnerable populations. PMID:29601546

Assessing Vulnerability to Urban Heat: A Study of Disproportionate Heat Exposure and Access to Refuge by Socio-Demographic Status in Portland, Oregon.

PubMed

Voelkel, Jackson; Hellman, Dana; Sakuma, Ryu; Shandas, Vivek

2018-03-30

Extreme urban heat is a powerful environmental stressor which poses a significant threat to human health and well-being. Exacerbated by the urban heat island phenomenon, heat events are expected to become more intense and frequent as climate change progresses, though we have limited understanding of the impact of such events on vulnerable populations at a neighborhood or census block group level. Focusing on the City of Portland, Oregon, this study aimed to determine which socio-demographic populations experience disproportionate exposure to extreme heat, as well as the level of access to refuge in the form of public cooling centers or residential central air conditioning. During a 2014 heat wave, temperature data were recorded using a vehicle-traverse collection method, then extrapolated to determine average temperature at the census block group level. Socio-demographic factors including income, race, education, age, and English speaking ability were tested using statistical assessments to identify significant relationships with heat exposure and access to refuge from extreme heat. Results indicate that groups with limited adaptive capacity, including those in poverty and non-white populations, are at higher risk for heat exposure, suggesting an emerging concern of environmental justice as it relates to climate change. The paper concludes by emphasizing the importance of cultural sensitivity and inclusion, in combination with effectively distributing cooling centers in areas where the greatest burden befalls vulnerable populations.

Plant communities of Santa Rosa Island, Channel Islands National Park

USGS Publications Warehouse

Clark, Ronilee A.; Halvorson, William L.; Sawdo, Andell A.; Danielsen, Karen C.

1990-01-01

A survey of the plant communities on Santa Rosa Island, Channel Islands National Park, was conducted from January through July 1988.  Vegetation data were collected at 296 sites using a releve technique.  The plant communities described include: grassland, coastal marsh, caliche scrub, coastal sage scrub, lupine scrub, baccharis scrub, coastal bluff scrub, coastal dune scrub, mixed chaparral, mixed woodland, torrey pine woodland, closed-cone pine woodland, island oak woodland, riparian woodland, and riparian herbaceous vegetation. The areal extent of each community was mapper on USGS 7.5' topographic maps, and digitized for GIS manipulation.

Modeling the air-sea feedback system of Madeira Island

NASA Astrophysics Data System (ADS)

Pullen, Julie; Caldeira, Rui; Doyle, James D.; May, Paul; Tomé, Ricardo

2017-07-01

A realistic nested data-assimilating two-way coupled ocean/atmosphere modeling study (highest resolution 2 km) of Madeira Island was conducted for June 2011, when conditions were favorable for atmospheric vortex shedding. The simulation's island lee region exhibited relatively cloud-free conditions, promoting warmer ocean temperatures (˜2°C higher than adjacent waters). The model reasonably reproduced measured fields at 14 meteorological stations, and matched the dimensions and magnitude of the warm sea surface temperature (SST) wake imaged by satellite. The warm SSTs in the wake are shown to imprint onto the atmospheric boundary layer (ABL) over several diurnal cycles by modulating the ABL depth up to ˜200-500 m. The erosion and dissipation of the warm ocean wake overnight was aided by atmospheric drainage flow and offshore advection of cold air (ΔT = 2°C) that produced strong upward heat fluxes (˜50 W/m2 sensible and ˜250 W/m2 latent) on an episodic basis. Nevertheless, the warm wake was never entirely eroded at night due to the cumulative effect of the diurnal cycle. The spatial pattern of the diurnal warming varied day-to-day in location and extent. Significant mutual interaction of the oceanic and atmospheric boundary layers was diagnosed via fluxes and temperature cross sections and reinforced by sensitivity runs. The simulation produces for the first time the interactive nature of the ocean and atmosphere boundary layers in the warm wake region of an island with complex terrain.

Vegetation assessment of forests of Pagan Island, Commonwealth of the Northern Mariana Islands

USGS Publications Warehouse

Pratt, Linda W.

2011-01-01

During vegetation surveys in June–July 2010, 215 vascular plant species were observed on Pagan; 21 new island records of alien plants and 12 new island records of native plants were documented. Many of the new and recently sighted alien plants of the northern section of the island appeared to be in the incipient stage of invasion. Most of the new native plant sightings and a number of other rare tree and shrub species of Pagan were limited to forests of the rugged southern half of the island.

Japan: Shikoku Island

Atmospheric Science Data Center

2016-08-24

... and island stations in the waters surrounding Japan and Korea. They characterized meteorological conditions, measured the atmospheric ... flew overhead. These MISR images, centered just north of Shikoku Island in southwest Japan, were acquired on April 13, 2001 ...

Is heterostyly rare on oceanic islands?

PubMed Central

Watanabe, Kenta; Sugawara, Takashi

2015-01-01

Heterostyly has been considered rare or absent on oceanic islands. However, there has been no comprehensive review on this issue. Is heterostyly truly rare on oceanic islands? What makes heterostyly rare on such islands? To answer these questions, we review the reproductive studies on heterostyly on oceanic islands, with special emphasis on the heterostylous genus Psychotria in the Pacific Ocean as a model system. Overall, not many reproductive studies have been performed on heterostylous species on oceanic islands. In Hawaiian Psychotria, all 11 species are thought to have evolved dioecy from distyly. In the West Pacific, three species on the oceanic Bonin and Lanyu Islands are distylous (Psychotria homalosperma, P. boninensis and P. cephalophora), whereas three species on the continental Ryukyu Islands show various breeding systems, such as distyly (P. serpens), dioecy (P. rubra) and monoecy (P. manillensis). On some other Pacific oceanic islands, possibilities of monomorphy have been reported. For many Psychotria species, breeding systems are unknown, although recent studies indicate that heterostylous species may occur on some oceanic islands. A shift from heterostyly to other sexual systems may occur on some oceanic islands. This tendency may also contribute to the rarity of heterostyly, in addition to the difficulty in colonization/autochthonous evolution of heterostylous species on oceanic islands. Further investigation of reproductive systems of Psychotria on oceanic islands using robust phylogenetic frameworks would provide new insights into plant reproduction on oceanic islands. PMID:26199401

33 CFR 165.152 - Coast Guard Station Fire Island, Long Island, New York-safety zone.

Code of Federal Regulations, 2011 CFR

2011-07-01

... § 165.152 Coast Guard Station Fire Island, Long Island, New York—safety zone. (a) Location. The following waters of Fire Island Inlet are a safety zone: Beginning at a point on shore at 40°37.523′ N, 073... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Coast Guard Station Fire Island...

Relationship Between Fine-Particle Pollution and the Urban Heat Island in Beijing, China: Observational Evidence

NASA Astrophysics Data System (ADS)

Zheng, Zuofang; Ren, Guoyu; Wang, Hong; Dou, Junxia; Gao, Zhiqiu; Duan, Chunfeng; Li, Yubin; Ngarukiyimana, Jean Paul; Zhao, Chun; Cao, Chang; Jiang, Mei; Yang, Yuanjian

2018-05-01

Urbanization has led to a significant urban heat island (UHI) effect in Beijing in recent years. At the same time, air pollution caused by a large number of fine particles significantly influences the atmospheric environment, urban climate, and human health. The distribution of fine particulate matter (PM 2.5 ) concentration and its relationship with the UHI effect in the Beijing area are analyzed based on station-observed hourly data from 2012 to 2016. We conclude that, (1) in the last five years, the surface concentrations of PM 2.5 averaged for urban and rural sites in and around Beijing are 63.2 and 40.7 µg m-3, respectively, with significant differences between urban and rural sites (ΔPM 2.5 ) at the seasonal, monthly and daily scales observed; (2) there is a large correlation between ΔPM 2.5 and the UHI intensity defined as the differences in the mean (ΔT ave ), minimum (ΔT min ), and maximum (ΔT max ) temperatures between urban and rural sites. The correlation between ΔPM 2.5 and ΔT min (ΔT max ) is the highest (lowest); (3) a Granger causality analysis further shows that ΔPM 2.5 and ΔT min are most correlated for a lag of 1-2 days, while the correlation between ΔPM 2.5 and ΔT ave is lower; there is no causal relationship between ΔPM 2.5 and ΔT max ; (4) a case analysis shows that downwards shortwave radiation at the surface decreases with an increase in PM 2.5 concentration, leading to a weaker UHI intensity during the daytime. During the night, the outgoing longwave radiation from the surface decreases due to the presence of daytime pollutants, the net effect of which is a slower cooling rate during the night in cities than in the suburbs, leading to a larger ΔT min .

Urban Heat Wave Hazard Assessment

NASA Astrophysics Data System (ADS)

Quattrochi, D. A.; Jedlovec, G.; Crane, D. L.; Meyer, P. J.; LaFontaine, F.

2016-12-01

Heat waves are one of the largest causes of environmentally-related deaths globally and are likely to become more numerous as a result of climate change. The intensification of heat waves by the urban heat island effect and elevated humidity, combined with urban demographics, are key elements leading to these disasters. Better warning of the potential hazards may help lower risks associated with heat waves. Moderate resolution thermal data from NASA satellites is used to derive high spatial resolution estimates of apparent temperature (heat index) over urban regions. These data, combined with demographic data, are used to produce a daily heat hazard/risk map for selected cities. MODIS data are used to derive daily composite maximum and minimum land surface temperature (LST) fields to represent the amplitude of the diurnal temperature cycle and identify extreme heat days. Compositing routines are used to generate representative daily maximum and minimum LSTs for the urban environment. The limited effect of relative humidity on the apparent temperature (typically 10-15%) allows for the use of modeled moisture fields to convert LST to apparent temperature without loss of spatial variability. The daily max/min apparent temperature fields are used to identify abnormally extreme heat days relative to climatological values in order to produce a heat wave hazard map. Reference to climatological values normalizes the hazard for a particular region (e.g., the impact of an extreme heat day). A heat wave hazard map has been produced for several case study periods and then computed on a quasi-operational basis during the summer of 2016 for Atlanta, GA, Chicago, IL, St. Louis, MO, and Huntsville, AL. A hazard does not become a risk until someone or something is exposed to that hazard at a level that might do harm. Demographic information is used to assess the urban risk associated with the heat wave hazard. Collectively, the heat wave hazard product can warn people in urban

Barrier Island Failure During Hurricane Katrina

NASA Astrophysics Data System (ADS)

Sallenger, A.; Howd, P.; Stockdon, H.; Wright, C. W.; Fauver, L.; Guy, K.

2006-12-01

Classical models of barrier-island response to storms predict that wave runup can periodically overtop an island and transport sand from its seaside to its bayside, forcing the island to migrate landward. While this process can destroy fixed human developments, the island survives with little net change in form or dimensions. In contrast, we find that Louisiana's Chandeleur Islands during Hurricane Katrina were not periodically overtopped by waves, but were continuously inundated by storm surge. When such inundation occurs locally on a barrier island, it can force the erosion of a narrow breach that connects sea and bay. However, little is known about the response of a barrier island when it is entirely submerged. Here, we show that the Chandeleur Islands approached complete failure, losing 84% of their surface area. Their Gulf of Mexico shorelines retreated landward an average of 268 m, the largest retreat ever reported for a storm. Sand was stripped from the islands, reducing their peak elevation from >6 m to <3 m and exposing them to further degradation and potential failure by future hurricanes of less intensity than Katrina. Further, the islands that survived Katrina were marsh remnants composed of mud and vegetation that relatively small waves diminished following the storm. The Chandeleur Islands are prone to failure because of their location on the Mississippi delta where small sand supply and large sea-level rise (induced locally by land subsidence) limit natural rebuilding of the islands following a storm. The response of the delta's barrier islands during Hurricane Katrina provides a warning of how the world's barrier islands might respond to storm-surge inundation should predictions of accelerated global sea level rise prove accurate.

Energy Transition Initiative, Island Energy Snapshot - British Virgin Islands (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2015-03-01

This profile provides a snapshot of the energy landscape of the British Virgin Islands (BVI), one of three sets of the Virgin Island territories in an archipelago making up the northern portion of the Lesser Antilles.

Resurrection Peninsula and Knight Island ophiolites and recent faulting on Montague Island, southern Alaska

USGS Publications Warehouse

Nelson, Steven W.; Miller, Marti L.; Dumoulin, Julie A.

1987-01-01

The Resurrection Peninsula forms the east side of Resurrection Bay (Fig. 1). The city of Seward is located at the head of the bay and can be reached from Anchorage by highway (127 mi;204 km). Relief ranges from 1,434 ft (437 m) at the southern end of the peninsula to more than 4,800 ft (1,463 m) 17 mi (28 km) to the north. All rock units composing the informally named Resurrection Peninsula ophiolite are visible and (or) accessible by boat.The eastern half of the peninsula is located within the Chugach National Forest; the western half is mainly state land, but there is some private land with recreational cabins. The Seward A6 and A7 and Blying Sound D6 and D7 maps at 1:63,360 scale (mile-to-the-inch) cover the entire Resurrection Peninsula.Knight Island is located 53 mi (85 km) east of Seward (Fig. 1). Numerous fiords indent the 31-mi-long (50 km) by 7.4-mi-wide (12 km) island and offer excellent bedrock exposures. The island is rugged and has a maximum elevation of 3,000 ft (914 m). It has numerous mineral prospects (Tysdal, 1978; Nelson and others, 1984; Jansons and others, 1984; Koski and others, 1985), and several abandoned canneries are located on the island. Knight Island lies entirely within the Chugach National Forest—state and private inholdings constitute less than five percent of its total land area. The Seward A2, A3, B2, B3, and C2, 1:63,360-scale U.S. Geological Survey topographic maps cover the entire island.Montague Island, 50 mi (80 km) long and up to 11 mi (18 km) wide, lies 10.6 mi (17 km) southeast of Knight Island. It belongs to an island group that forms the southern margin of Prince William Sound (Fig. 1). Montague Island is less rugged and less heavily vegetated than either the Resurrection Peninsula or Knight Island. Rock exposures are excellent along the beaches, and ground disruption due to recent fault movements is clearly visible. The Seward Al and A2 and Blying Sound Dl, D2, and D3 maps cover the areas of interest on Montague Island

76 FR 19781 - Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, San Juan, Skagit...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-08

...., Lopez Island, WA 98261. North Olympic Public Library..... 630 N. Sequim Ave., 360-683-1161 Sequim, WA...] Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, San Juan, Skagit, Island, and Whatcom Counties, WA; Final Comprehensive Conservation Plan, Wilderness Stewardship Plan, and Finding of...

Cognitive Constraints and Island Effects

PubMed Central

Hofmeister, Philip; Sag, Ivan A.

2012-01-01

Competence-based theories of island effects play a central role in generative grammar, yet the graded nature of many syntactic islands has never been properly accounted for. Categorical syntactic accounts of island effects have persisted in spite of a wealth of data suggesting that island effects are not categorical in nature and that non-structural manipulations that leave island structures intact can radically alter judgments of island violations. We argue here, building on work by Deane, Kluender, and others, that processing factors have the potential to account for this otherwise unexplained variation in acceptability judgments. We report the results of self-paced reading experiments and controlled acceptability studies which explore the relationship between processing costs and judgments of acceptability. In each of the three self-paced reading studies, the data indicate that the processing cost of different types of island violations can be significantly reduced to a degree comparable to that of non-island filler-gap constructions by manipulating a single non-structural factor. Moreover, this reduction in processing cost is accompanied by significant improvements in acceptability. This evidence favors the hypothesis that island-violating constructions involve numerous processing pressures that aggregate to drive processing difficulty above a threshold so that a perception of unacceptability ensues. We examine the implications of these findings for the grammar of filler-gap dependencies.* PMID:22661792

The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China.

PubMed

Huang, Qunfang; Lu, Yuqi

2015-07-27

The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957-2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming.

The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China

PubMed Central

Huang, Qunfang; Lu, Yuqi

2015-01-01

The Yangtze River Delta (YRD) has experienced rapid urbanization and dramatic economic development since 1978 and the Yangtze River Delta urban agglomeration (YRDUA) has been one of the three largest urban agglomerations in China. We present evidence of a significant urban heat island (UHI) effect on climate warming based on an analysis of the impacts of the urbanization rate, urban population, and land use changes on the warming rate of the daily average, minimal (nighttime) and maximal (daytime) air temperature in the YRDUA using 41 meteorological stations observation data. The effect of the UHI on climate warming shows a large spatial variability. The average warming rates of average air temperature of huge cities, megalopolises, large cities, medium-sized cities, and small cities are 0.483, 0.314 ± 0.030, 0.282 ± 0.042, 0.225 ± 0.044 and 0.179 ± 0.046 °C/decade during the period of 1957–2013, respectively. The average warming rates of huge cities and megalopolises are significantly higher than those of medium-sized cities and small cities, indicating that the UHI has a significant effect on climate warming (t-test, p < 0.05). Significantly positive correlations are found between the urbanization rate, population, built-up area and warming rate of average air temperature (p < 0.001). The average warming rate of average air temperature attributable to urbanization is 0.124 ± 0.074 °C/decade in the YRDUA. Urbanization has a measurable effect on the observed climate warming in the YRD aggravating the global climate warming. PMID:26225986

Population size of island loggerhead shrikes on Santa Rosa and Santa Cruz Islands

USGS Publications Warehouse

Stanley, Thomas R.; Teel, Susan; Hall, Linnea S.; Dye, Linda C.; Laughrin, Lyndal L.

2012-01-01

Island loggerhead shrikes (Lanius ludovicianus anthonyi) are an endemic, genetically distinct subspecies of loggerhead shrike on California's Santa Rosa, Santa Cruz, and Santa Catalina Islands (USA). This subspecies is listed as a Species of Special Concern by the California Department of Fish and Game and has been petitioned for federal listing under the Endangered Species Act. The combination of suspected low numbers and the possibility of federal listing, prompted us to undertake a study to rigorously estimate the number of remaining individuals on Santa Rosa and Santa Cruz Islands. During the 2009 and 2010 breeding seasons, we surveyed sample units on Santa Rosa and Santa Cruz Islands using a double-observer method with independent observers to estimate joint detection probabilities (p), where we selected units under a stratified random sampling design. We estimated shrike abundance to be 169 in 2009 (p = 0.476) and 240 in 2010 (p = 0.825) for Santa Rosa Island, and 35 in 2009 (p = 0.816) and 42 in 2010 (p = 0.710) for Santa Cruz Island. These numbers, especially for Santa Rosa Island, are higher than previously reported but nevertheless are still low. Rapid vegetation change on both islands due to recent removal of nonnative herbivores may threaten the habitat and status of this subspecies and, therefore, we suggest that intensive demographic and habitat use research be initiated immediately to obtain additional information vital for the management of this subspecies. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Historical GIS Data and Changes in Urban Morphological Parameters for the Analysis of Urban Heat Islands in Hong Kong

NASA Astrophysics Data System (ADS)

Peng, F.; Wong, M. S.; Nichol, J. E.; Chan, P. W.

2016-06-01

Rapid urban development between the 1960 and 2010 decades have changed the urban landscape and pattern in the Kowloon Peninsula of Hong Kong. This paper aims to study the changes of urban morphological parameters between the 1985 and 2010 and explore their influences on the urban heat island (UHI) effect. This study applied a mono-window algorithm to retrieve the land surface temperature (LST) using Landsat Thematic Mapper (TM) images from 1987 to 2009. In order to estimate the effects of local urban morphological parameters to LST, the global surface temperature anomaly was analysed. Historical 3D building model was developed based on aerial photogrammetry technique using aerial photographs from 1964 to 2010, in which the urban digital surface models (DSMs) including elevations of infrastructures and buildings have been generated. Then, urban morphological parameters (i.e. frontal area index (FAI), sky view factor (SVF)), vegetation fractional cover (VFC), global solar radiation (GSR), Normalized Difference Built-Up Index (NDBI), wind speed were derived. Finally, a linear regression method in Waikato Environment for Knowledge Analysis (WEKA) was used to build prediction model for revealing LST spatial patterns. Results show that the final apparent surface temperature have uncertainties less than 1 degree Celsius. The comparison between the simulated and actual spatial pattern of LST in 2009 showed that the correlation coefficient is 0.65, mean absolute error (MAE) is 1.24 degree Celsius, and root mean square error (RMSE) is 1.51 degree Celsius of 22,429 pixels.

Identifying Local Scale Climate Zones of Urban Heat Island from HJ-1B Satellite Data Using Self-Organizing Maps

NASA Astrophysics Data System (ADS)

Wei, C. Z.; Blaschke, T.

2016-10-01

With the increasing acceleration of urbanization, the degeneration of the environment and the Urban Heat Island (UHI) has attracted more and more attention. Quantitative delineation of UHI has become crucial for a better understanding of the interregional interaction between urbanization processes and the urban environment system. First of all, our study used medium resolution Chinese satellite data-HJ-1B as the Earth Observation data source to derive parameters, including the percentage of Impervious Surface Areas, Land Surface Temperature, Land Surface Albedo, Normalized Differential Vegetation Index, and object edge detector indicators (Mean of Inner Border, Mean of Outer border) in the city of Guangzhou, China. Secondly, in order to establish a model to delineate the local climate zones of UHI, we used the Principal Component Analysis to explore the correlations between all these parameters, and estimate their contributions to the principal components of UHI zones. Finally, depending on the results of the PCA, we chose the most suitable parameters to classify the urban climate zones based on a Self-Organization Map (SOM). The results show that all six parameters are closely correlated with each other and have a high percentage of cumulative (95%) in the first two principal components. Therefore, the SOM algorithm automatically categorized the city of Guangzhou into five classes of UHI zones using these six spectral, structural and climate parameters as inputs. UHI zones have distinguishable physical characteristics, and could potentially help to provide the basis and decision support for further sustainable urban planning.

Terrestrial bird population trends on Aguiguan (Goat Island), Mariana Islands

USGS Publications Warehouse

Amidon, Fred; Camp, Richard J.; Marshall, Ann P.; Pratt, Thane K.; Williams, Laura; Radley, Paul; Cruz, Justine B.

2014-01-01

The island of Aguiguan is part of the Mariana archipelago and currently supports populations of four endemic species, including one endemic genus, Cleptornis. Bird population trends since 1982 were recently assessed on the neighbouring islands of Saipan, Tinian, and Rota indicating declines in some native species. Point-transect surveys were conducted in 2008 by the U.S. Fish and Wildlife Service to assess population densities and trends on Aguiguan. Densities for six of the nine native birds—White-throated Ground-dove Gallicolumba xanthonura, Collared Kingfisher Todiramphus chloris, Rufous Fantail Rhipidura rufifrons, Golden White-eye Cleptornis marchei, Bridled White-eye Zosterops conspicillatus and Micronesian Starling Aplonis opaca—and the non-native bird—Island Collared-dove Streptopelia bitorquata—were significantly greater in 2008 than in 1982. No differences in densities were detected among the surveys for Mariana Fruit-dove Ptilinopus roseicapilla, and Micronesian MyzomelaMyzomela rubratra. Three federally and locally listed endangered birds—Nightingale Reed-warbler Acrocephalus luscinius, Mariana Swiftlet Collocalia bartschi, and Micronesian Megapode Megapodius laperous)—were either not detected during the point-transect counts, the surveys were not appropriate for the species, or the numbers of birds detected were too small to estimate densities. The factors behind the increasing trends for some species are unknown but may be related to increased forest cover on the island since 1982. With declining trends for some native species on neighbouring islands, the increasing and stable trends on Aguiguan is good news for forest bird populations in the region, as Aguiguan populations can help support conservation efforts on other islands in the archipelago.

Genetic and phylogenetic consequences of island biogeography.

PubMed

Johnson, K P; Adler, F R; Cherry, J L

2000-04-01

Island biogeography theory predicts that the number of species on an island should increase with island size and decrease with island distance to the mainland. These predictions are generally well supported in comparative and experimental studies. These ecological, equilibrium predictions arise as a result of colonization and extinction processes. Because colonization and extinction are also important processes in evolution, we develop methods to test evolutionary predictions of island biogeography. We derive a population genetic model of island biogeography that incorporates island colonization, migration of individuals from the mainland, and extinction of island populations. The model provides a means of estimating the rates of migration and extinction from population genetic data. This model predicts that within an island population the distribution of genetic divergences with respect to the mainland source population should be bimodal, with much of the divergence dating to the colonization event. Across islands, this model predicts that populations on large islands should be on average more genetically divergent from mainland source populations than those on small islands. Likewise, populations on distant islands should be more divergent than those on close islands. Published observations of a larger proportion of endemic species on large and distant islands support these predictions.

33 CFR 334.515 - Blount Island Command and Marine Corps Support Facility-Blount Island; Jacksonville, Florida...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Blount Island Command and Marine... AND RESTRICTED AREA REGULATIONS § 334.515 Blount Island Command and Marine Corps Support Facility... identified as Blount Island Command and Marine Corps Support Facility-Blount Island (MCSF-BI). The three...

33 CFR 334.515 - Blount Island Command and Marine Corps Support Facility-Blount Island; Jacksonville, Florida...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Blount Island Command and Marine... AND RESTRICTED AREA REGULATIONS § 334.515 Blount Island Command and Marine Corps Support Facility... identified as Blount Island Command and Marine Corps Support Facility-Blount Island (MCSF-BI). The three...

33 CFR 334.515 - Blount Island Command and Marine Corps Support Facility-Blount Island; Jacksonville, Florida...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Blount Island Command and Marine... AND RESTRICTED AREA REGULATIONS § 334.515 Blount Island Command and Marine Corps Support Facility... identified as Blount Island Command and Marine Corps Support Facility-Blount Island (MCSF-BI). The three...

33 CFR 334.515 - Blount Island Command and Marine Corps Support Facility-Blount Island; Jacksonville, Florida...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Blount Island Command and Marine... AND RESTRICTED AREA REGULATIONS § 334.515 Blount Island Command and Marine Corps Support Facility... identified as Blount Island Command and Marine Corps Support Facility-Blount Island (MCSF-BI). The three...

33 CFR 334.515 - Blount Island Command and Marine Corps Support Facility-Blount Island; Jacksonville, Florida...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Blount Island Command and Marine... AND RESTRICTED AREA REGULATIONS § 334.515 Blount Island Command and Marine Corps Support Facility... identified as Blount Island Command and Marine Corps Support Facility-Blount Island (MCSF-BI). The three...

Field study of thermal comfort in non-air-conditioned buildings in a tropical island climate.

PubMed

Lu, Shilei; Pang, Bo; Qi, Yunfang; Fang, Kun

2018-01-01

The unique geographical location of Hainan makes its climate characteristics different from inland areas in China. The thermal comfort of Hainan also owes its uniqueness to its tropical island climate. In the past decades, there have been very few studies on thermal comfort of the residents in tropical island areas in China. A thermal environment test for different types of buildings in Hainan and a thermal comfort field investigation of 1944 subjects were conducted over a period of about two months. The results of the survey data show that a high humidity environment did not have a significant impact on human comfort. The neutral temperature for the residents in tropical island areas was 26.1 °C, and the acceptable temperature range of thermal comfort was from 23.1 °C to 29.1 °C. Residents living in tropical island areas showed higher heat resistance capacity, but lower cold tolerance than predicted. The neutral temperature for females (26.3 °C) was higher than for males (25.8 °C). Additionally, females were more sensitive to air temperature than males. The research conclusions can play a guiding role in the thermal environment design of green buildings in Hainan Province. Copyright © 2017 Elsevier Ltd. All rights reserved.

On Heating Large Bright Coronal Loops by Magnetic Microexplosions at their Feet

NASA Technical Reports Server (NTRS)

Moore, Ronald L; Falconer, D. A.; Porter, Jason G.

1999-01-01

In previous work, by registering Yohkoh SXT coronal X-ray images with MSFC vector magnetograms, we found that: (1) many of the larger bright coronal loops rooted at one or both ends in an active region are rooted around magnetic islands of included polarity, (2) the core field encasing the neutral line encircling the island is strongly sheared, and (3) this sheared core field is the seat of frequent microflares. This suggests that the coronal heating in these extended bright loops is driven by many small explosive releases of stored magnetic energy from the sheared core field at their feet, some of which magnetic microexplosions also produce the microflare heating in the core fields. In this paper, we show that this scenario is feasible in terms of the energy Abstract: required for the observed coronal heating and the magnetic energy available in the observed sheared core fields. In a representative active region, from the X-ray and vector field data, we estimate the coronal heating consumption by a selected typical large bright loop, the coronal heating consumption by a typical microflare at the foot of this loop, the frequency of microflares at the foot, and the available magnetic energy in the microflaring core field. We find that: (1) the rate of magnetic energy release to power the microflares at the foot (approx. 6 x 10(ext 25)erg/s) is enough to also power the coronal heating in the body of the extended loop (approx. 2 x l0(exp 25 erg/s), and (2) there is enough stored magnetic energy in the sheared core field to sustain the microflaring and extended loop heating for about a day, which is a typical time for buildup of neutral-line magnetic shear in an active region. This work was funded by the Solar Physics Branch of NASA's Office of Space Science through the SR&T Program and the SEC Guest Investigator Program.

77 FR 34894 - Safety Zone; Bostock 50th Anniversary Fireworks, Long Island Sound; Manursing Island, NY

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-12

... 1625-AA00 Safety Zone; Bostock 50th Anniversary Fireworks, Long Island Sound; Manursing Island, NY... establish a temporary safety zone on the navigable waters of Long Island Sound in the vicinity of Manursing... from a portion of Long Island Sound before, during, and immediately after the fireworks event. DATES...

Henderson Island, South Pacific

NASA Image and Video Library

2017-06-15

Uninhabited Henderson Island is part of the United Kingdom's Pitcairn Islands group in the South Pacific. According to a study by the University of Tasmania published in the Proceedings of the National Academy of Science, the island has the highest density of plastic waste anywhere in the world, an estimated 38 million pieces of rubbish. The island is near the center of an ocean current, so it collects rubbish from boats and South America. The image was acquired February 7, 2012, covers an area of 10.3 by 12.3 km, and is located at 24.3 degrees south, 128.3 degrees west. https://photojournal.jpl.nasa.gov/catalog/PIA21691