Science.gov

Sample records for heat islands

  1. Urban heat island

    NASA Technical Reports Server (NTRS)

    Kim, Hongsuk H.

    1991-01-01

    The phenomenon of urban heat island was investigated by the use of LANDSAT Thematic Mapper data sets collected over the metropolitan area of Washington DC (U.S.). By combining the retrieved spectral albedos and temperatures, urban modification on radiation budgets of five surface categories were analyzed. The surface radiation budget imagery of the area show that urban heating is attributable to a large heat flux from the rapidly heating surfaces of asphalt, bare soil and short grass. In summer, symptoms of diurnal heating begin to appear by mid morning and can be about 10 degrees warmer than nearby woodlands in summer.

  2. Controlling summer heat islands: Proceedings

    SciTech Connect

    Garbesi, K.; Akbari, H.; Martien, P.

    1989-11-01

    A workshop was held on the energy and pollution implications of summertime urban heat islands and the potential to control them. The presentations, papers, and discussions fell into four broad categories: (1) the potential to conserve energy, reduce atmospheric pollution, and slow global warming by reducing summer heat islands; (2) the use of computer models to understand and simulate the heat island phenomenon; (3) measurements of heat islands; and (4) the design and implementation of heat island mitigation strategies. On the afternoon of the second day of the workshop, the participants divided into three workgroups. Group 1 discussed research needs to better quantify the effect of heat island mitigation on energy use. Group 2 discussed future research on the characterization and modeling of heat islands. And Group 3 discussed the development of a manual that would present to policy makers our current knowledge of techniques to mitigate heat islands and thereby save energy. This Proceedings documents the presentations and outcome of the Workshop.

  3. HEAT ISLAND REDUCTION STRATEGIES GUIDEBOOK

    EPA Science Inventory

    This heat island reduction strategies guidebook provides an overview of urban heat islands and steps communities can take to reduce them. In particular, this guidebook provides background basics and answers the questions: “What is a heat island?” “What are its impacts?" "What ar...

  4. Observations in Nonurban Heat Islands.

    NASA Astrophysics Data System (ADS)

    Hogan, A. W.; Ferrick, M. G.

    1998-02-01

    The urban heat island is a well-known and well-described temperature anomaly, but other types of heat islands are also infrequently reported. A 10 km × 30 km data field containing more than 100 individual winter morning air temperature measurement points was examined for areas characteristically warmer than surrounding areas. The very small `downtown' of Hanover, New Hampshire, was found to be 1°-2°C warmer than nearby open areas at the same elevation. The same technique was applied to examine the morning air temperature within a nearby hamlet consisting of about 60 wooden buildings within an area less than 0.3 km2. The bulk of observations and observations stratified by snow and sky cover showed no systematic difference between hamlet air temperatures and those obtained in surrounding terrain. Morning air temperatures along a freezing river were measured and found to be systematically warmer than nearby air temperatures for several days, until a significant snowfall diminished the ice growth rate. A thorough examination of temperature profiles near the river showed that the increase in air temperature beneath the overnight inversion during this freezing period was proportional to the heat release resulting from river ice growth.

  5. The Urban Heat Island Pilot Project (UHIPP)

    NASA Technical Reports Server (NTRS)

    Luvall, Jeff; Morris, Lynn; Stewart, Fran; Thretheway, Ray; Gartland, Lisa; Russell, Camille; Reddish, Merrill; Arnold, James E. (Technical Monitor)

    2001-01-01

    Urban heat islands increase the demand for cooling energy and accelerate the formation of smog. They are created when natural vegetation is replaced by heat-absorbing surfaces such as building roofs and walls, parking lots, and streets. Through the implementation of measures designed to mitigate the urban heat island, communities can decrease their demand for energy and effectively "cool" the metropolitan landscape. Measures to reverse the urban heat island include afforestation and the widespread use of highly reflective surfaces. To demonstrate the potential benefits of implementing these measures, EPA has teamed up with NASA and LBNL to initiate a pilot project with three U.S. cities. As part of the pilot, NASA is using remotely-sensed data to quantify surface temperature, albedo, the thermal response number and NDVI vegetation of each city. To pursue these efforts, more information is needed about specific characteristics of several different cities. NASA used the Advanced Thermal and Land Applications Sensor (ATLAS) to obtain high spatial resolution (10 m pixel resolution) over each of the three pilot cities (Baton Rouge, Sacramento, and Salt Lake City). The goal of the UHIPP is to use the results from the NASA/LBNL analysis, combined with knowledge gained through working with various organizations within each pilot city to identify the most effective means of implementing strategies designed to mitigate the urban heat island, These "lessons learned" will be made available and used by cities across the U.S. to assist policy makers and others within various communities to analyze their own urban heat islands and determine which, if any, measures can be taken to help save energy and money, and to prevent pollution. The object of this session is for representatives from each of the pilot cities to present their results of the study and share the experience of working with these data in managing their urban landscape.

  6. Urban heat island in the subsurface

    NASA Astrophysics Data System (ADS)

    Ferguson, Grant; Woodbury, Allan D.

    2007-12-01

    The urban heat island effect has received significant attention in recent years due to the possible effect on long-term meteorological records. Recent studies of this phenomenon have suggested that this may not be important to estimates of regional climate change once data are properly corrected. However, surface air temperatures within urban environments have significant variation, making correction difficult. In the current study, we examine subsurface temperatures in an urban environment and the surrounding rural area to help characterize the nature of this variability. The results of our study indicate that subsurface temperatures are linked to land-use and supports previous work indicating that the urban heat island effect has significant and complex spatial variability. In most situations, the relationship between subsurface and surface processes cannot be easily determined, indicating that previous studies that relying on such a linkage may require further examination.

  7. Heat waves in urban heat islands: interactions, impacts, and mitigation

    NASA Astrophysics Data System (ADS)

    Bou-Zeid, E.; Li, D.

    2013-12-01

    Urbanization rates and the intensity of anthropogenic global warming are both on the rise. By the middle of this century, climate change impacts on humans will be largely manifested in urban regions and will result from a combination of global to regional impacts related to greenhouse gas emissions, as well as regional to local impacts related to land-cover changes associated with urbanization. Alarmingly, our understanding of how these two distinct impacts will interact remains very poor. One example, which is the focus of this study, is the interaction of urban heat islands and heat waves. Urban heat islands (UHIs) are spatial anomalies consisting of higher temperatures over built terrain; while their intensity varies with many factors, it consistently increases with city size. UHIs will hence intensify in the future as cities expand. Heat waves are temporal anomalies in the regional temperatures that affect both urban and rural areas; there is high certainty that the frequency and intensity of such waves will increase as a result global warming. However, whether urban and rural temperatures respond in the same way to heat waves remains a critical unanswered question. In this study, a combination of observational and modeling analyses of a heat wave event over the Baltimore-Washington urban corridor reveals synergistic interactions between urban heat islands and heat waves. Not only do heat waves increase the regional temperatures, but they also intensify the difference between urban and rural temperatures. That is, their impact is stronger in cities and the urban heat stress during such waves is larger than the sum of the background urban heat island effect and the heat wave effect. We also develop a simple analytical model of this interaction that suggests that this exacerbated impact in urban areas is primarily to the lack of surface moisture, with low wind speeds also playing a smaller role. Finally, the effectiveness of cool and green roofs as UHI mitigation

  8. 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.

  9. Paving materials for heat island mitigation

    SciTech Connect

    Pomerantz, M.; Akbari, H.; Chen, A.; Taha, H.; Rosenfeld, A.H.

    1997-11-01

    This report summarizes paving materials suitable for urban streets, driveways, parking lots and walkways. The authors evaluate materials for their abilities to reflect sunlight, which will reduce their temperatures. This in turn reduces the excess air temperature of cities (the heat island effect). The report presents the compositions of the materials, their suitability for particular applications, and their approximate costs (in 1996). Both new and resurfacing are described. They conclude that, although light-colored materials may be more expensive than conventional black materials, a thin layer of light-colored pavement may produce energy savings and smog reductions whose long-term worth is greater than the extra cost.

  10. STUDY OF THE SUBARCTIC HEAT ISLAND AT FAIRBANKS, ALASKA

    EPA Science Inventory

    The heat island associated with the City of Fairbanks, Alaska was studied as a means of isolating the effects of self-heating modified radiative transfer from other causes of heat islands. Minimal winter insolation virtually eliminated the effects of variable albedo and the daily...

  11. The Urban Heat Island Phenomenon and Potential Mitigation Strategies

    NASA Technical Reports Server (NTRS)

    Estes, Maurice G., Jr.; Gorsevski, Virginia; Russell, Camille; Quattrochi, Dale; Luvall, Jeffrey

    1999-01-01

    A survey of urban heat island research is provided to describe how heat islands develop, urban landscape and meteorological characteristics that facilitate development, use of aircraft remote sensing data, and why heat islands are of interest to planners, elected officials, and the public. The roles of the National Aeronautics and Space Administration (NASA), the Environmental Protection Agency (EPA), other federal agencies, national laboratories and universities, state and local governments, and non-governmental organizations (NGOS) in studying the urban heat island effect and developing mitigation strategies are explored. Barriers that hamper mitigation efforts and case studies in Atlanta and Salt Lake City are discussed.

  12. 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. PMID:23178772

  13. Satellite-derived subsurface urban heat island.

    PubMed

    Zhan, Wenfeng; Ju, Weimin; Hai, Shuoping; Ferguson, Grant; Quan, Jinling; Tang, Chaosheng; Guo, Zhen; Kong, Fanhua

    2014-10-21

    The subsurface urban heat island (SubUHI) is one part of the overall UHI specifying the relative warmth of urban ground temperatures against the rural background. To combat the challenge on measuring extensive underground temperatures with in situ instruments, we utilized satellite-based moderate-resolution imaging spectroradiometer data to reconstruct the subsurface thermal field over the Beijing metropolis through a three-time-scale model. The results show the SubUHI's high spatial heterogeneity. Within the depths shallower than 0.5 m, the SubUHI dominates along the depth profiles and analyses imply the moments for the SubUHI intensity reaching first and second extremes during a diurnal temperature cycle are delayed about 3.25 and 1.97 h per 0.1 m, respectively. At depths shallower than 0.05 m in particular, there is a subsurface urban cool island (UCI) in spring daytime, mainly owing to the surface UCI that occurs in this period. At depths between 0.5 and 10 m, the time for the SubUHI intensity getting to its extremes during an annual temperature cycle is lagged 26.2 days per meter. Within these depths, the SubUHI prevails without exception, with an average intensity of 4.3 K, varying from 3.2 to 5.3 K. PMID:25222374

  14. Urban Heat Island Characteristics Of Istanbul

    NASA Astrophysics Data System (ADS)

    Bilgen, S. I.; Unal, Y. S.; Yürük, C.; Göktepe, N.; Diren, D. H.; Topçu, S.; Güney, C.; Doğru, A. O.

    2015-12-01

    Urban heat island (UHI) is defined as the temperature difference between the urbanized areas and their surroundings due to local surface energy balance since urban materials and build up structures modify the heating and cooling rates of the ambient air. Istanbul is the largest city of Turkey with the population over 14 million inhabitants and the urbanization is drastically expanded since 1965 due to the population increase from 2 million to 14 million. In this study we investigate impacts of urban expansion on meteorological variables in relation to the UHI effect in Istanbul. To estimate the strength of UHI, temperature differences between urban and suburban stations are calculated by using temperature observations from 6 stations for 1960-2012 years, and 34 stations for 2007-2012. The results show that, the UHI intensity is stronger during summer season and Kartal experiences intensified UHI effect more than the others. The daytime(nighttime) UHI intensity defined with respect to Şile (suburban) varies between 0.41 and 3.01oC (1.02 and 2.18oC). The atmospheric UHI usually reaches its highest intensity on summer nights, and under calm air and a cloudless sky. Therefore, the total of 127 dry days which have cloudiness less than 2/8 and wind speed less than 2 m/s are selected to estimate the strength of UHI in Istanbul. The hourly temperature differences between a selected urban station (Pendik) and a rural station (Terkos), are calculated as 5oC for daytime and 8oC for the nighttime. The relationship between urbanization and long-term modification of the urban climate of Istanbul is investigated by modeling the present-day spatial distribution of the urban heat load. Geographical data of the Istanbul Metropolitan Municipality and CORINE Land Cover Raster Data are used to generate the land use distribution. Furthermore, the new urban land use types are defined by considering the spatial coverage and the average height of the buildings. Effects of change in land

  15. What is an urban heat island?

    NASA Astrophysics Data System (ADS)

    Wang, Kaicun; Jiang, Shaojing; Zhou, Chunlüe; Wang, Jiankai; Wang, Xiaoyan; Lee, Xuhui

    2016-04-01

    Urban heat islands (UHIs) have been extensively studied in cities of different sizes and climates. However, defining and quantifying the magnitude of a UHI and the primary mechanism responsible for this type of phenomenon are still debated. This study investigated a UHI using hourly air temperature (Ta) collected at 263 stations and land surface temperature (Ts) collected four times daily in Beijing in 2013. Five typical urban area types were studied: parking lots, building roofs, warning towers (on streets), city grasslands, and city parks. The daytime UHI quantified by Ta was substantially less than that at night, and the highest UHI quantified by Ta was during nighttime in winter. The dominating factor of the diurnal and seasonal cycles of the nighttime UHI by Ta is the storage of energy by urban materials in the morning and the release of this energy later, dependent on urban structure and solar elevation. The amplitude and seasonal cycle of the nighttime UHI by Ts were similar to that quantified by Ta, and the largest values were in winter. The daytime UHI by Ts had a significantly different seasonal cycle, with the largest values in summer. The urban-rural contrast in evapotranspiration resulted in greater energy being absorbed by urban floors, the dictating factor for the daytime UHI by Ts and its seasonal cycle. These results have important implications for the impact of UHIs on the homogeneity of Ta observations and mitigating the impact of UHIs on extremely hot events in urban areas.

  16. 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.

  17. Link between Surface and Subsurface Urban Heat Islands

    NASA Astrophysics Data System (ADS)

    Benz, Susanne; Bayer, Peter; Olesen, Folke; Goettsche, Frank; Blum, Philipp

    2016-04-01

    Urban heat islands exist in all diverse layers of modern cities, such as surface and subsurface. While both layers are typically investigated separately, the coupling of surface and subsurface urban heat islands is insufficiently understood. Hence, this study focuses on the interrelation of both zones and the influence of additional underground heat sources, such as heated basements, on this interaction. Using satellite derived land surface temperatures and interpolated groundwater temperature measurements the spatial properties of both heat islands are compared. Significant correlations of 0.5 up to more than 0.8 are found between surface and subsurface urban heat islands. If groundwater flow is considered this correlation increases by approximately 10%. Next we analyzed the dissimilarities between both heat islands in order to understand the interaction between the urban surface and subsurface. We find that local groundwater hotspots under the city center and industrial areas are not revealed in satellite derived land surface temperatures. Overall groundwater temperatures are higher than land surface temperatures in 95% of the analyzed area due to the influence of below ground anthropogenic heat sources such as sewage systems, district heating systems, and especially elevated basement temperatures. Thus, an estimation method is proposed that relates groundwater temperatures to mean annual land surface temperatures, building density, and elevated basement temperatures. Using this method regional groundwater temperatures can be accurately estimated with a mean absolute error of 0.9 K. Since land surface temperatures and building densities are available from remote sensing, this method has the potential for a large scale estimations of urban groundwater temperatures. Thus, it is feasible to detect subsurface urban heat islands on a global level and to investigate sustainable geothermal potentials using satellite derived data.

  18. Countermeasures to Urban Heat Islands: A Global View

    SciTech Connect

    Meier, Alan

    2006-07-17

    An important milestone was passed this year when the fraction of the world's population living in cities exceeded 50%. This shift from the countryside to urban areas is certain to continue and, for many, the destination will be large cities. Already there are over 400 cities with populations greater than one million inhabitants and twenty cities with populations greater than ten million inhabitants. With a growing fraction of the population living in an urban environment, the unique aspects of an urban climate also rise in importance. These include features like air pollution and increased humidity. Another unique feature of the urban climate is the phenomenon of the urban heat island. The urban heat island phenomenon was first observed over one hundred years ago in northern latitude cities, where the city centers were slightly warmer than the suburbs. (Instantaneous communications probably played a role in its identification, much as it did for other weather-related events.) For these cities, a heat island was generally a positive effect because it resulted in reduced heating requirements during the winters. It was only in the 1960s, as air conditioning and heavy reliance on automobiles grew, that the negative impacts of heat islands became apparent. The heat islands made summer conditions much less comfortable and increased air conditioning energy use. Since then the summer heat island has become the dominant environmental concern. Measurements in thousands of sites, plus the development of sophisticated dynamic simulations of urban air basins, has enabled us to better understand the relationships between urban temperatures, sunlight, and rates of formation of air pollutants. These models have also given us insights into the roles of vegetation and other characteristics of the land surface. More recently-roughly the last fifteen years-it has become possible to quantify the roles of the major features influencing the formation and persistence of urban heat islands

  19. Heat waves and urban heat islands in Europe: A review of relevant drivers.

    PubMed

    Ward, Kathrin; Lauf, Steffen; Kleinschmit, Birgit; Endlicher, Wilfried

    2016-11-01

    The climate change and the proceeding urbanization create future health challenges. Consequently, more people around the globe will be impaired by extreme weather events, such as heat waves. This study investigates the causes for the emergence of surface urban heat islands and its change during heat waves in 70 European cities. A newly created climate class indicator, a set of meaningful landscape metrics, and two population-related parameters were applied to describe the Surface Urban Heat Island Magnitude (SUHIM) - the mean temperature increase within the urban heat island compared to its surrounding, as well as the Heat Magnitude (HM) - the extra heat load added to the average summer SUHIM during heat waves. We evaluated the relevance of varying urban parameters within linear models. The exemplary European-wide heat wave in July 2006 was chosen and compared to the average summer conditions using MODIS land surface temperature with an improved spatial resolution of 250m. The results revealed that the initial size of the urban heat island had significant influence on SUHIM. For the explanation of HM the size of the heat island, the regional climate and the share of central urban green spaces showed to be critical. Interestingly, cities of cooler climates and cities with higher shares of urban green spaces were more affected by additional heat during heat waves. Accordingly, cooler northern European cities seem to be more vulnerable to heat waves, whereas southern European cities appear to be better adapted. Within the ascertained population and climate clusters more detailed explanations were found. Our findings improve the understanding of the urban heat island effect across European cities and its behavior under heat waves. Also, they provide some indications for urban planners on case-specific adaptation strategies to adverse urban heat caused by heat waves. PMID:27366983

  20. Laboratory simulation of turbulent convection over an urban heat island

    SciTech Connect

    Lu, J.; Arya, S.P.S.; Snyder, W.H.; Lawson, R.E.

    1992-01-01

    A systematic experimental study of the heat-island-induced circulation under turbulent conditions was conducted in the laboratory for an idealized, circular heat island in an initially thermally stratified fluid (water) in a convection tank with no ambient flow. The primary objectives of the study were to obtain a better understanding of the mean and turbulent flow generated by the heat island and to identify the appropriate similarity parameters and scales for simulating such a flow. Three non-dimensional similarity parameters were derived from the governing equations of motion. They are the convection Reynolds number (Re), the Froude number (Fr), and the Prandtl number (Pr). The data indicate that at sufficiently large Re, turbulent convection in the main flow becomes independent of Re which is the basis of the laboratory simulation. These measurements are also compared with field data from several cities and they agree with each other satisfactorily.

  1. The NSF-RCN Urban Heat Island Network

    NASA Astrophysics Data System (ADS)

    Twine, T. E.; Snyder, P. K.; Hamilton, P.; Shepherd, M.; Stone, B., Jr.

    2014-12-01

    In much of the world cities are warming at twice the rate of outlying rural areas. The frequency of urban heat waves is projected to increase with climate change through the 21stcentury. Addressing the economic, environmental, and human costs of urban heat islands requires a better understanding of their behavior from many disciplinary perspectives. The goal of this four-year Urban Heat Island Network is to (1) bring together scientists studying the causes and impacts of urban warming, (2) advance multidisciplinary understanding of urban heat islands, (3) examine how they can be ameliorated through engineering and design practices, and (4) share these new insights with a wide array of stakeholders responsible for managing urban warming to reduce their health, economic, and environmental impacts. The Urban Heat Island Network involves atmospheric scientists, engineers, architects, landscape designers, urban planners, public health experts, and education and outreach experts, who will share knowledge, evaluate research directions, and communicate knowledge and research recommendations to the larger research community as well as stakeholders engaged in developing strategies to adapt to and mitigate urban warming. The first Urban Climate Institute was held in Saint Paul, Minnesota in July 2013 and focused on the characteristics of urban heat islands. Scientists engaged with local practitioners to improve communication pathways surrounding issues of understanding, adapting to, and mitigating urban warming. The second Urban Climate Institute was held in Atlanta, Georgia in July 2014 and focused on urban warming and public health. Scientists discussed the state of the science on urban modeling, heat adaptation, air pollution, and infectious disease. Practitioners informed participants on emergency response methods and protocols related to heat and other extreme weather events. Evaluation experts at the Science Museum of Minnesota have extensively evaluated both Institutes

  2. Terrestrial heat flow in the North Island of New Zealand

    NASA Astrophysics Data System (ADS)

    Pandey, Om Prakash

    1981-07-01

    Large variations in terrestrial heat flow from 21 to 209 mW/m 2 have been observed over the North Island, New Zealand. This is generally in good agreement with the pattern of existing geological and geophysical observations. A high heat flow zone with a value of 92 ±3 mW/m 2, which corresponds to melting temperatures near the base of the crust, is delineated in the northern part of the Taranaki Basin. In the rest of the island, heat flow appears to be low to normal, but some isolated high values are also found. Observed results are interpreted in terms of crust and mantle structure in a region of plate subduction.

  3. Air pollution prevention through urban heat island mitigation: An update on the urban heat island pilot project

    SciTech Connect

    Gorsevski, V.; Taha, H.; Quattrochi, D.; Luvall, J.

    1998-07-01

    Urban heat islands increase the demand for cooling energy and accelerate the formation of smog. They are created when natural vegetation is replaced by heat-absorbing surfaces such as building roofs and walls, parking lots, and streets. Through the implementation of measures designed to mitigate the urban heat island, communities can decrease their demand for energy and effectively cool the metropolitan landscape. In addition to the economic benefits, using less energy leads to reductions in emission of CO{sub 2}--a greenhouse gas--as well as ozone (smog) precursors such as NOx and VOCs. Because ozone is created when NOx and VOCs photochemically combine with heat and solar radiation, actions taken to lower ambient air temperature can significantly reduce ozone concentrations in certain areas. Measures to reverse the urban heat island include afforestation and the widespread use of highly reflective surfaces. To demonstrate the potential benefits of implementing these measures, EPA has teamed up with NASA and LBNL to initiate a pilot project with three US cities. As part of the pilot, NASA will use remotely-sensed data to quantify surface temperature, albedo, the thermal response number and NDVI vegetation of each city. This information will be used by scientists at Lawrence Berkeley National Laboratory (LBNL) along with other data as inputs to model various scenarios that will help quantify the potential benefits of urban heat island mitigation measures in terms of reduced energy use and pollution. This paper will briefly describe this pilot project and provide an update on the progress to date.

  4. Pool heating system on island brings year-round enjoyment

    SciTech Connect

    Not Available

    1993-01-01

    The Bahamas is not generally thought of as a place in need of pool heating. However, the remote Bahamian island of Treasure Cay is actually situated north of Ft. Lauderdale, Florida. Pool temperatures drop during the winter, thus shortening the swimming season. The Beach Villas Homeowners Association of Treasure Cay investigated pool-heating options some time ago. Energy on Treasure Cay is expensive - about 25 cents/kWh - making cost a major concern for the association as they evaluated their choices. An electric heat pump was rule out as it would place too great a burden on the electricity load of the remote island. Heating the pool with propane gas was deemed far too costly. After evaluating each of these heating methods on the basis of economics, energy efficiency, and comfort, the association concluded that solar would be the best method. They selected a solar pool heating system manufactured by FAFCO, Inc. and installed by SUNWORKS in Ft. Lauderdale. The system requires virtually no daily maintenance, and there have been no problems with the system since its installation. In addition to being trouble-free, the FAFCO solar pool heater has saved Treasure Cay a great deal of money. The equipment cost about $9,500; lumber, PVC, and labor brought the total cost to $13,000. By comparison, a propane-gas system would have cost $4,000 but would have generated a yearly gas bill of $12,000. Therefore, payback on the system began immediately upon installation.

  5. The urban heat island dynamics during heat waves: a study of cities in the United States

    NASA Astrophysics Data System (ADS)

    Hu, Leiqiu

    2016-04-01

    The urban heat island (UHI) is a common phenomenon describing that metropolitan areas are usually warmer than their rural surroundings. This effect is compounded by extreme heat events, which are a leading cause of weather-related human mortality in many countries worldwide. However, the spatial and diurnal variability of temperature and humidity in urban and adjacent rural areas during extreme heat events is not well measured and therefore not well understood. The recently developed dataset of near-surface air and dew temperature from MODIS atmospheric profiles and the new method for the UHI quantification--urban heat island curve are used to quantify the urban climatic changes during heat waves in cities of the United States. The enhanced and weakened UHIs are observed in various cities. The causes of UHI changes during heat waves are discussed, including climate region, vegetation type and amount, city geolocation, etc.

  6. The NSF-RCN Urban Heat Island Network

    NASA Astrophysics Data System (ADS)

    Twine, T. E.; Snyder, P. K.; Hamilton, P.; Shepherd, M.; Stone, B., Jr.

    2015-12-01

    In much of the world cities are warming at twice the rate of outlying rural areas. The frequency of urban heat waves is projected to increase with climate change through the 21st century. Addressing the economic, environmental, and human costs of urban heat islands requires a better understanding of their behavior from many disciplinary perspectives. The goal of this four-year Urban Heat Island Network is to (1) bring together scientists studying the causes and impacts of urban warming, (2) advance multidisciplinary understanding of urban heat islands, (3) examine how they can be ameliorated through engineering and design practices, and (4) share these new insights with a wide array of stakeholders responsible for managing urban warming to reduce their health, economic, and environmental impacts. The NSF-RCN Urban Heat Island Network involves atmospheric scientists, engineers, architects, landscape designers, urban planners, public health experts, and education and outreach experts, who will share knowledge, evaluate research directions, and communicate knowledge and research recommendations to the larger research community as well as stakeholders engaged in developing strategies to adapt to and mitigate urban warming. The first Urban Climate Institute was held in Saint Paul, MN in July 2013 and focused on the characteristics of urban heat islands. Scientists engaged with local practitioners to improve communication pathways surrounding issues of understanding, adapting to, and mitigating urban warming. The second Urban Climate Institute was held in Atlanta, Georgia in July 2014 and focused on urban warming and public health. The third Urban Climate Institute was held in Athens, GA in July 2015 and focused on urban warming and the role of the built environment. Scientists and practitioners discussed strategies for mitigation and adaptation. Evaluation experts at the Science Museum of Minnesota have extensively evaluated the Institutes to inform other research

  7. Quantifying urban heat island intensity in Hong Kong SAR, China.

    PubMed

    Siu, Leong Wai; Hart, Melissa A

    2013-05-01

    This paper addresses the methodological concerns in quantifying urban heat island (UHI) intensity in Hong Kong SAR, China. Although the urban heat island in Hong Kong has been widely investigated, there is no consensus on the most appropriate fixed point meteorological sites to be used to calculate heat island intensity. This study utilized the Local Climate Zones landscape classification system to classify 17 weather stations from the Hong Kong Observatory's extensive fixed point meteorological observation network. According to the classification results, the meteorological site located at the Hong Kong Observatory Headquarters is the representative urban weather station in Hong Kong, whereas sites located at Tsak Yue Wu and Ta Kwu Ling are appropriate rural or nonurbanized counterparts. These choices were validated and supported quantitatively through comparison of long-term annual and diurnal UHI intensities with rural stations used in previous studies. Results indicate that the rural stations used in previous studies are not representative, and thus, the past UHI intensities calculated for Hong Kong may have been underestimated. PMID:23007798

  8. Surface urban heat island across 419 global big cities.

    PubMed

    Peng, Shushi; Piao, Shilong; Ciais, Philippe; Friedlingstein, Pierre; Ottle, Catherine; Bréon, François-Marie; Nan, Huijuan; Zhou, Liming; Myneni, Ranga B

    2012-01-17

    Urban heat island is among the most evident aspects of human impacts on the earth system. Here we assess the diurnal and seasonal variation of surface urban heat island intensity (SUHII) defined as the surface temperature difference between urban area and suburban area measured from the MODIS. Differences in SUHII are analyzed across 419 global big cities, and we assess several potential biophysical and socio-economic driving factors. Across the big cities, we show that the average annual daytime SUHII (1.5 ± 1.2 °C) is higher than the annual nighttime SUHII (1.1 ± 0.5 °C) (P < 0.001). But no correlation is found between daytime and nighttime SUHII across big cities (P = 0.84), suggesting different driving mechanisms between day and night. The distribution of nighttime SUHII correlates positively with the difference in albedo and nighttime light between urban area and suburban area, while the distribution of daytime SUHII correlates negatively across cities with the difference of vegetation cover and activity between urban and suburban areas. Our results emphasize the key role of vegetation feedbacks in attenuating SUHII of big cities during the day, in particular during the growing season, further highlighting that increasing urban vegetation cover could be one effective way to mitigate the urban heat island effect. PMID:22142232

  9. 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

  10. An alternative method to characterize the surface urban heat island.

    PubMed

    Martin, Philippe; Baudouin, Yves; Gachon, Philippe

    2015-07-01

    An urban heat island (UHI) is a relative measure defined as a metropolitan area that is warmer than the surrounding suburban or rural areas. The UHI nomenclature includes a surface urban heat island (SUHI) definition that describes the land surface temperature (LST) differences between urban and suburban areas. The complexity involved in selecting an urban core and external thermal reference for estimating the magnitude of a UHI led us to develop a new definition of SUHIs that excludes any rural comparison. The thermal reference of these newly defined surface intra-urban heat islands (SIUHIs) is based on various temperature thresholds above the spatial average of LSTs within the city's administrative limits. A time series of images from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) from 1984 to 2011 was used to estimate the LST over the warm season in Montreal, Québec, Canada. Different SIUHI categories were analyzed in consideration of the global solar radiation (GSR) conditions that prevailed before each acquisition date of the Landsat images. The results show that the cumulative GSR observed 24 to 48 h prior to the satellite overpass is significantly linked with the occurrence of the highest SIUHI categories (thresholds of +3 to +7 °C above the mean spatial LST within Montreal city). The highest correlation (≈0.8) is obtained between a pixel-based temperature that is 6 °C hotter than the city's mean LST (SIUHI + 6) after only 24 h of cumulative GSR. SIUHI + 6 can then be used as a thermal threshold that characterizes hotspots within the city. This identification approach can be viewed as a useful criterion or as an initial step toward the development of heat health watch and warning system (HHWWS), especially during the occurrence of severe heat spells across urban areas. PMID:25234752

  11. An alternative method to characterize the surface urban heat island

    NASA Astrophysics Data System (ADS)

    Martin, Philippe; Baudouin, Yves; Gachon, Philippe

    2015-07-01

    An urban heat island (UHI) is a relative measure defined as a metropolitan area that is warmer than the surrounding suburban or rural areas. The UHI nomenclature includes a surface urban heat island (SUHI) definition that describes the land surface temperature (LST) differences between urban and suburban areas. The complexity involved in selecting an urban core and external thermal reference for estimating the magnitude of a UHI led us to develop a new definition of SUHIs that excludes any rural comparison. The thermal reference of these newly defined surface intra-urban heat islands (SIUHIs) is based on various temperature thresholds above the spatial average of LSTs within the city's administrative limits. A time series of images from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) from 1984 to 2011 was used to estimate the LST over the warm season in Montreal, Québec, Canada. Different SIUHI categories were analyzed in consideration of the global solar radiation (GSR) conditions that prevailed before each acquisition date of the Landsat images. The results show that the cumulative GSR observed 24 to 48 h prior to the satellite overpass is significantly linked with the occurrence of the highest SIUHI categories (thresholds of +3 to +7 °C above the mean spatial LST within Montreal city). The highest correlation (≈0.8) is obtained between a pixel-based temperature that is 6 °C hotter than the city's mean LST (SIUHI + 6) after only 24 h of cumulative GSR. SIUHI + 6 can then be used as a thermal threshold that characterizes hotspots within the city. This identification approach can be viewed as a useful criterion or as an initial step toward the development of heat health watch and warning system (HHWWS), especially during the occurrence of severe heat spells across urban areas.

  12. Linking Surface Urban Heat Islands with Groundwater Temperatures.

    PubMed

    Benz, Susanne A; Bayer, Peter; Goettsche, Frank M; Olesen, Folke S; Blum, Philipp

    2016-01-01

    Urban temperatures are typically, but not necessarily, elevated compared to their rural surroundings. This phenomenon of urban heat islands (UHI) exists both above and below the ground. These zones are coupled through conductive heat transport. However, the precise process is not sufficiently understood. Using satellite-derived land surface temperature and interpolated groundwater temperature measurements, we compare the spatial properties of both kinds of heat islands in four German cities and find correlations of up to 80%. The best correlation is found in older, mature cities such as Cologne and Berlin. However, in 95% of the analyzed areas, groundwater temperatures are higher than land surface temperatures due to additional subsurface heat sources such as buildings and their basements. Local groundwater hot spots under city centers and under industrial areas are not revealed by satellite-derived land surface temperatures. Hence, we propose an estimation method that relates groundwater temperatures to mean annual land-surface temperatures, building density, and elevated basement temperatures. Using this method, we are able to accurately estimate regional groundwater temperatures with a mean absolute error of 0.9 K. PMID:26595444

  13. 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.

  14. 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

  15. Vertical extension of the urban heat island above Moscow

    NASA Astrophysics Data System (ADS)

    Lokoshchenko, M. A.; Korneva, I. A.; Kochin, A. V.; Dubovetsky, A. Z.; Novitsky, M. A.; Razin, P. Ye.

    2016-01-01

    The vertical extension of the urban "heat island" (UHI) has been studied on the basis of long-term data of contact air temperature measurements at three places for the example of Moscow. The existence of steady thermal anomaly related to the city in the form of a UHI in the surface layer at any time of the day and also the existence of a cold layer over it at heights higher than 100 m at night were confirmed. The mean daily altitudinal extension of this anomaly is approximately 300 m.

  16. Monitoring the Surface Heat Island (shi) Effects of Industrial Enterprises

    NASA Astrophysics Data System (ADS)

    Şekertekin, A.; Kutoglu, Ş. H.; Kaya, S.; Marangoz, A. M.

    2016-06-01

    The aim of this study is to present the effects of industrial enterprises on Land Surface Temperature (LST) and to retrieve Surface Heat Island (SHI) maps of these regions. SHI is one of the types of Urban Heat Island (UHI) and as the urban areas grow in a city, UHI effect becomes bigger. The city centre of Zonguldak was chosen as study area and Landsat 5 satellite data were used as materials. Zonguldak has important industrial enterprises like thermal power plants and iron and steel plant. ERDEMIR is the biggest iron and steel plant in Turkey and it is one of the biggest ones in Europe, as well. There are three operating thermal power plants in the region namely CATES, ZETES1 and ZETES2. In order to investigate these industrial regions, Landsat 5 satellite data were processed using mono-window algorithm to retrieve LST and they were acquired on 11.09.1987, 18.09.2007 and 29.09.2011, respectively. The obtained results revealed that from 1987 to 2011, spatial and temporal variability in LST in industrial enterprises became higher than the surroundings. Besides, the sizes of SHIs in 2011 are bigger than the ones in 1987. For the countries and governments, having industrial enterprises is crucial for the development and it is also important to present the community better conditions in life. Thus, decision makers should consider mitigating the effects of these regions on LST.

  17. Mesoscale thermal model for urban heat island mitigation

    NASA Astrophysics Data System (ADS)

    Silva, Humberto Ramon

    A simple energy balance model is created for use in developing mitigation strategies for the Urban Heat Island (UHI) effect. The model is applied to the city of Phoenix, Arizona, USA. There are six primary contributions to the overall energy balance: incident solar radiation, anthropogenic heat input, conduction heat loss, outgoing evapotranspiration, outgoing convection, and outgoing emitted radiation. The model temperature is shown to have the same periodic behavior as the experimentally measured air temperatures. The present model, while maintaining valid energy-balance physics, allows users to quickly and easily predict the relative effects of urban heat island mitigation measures. Accordingly, this model is applied here to show the relative effects of four common mitigation strategies: increasing the overall (1) emissivity, (2) percentage of vegetated area, (3) thermal conductivity, and (4) albedo of the urban environment in a series of percentage increases by 5, 10, 15, and 20 percent from baseline values. In addition to modeling mitigation strategies, the model is utilized to evaluate human health vulnerability from excessive heat-related events, based on heat-related emergency service data from 2002 to 2006. The four modeled UHI mitigation strategies, taken in combination, would lead to a 48 percent reduction in annual heat-related emergency service calls, where increasing the albedo is the single most effective UHI mitigation strategy. Finally, a spatial superposition design is presented that couples this model with the more robust fifth-generation Pennsylvania State University - National Center for Atmospheric Research Mesoscale Model (MM5). As a result, a new hypothesis is conceived which states that perturbation values from the norm temperature do not change when certain mitigation strategies are imposed. It is shown from demonstrative spatial mitigation schemes that having a fewer number of mitigated points (by almost half) on a square urban grid in

  18. Long-term evolution of anthropogenic heat fluxes into a subsurface urban heat island.

    PubMed

    Menberg, Kathrin; Blum, Philipp; Schaffitel, Axel; Bayer, Peter

    2013-09-01

    Anthropogenic alterations in urban areas influence the thermal environment causing elevated atmospheric and subsurface temperatures. The subsurface urban heat island effect is observed in several cities. Often shallow urban aquifers exist with thermal anomalies that spread laterally and vertically, resulting in the long-term accumulation of heat. In this study, we develop an analytical heat flux model to investigate possible drivers such as increased ground surface temperatures (GSTs) at artificial surfaces and heat losses from basements of buildings, sewage systems, subsurface district heating networks, and reinjection of thermal wastewater. By modeling the anthropogenic heat flux into the subsurface of the city of Karlsruhe, Germany, in 1977 and 2011, we evaluate long-term trends in the heat flux processes. It revealed that elevated GST and heat loss from basements are dominant factors in the heat anomalies. The average total urban heat flux into the shallow aquifer in Karlsruhe was found to be ∼759 ± 89 mW/m(2) in 1977 and 828 ± 143 mW/m(2) in 2011, which represents an annual energy gain of around 1.0 × 10(15) J. However, the amount of thermal energy originating from the individual heat flux processes has changed significantly over the past three decades. PMID:23895264

  19. [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. PMID:24697063

  20. 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

  1. The footprint of urban heat island effect in China.

    PubMed

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

    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 (FP, including urban area) was 2.3 and 3.9 times of urban size for the day and night, respectively, with large spatiotemporal heterogeneities. We further revealed that ignoring the FP may underestimate the UHI intensity in most cases and even alter the direction of UHI estimates for few cities. Our results provide new insights to the characteristics of UHI effect and emphasize the necessity of considering city- and time-specific FP when assessing the urbanization effects on local climate. PMID:26060039

  2. The footprint of urban heat island effect in China

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

    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 (FP, including urban area) was 2.3 and 3.9 times of urban size for the day and night, respectively, with large spatiotemporal heterogeneities. We further revealed that ignoring the FP may underestimate the UHI intensity in most cases and even alter the direction of UHI estimates for few cities. Our results provide new insights to the characteristics of UHI effect and emphasize the necessity of considering city- and time-specific FP when assessing the urbanization effects on local climate.

  3. The footprint of urban heat island effect in China

    PubMed Central

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

    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 (FP, including urban area) was 2.3 and 3.9 times of urban size for the day and night, respectively, with large spatiotemporal heterogeneities. We further revealed that ignoring the FP may underestimate the UHI intensity in most cases and even alter the direction of UHI estimates for few cities. Our results provide new insights to the characteristics of UHI effect and emphasize the necessity of considering city- and time-specific FP when assessing the urbanization effects on local climate. PMID:26060039

  4. 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. PMID:21481997

  5. Data concurrency is required for estimating urban heat island intensity.

    PubMed

    Zhao, Shuqing; Zhou, Decheng; Liu, Shuguang

    2016-01-01

    Urban heat island (UHI) can generate profound impacts on socioeconomics, human life, and the environment. Most previous studies have estimated UHI intensity using outdated urban extent maps to define urban and its surrounding areas, and the impacts of urban boundary expansion have never been quantified. Here, we assess the possible biases in UHI intensity estimates induced by outdated urban boundary maps using MODIS Land surface temperature (LST) data from 2009 to 2011 for China's 32 major cities, in combination with the urban boundaries generated from urban extent maps of the years 2000, 2005 and 2010. Our results suggest that it is critical to use concurrent urban extent and LST maps to estimate UHI at the city and national levels. Specific definition of UHI matters for the direction and magnitude of potential biases in estimating UHI intensity using outdated urban extent maps. PMID:26243476

  6. Investigation of Urban Heat Island Intensity in Istanbul

    NASA Astrophysics Data System (ADS)

    Irem Bilgen, Simge; Unal, Yurdanur S.; Yuruk, Cemre; Goktepe, Nur; Diren, Deniz; Topcu, Sema; Mentes, Sibel; Incecik, Selahattin; Guney, Caner; Ozgur Dogru, Ahmet

    2016-04-01

    Urban heat island (UHI) is defined as the temperature difference between the urbanized areas and their surroundings due to local surface energy balance since urban materials and build up structures modify the heating and cooling rates of the ambient air. Istanbul is the largest city of Turkey with the population over 14 million inhabitants and the urbanization is drastically expanded since 1965 due to the population increase from 2 million to 14 million. In this study we investigate impacts of urban expansion on meteorological variables in relation to the UHI effect in Istanbul. To estimate the strength of UHI, temperature differences between urban and suburban stations are calculated by using temperature observations from 6 stations for 1960-2013 years, and 34 stations for 2007-2012. The results show that, the UHI intensity is stronger during summer season and Kartal experiences intensified UHI effect more than the others. The daytime(nighttime) UHI intensity defined with respect to Şile (suburban) varies between 0.41°C and 3.0°C (1.02°C and 2.18°C). The atmospheric UHI usually reaches its highest intensity on summer nights, and under calm air and a cloudless sky. Therefore, the total of 127 dry days, which have cloudiness less than 2/8 and wind speed less than 2 m/s are selected to estimate the strength of UHI in Istanbul. The hourly temperature differences between a selected urban station (Pendik) and a rural station (Terkos), are calculated as 5°C for daytime and 8°C for the nighttime. The urbanization negatively impacts the heat stress of urban areas. So that it is important to investigate what type of changes in the urban landscape affect the near-surface climate and elevate the intensity of UHI in the city. The relationship between urbanization and long-term modification of the urban climate of Istanbul is investigated by modeling the present-day spatial distribution of the urban heat load. Geographical data of the Istanbul Metropolitan Municipality

  7. Cooler paving materials for heat-island mitigation

    SciTech Connect

    Pomerantz, M.; Akbari, H.

    1998-07-01

    Many cities suffer summer daytime temperatures greater than their suburban or rural surroundings. One of the causes of this heat island phenomenon is the absorption of sunlight by dark pavements. In warm climates, the urban heating damages the environment by adding to air-conditioning demand and creating smog. If urban roads, driveways and walkways were paved with light colored, and consequently cooler, materials these penalties would be diminished. However, lighter materials may cost more than the usual asphalt materials, In this report, the dollar value of potential air conditioning and smog savings from lighter pavements is estimated, and compared to the extra cost of such roads. The extra cost is minimized if the lighter-colored coating is applied as a thin layer when normal maintenance is performed. The authors find that, in Los Angeles, increasing the albedo from 0.1 to 0.35, could produce an air-conditioning saving of $0.012/m{sub 2}-yr. and smog savings of about $0.06/m{sub 2}-yr. The present value of these savings, for the 5 year lifetime of the resurfacing, is about 5 times the annual saving, or about $0.36/m{sub 2}. (The particular climate and smog problem clearly influence this result.) Thus one could purchase a cooler material whose extra cost is this amount, with no net expense. If roads are cooler they may also last longer and thus save money.

  8. Mitigation of urban heat islands: meteorology, energy, and airquality impacts

    SciTech Connect

    Taha, Haider; Meier, Alan; Gao, Weijun; Ojima, Toshio

    1999-09-30

    This paper presents results from energy, meteorological andphotochemical (air quality) modeling for the Los Angeles Basin, one ofthe largest and smoggiest urban regions in the U.S. and the world. Oursimulations suggest that by mitigating urban heat islands, savings of 5to 10 percent peak utility load may be possible. In addition, heat islandmitigation can reduce smog formation by 10-20 percent. in summer, whichis as effective as controlling emissions from all mobile sources in theregion. For a typical late-August episode, our simulations suggest thatimplementing cool cities in the Los Angeles Basin would have a net effectof reducing ozone concentrations. Peak concentrations at 3 pm decrease byup to 7 percent (from 220 down to 205 ppb) while the total ozone mass inthe mixed layer decreases by up to 640 metric tons (a decrease of 4.7percent). Largest reductions in concentrations at 3 pm are on the orderof 50 ppb whereas the largest increases are on the order of 20 ppb. Withrespect to the National Ambient Air Quality Standard, domain widepopulation weighted exceedance exposure to ozone decreases by up to 20percent during peak afternoon hours and by up to 10 percent during thedaytime.

  9. Urban heat islands in China enhanced by haze pollution

    PubMed Central

    Cao, Chang; Lee, Xuhui; Liu, Shoudong; Schultz, Natalie; Xiao, Wei; Zhang, Mi; Zhao, Lei

    2016-01-01

    The urban heat island (UHI), the phenomenon of higher temperatures in urban land than the surrounding rural land, is commonly attributed to changes in biophysical properties of the land surface associated with urbanization. Here we provide evidence for a long-held hypothesis that the biogeochemical effect of urban aerosol or haze pollution is also a contributor to the UHI. Our results are based on satellite observations and urban climate model calculations. We find that a significant factor controlling the nighttime surface UHI across China is the urban–rural difference in the haze pollution level. The average haze contribution to the nighttime surface UHI is 0.7±0.3 K (mean±1 s.e.) for semi-arid cities, which is stronger than that in the humid climate due to a stronger longwave radiative forcing of coarser aerosols. Mitigation of haze pollution therefore provides a co-benefit of reducing heat stress on urban residents. PMID:27551987

  10. Urban heat islands in China enhanced by haze pollution.

    PubMed

    Cao, Chang; Lee, Xuhui; Liu, Shoudong; Schultz, Natalie; Xiao, Wei; Zhang, Mi; Zhao, Lei

    2016-01-01

    The urban heat island (UHI), the phenomenon of higher temperatures in urban land than the surrounding rural land, is commonly attributed to changes in biophysical properties of the land surface associated with urbanization. Here we provide evidence for a long-held hypothesis that the biogeochemical effect of urban aerosol or haze pollution is also a contributor to the UHI. Our results are based on satellite observations and urban climate model calculations. We find that a significant factor controlling the nighttime surface UHI across China is the urban-rural difference in the haze pollution level. The average haze contribution to the nighttime surface UHI is 0.7±0.3 K (mean±1 s.e.) for semi-arid cities, which is stronger than that in the humid climate due to a stronger longwave radiative forcing of coarser aerosols. Mitigation of haze pollution therefore provides a co-benefit of reducing heat stress on urban residents. PMID:27551987

  11. Temporal dynamics of the urban heat island of Singapore

    NASA Astrophysics Data System (ADS)

    Chow, Winston T. L.; Roth, Matthias

    2006-12-01

    The temporal variability of the canopy-level urban heat island (UHI) of Singapore is examined for different temporal scales on the basis of observations during a 1-year period. Temperature data obtained from different urban areas (commercial, Central Business District (CBD), high-rise and low-rise housing) are compared with rural reference data and analysed with respect to meteorological variables and differences in land use. The results indicate that the peak UHI magnitude occurs 3-4 h (>6 h) after sunset in the commercial area, (at other urban sites). Higher UHI intensities generally occur during the southwest monsoon period of May-August, with a maximum of 7 °C observed in the commercial area under ideal meteorological conditions. Variations in seasonal precipitation explain some of the differences in urban-rural cooling. No clear relationship between urban geometry and UHI intensity can be seen, and intra-urban variations of temperature are also shown to be influenced by other site factors, e.g. the extent of green space and anthropogenic heat. Lastly, results from the present study are compared with UHI data from other tropical and mid-latitude cities.

  12. Strong contributions of local background climate to urban heat islands.

    PubMed

    Zhao, Lei; Lee, Xuhui; Smith, Ronald B; Oleson, Keith

    2014-07-10

    The urban heat island (UHI), a common phenomenon in which surface temperatures are higher in urban areas than in surrounding rural areas, represents one of the most significant human-induced changes to Earth's surface climate. Even though they are localized hotspots in the landscape, UHIs have a profound impact on the lives of urban residents, who comprise more than half of the world's population. A barrier to UHI mitigation is the lack of quantitative attribution of the various contributions to UHI intensity (expressed as the temperature difference between urban and rural areas, ΔT). A common perception is that reduction in evaporative cooling in urban land is the dominant driver of ΔT (ref. 5). Here we use a climate model to show that, for cities across North America, geographic variations in daytime ΔT are largely explained by variations in the efficiency with which urban and rural areas convect heat to the lower atmosphere. If urban areas are aerodynamically smoother than surrounding rural areas, urban heat dissipation is relatively less efficient and urban warming occurs (and vice versa). This convection effect depends on the local background climate, increasing daytime ΔT by 3.0 ± 0.3 kelvin (mean and standard error) in humid climates but decreasing ΔT by 1.5 ± 0.2 kelvin in dry climates. In the humid eastern United States, there is evidence of higher ΔT in drier years. These relationships imply that UHIs will exacerbate heatwave stress on human health in wet climates where high temperature effects are already compounded by high air humidity and in drier years when positive temperature anomalies may be reinforced by a precipitation-temperature feedback. Our results support albedo management as a viable means of reducing ΔT on large scales. PMID:25008529

  13. 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.

  14. 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.

  15. Strong contributions of local background climate to urban heat islands

    NASA Astrophysics Data System (ADS)

    Zhao, Lei; Lee, Xuhui; Smith, Ronald B.; Oleson, Keith

    2014-07-01

    The urban heat island (UHI), a common phenomenon in which surface temperatures are higher in urban areas than in surrounding rural areas, represents one of the most significant human-induced changes to Earth's surface climate. Even though they are localized hotspots in the landscape, UHIs have a profound impact on the lives of urban residents, who comprise more than half of the world's population. A barrier to UHI mitigation is the lack of quantitative attribution of the various contributions to UHI intensity (expressed as the temperature difference between urban and rural areas, ΔT). A common perception is that reduction in evaporative cooling in urban land is the dominant driver of ΔT (ref. 5). Here we use a climate model to show that, for cities across North America, geographic variations in daytime ΔT are largely explained by variations in the efficiency with which urban and rural areas convect heat to the lower atmosphere. If urban areas are aerodynamically smoother than surrounding rural areas, urban heat dissipation is relatively less efficient and urban warming occurs (and vice versa). This convection effect depends on the local background climate, increasing daytime ΔT by 3.0 +/- 0.3 kelvin (mean and standard error) in humid climates but decreasing ΔT by 1.5 +/- 0.2 kelvin in dry climates. In the humid eastern United States, there is evidence of higher ΔT in drier years. These relationships imply that UHIs will exacerbate heatwave stress on human health in wet climates where high temperature effects are already compounded by high air humidity and in drier years when positive temperature anomalies may be reinforced by a precipitation-temperature feedback. Our results support albedo management as a viable means of reducing ΔT on large scales.

  16. Diurnal cycle of the Oklahoma City urban heat island

    NASA Astrophysics Data System (ADS)

    Basara, Jeffrey B.; Hall, Peter K.; Schroeder, Amanda J.; Illston, Bradley G.; Nemunaitis, Kodi L.

    2008-10-01

    Between the dates of 28 June and 31 July 2003, the Joint Urban 2003 (JU2003) field project was conducted in Oklahoma City and was the largest urban dispersion experiment ever in North America. Because the focus of JU2003 was on atmospheric processes within the urban environment, an extremely dense network of instrumentation was deployed in and around the central business district (CBD) both prior to and during the field experiment. Among the variables collected were high-resolution observations of air temperature from various instrument sources. Additional observations of air temperature were also collected at Oklahoma Mesonet stations in the rural areas surrounding Oklahoma City. Using an index value, the diurnal cycle of the urban heat island (UHI) for Oklahoma City, with respect to the surrounding rural terrain, was quantified. The results revealed a consistent mean nocturnal UHI greater than 1.5°C at both 2 and 9 m. However, observations at 2 m during JU2003 revealed a significant urban "cool" island during the convective portion of the day. The mean variability of temperature within the urban core of Oklahoma City increased significantly after sunrise, increased to a maximum near solar noon, and decreased following sunset. These results were inconsistent with the rural observations wherein the variability among sites was maximized during the nocturnal period. Finally, the vertical temperature gradient between 2 and 9 m demonstrated a clear and strong diurnal trend at the rural locations, whereas observations from the urban environment were nearly isothermal and consistent with near-neutral conditions throughout JU2003.

  17. 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

  18. Tracking the Spatial Evolution of Urban Heat Islands

    NASA Astrophysics Data System (ADS)

    Zhu, Rui; Guilbert, Eric; Wong, Man Sing

    2016-06-01

    The urban heat island (UHI) phenomenon occurring in the urban areas or city-clusters is increasingly becoming a severe problem in the urbanization process. Previous research mainly rely on grid analysis techniques to study temperature data from images recorded at fixed time instants. The evolutionary process of UHI in both time and space has not been investigated yet. This research designs an object-oriented spatiotemporal model to reconstruct the evolution of UHI and provide a qualitative interpretation. Each UHI is modeled as a spatiotemporal field object with it own life cycle. Dynamic behavior of an UHI is defined by sequences of spatial changes (e.g. contraction or expansion) and topological transformations (e.g. merge or split). The model is implemented in an object-relational database and applied to air temperature data collected from weather stations every hour over three days. UHIs with their behavior were extracted from the data. Results suggest that the model can effectively track and provide a qualitative description of the UHI evolution.

  19. Temporal variability of the Buenos Aires, Argentina, urban heat island

    NASA Astrophysics Data System (ADS)

    Camilloni, Inés; Barrucand, Mariana

    2012-01-01

    This paper describes the statistical characteristics and temporal variability of the urban heat island (UHI) intensity in Buenos Aires using 32-year surface meteorological data with 1-h time intervals. Seasonal analyses show that the UHI intensity is strongest during summer months and an "inverse" effect is found frequently during the afternoon hours of the same season. During winter, the UHI effect is in the minimal. The interannual trend and the seasonal variation of the UHI for the main synoptic hours for a longer record of 48 years are studied and associated to changes in meteorological factors as low-level circulation and cloud amount. Despite the population growth, it was found a negative trend in the nocturnal UHI intensity that could be explained by a decline of near clear-sky conditions, a negative trend in the calm frequencies and an increase in wind speed. Urban to rural temperature differences and rural temperatures are negatively correlated for diurnal and nocturnal hours both for annual and seasonal scales. This result is due to the lower interannual variability of urban temperatures in comparison to rural ones.

  20. 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.

  1. 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.

  2. 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)

  3. The urban heat island in a small city in coastal Portugal.

    PubMed

    Pinho, O S; Orgaz, M D

    2000-11-01

    This project arose from the need to study the phenomenon of the urban heat island, since only by recognising this phenomenon can we moderate it to improve the human and urban environments. Not only big cities develop urban heat islands. This study detected the presence and recorded the characteristics of an urban heat island in the small coastal city of Aveiro, Portugal. The study was developed through the scheduled measurements of air temperature and the analysis of the geographical, meteorological and urban conditions. The form and intensity of Aveiro's heat island are a response to the interaction of three principal factors: the urban morphology (the hottest zones in the city are those with the tallest and the highest density of buildings, without green spaces and with intense generation of heat from traffic, commerce and services); the meteorological conditions (the intensity of the island is at its maximum when the sky is totally clear and there is no wind, and at its minimum in those situations when there is atmospheric instability, such as wind, cloud and precipitation); and the proximity of the coastal lagoon (which borders the city to the west and northwest and moderates seasonal temperatures. The urban heat island influences the comfort and health of its inhabitants, thus urban planning is very important in the moderation and prevention of this phenomenon. PMID:11131292

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

    SciTech Connect

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

    2009-03-15

    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 {chi}{sub e} inside the island is determined by matching the simulated signals with the experimental ones. Inside the island, {chi}{sub e} 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.

  5. A Multi-City Analysis of the Natural and Human Drivers of the Urban Heat Island

    NASA Astrophysics Data System (ADS)

    Hertel, William Frederick

    The world's population is increasingly moving to cities, with a present day urban population of over 3.6 billion that is expected to nearly double by 2050. One of the key features of the urban environment is an increase in temperature relative to the surrounding rural areas, called the urban heat island, which can have negative impacts on the health and wellbeing of urban dwellers. This study uses a novel approach of analyzing a large number of cities from around the world to investigate the similarities and differences in urban environments among cities to explore the behavior and drivers of the urban heat island. This methodology reveals two new conditions that increase the magnitude of the heat island---low dewpoint temperature and high air temperature. Many of the cities show increases in the magnitude of the heat island during hot or dry periods of 1.0°C or more during the daytime and 2.0°C at night relative to cool or humid periods. The heat wave results are of particular note due to the added stress on urban residents during periods when the population is already at risk. For cities in temperate climate regimes, differences among cities in vegetative cover or impervious surface area leads to increases in urban temperatures of up to 1.0°C during the summer, while cities with high pollution can see reductions in the heat island by 1.5°C. Cities in tropical or Mediterranean climates have the strongest heat islands during the dry season indicating that urban infrastructure is the key driver in these cities. These results indicate that mitigation of the urban heat island is possible by altering the urban landscape through changes in the urban vegetation and the structure of the built environment.

  6. Characterizing the Urban Heat Island with a Dense Sensor Network

    NASA Astrophysics Data System (ADS)

    Snyder, P. K.; Twine, T. E.; Smoliak, B. V.; Mykleby, P.; Hertel, W. F.

    2014-12-01

    Urban heat islands (UHIs) occur when urban and suburban areas experience temperatures that are elevated relative to their rural surroundings because of differences in the fraction of gray and green infrastructure. Traditional methods of characterizing UHIs rely on the comparison of near-surface air temperature measurements between few sites in an urban area with those in a nearby rural area. This methodology assumes (1) that the UHI can be characterized by the difference in air temperature from a small number of points, and (2) that these few points represent the urban and rural signatures of the region. While this methodology makes it possible to compare the UHI of cities around the globe, it ignores the rich information that could be gained from measurements across the urban to rural transect. This transect could traverse elevations, water bodies, vegetation fraction, and other land surface properties. We deployed a network of ~200 temperature sensors across the Twin Cities Metropolitan Area (TCMA) beginning in July 2011 and continuing to the present. Our network covers a 5000-km2 area encompassing the cities of Minneapolis and Saint Paul as well as suburban and rural areas within the seven-county region. The TCMA includes ~3.4 million people, nearly 900 lakes, and two major interstate highways and a beltway system. We employed a cokriging method to interpolate sensor measurements onto a continuous grid using satellite-based impervious surface fraction data. Our results show consistent warm anomalies, when compared with a background rural temperature, over the two downtown cores and along major highways and dense suburban areas. Anomalies switch between positive and negative values (i.e., warmer or cooler than the rural, respectively) depending on season over large lakes. The warm season (May - October) average TCMA UHI (all urban areas - all rural areas) peaks at night at 1.5 °C, while the cold season (November - April) UHI is ~1 °C and is less variable over

  7. Potential Drivers of Urban Heat Island in Northeast USA Cities

    NASA Astrophysics Data System (ADS)

    Zhang, P.; Imhoff, M. L.; Wolfe, R. E.; Bounoua, L.

    2010-12-01

    Impervious surface area (ISA) from National Land Cover Database 2001 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 settlement size and shape, population, development intensity distribution, and land cover component over the surrounding rural area for 40 urban settlements embedded in forests biomes over Northeast USA. Development intensity zones based on %ISA were defined for each urban area emanating outward from the urban core to the non-urban rural areas nearby and used to stratify sampling for land surface temperatures. Sampling was further constrained by biome and elevation to insure objective intercomparisons between zones and between settlements. Stratification based in ISA permits the definition of hierarchically ordered zones that are consistent across urban areas and scales. We find that the besides ecological context, settlement size and shape as well as development intensity distribution significantly influence the amplitude of summer daytime UHI. Within the North-eastern temperate broadleaf mixed forest biome, UHI magnitude has been found positively related (correlation R>0.84) with logarithm of the urban area, population, and the area to perimeter ratio. Our case studies indicate that when the area sizes are similar, the development intensity distribution is one of the major drivers that cause the significant UHI difference. For instance, Providence with a high density skewed ISA profile tends to have more significant UHI (12.2C) than Buffalo (7.2C) which has a low density skewed ISA distribution. In addition to urban area and development intensity distribution, the difference in shape (represented by area to perimeter ratio) also causes the significant UHI difference in Syracuse (10.6C) and Harrisburg (7.6C). At last, the land cover component of the surrounding rural area will also affect

  8. 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

  9. A LABORATORY SIMULATION OF TURBULENT CONVECTION OVER AN URBAN HEAT ISLAND

    EPA Science Inventory

    A systematic experimental study of the heat-island-induced circulation under turbulent conditions was conducted in the laboratory for an idealized, circular heat isalnd in an initially thermally stratified fluid (water) in a convection tank with no ambient flow. he primary object...

  10. The use of NOAA AVHRR data for assessment of the urban heat island effect

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Mcnab, A. L.; Karl, T. R.; Brown, J. F.; Hood, J. J.; Tarpley, J. D.

    1993-01-01

    The objective of the study was to evaluate the use of a satellite-derived vegetation index and surface temperature estimates for the assessment of the difference in urban and rural air temperature due to the urban heat island effect. The difference in the ND (normalized difference) index between urban and rural regions appears to be an indicator of the difference in surface properties (evaporation and heat storage capacity) between the two environments that are responsible for the urban heat island effect. The use of the approach proposed here may provide a globally consistent method for assessing this phenomenon.

  11. 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

  12. Relationship Between Observed Heat Trends and Urban Heat Island in Manaus City, Brazil

    NASA Astrophysics Data System (ADS)

    de Souza, D. O.; Alvalá, R. S.

    2011-12-01

    In this work, the Urban Heat Island (UHI) of the city of Manaus, Amazonas State, Brazil, was evaluated. Initially, a statistical study of the evolution of temperature and precipitation fields in the past 50 years was performed. A heating trend of +0.74oC in the temperature dataset was observed, as well as an increase in the annual accumulated precipitation, which are possibly related to the intense urbanization of the study area. The impact of urbanization on the microclimate of Manaus was also evaluated with a comparison between NCEP reanalysis and data collected in the urban area. This comparison show that have a difference about +2.09oC, which could be related with the urbanization. Also, differences were observed in temperature and humidity between the urban area and adjacent forest, which provides evidence for an UHI. Analyses of the UHI showed that it has become more intense during the end of the dry season, having been observed that on average the city is up to 2.98oC warmer than the forest. The UHI intensity diurnal cycle presented distinct behavior from those found in various studies, exhibiting two peaks of highest intensity, one at 8 (LT) and one between the 15 and 17 (LT). It also highlighted that the urban area tends to heat first and more slowly and cool down later and faster than the forest, which explains the distinct behavior of the diurnal cycle of the UHI. Other characteristic of the microclimate of Manaus is that the local circulations, the river breeze, presented a pattern related with the UHI intensity. Furthermore, these heating extremes can possibly be associated with the liberation of heat from automobile and industrial sources, as well as with changes in the energy partitioning between the urban and forest areas. The obtained results provide evidence for the presence of an UHI in the city of Manaus and its influence on the local microclimate, showing that the process of urbanization is directly related with the heating trends observed in

  13. Response of a stably stratified atmosphere to low-level heating - An application to the heat island problem

    NASA Technical Reports Server (NTRS)

    Baik, Jong-Jin

    1992-01-01

    Two-dimensional airflow characteristics past a heat island are investigated using both a linear analytic model and a nonlinear numerical model in the context of the response of a stably stratified atmosphere to specified low-level heating in a constant shear flow. Results from the steady-state, linear, analytic solutions exhibit typical flow response fields that gravity waves produce in response to the local heat source in the presence of environmental flow. The magnitude of the perturbation vertical velocity is shown to be much larger in the shear-flow case than in the uniform-flow case. Two distinct flow features are observed for larger heating amplitude (hence, larger nonlinearity factor): the gravity-wave-type response field on the upstream side of the heat island and the strong updraft circulation cell located on the downstream side. As the heating amplitude increases, the updraft circulation cell strengthens and shifts farther downwind. The strong updraft cell is believed to be partly responsible for precipitation enhancement observed on the downstream side of the heat island. It is found that the continuing downwind propagation of the updraft circulation cell is related to basic-state wind speed.

  14. Numerical modeling of diffusive heat transport across magnetic islands and highly stochastic layers

    SciTech Connect

    Hoelzl, M.; Guenter, S.; Yu, Q.; Lackner, K.

    2007-05-15

    Diffusive heat transport across magnetic islands and highly stochastic layers is studied numerically for realistic values of {chi}{sub parallel}/{chi}{sub perpendicular} in cylindrical geometry, where {chi}{sub parallel} denotes the heat diffusion coefficient parallel and {chi}{sub perpendicular} the one perpendicular to the magnetic field lines. The computations are performed with a second-order finite difference scheme, for which the numerical errors are independent from the value of {chi}{sub parallel}/{chi}{sub perpendicular} [S. Guenter et al., J. Comput. Phys. 209, 354 (2005)]. Sufficient spatial resolution is ensured by using an unsheared helical coordinate system. The heat flux around magnetic islands as well as the effective radial heat diffusivity {chi}{sub r} are examined and compared to analytical theory. The temperature perturbations caused by magnetic islands and the resulting bootstrap current perturbations essential for the stability of neoclassical tearing modes are analyzed and compared to analytical predictions [R. Fitzpatrick, Phys. Plasmas 2, 825 (1995)]. Agreement is found in the 'small' and 'large' island limits, but an enhanced NTM drive is observed in between. A correction factor that can reproduce the numerical results very well is presented. For a highly stochastic layer, produced by five strongly overlapping islands, the radial heat diffusivity {chi}{sub r} is determined and compared to several analytical theories.

  15. Data and techniques for studying the urban heat island effect in Johannesburg

    NASA Astrophysics Data System (ADS)

    Hardy, C. H.; Nel, A. L.

    2015-04-01

    The city of Johannesburg contains over 10 million trees and is often referred to as an urban forest. The intra-urban spatial variability of the levels of vegetation across Johannesburg's residential regions has an influence on the urban heat island effect within the city. Residential areas with high levels of vegetation benefit from cooling due to evapo-transpirative processes and thus exhibit weaker heat island effects; while their impoverished counterparts are not so fortunate. The urban heat island effect describes a phenomenon where some urban areas exhibit temperatures that are warmer than that of surrounding areas. The factors influencing the urban heat island effect include the high density of people and buildings and low levels of vegetative cover within populated urban areas. This paper describes the remote sensing data sets and the processing techniques employed to study the heat island effect within Johannesburg. In particular we consider the use of multi-sensorial multi-temporal remote sensing data towards a predictive model, based on the analysis of influencing factors.

  16. Transient analysis of containment heat removal at Prairie Island with boiling in the fan coil tubes

    SciTech Connect

    Elicson, T.; Fraser, B.; Anderson, D.; Thomas, S.

    1996-12-31

    An analysis has been performed to determine the equilibrium cooling water flow rates and heat removal rates through the Prairie Island Nuclear Generating Plant containment fan coil units (CFCUs) under postulated accident conditions which leads to boiling in the CFCUs. Key components of the analysis include a detailed fan coil heat exchanger model, mass and energy conservation in the cooling tubes, two-phase flow effects on heat transfer and pressure drop, and pipe network modeling.

  17. Urban heat islands in China and decadal-scale temperature variability

    SciTech Connect

    Portman, D.A.

    1997-11-01

    The paper describes an investigation involving careful examination of data homogeneity and calculation of urban heat island effects in Chinese surface temperatures. As part of this study, monthly mean temperatures, mean minimum temperatures, and mean maximum temperatures from more than 400 stations were collected and merged. Large seasonal and regional variations were shown; however, results indicate that urban heat island biases are greatest in magnitude during the coldest months. The biases in monthly mean temperature and in mean diurnal temperature range have increased since the 1950s, while those in the minimum temperature appear to have decreased. These changes are significant in comparison to the interdecadal fluctuations during the same 40-year time period. Despite large variations, preliminary results suggest that the Chinese urban heat islands not only produce a warm bias in monthly mean temperature, but also constitute a principal source of the persistent decrease in mean diurnal temperature range.

  18. Analyzing the heat island magnitude and characteristics in one hundred Asian and Australian cities and regions.

    PubMed

    Santamouris, M

    2015-04-15

    Urban heat island is the more documented phenomenon of climate change. Information on the magnitude and the characteristics of the canopy layer urban heat island measured in 101 cities and regions of Asia and Australia and collected through 88 scientific articles, are compiled, evaluated and presented. Data are classified in several clusters according to the experimental protocol used and the type of statistical information reported regarding the magnitude of the urban heat island. Results and detailed analysis are given for each defined cluster. Very significant differences on the UHI intensity are found between the clusters and analyzed in detail. The detailed impact of the main weather parameters and conditions on the magnitude of the UHI is also investigated. The specific influence of anthropogenic thermal fluxes as well as of the urban morphological and construction characteristics to UHI is thoroughly examined. The relation between the UHI intensity and the city size is assessed and global relationships of UHI as a function of the urban population are proposed. The seasonal and diurnal variability of the UHI is analyzed and discussed while specific features and conditions like the urban heat island characteristics in coastal cities and the existence of daytime cool islands are explored. Finally, the impact of the selected reference station and its characteristics is considered. PMID:25647373

  19. 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.

  20. Analysis of Kuwait Temperature Records: Test of Heat Island Existence in Kuwait City Arid Environment.

    NASA Astrophysics Data System (ADS)

    Nasrallah, Hasan Ali

    Very few arid land cities have been studied to determine local climate effects developing from rapid urban growth in the twentieth century. Kuwait City in the State of Kuwait is examined to determine the significance of urban growth on heating in the region. The study examines recent changes in temperature for the State of Kuwait for the period 1958-1980. During this time period, Kuwait has experienced explosive urban growth from 0.2 million to 1.7 million population. Simple parametric inferential statistics are employed to monthly temperature records from seven locations in and adjacent to Kuwait City. These tests are conducted to determine the connection between urbanization and the development of urban heating effects. The statistical tests employ a national "benchmark" desert site; a rural, agricultural benchmark site in the State of Kuwait; and stations in Bahrain, Eilat, Riyadh, Abadan, and Baghdad. The analysis illustrates that there is only a modest level of urban heating detectable in temperature records from the region of Kuwait. This finding runs counter to prevailing literature on urban climatology, which generally states that urban heating depends strongly on urban extent and population growth. Upon inspection of geographic location and surficial characteristics of Kuwait City, two hypotheses are suggested for the low order urban heating detected: (1) cooling effects of advected Arabian Gulf air across the city, and, (2) the lack of substantive spatial differences of surface albedo, thermal inertia, surface moisture, and aerosol heating. However, Kuwait's morphological (i.e., building geometry) characteristics, according to urban canyon-heat island theory, should have promoted a 7 ^circC heat island in Kuwait City. A test of this theory revealed no such heat island of that magnitude. One major reason relates to station network inadequacy to portray the extent of Kuwait City's heat island development through time. More research, including modeling and

  1. Numerical model of the urban heat island in a calm and stably stratified environment

    NASA Astrophysics Data System (ADS)

    Kurbatskiy, A.; Kurbatskaya, L.

    2015-11-01

    The RANS high close approach for the turbulent fluxes of momentum, heat and mass for simulating of the circulation structure and dispersion pollutant over the urban heat island in a stably stratified environment under nearly calm conditions is formulated. The turbulent fluxes of momentum - uiuj , heat -uiθ and mass -uic in this approach determined from the gradient diffusion type models with the turbulent kinetic energy (TKE), its spectral consumption (or dissipation), the temperature variance and the covariance for cθ as parameters which are obtained from transport equations. Such the RANS approach minimizes difficulties in the turbulent transport modeling in a stably stratified environment and reduces efforts needed for the numerical implementation of the numerical model. The simulation results demonstrates that the three-four equations RANS approach is able to predict the structure of turbulent circulation flow induced by the heat island that is in good agreement with the experimental data.

  2. 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

  3. 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.

  4. 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

  5. The use of a satellite derived vegetation index for assessment of the urban heat island effect

    NASA Technical Reports Server (NTRS)

    Gallo, Kevin P.; Tarpley, J. D.; Mcnab, Alan L.; Karl, Thomas R.; Brown, Jesslyn F.

    1993-01-01

    Satellite derived normalized difference (ND) vegetation index data, based on urban and rural region composed of a variety of land surface environments, are evaluated. These data are linearly related to the difference in observed urban and rural minimum temperatures. It is concluded that the difference in the ND index between urban and rural regions reflects the difference in the surface properties (evaporation and heat storage capacity) of these two environments and urban and rural minimum temperatures (the urban heat island effect).

  6. Interdecadal variations and trends of the Urban Heat Island in Athens (Greece) and its response to heat waves

    NASA Astrophysics Data System (ADS)

    Founda, D.; Pierros, F.; Petrakis, M.; Zerefos, C.

    2015-07-01

    The study explores the interdecadal and seasonal variability of the urban heat island (UHI) intensity in the city of Athens. Daily air temperature data from a set of urban and surrounding non urban stations over the period 1970-2004 were used. Nighttime and daytime heat island revealed different characteristics as regards the mean amplitude, seasonal variability and temporal variation and trends. The difference of the annual mean air temperature between urban and rural stations exhibited a progressive statistically significant increase over the studied period, with rates equal to + 0.2 °C/decade. A gradual and constant increase of the daytime UHI intensity was detected, in contrast to the nighttime UHI intensity which increases only in summer, after the mid 1980s. UHI phenomenon was found to be related to higher increasing rates of hot days frequency at the urban stations. It was found that the interaction between heat waves and heat island in Athens, results to pronounced amplification of nocturnal UHI intensity under exceptionally hot weather.

  7. 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.

  8. The Urban Heat Island: a Student Field Project with Community Interest Overtones.

    ERIC Educational Resources Information Center

    Mattingly, Paul

    1979-01-01

    Describes a student field project which measured and interpreted ground-level aspects of the urban heat island in Bloomington-Normal, Illinois. Discusses procedural steps and decisions, field procedures, data compiling, findings, evaluation, and dissemination of results. (Author/CK)

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

    NASA Astrophysics Data System (ADS)

    Ida, K.; Kobayashi, T.; Yoshinuma, M.; Suzuki, Y.; Narushima, Y.; Evans, T. E.; Ohdachi, S.; Tsuchiya, H.; Inagaki, S.; Itoh, K.

    2016-09-01

    Bifurcation physics of a 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 a large helical device (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 the magnetic island with larger thermal diffusivity and that with smaller thermal 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. This observation suggests that this flow damping is due to the change in the non-diffusive term of momentum transport.

  10. Investigating the Urban Heat Island Effect with a Collaborative Inquiry Project.

    ERIC Educational Resources Information Center

    George, Linda A.; Becker, William G.

    2003-01-01

    Explains a collaborative research project in which students study a phenomenon known as the Urban Heat Island (UHI) effect which is a measure of the near-surface air temperature contrast between urbanized and adjoining rural areas. Includes background content and literature review, preliminary studies, development of research questions,…

  11. DETECTION OF CENTRIPETAL HEAT-ISLAND CIRCULATIONS FROM TOWER DATA IN ST. LOUIS

    EPA Science Inventory

    Hourly averaged meteorological data gathered by a 25-tower network about St. Louis during 1976 are used in a search for centripetal circulations generated by the urban heat island. Considering data collected when the network resultant speed was less than 1.5 m/s, two data classes...

  12. Urban Heat Island and Its Influence on Atmospheric Boundary Layer Temperature Field

    NASA Astrophysics Data System (ADS)

    Kadygrov, N.; Kruchenitsky, G.; Lykov, A.

    2006-12-01

    The effect of megacity on atmospheric boundary layer (ABL) temperature is a well known phenomenon called "Urban Heat Island" revealed in increasing temperature over megacity relative to its suburb. Until recently the only way to investigate and gather the data about its vertical distribution was to observe temperature on the meteorological, TV towers and by radiosonde. The available information appears to be irregular in time and space. The situation has changed in recent years since the advent of temperature profiler based on microwave radiometer, which can produce the vertical distribution of ABL temperature up to 600 meters ASL with 5 minute sampling period. The station in the center of Moscow megacity and 2 observation sites near Moscow (20 km and 50 km away from city center) were equipped by MTP-5 radiometer in order to get quantitative estimations of the Heat Island Effect on ABL temperature field. Three sites were selected in order to look at transition from megacity to suburb. The main aim was not to get the climatological averages but to get the differences between Heat Island and its background (suburb). The period of observation was from beginning of 2000 till the middle of 2004. The ABL temperature model was developed separately for each station in the multiplicative manner as the product of seasonal and diurnal variations of ABL temperature in order to obtain the differences between Urban Heat Island and suburb ABL temperatures. As the result of data analysis, the amplitudes and phases of seasonal and diurnal harmonics, average annual noon temperature value, average temperature gradients and daily altitude-time crossection of ABL temperature were obtained. The analysis performed in this work has given us a better insight into the mechanism of Urban Heat Island influence on ABL temperature field with quantitative estimations of such influence.

  13. Variation of daily warm season mortality as a function of micro-urban heat islands

    PubMed Central

    Smargiassi, A; Goldberg, M S; Plante, C; Fournier, M; Baudouin, Y; Kosatsky, T

    2009-01-01

    Background: Little attention has been paid to how heat-related health effects vary with the micro-urban variation of outdoor temperatures. This study explored whether people located in micro-urban heat islands are at higher risk of mortality during hot summer days. Methods: Data used included (1) daily mortality for Montreal (Canada) for June–August 1990–2003, (2) daily mean ambient outdoor temperatures at the local international airport and (3) two thermal surface images (Landsat satellites, infrared wavelengths). A city-wide temperature versus daily mortality function was established on the basis of a case-crossover design; this function was stratified according to the surface temperature at decedents’ place of death. Results: The risk of death on warm summer days in areas with higher surface temperatures was greater than in areas with lower surface temperatures. Conclusions: This study suggests that measures aimed at reducing the temperature in micro-urban heat islands (eg, urban greening activities) may reduce the health impact of hot temperatures. Further studies are needed to document the variation of heat-related risks within cities and to evaluate the health benefits of measures aimed at reducing the temperature in micro-urban heat islands. PMID:19366997

  14. The use of remotely sensed data as a tool in urban heat island investigations: An overview

    SciTech Connect

    Orvis, K.H.; Akbari, H.

    1992-01-01

    Remotely sensed data contribute an important tool to areawide, cost-effective studies of urban heat island phenomena. This paper provides an overview of its use dating from the first satellite thermal images of urban heat signatures in the early 1970`s, and briefly examines the range of previous uses of remotely sensed data in urban studies, including identification and analysis of heat island effects, modeling of energy budgets, attempts to analyze and classify the urban landscape, and temporal analyses. The intent is not to provide an exhaustive review but rather to describe research trends and patterns. In addition the paper lists an compares those sensing devices that have seen significant use in urban studies and briefly discusses potential strengths and weaknesses of remotely sensed data for use in urban analyses. Three annotated bibliographies, divided by subject, are included. 95 refs.

  15. Assessment of the urban heat island effect through the use of satellite data

    NASA Technical Reports Server (NTRS)

    Price, J. C.

    1979-01-01

    A recent NASA satellite is obtaining high spatial resolution thermal infrared data at times of day appropriate for the study of the urban heat island effect. Quantitative estimates of the extent and intensity of urban surface heating are obtained by analysis of digital data acquired over the New York City-New England area. In many large cities satellite sensed temperatures are 10-15 C warmer than in surrounding rural areas. A thorough interpretation of the elevated urban surface temperature will require studies of (1) the relationship between remotely sensed surface temperatures and air temperatures, and (2) compensation for observed very localized heating due to industry and/or power plants.

  16. 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

  17. 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. PMID:18572534

  18. Characteristics of urban heat island distribution in Guangxi Beibu Gulf Economic Zone based on MOD11A2

    NASA Astrophysics Data System (ADS)

    Wang, Yong-feng; Jing, Juan-li

    2015-12-01

    The diurnal variation and inter-annual variation of urban heat island in Beibu Gulf Economic Zone were quantitatively analyzed, based on 2005-2014 MOD11A2 land surface temperature dataset, by the method of land surface temperature departure. Furthermore, the relationship between vegetation NDVI and urban heat island intensity were studied. Results showed: (1) Spatial distribution and extent of urban heat island in Beibu Gulf Economic Zone had a certain difference between daytime and nighttime in summer, the temperature departure decrease with distance from the city center increasing, and the decreasing trend of daytime was significant compared with nighttime. The temperature difference was about 4 to °C between the city and suburb in the daytime, and was about 2-6°C at night (2) The inter-annual variation intensity of urban heat island was not obvious in summer daytime during 2005-2014, while the difference of spatial distribution was significant. The urban heat island intensity increased in Nanning city during 2005-2011, and slowed in 2014. The heat island variation intensity was not obvious in Beihai city before 2011, but increased significantly in 2014. (3) The correlation coefficient between NDVI and land surface temperature in summer is -0.29, which showed high vegetation coverage plays an important role in reducing the urban heat island.

  19. The impact of summer heat islands on cooling energy consumption and CO{sub 2} emissions

    SciTech Connect

    Akbari, H.; Huang, J.; Martien, P.; Rainer, L.; Rosenfeld, A.; Taha, H.

    1988-08-01

    It has been well documented that summer heat islands increase the demand for air conditioning. Several studies have suggested developing guidelines to mitigate this negative effect, on both micro- and meso-scales. Reducing summer heat islands saves cooling energy, reduces peak demand, and reduces the emission of CO{sub 2} from electric power plants. This paper summarizes some of the efforts to quantify the effects of techniques to reduce heat islands. In particular, the authors summarize simulations they have made on the effects of plating trees and switching to light colored surfaces in cities. The results indicate that these techniques effectively reduce building cooling loads and peak power in selected US cities, and are the cheapest way to save energy and reduce CO{sub 2} emissions. This paper compares the economics of technologies to mitigate summer heat islands with other types of conservation measures. The authors estimate the cost of energy conserved by planting trees and recoating surfaces on a national level and compare it with the cost of energy conserved by increasing efficiencies in electrical appliances and cars. Early results indicate that the cost of energy saved by controlling heat islands is less than 1{cents}/kWh, more attractive than efficient electric appliances ({approximately} 2{cents}/kWh), and far more attractive than new electric supplies ({approximately}10{cents}/kWh). In transportation, the cost of conserving a gallon of gasoline, though far more attractive than buying gasoline at current prices, is again more expensive than controlling heat islands. By accounting for the carbon content of the fuels used for power generation and transportation, the authors restate these comparisons in terms of cents per avoided pound of carbon emitted as CO{sub 2}. The results show that the cost of avoided CO{sub 2} from planting trees/increasing albedo is about 0.3--1.3{cents}/lb. of carbon; for buying efficient electric appliances, 2.5{cents}/lb. of

  20. Comparison of local and regional heat transport processes into the subsurface urban heat island of Karlsruhe, Germany

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Temperatures in shallow urban ground are typically elevated. They manifest as subsurface urban heat islands, which are observed worldwide in different metropolitan areas and which have a site-specific areal extent and intensity. As of right now the governing heat transport processes accumulating heat in the subsurface of cities are insufficiently understood. Based on a spatial assessment of groundwater temperatures, six individual heat flux processes could be identified: (1) heat flux from elevated ground surface temperatures (GST), (2) heat flux from basements of buildings, (3) reinjection of thermal waste water, (4) sewage drains, (5) sewage leakage, and (6) district heating. In this study, the contributions of these processes are quantified on local and regional scales for the city of Karlsruhe in Germany. For the regional scale, the Regionalized Monte Carlo (RMC) method is used. This method applies a single Monte Carlo (MC) simulation for the entire study area. At relatively low data demand, the RMC method provides basic insights into the heat contribution for the entire city. For the local scale, the Local Monte Carlo (LMC) method was developed and applied. This method analyzes all dominant heat fluxes spatially dependent by performing an MC simulation for each arbitrary sized pixel of the study area (here 10 x 10 m). This more intricate approach allows for a spatial representation of all heat flux processes, which is necessary for the local planning of geothermal energy use. In order to evaluate the heat transport processes on a regional scale, we compared the mean annual thermal energies that result from the individual heat flux processes. Both methods identify the heat flux from elevated GST and the heat flux from buildings as the dominant regional processes. However, reinjection of thermal wastewater is by far the most dominant local heat flux processes with an average heat flux of 16 ± 2 W/m2 in the affected areas. Although being dominant on the regional

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

    NASA Astrophysics Data System (ADS)

    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.

  2. 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. PMID:25537502

  3. Including the urban heat island in spatial heat health risk assessment strategies: a case study for Birmingham, UK

    PubMed Central

    2011-01-01

    Background Heatwaves present a significant health risk and the hazard is likely to escalate with the increased future temperatures presently predicted by climate change models. The impact of heatwaves is often felt strongest in towns and cities where populations are concentrated and where the climate is often unintentionally modified to produce an urban heat island effect; where urban areas can be significantly warmer than surrounding rural areas. The purpose of this interdisciplinary study is to integrate remotely sensed urban heat island data alongside commercial social segmentation data via a spatial risk assessment methodology in order to highlight potential heat health risk areas and build the foundations for a climate change risk assessment. This paper uses the city of Birmingham, UK as a case study area. Results When looking at vulnerable sections of the population, the analysis identifies a concentration of "very high" risk areas within the city centre, and a number of pockets of "high risk" areas scattered throughout the conurbation. Further analysis looks at household level data which yields a complicated picture with a considerable range of vulnerabilities at a neighbourhood scale. Conclusions The results illustrate that a concentration of "very high" risk people live within the urban heat island, and this should be taken into account by urban planners and city centre environmental managers when considering climate change adaptation strategies or heatwave alert schemes. The methodology has been designed to be transparent and to make use of powerful and readily available datasets so that it can be easily replicated in other urban areas. PMID:21682872

  4. Existing climate data sources and Their Use in Heat IslandResearch

    SciTech Connect

    Akbari, Hashem; Pon, Brian; Smith, Craig Kenton; Stamper-Kurn, Dan Moses

    1998-10-01

    Existing climate data sources can be used in two general types of analysis for the detection of urban heat islands. Historical analyses use long-term data records-preferentially from several locations in and around an urban area-to trace the gradual influence of urban development on its climate. Primary sources of such data include the cooperative network, first-order National Weather Service stations, and military weather stations. Analyses of short-term data use information from a dense urban weather station network to discern the location, extent, and magnitude of urban heat islands. Such analyses may use the aforementioned national networks or regional networks such as agricultural, air quality monitoring, or utility networks. We demonstrate the use of existing data sources with a historical analysis of temperature trends in Los Angeles, California, and an analysis of short-term data of the urban temperature profile for Phoenix, Arizona. The Los Angeles climate was examined with eleven long-term data records from the cooperative network. Statistically significant trends of rising temperature were detected at Los Angeles Civic Center and other stations over some parts of the year, although timing of the increase varied from station to station. Observed increases in temperatures maybe due to long-term climate changes, microclimate influences, or local-scale heat islands. The analysis of short-term data was made for Phoenix using the PRISMS station network. Mean diurnal temperature profiles for a month were examined and compared with those for adjacent rural areas. Data fi-om stations in the center of Phoenix showed clear and significant nighttime and daytime temperature differences of 1- 2K (3 - 4"F). These temperature increases maybe attributable to a local-scale heat island.

  5. Urban heat island in southern Europe: The case study of Hania, Crete

    SciTech Connect

    Kolokotsa, D.; Psomas, A.; Karapidakis, E.

    2009-10-15

    The aim of the present paper is to analyze the results of the urban heat island research for a coastal densely built small Mediterranean town namely Hania, Crete, Greece. The specific research targets to verify the existence, the intensity, the size and the form of the urban heat island phenomenon in the specific region as well as to understand its correlation with the local weather conditions. Nine urban and three rural meteorological stations are used for this study. Temperature and relative humidity measurements are collected from May 26, 2007 until October 24, 2007. In parallel, meteorological data including wind speed and direction, barometric pressure, sunlight and precipitation for the specific region are collected and elaborated for cross-correlation with the appearance of the urban heat island (UHI) phenomenon. During summer period, where the temperature is high, the UHI takes its maximum intensity, of about 8 C. Also, the form of the UHI is strongly influenced from the wind speed and direction. The northern winds expand the UHI front, while the western winds contribute to the UHI reduction. Finally the Discomfort Index (DI) is calculated for the 2007 summer period to indicate the outdoor living conditions. (author)

  6. Spatial variation of temperature and indicative of the urban heat island in Chennai Metropolitan Area, India

    NASA Astrophysics Data System (ADS)

    Jeganathan, Anushiya; Andimuthu, Ramachandran; Prasannavenkatesh, Ramachandran; Kumar, Divya Subash

    2016-01-01

    Heat island is the main product of urban climate, and one of the important problems of twenty-first century. Cities in tropical countries suffer extensively due to the urban heat island effect, and urban climate studies are necessary to improve the comfort level and city planning. Chennai is the tropical city; it is the fourth largest metropolis in India and one of the fastest growing economic and industrial growth centers in South Asia. The spatial distribution of heat intensity in Chennai Metropolitan Area was studied, and the influence of land use and green cover were analyzed in the present work. Mobile measurements were carried out throughout the study area using a grid network to represent various land use patterns of the city. The study revealed some heat and cool pockets within the city limit; the maximum intensities of temperature were noticed in the central core city and north Chennai, which are distinguished for their commercial centers and densely populated residential areas. In morning time, temperature differences between fringes and central parts of heat packets were in the range of 3-4.5 °C. Land use and green cover play a critical role in microclimate and influences it. Green cover has a significant negative correlation with observed microclimate variations. Thus, the study urges city administration, policy makers, and architects to take up effective mitigation and adaptation strategies in the city to make people more comfortable.

  7. 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.

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

    SciTech Connect

    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 atmosphere 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 of heat

  9. Rifting, heat flux, and water availability beneath the catchment of Pine Island Glacier

    NASA Astrophysics Data System (ADS)

    Jordan, T. A.; Ferraccioli, F.; Hindmarsh, R. C.

    2012-04-01

    The West Antarctic Rift System (WARS) is a major rift system that developed in the Cretaceous and Cenozoic. It forms the lithsopheric cradle for the marine-based, and potentially unstable West Antarctic Ice Sheet (WAIS). Determining the geological boundary conditions beneath the WAIS and in particular geothermal heat flux may help model its response to external climatic forcing. However, in the Amundsen Sea Embayment sector of WAIS, where major glaciers such as Pine Island and Thwaites are rapidly changing today, fundamental properties such as geothermal heat flux to the base of the ice sheet have remained poorly constrained due to sparse geophysical data coverage and the lack of drilling sites. New crustal thickness estimates derived from airborne gravity data (Jordan et al., 2010, GSA Bul.), are interpreted to show a continuation of the WARS beneath Pine Island Glacier, and suggest two phases of continental rifting affected this region. Here we explore the impact of continental rifting on geothermal heat flux variations and basal water availability beneath Pine Island Glacier. Using 1D thermal models of rift evolution, we assess geothermal heat flux configurations resulting from either single or two-phase rifting and explore the dependency on the age of rifting and pre-rift setting. Additionally, 1D glaciological models were implemented to predict the changes in subglacial water distribution created by different rifting models. Our modelling reveals that geothermal heat-flux beneath the WAIS is critically sensitive to rift age and evolution and has the potential to significantly alter basal conditions if it continued to be active in the Neogene as some recent geological interpretations suggest.

  10. 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.

  11. 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.

  12. Large-Eddy Simulation of Mesoscale Circulations Forced by Inhomogeneous Urban Heat Island

    NASA Astrophysics Data System (ADS)

    Zhang, Ning; Wang, Xueyuan; Peng, Zhen

    2014-04-01

    The large-eddy simulation mode of the Weather Research and Forecasting model is employed to simulate the planetary boundary-layer characteristics and mesoscale circulations forced by an ideal urban heat island (UHI). In our simulations, the horizontal heterogeneity of the UHI intensity distribution in urban areas is considered and idealized as a cosine function. Results indicate that the UHI heating rate and the UHI intensity heterogeneity affect directly the spatial distribution of the wind field; a stronger UHI intensity produces a maximum horizontal wind speed closer to the urban centre. The strong advection of warm air from the urban area to the rural area in the upper part of the planetary boundary-layer causes a more stable atmospheric stratification over both the urban and rural areas. The mesoscale sensible heat flux caused by the UHI circulation increases with UHI intensity but vanishes when the background wind speed is sufficiently high 3.0.

  13. Some aspects of the three-dimensional heat island in Moscow

    NASA Astrophysics Data System (ADS)

    Shahgedanova, M.; Burt, T. P.; Davies, T. D.

    1997-11-01

    The thermal climate in Moscow was studied for 1990. Air temperatures near the surface were analysed for a number of locations representing different land-use types. The urban-rural temperature differences ranged mainly between 1° and 3°C, with an absolute maximum of 9.8°C. In summer, the heat island intensity exceeded 3°C on 29 per cent of all early morning observations, confirming the widely held view that anticyclonic conditions generate strong heat islands. Temperature variations within the city were small, with a notable exception of the urban park; in winter, the lee periphery of the city was often warmer than the urban centre. Vertical temperature profiles in the lowest 500 m were studied using data obtained at the Ostankino TV tower at seven levels. Although the daytime profiles throughout the year and the nocturnal profiles in winter confirmed observations elsewhere, the nocturnal summer profiles were unlike those registered in other urban areas with an unexpectedly high frequency of strong ground-based inversions. In July and August, ground-based inversions were registered on 57 per cent of all nocturnal observations. This phenomenon can be explained by the open street geometry that is typical of Moscow and a reduced (in comparison with winter) input of artificial heat.

  14. 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.

  15. a Temporal and Spatial Analysis of Urban Heat Island in Basin City Utilizing Remote Sensing Techniques

    NASA Astrophysics Data System (ADS)

    Chang, Hsiao-Tung

    2016-06-01

    Urban Heat Island (UHI) has been becoming a key factor in deteriorating the urban ecological environment. Spatial-temporal analysis on its prototype of basin city's UHI and quantitatively evaluating effect from rapid urbanization will provide theoretical foundation for relieving UHI effect. Based on Landsat 8, ETM+ and TM images of Taipei basin areas from 1900 to 2015, this article has retrieved the land surface temperature (LST) at summer solstice of each year, and then analysed spatial-temporal pattern and evolution characters of UHI in Taipei basin in this decade. The results showed that the expansion built district, UHI area constantly expanded from centre city to the suburb areas. The prototype of UHI in Taipei basin that showed in addition to higher temperatures in the centre city also were relatively high temperatures gathered boundaries surrounded by foot of mountains side. It calls "sinking heat island". From 1900 to 2000, the higher UHI areas were different land use type change had obvious difference by public infrastructure works. And then, in next 15 years till 2015, building density of urban area has been increasing gradually. It has the trend that UHI flooding raises follow urban land use density. Hot spot of UHI in Taipei basin also has the same characteristics. The results suggest that anthropogenic heat release probably plays a significant role in the UHI effect, and must be considered in urban planning adaptation strategies.

  16. Comparative Study of Msocow and New York Urban Heat Islands Development

    NASA Astrophysics Data System (ADS)

    Ginzburg, A. S.; Rubinstein, K. G.

    The most important urban climate effect is the existing and development so called Sur- & cedil;ban heat islandT. Moscow as one of more intensively developing megalopolis of Eu- rope is the largest source of neat within the Central and Eastern Europe. New York City is the largest urban heat source at ocean costs around the world. The paper presents the study of the urban heat island trends in Moscow agglomeration using the analysis of the data set from the beginning of XX century up to year 2000 in the comparison with similar New York study made by Rosenzweig C. and Solecki W.D. (Environment. 2001. V. 43. No 3. 8-18). The new last decade date confirmed the authorsS conclusion about slight decreasing of summer temperature in Moscow and much more signifi- cant increasing of winter temperatures. The comparison Moscow and New York tem- perature and precipitation trends show that in spite of difference in the Moscow and New-York climate zones, temperature and precipitation trends in both cities are very similar. The some differences in mean values and trends came from different Moscow and New York locations U in the continental and cost areas. The mean temperature and precipitation in New York are highly than in Moscow. The long-term trends of temperature and precipitation are more significant in Moscow than in New York.

  17. [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. PMID:23189682

  18. An urban heat islands climatology in Russia and linkages to the climate change.

    NASA Astrophysics Data System (ADS)

    Kukanova, Evgenia; Konstantinov, Pavel

    2014-05-01

    Phenomenon of urban heat islands (UHI) was researched by many authors of scientific community. More investigators were focused on heat island of tropical city. (for example: Tropical urban heat islands: climate, buildings and greenery / Nyuk Hien Wong and Yu Chen. - London, 2009; 259 p.) However dynamics UHI in arctic, subarctic and sharp continental climates is poorly investigated. This situation is due to the fact that there isn't large cities in Europe and Northern America within that climate type. In this paper we investigate long-term, seasonal and diurnal dynamics UHI intensity for more than 20 cities of the Russian Federation (large than 100 000 population). Was calculated and analyzed changes UHI intensity within days and year. Also was detailed reviewed extreme values UHI and was discussed their relation with synoptic situations. In that investigation data created by regular state meteorological observation ROSHYDROMET network was used. For every city we selected couple of stations: one located into city in high and midrise buildings area (including extensive lowrise and high-energy industrial - LCZ classification) and second one located in rural site (sparsely built or open-set and lightweight lowrise according LCZ classification). Also couples of stations must be close by distance (less than 100 km) and altitude. For selection operation was constructed spatial database in ESRI ArcGIS Desktop environmental. Advantage investigation UHI of Russian city is diversity of climate condition. Selected cities locate within territory from 40N to 70N latitude and from 20E to 160E. That fact allows research UHI phenomenon in space term. Were detected intensity UHI patterns depends on geographical location of the city.

  19. The Impact of Heat Islands on Mortality in Paris during the August 2003 Heat Wave

    PubMed Central

    Zeghnoun, Abdelkrim; Dousset, Bénédicte; Bretin, Philippe; Vandentorren, Stéphanie; Giraudet, Emmanuel; Beaudeau, Pascal

    2011-01-01

    Background: Heat waves have a drastic impact on urban populations, which could increase with climate change. Objectives: We evaluated new indicators of elderly people’s exposure to heat in Paris, from a public health prevention perspective, using satellite thermal images. Methods: We used a time series of 61 images from the satellites of the National Oceanic and Atmospheric Administration’s (NOAA) Advanced Very High Resolution Radiometer (AVHRR) taken from 1 to 13 August 2003 to produce thermal indicators of minimum, maximum, and mean surface temperatures and diurnal temperature amplitude, with different lags between the meteorological data and the health impact. Health data came from a case–control study involving 241 people ≥ 65 years of age who died in the city of Paris or the nearby suburban area of Val-de-Marne during the August 2003 heat wave, and 241 controls who were matched to cases on age, sex, and residential zone. For each person, we integrated the thermal indicators in a conditional logistic regression model, adjusted for age and other potential confounders. We computed odds ratios (ORs) comparing the 90th and 50th percentiles of the temperature differences between cases and controls for various indicators. Results: Mortality risk was significantly associated with exposure for two indicators: minimum temperatures averaged for 1–13 August [for a 0.41°C increase, OR = 2.17; 95% confidence interval (CI): 1.14, 4.16] and minimum temperature averaged on the day of death and the 6 preceding days (for a 0.51°C increase: OR = 2.24; 95% CI: 1.03, 4.87). Conclusions: Our results support the influence of night temperatures on the health impact of heat waves in urban areas. Urban heat exposure indicators based on satellite imagery have the potential to identify areas with higher risk of death, which could inform intervention decisions by key stakeholders. PMID:21885383

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

    SciTech Connect

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

    1988-01-01

    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 maintain 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.

  1. Urban heat islands in the subsurface as sustainable source for geothermal energy

    NASA Astrophysics Data System (ADS)

    Menberg, Kathrin; Bayer, Peter; Blum, Philipp

    2014-05-01

    The urban heat island (UHI) is not a phenomenon that solely occurs in the atmosphere with increased air temperatures. We also observe it in the subsurface, and groundwater temperatures in shallow aquifers are strongly influenced by anthropogenic land surface alterations. Widespread thermal anomalies, which are triggered by various processes, such as increased ground surface temperatures (GST) and heat loss from buildings, can be found under many urban areas. With groundwater temperatures elevated by several degrees these aquifers represent large amounts of stored thermal energy. However, to exploit these attractive geothermal reservoirs efficiently and sustainably, the processes, which lead to the profound subsurface urban warming, need to be identified and quantified. In the current study, the spatial extension of the heat anomalies beneath several German cities, such as Berlin, Munich, Karlsruhe and Cologne, is scrutinized by mapping groundwater temperatures in a dense network of observation wells. With the high-resolved spatial distribution of groundwater temperatures, the dominant heat sources and important driving factors can be identified and incorporated into an analytical heat flux model. The annual anthropogenic heat input into the aquifer originating from several heat sources, such as increased GST, basements, sewage networks, district heating networks and reinjections of thermal waste water, is estimated by a Monte Carlo simulation for the cities of Cologne and Karlsruhe. All studied cities exhibit aquifers with significantly elevated temperatures, with the highest temperatures of up to 18°C prevailing in the densely built-up city centers. But also in suburban and industrial areas groundwater temperatures are several degrees above the rural background. The accumulated heat content in the urban aquifers can be estimated based on the thermal ground properties. This content is compared to the annual space heating demand in order to analyze the space

  2. Experimental Urban Heat Island Research of Four Biggest Polar Cities in Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Konstantinov, Pavel; Baklanov, Alexander; Varentsov, Mikhail; Kukanova, Evgenia; Repina, Irina; Shuvalov, Sergey; Samsonov, Timofey

    2014-05-01

    Urban Heat Island (UHI) effect is well-known in modern climatology due to its influence on different economic features and urban air quality (Oke, 1987). Also UHI characteristics differs in different climate zones, for example in summer in Mediterranean and subtropical monsoon climate types it leads to growing energy consumption due to AC systems using (Ohashi et al, 2007). But there is only a few papers about UHI (Magee et al, 1999) in high latitudes, for the cities over the Polar Circle and especially about behavior of the heat islands during the polar night, while anthropogenic heat is the main source of thermal energy. The main goal of this study is to mitigate this lack of information about climatology of UHI formation in big cities (with population exceeding 50 000) of Arctic zone. In this paper, we consider the results of experimental research of the UHI of 4 biggest Arctic Cities (Murmansk, Norilsk, Apatity and Vorkuta), which were obtained during the expedition of Russian Geographic Society in 2013-2014. During the project we used a different measurements techniques: 1. Installation of two automatic weather stations (AWS) in rural zone and city center 2. Installation of small temperature sensors (iButton) network in the city and suburbs 3. Regular car-based temperature sounding of the city with AWS. 4. Using MTP-5 microwave temperature profiler. This investigations allowed to collect unique data about UHI in high latitudes. Analysis of the collected data showed the existence of UHI with the difference between city center and surrounding landscape up to few degrees Celcius. UHI characteristics in view of synoptic conditions was analyzed for several typical situations, for some cities (Norilsk) the negative correlation of the UHI power with air temperature was determined. The reported study was supported by RGS (Russian Geographical Society ), research project No.27/2013-NZ References: 1. Magee N., Curtis J., Wendler G., The Urban Heat Island Effect at

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

    SciTech Connect

    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. 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-payers from

  4. Contrasting responses of urban and rural surface energy budgets to heat waves explain synergies between urban heat islands and heat waves

    NASA Astrophysics Data System (ADS)

    Li, Dan; Sun, Ting; Liu, Maofeng; Yang, Long; Wang, Linlin; Gao, Zhiqiu

    2015-05-01

    Heat waves (HWs) are projected to become more frequent and last longer over most land areas in the late 21st century, which raises serious public health concerns. Urban residents face higher health risks due to synergies between HWs and urban heat islands (UHIs) (i.e., UHIs are higher under HW conditions). However, the responses of urban and rural surface energy budgets to HWs are still largely unknown. This study analyzes observations from two flux towers in Beijing, China and reveals significant differences between the responses of urban and rural (cropland) ecosystems to HWs. It is found that UHIs increase significantly during HWs, especially during the nighttime, implying synergies between HWs and UHIs. Results indicate that the urban site receives more incoming shortwave radiation and longwave radiation due to HWs as compared to the rural site, resulting in a larger radiative energy input into the urban surface energy budget. Changes in turbulent heat fluxes also diverge strongly for the urban site and the rural site: latent heat fluxes increase more significantly at the rural site due to abundant available water, while sensible heat fluxes and possibly heat storage increase more at the urban site. These comparisons suggest that the contrasting responses of urban and rural surface energy budgets to HWs are responsible for the synergies between HWs and UHIs. As a result, urban mitigation and adaption strategies such as the use of green roofs and white roofs are needed in order to mitigate the impact of these synergies.

  5. Diurnal and seasonal variability of surface urban heat island phenomena in Warsaw (Poland)

    NASA Astrophysics Data System (ADS)

    Gawuć, Lech; Struzewska, Joanna

    2014-05-01

    The phenomenon of urbanization is an important environmental and social issue that modern society has to face. According to current estimates half of world's population lives in urban areas. It is expected that urban population will grow in the future. Urbanization and subsequent release of anthropogenic heat pollution lead to formation of an urban heat island (UHI). Development of UHI is a highly non-linear process (Kato et al., 2007) that depends on a number of factors such as magnitude of the anthropogenic heat flux, the texture of the city, local geophysical conditions and mesoscale meteorology (Sailor and Lu, 2004 after Narumi et al., 2003). We will present analyses of the magnitude and spatial extend of Surface Urban Heat Island (SUHI) in the capital of Poland, Warsaw. SUHI characteristics will be identified based on the Land Surface Temperature (LST) product derived for MODIS observations, which will be collected for time-series for April 2009 (34 acquisitions) and November 2011 (33 acquisitions). We will present maps of SUHI for morning, evening and night hours, for April and November separately. Several locations representing different types of land cover will be selected in order to analyze the temporal variability and amplitude of surface temperature in various parts of the city. In addition, air temperature from six automatic stations, maintained by Voivodeship Inspectorate of Environmental Protection, for periods coincident with satellite observations will be collected. Air and land temperature comparisons will be performed in order to investigate correspondence between surface UHI and air UHI. Impact of the synoptic conditions will be also discussed, with a particular caution for those terms when effect of UHI will be the strongest.

  6. 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. PMID:24764007

  7. Urban surface temperature behaviour and heat island effect in a tropical planned city

    NASA Astrophysics Data System (ADS)

    Ahmed, Adeb Qaid; Ossen, Dilshan Remaz; Jamei, Elmira; Manaf, Norhashima Abd; Said, Ismail; Ahmad, Mohd Hamdan

    2015-02-01

    Putrajaya is a model city planned with concepts of a "city in the garden" and an "intelligent city" in the tropics. This study presents the behaviour of the surface temperature and the heat island effect of Putrajaya. Findings show that heat island intensity is 2 °C on average at nighttime and negligible at daytime. But high surface temperature values were recorded at the main boulevard due to direct solar radiation incident, street orientation in the direction of northeast and southwest and low building height-to-street width ratio. Buildings facing each other had cooling effect on surfaces during the morning and evening hours; conversely, they had a warming effect at noon. Clustered trees along the street are effective in reducing the surface temperature compared to scattered and isolated trees. Surface temperature of built up areas was highest at noon, while walls and sidewalks facing northwest were hottest later in the day. Walls and sidewalks that face northwest were warmer than those that face southeast. The surface temperatures of the horizontal street surfaces and of vertical façades are at acceptable levels relative to the surface temperature of similar surfaces in mature cities in subtropical, temperate and Mediterranean climates.

  8. Utilizing LANDSAT TM thermal data to map urban heat islands in Dallas/Fort Worth

    SciTech Connect

    Aniello, C.A.; Lowry, S.A.; Morgan, K.; Newland, L.; Busbey, A.B. . Dept. of Geology)

    1993-02-01

    Many cities experience loss of vegetation due to urbanization. A recognized result of this defoliation is the occurrence of hot spots' which act to increase the temperature of surrounding areas. These heat islands' lead to higher energy consumption and costs. In this study a methodology was developed to produce thermal/land cover satellite images of areas in the Metroplex using visible, infrared and thermal TM bands. An index of vegetation cover was made from bands 3 and 4 to differentiate areas of vegetation and to provide a basis for temperature comparisons. TM band 6 was merged with the vegetation index image, classified and color coded to show temperature differences in the study areas, then verified in the field. Verified hot spots included roads, parking lots, strip malls and developed intersections. This study was done in cooperation with the Texas Forest Service in an effort to identify heat islands that need tree planting to help cool down cities and filter out harmful air pollutants.

  9. 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. PMID:24995636

  10. Research on the impact of impervious surface area on urban heat island in Jiangsu Province

    NASA Astrophysics Data System (ADS)

    Yang, Yingbao; Pan, Ping

    2011-10-01

    Land surface temperature (LST), vegetation index, and other surface characteristics that obtained from remote sensing data have been widely used to describe urban heat island (UHI) phenomenon, but through impervious surface area (ISA) to describe the phenomenon has only used in a few study areas in our country. In a high urbanization and high population density region like Jiangsu Province, a wide range of extraction of ISA to study its relationship with UHI is less. In this paper, we use multi-temporal remote sensing images as data sources, and extract ISA from it in a large-scale by using decision tree classifier (DTC) and linear spectral mixture analysis (LSMA). Then combine the average surface temperature from the sixth band of Landsat TM by mono-window algorithm for spatial analysis, to assess the change of the urban heat island temperature amplitude and its relationship with the urban development density, size and ecological environment. Finally we use statistical methods to analyze the relationship between ISA, LST and UHI. The results show that ISA has a positive correlation with surface temperature. The ratio of ISA is higher and the difference value of the temperature is larger, thus the UHI will be more obvious.

  11. 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.

  12. Development of an operational modeling system for urban heat islands: an application to Athens, Greece

    NASA Astrophysics Data System (ADS)

    Giannaros, T. M.; Melas, D.; Daglis, I. A.; Keramitsoglou, I.

    2014-02-01

    The urban heat island (UHI) effect is one prominent form of localized anthropogenic climate modification. It represents a significant urban climate problem since it occurs in the layer of the atmosphere where almost all daily human activities take place. This paper presents the development of a high-resolution modeling system that could be used for simulating the UHI effect in the context of operational weather forecasting activities. The modeling system is built around a state-of-the-art numerical weather prediction model, properly modified to allow for the better representation of the urban climate. The model performance in terms of simulating the near-surface air temperature and thermal comfort conditions over the complex urban area of Athens, Greece, is evaluated during a 1.5-month operational implementation in the summer of 2010. Results from this case study reveal an overall satisfactory performance of the modeling system. The discussion of the results highlights the important role that, given the necessary modifications, a meteorological model can play as a supporting tool for developing successful heat island mitigation strategies. This is further underlined through the operational character of the presented modeling system.

  13. Development of an operational modelling system for urban heat islands: an application to Athens, Greece

    NASA Astrophysics Data System (ADS)

    Giannaros, T. M.; Melas, D.; Daglis, I. A.; Keramitsoglou, I.

    2013-09-01

    The urban heat island (UHI) effect is one prominent form of localized anthropogenic climate modification. It represents a significant urban climate problem since it occurs in that layer of the atmosphere where almost all daily human activities take place. This paper presents the development of a high-resolution modelling system that could be used for simulating the UHI effect in the context of operational weather forecasting activities. The modelling system is built around a state-of-the-art numerical weather prediction model, properly modified to allow for the better representation of the urban climate. The model performance in terms of simulating the near-surface air temperature and thermal comfort conditions over the complex urban area of Athens, Greece, is evaluated during a 1.5-month operational implementation in the summer of 2010. Results from this case study reveal an overall satisfactory performance of the modelling system. The discussion of the results highlights the important role that, given the necessary modifications, a meteorological model can play as a supporting tool for developing successful heat island mitigation strategies. This is further underlined through the operational character of the presented modelling system.

  14. Analysis of climate change impacts on Urban Heat Island through geospatial data

    NASA Astrophysics Data System (ADS)

    Zoran, M.

    2010-09-01

    Through spatio-temporal changes of micro and macro-meteorological conditions in metropolitan areas, climate change due to increased anthropogenic emissions of greenhouse gases and carbon dioxide (CO2) represents a long-term climate hazard with high potential to alter the intensity, temporal pattern, and spatial extent of the urban heat island (UHI). Instrumental observations and numerical reconstructions of global temperature evolution reveal a pronounced warming during the past 150 years. One expression of this warming is the observed increase in the occurrence of summer heat waves. Conceptually this increase is understood as a shift of the statistical distribution towards warmer temperatures, while changes in the width of the distribution are often considered small. Urban areas tend to experience a relatively higher temperature compared with the surrounding rural areas. This thermal difference, in conjunction with waste heat released from urban houses, transportation and industry, contribute to the development of urban heat island (UHI). Summer heat waves will affect much more urban temperatures and microclimates with adverse effects on human health. Remote sensing is a key application in global change science and urban climatology. Urbanization, the conversion of other types of land to uses associated with growth of populations and economy has a great impact on both micro-climate as well as macro-climate. Remote sensing derived biophysical attributes provide great potential for establishing parameters describing urban land cover/use (construction materials and the composition and structure of urban canopies) for improving the understanding of the urban surface energy budgets, and observing the urban heat island (UHI) effect.In this study, Landsat TM and ETM+ , MODIS, IKONOS images over Bucharest metropolitan area from 1988 to 2008 have been selected to retrieve the urban biogeophysical parameters and brightness temperatures in relation with changes of cover

  15. 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. PMID:21147508

  16. On relationships between heat island and sky view factor in the cities of Tama River basin, Japan

    NASA Astrophysics Data System (ADS)

    Yamashita, Shuji; Sekine, Kiyoshi; Shoda, Masahiro; Yamashita, Kohji; Hara, Yoshio

    This study aims at firstly identifying heat island phenomena, secondly relating heat island intensity to city size, and thirdly providing basic urban climatic information to city planners or ordinary citizens. Horizontal distributions of dry- and wet-bulb temperature were measured seasonally in small to medium sized cities by mobile observers. Also, at a fixed station, wind speed and wind direction in addition to temperature were observed. The cities selected for this were Tachikawa, Fuchu, Fussa, Higashimurayama and Akikawa, which are suburban cities in the W part of Tokyo. This area is part of the middle basin of Tama River. Observations were made both during the day and at night in winter (February and December), spring (March and May), summer (July and August) and autumn (October and November) over a period of maximum duration of 1.5 h. In all cities heat islands were observed to develop to some extent. Their intensities were largely dependent on weather conditions. Cities in Japan have been growing rapidly and randomly, and merging into neighbouring small cities or towns. This expansion is called sprawl. Due to these factors it is very difficult to determine a good indicator of city sizes, i.e. population or DID (Densely Inhabited District) population does not represent the effect of city size on heat island intensity. Sky view factors were determined using a fish-eye lens and a calculation chart. We therefore examined central urban area and sky view factor as a cause factor for heat islands. It is concluded that sky view factor is a very useful indicator of the effect of urbanization on heat island intensity.

  17. Field Performance of Heat Pump Water Heaters in the Northeast, Massachusetts and Rhode Island (Fact Sheet)

    SciTech Connect

    Not Available

    2013-12-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publicly available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring, A.O. Smith Voltex, and Stiebel Eltron Accelera 300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  18. The use of NOAA AVHRR data for assessment of the urban heat island effect

    SciTech Connect

    Gallo, K.P.; Tarpley, J.D. ); McNab, A.L.; Karl, T.R. ); Brown, J.F. ); Hood, J.J. )

    1993-05-01

    A vegetation index and a radiative surface temperature were derived from satellite data acquired at approximately 1330 LST for each of 37 cities and for their respective nearby rural regions from 28 June through 8 August 1991. Urban-rural differences for the vegetation index and the surface temperatures were computed and then compared to observed urban-rural differences in minimum air temperatures. The purpose of these comparisons was to evaluate the use of satellite data to assess the influence of the urban environment on observed minimum air temperatures (the urban heat island effect). The temporal consistency of the data, from daily data to weekly, biweekly, and monthly intervals, was also evaluated. The satellite-derived normalized difference (ND) vegetation-index data, samples over urban and rural regions composed of a variety of land surface environments, were linearly related to the difference in observed urban and rural minimum temperatures. The relationship between the ND index and observed differences in minimum temperature was improved when analyses were restricted by elevation differences between the sample locations and when biweekly or monthly intervals were utilized. The difference in the ND index between urban and rural regions appears to be an indicator of the difference in surface properties (evaporation and heat storage capacity) between the two environments that are responsible for differences in urban and rural minimum temperatures. The urban and rural differences in the ND index explain a greater amount of the variation observed in minimum temperature differences than past analyses that utilized urban population data. The use of satellite data may contribute to a globally consistent method for analysis of urban heat island bias. 36 refs., 7 figs., 4 tabs.

  19. 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.

  20. Enhancement of Eddy Heat Transport due to the Anticyclonic Submesoscale Eddies around Ryukyu Islands near Kuroshio in East China Sea

    NASA Astrophysics Data System (ADS)

    Kamidaira, Y.; Uchiyama, Y.; Mitarai, S.; Miyazawa, Y.

    2014-12-01

    A synoptic, regional downscaling experiment of Kuroshio off Ryukyu Islands, Japan, exhibits the evident predominance of submesoscale anticyclonic eddies over cyclones in the narrow strip between Kuroshio and the islands (Uchiyama et al., 2013). In the present study, the mechanism and impacts of the anticyclone dominance are examined with a detailed oceanic downscaling model in a double nested ROMS configuration at the horizontal resolution of 3km (ROMS-L1) and 1km (ROMS-L2), forced by the assimilative JCOPE2 oceanic reanalysis and the JMA GPV-MSM atmospheric hindcast. The model results are extensively validated against a variety of data including shipboard hydrography and satellite altimetry and temperature data to show a good agreement. An alternative ROMS-L2 experiment is also conducted to examine topographic effects on the anticyclones around the Ryukyu Islands by eliminating all the island topography above z > -1000 m, while the other configurations are held unchanged. If the islands are removed, the submesoscale negative vortices on the eastern side of the Kuroshio become much weaker than those of the original case with the islands. The experiment clearly demonstrates that dominance of the negative vorticity between Kuroshio and the Ryukyu Islands is caused by enhanced lateral shear due to the concentrated Kuroshio mean current associated with appropriate formation of the eastern branch, the northward-drifting Ryuku Current, and resultant eddy shedding in the narrow channel between the continental shelf of the East China Sea and the Okinawan ridge. A diagnostic eddy heat flux analysis illustrates that the submesoscale anticyclonic eddies play a crucial role in enhancing the eddy heat transport and thus the lateral mixing between Kuroshio and the islands as compared to those in the coarser resolution models (L1 and JCOPE2), resulting in promoting regional larval and material transport from Kuroshio to the islands.

  1. Observation of heat transfer across x point of the islands during sawtooth crash on the HT-7 tokamak

    NASA Astrophysics Data System (ADS)

    Sun, Youwen; Wan, Baonian; Hu, Liqun; Chen, Kaiyun; Shen, Biao; Mao, Jianshan

    2009-06-01

    It is observed that a large heat flow abruptly transfers across the x point (which can be located at both the high field side and the low field side) of the 1/1 or 2/2 magnetic islands during a sawtooth crash on the HT-7 tokamak by using tomography of the high-resolution soft-x-ray emission together with the singular value decomposition technique. Although the poloidally asymmetric heat flow contributes an m = 1 component of perturbation in the signals, the heat flow is obviously different from the growth of the m = 1 magnetic island. Furthermore, it is also shown that the large heat flow or the displacement of the hot core occurs only after the crash. Hence, the large displacement of the hot core is just a result of the crash rather than the cause. The heat flow from both the x points of the m = 2 island is also observed. This observation demonstrates that a purely fast reconnection of the m = 1 magnetic island is not responsible for the crash, but that it may be due to the rapid energy and particle diffusion in the stochastic region.

  2. 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

  3. 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

  4. Modelling reduction of the Urban Heat Island effect via increasing the reflective properties of buildings

    NASA Astrophysics Data System (ADS)

    Andre, Konrad; Zuvela-Aloise, Maja; Schwaiger, Hannes; Bird, David Neil; Gallaun, Heinz

    2015-04-01

    The increased intensity or frequency of heat waves due to a changing climate could have far reaching implications. The phenomenon of Urban Heat Islands (UHIs) observed in cities is expected to strengthen and will further contribute to heat stress, creating an increased need for energy for cooling and ventilation as well as lowering human comfort. The KELVIN project studies the effects of modifying the reflective properties of buildings and urban areas to reduce the UHI-effect. The improvement of the reflection properties of roofs and other surfaces is one possible way to increase the energy efficiency in urban areas and at the same time adapt to climate change by addressing the problem of the UHIs. Within the project, low-cost adaptation measures to reduce heat stress are investigated. These measures are constrained, in historical city centres, because the colouring of tile roofs should not be changed significantly, and the appearance should remain as unchanged as possible. The project examines the potential of a climate adaptation measure to reduce the UHI-effect through changes in properties of the urban surfaces (roof albedo, green roofs etc.) and related emission-reduction through decreased cooling demand. It uses the city of Vienna as an example. The input parameters required for climate modelling, such as surface albedo, are determined based on the satellite image time series for Vienna from 2000 to 2014. Urban climate model simulations are conducted using high-resolution topography and land use data for Vienna. Potential changes in local climate in the urban environment resulting from the changes in surface albedo are examined and the possibility of reducing the heat load on a city scale is quantified. Results of modelling the city climate serve as a basis for calculating the potential reduction in electricity demand for cooling (including CO2- equivalent savings) in metropolitan landscapes. In addition, the potential change in radiative forcing induced by

  5. Weekly cycles in peak time temperatures and urban heat island intensity

    NASA Astrophysics Data System (ADS)

    Earl, Nick; Simmonds, Ian; Tapper, Nigel

    2016-07-01

    Regular diurnal and weekly cycles (WCs) in temperature provide valuable insights into the consequences of anthropogenic activity on the urban environment. Different locations experience a range of identified WCs and have very different structures. Two important sources of urban heat are those associated with the effect of large urban structures on the radiation budget and energy storage and those from the heat generated as a consequence of anthropogenic activity. The former forcing will remain relatively constant, but a WC will appear in the latter. WCs for specific times of day and the urban heat island (UHI) have not been analysed heretofore. We use three-hourly surface (2 m) temperature data to analyse the WCs of seven major Australian cities at different times of day and to determine to what extent one of our major city’s (Melbourne) UHI exhibits a WC. We show that the WC of temperature in major cities differs according to the time of day and that the UHI intensity of Melbourne is affected on a WC. This provides crucial information that can contribute toward the push for healthier urban environments in the face of a more extreme climate.

  6. 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.

  7. Streamlined energy-savings calculations for heat-island reduction strategies

    SciTech Connect

    Akbari, Hashem; Konopacki, Steven J.

    2003-03-15

    We have developed summary tables (sorted by heating- and cooling-degree-days) to estimate the potential of Heat-Island Reduction (HIR) strategies (i.e., solar-reflective roofs, shade trees, reflective pavements, and urban vegetation) to reduce cooling-energy use in buildings. The tables provide estimates of savings for both direct effect (reducing heat gain through the building shell) and indirect effect (reducing the ambient air temperature). In this analysis, we considered three building types that offer the most savings potential : residences, offices, and retail stores. Each building type was characterized in detail by Pre-1980 (old) or 1980+ (new) construction vintage and with natural gas or electricity as heating fuel. We defined prototypical-building characteristics for each building type and simulated the effects of HIR strategies on building cooling and heating energy use and peak power demand using the DOE-2.1E model and weather data for about 240 locations in the U.S. A statistical analysis of previously completed simulations for five cities was used to estimate the indirect savings. Our simulations included the effect of (1) solar-reflective roofing material on building [direct effect], (2) placement of deciduous shade trees near south and west walls of building [direct effect], and (3) ambient cooling achieved by urban reforestation and reflective building surfaces and pavements [indirect effect]. Upon completion of estimating the direct and indirect energy savings for all the selected locations, we integrated the results in tables arranged by heating- and cooling-degree-days. We considered 15 bins for heating-degree-days, and 11 bins for cooling-degree-days. Energy use and savings are presented per 1000 ft2 of roof area. In residences heated with gas and in climates with greater than 1000 cooling-degree-days, the annual electricity savings in Pre-1980 stock ranged from 650 to 1300 kWh/1000ft2; for 1980+ stock savings ranged 300 to 600 kWh/1000 ft2

  8. Energy effects of heat-island reduction strategies in Toronto,Canada

    SciTech Connect

    Akbari, Hashem; Konopacki, Steven

    2003-08-26

    The effect of heat-island reduction (HIR) strategies on annual energy savings and peak-power avoidance of the building sector of the Greater Toronto Area is calculated, using an hourly building energy simulation model. Results show that ratepayers could realize potential annual energy savings of over $11M from the effects of HIR strategies. The residential sector accounts for over half (59%) of the total savings, offices 13% and retail stores 28%. Savings from cool roofs are about 20%, shade trees 30%, wind shielding of trees 37%, and ambient cooling by trees and reflective surfaces 12%. These results are preliminary and highly sensitive to the relative price of gas and electricity. Potential annual electricity savings are estimated at about 150GWh and potential peak-power avoidance at 250MW.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Urban heat islands (UHIs) develop when urban and suburban areas experience elevated temperatures relative to their rural surroundings. The difference in temperature between the city core and its surroundings is proportional to the size of the city and can be related to differences in vegetation cover, the amount of development, building materials, and the 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, and changes in the local meteorology. To begin to address UHI mitigation strategies, a comprehensive spatial and temporal analysis of the behavior of urban heat islands is necessary. Because the influence of UHIs is most notable in wintertime, solutions to mitigate them are compounded because of societal resistance to modifying the landscape and urban structures to reduce already low wintertime temperatures. To better understand the UHI behavior of a large northern latitude city and to evaluate mitigation strategies that have the desired effect year round, we have embarked on a comprehensive four-year research program - Islands in the Sun - aimed at 1) analyzing the UHIs of the largest urban areas on the planet, 2) monitoring the UHI of the Twin Cities Metropolitan Area (TCMA) and evaluating mitigation strategies for reducing urban warming, and 3) developing a numerical UHI model to quantify the effect of different mitigation strategies. Here we present results from an observational study of the TCMA, a 7,700 square kilometer urban and suburban region located in east central Minnesota that includes the two cities of Minneapolis and Saint Paul. The TCMA is home to 2.8 million residents within a seven county area comprising an

  10. Urban Heat Islands and Summertime Convective Thunderstorms in Atlanta: Three Case Studies

    NASA Technical Reports Server (NTRS)

    Bornstein, Robert; Lin, Qinglu; Goodman, H. Michael (Technical Monitor)

    1999-01-01

    Data from both 27 sites in the Atlanta mesonet surface meteorological network and eight National Weather Service sites were analyzed for the period from 26 July to 3 August 1996. Analysis of the six precipitation events over the city during the period (each on a different day) showed that its urban heat island (UHI) induced a convergence zone that initiated three of the storms at different times of the day, i.e., 0630,0845, and 1445 EDT. Previous analysis has shown that New York City (NYC) effects summer daytime thunderstorm formation and/or movement. That study found that during nearly calm regional flow conditions the NYC UHI initiates convective activity. Moving thunderstorms, however, tended to bifurcate and to move around the city, due to its building barrier effect. The current Atlanta results thus agree with the NYC results with respect to thunderstorm initiation.

  11. A study of the Oklahoma City urban heat island using ground measurements and remote sensing

    SciTech Connect

    Brown, M. J.; Ivey, A.; McPherson, T. N.; Boswell, D.; Pardyjak, E. R.

    2004-01-01

    Measurements of temperature and position were collected during the night from an instrumented van on routes through Oklahoma City and the rural outskirts. The measurements were taken as part of the Joint URBAN 2003 Tracer Field Experiment conducted in Oklahoma City from June 29, 2003 to July 30, 2003 (Allwine et al., 2004). The instrumented van was driven over four primary routes that included legs from the downtown core to four different 'rural' areas. Each route went through residential areas and most often went by a line of permanently fixed temperature probes (Allwine et al., 2004) for cross-checking purposes. Each route took from 20 to 40 minutes to complete. Based on seven nights of data, initial analyses indicate that there was a temperature difference of 0.5-6.5 C between the urban core and nearby 'rural' areas. Analyses also suggest that there were significant fine scale temperature differences over distances of tens of meters within the city and in the nearby rural areas. The temperature measurements that were collected are intended to supplement the meteorological measurements taken during the Joint URBAN 2003 Field Experiment, to assess the importance of the urban heat island phenomenon in Oklahoma City, and to test new urban canopy parameterizations that have been developed for regional scale meteorological codes (e.g., Chin et al., 2000; Holt and Shi, 2004). In addition to the ground measurements, skin temperature measurements were also analyzed from remotely sensed images taken from the Earth Observing System's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). A surface kinetic temperature thermal infrared image captured by the ASTER of the Oklahoma City area on July 21, 2001 was analyzed within ESRI's ArcGIS 8.3 to correlate variations in temperature with land use type. Analysis of this imagery suggests distinct variations in temperature across different land use categories. Through the use of remotely sensed imagery we hope to

  12. Energy Saving Potentials and Air Quality Benefits of Urban Heat Island Mitigation

    SciTech Connect

    Akbari, Hashem

    2005-08-23

    Urban areas tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term ''Urban Heat Island'' describes this phenomenon. The surfaces of buildings and pavements absorb solar radiation and become extremely hot, which in turn warm the surrounding air. Cities that have been ''paved over'' do not receive the benefit of the natural cooling effect of vegetation. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. In the United States, we have found that this increase in air temperature is responsible for 5-10% of urban peak electric demand for a/c use, and as much as 20% of population-weighted smog concentrations in urban areas. Simple ways to cool the cities are the use of reflective surfaces (rooftops and pavements) and planting of urban vegetation. On a large scale, the evapotranspiration from vegetation and increased reflection of incoming solar radiation by reflective surfaces will cool a community a few degrees in the summer. As an example, computer simulations for Los Angeles, CA show that resurfacing about two-third of the pavements and rooftops with reflective surfaces and planting three trees per house can cool down LA by an average of 2-3K. This reduction in air temperature will reduce urban smog exposure in the LA basin by roughly the same amount as removing the basin entire onroad vehicle exhaust. Heat island mitigation is an effective air pollution control strategy, more than paying for itself in cooling energy cost savings. We estimate that the cooling energy savings in U.S. from cool surfaces and shade trees, when fully implemented, is about $5 billion per year (about $100 per air-conditioned house).

  13. Urban heat island by means of city clusters: a statistical assessment of size influence and seasonality

    NASA Astrophysics Data System (ADS)

    Zhou, Bin; Rybski, Diego; Kropp, Jürgen P.

    2014-05-01

    In the last decades, influence factors of the Urban Heat Island (UHI) effect have been intensively investigated and further broadened through a variety of studies around the world. Briefly, compared to non-built surroundings, built-up areas of cities differ considerably in albedo, thermal capacity, roughness, etc. which can significantly modify the surface energy budget and make downtown areas of cities hotter than their vicinities. Most previous studies were built upon a limited number of cities, and suffered from inconsistency and instability with regard to the urban-rural definition, which hinders the inter-comparison between results. To overcome this limitation in the number of considered cities, we perform a systematic study of all cities in Europe to assess the Surface Urban Heat Island (SUHI) intensity by means of land surface temperature data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. After defining cities as spatial clusters of urban land cover based on CORINE data, we determine a boundary around the urban cluster of approximately equal area to the cluster area. SUHI intensity is thus defined as the difference between the mean temperature in the cluster and that of the surroundings. We investigate the relationships of the SUHI intensity, respectively with the cluster size and with the temperature of the surroundings. Our results show that in Europe, the SUHI intensity in summer has a strong correlation with the cluster size, which can be well fitted by an empirical sigmoid model. Furthermore, we find a pronounced seasonality of the SUHI intensity for individual clusters in the form of hysteresis-like curves. Characterizing the shape by means of Fourier series approximation and consequential work of clustering, we identify apparent regional patterns which suggest a climatological basis for the heterogeneity of UHI.

  14. The Development of Urban Heat Islands in the Southeast Region of the United States in the Winter Season

    NASA Astrophysics Data System (ADS)

    Hafner, Jan

    The study of the urban heat island has gained increased importance due to its relation to global warming. The effect of urbanization and land use changes in general on thermometer readings can bias long-term records resulting in a false global warming signal. Therefore, understanding the urban heat island phenomenon is important for an assessment of the global warming magnitude. A modeling approach has been chosen since it can overcome some restrictions of "conventional" methods (in situ and satellite observations), such as limited spatial and temporal resolution and topography effects. Models can provide better resolution and extend our understanding of the underlying physics of urban heat island development. In order to demonstrate this concept, the city of Atlanta was selected for numerical simulation under clear sky conditions on 6-7 and 25-26 February 1988. A mesoscale model developed by Pielke (1974) was employed in the numerical simulation. The first step was determination of the soil thermal inertia and moisture availability using AVHRR satellite-derived skin surface temperatures in a technique developed by Carlson et al. (1981). The thermal inertia exhibited elevated values over the city in both cases. The moisture availability field showed a larger degree of variability. The case of 25-26 February 1988 exhibited lower values of moisture availability in the city as compared to the rural surroundings, which is considered to be a typical situation. However, the case of 6-7 February 1988 showed extremely high moisture availability in the city. A possible explanation can be found in the cumulative rainfall, which shows a positive correlation between 14 -day cumulative rainfall amount and the moisture availability. A technique proposed by Hjelmfelt (1982) was used to simulate the urban effect. The urban heat island itself was investigated in terms of the skin surface and 2-m height temperatures. The horizontal and temporal evolution of these variables was

  15. 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

  16. On the influence of the urban heat island on the cooling load of a school building in Athens, Greece

    NASA Astrophysics Data System (ADS)

    Bagiorgas, H. S.; Mihalakakou, G.

    2016-02-01

    The present study investigates the effect of the urban heat island (UHI) phenomenon, measured in the Greater Athens Area (GAA), on the energy consumption of a typical modern school building. The energy performance of the selected building has been calculated using an accurate, extensively validated, transient simulation model for 17 different sites of the GAA, for the summer period. Calculations showed that the urban heat island phenomenon affects remarkably the thermal behavior of the school building, as suburban areas presented much lower cooling loads. The cooling load values fluctuated between 3304.3 kWh for the rural stations and 14,585.1 kWh for the central stations (for the year 2011) or between 3206.5 kWh and 14,208.3 kWh (for the year 2012), respectively. Moreover, the mean monthly cooling load values varied between 0.4-2 kWh/m2 for the rural stations and 4-6.9 kWh/m2 for the central stations, for the selected time period. Furthermore, a neural network model was designed and developed in order to quantify the contribution of various meteorological parameters (such as the mean daily air temperature values, the mean daily solar radiation values, the average wind speed and the urban heat island intensity) to the energy consumption of the building and it was found that the urban heat island intensity is the predominant parameter, influencing remarkably the energy consumption of the typical school building.

  17. Quantitative Links between Amundsen Sea Heat and Pine Island Ice Shelf Melt

    NASA Astrophysics Data System (ADS)

    Bindschadler, R.; Vaughan, D. G.; Vornberger, P.

    2010-12-01

    Previous researchers have established the strong connection between the Amundsen Sea and basal melt of Pine Island Glacier’s ice shelf in Antarctica. In this presentation we extend this work by focusing on a strong spatial pattern of ice thickness undulations observed on the ice shelf and the predicted temporal pattern of pulses of Circumpolar Deep Water (CDW) upwelled onto the Amundsen Sea continental shelf by variable surface winds (Thoma et al., 2008). After converting the temporal pattern to spatial position on the ice shelf, we show a remarkable correlation over the last decade of these records that allows us to quantitatively associate an amount of heat at the front of the ice shelf, with an amount of melt that occurs at the grounding line. By considering the excess melting driven by pulses of CDW separately from the background melting, we extract a set of heat vs. melt values that suggest a linear relationship supporting the results of Rignot and Jacobs (2002) and disputing the non-linear relationship suggested by Holland et al. (2008). We infer that the current delivering the ocean’s heat is approximately 3.4 cm/sec , that most of the heat is expended by melt, and that the majority of melting is spatially limited to the grounding line vicinity. References cited: Holland, P.R., A. Jenkins and D.M. Holland, 2008. The Response of Ice Shelf Basal Melting to Variations in Ocean Temperature. Journal of Climate, Vol. 21, pp. 2558-2572, DOI: 10.1175/2007JCLI1909.1 Rignot E. and S.S. Jacobs, 2002. Rapid bottom melting widespread near Antarctic ice sheet grounding lines, Science, Vol. 296, No. 5575, p. 2020-2023. Thoma, M., A. Jenkins, D. Holland, and S. Jacobs, 2008. Modelling Circumpolar Deep Water intrusions on the Amundsen Sea continental shelf, Antarctica, Geophysical Research Letters, Vol. 35, No. 18, L18602, doi: 10.1029/2008GL034939

  18. Role of snow cover on urban heat island intensity investigated by urban canopy model with snow effects

    NASA Astrophysics Data System (ADS)

    Sato, T.; Mori, K.

    2015-12-01

    Urban heat islands have been investigated around the world including snowy regions. However, the relationship between urban heat island and snow cover remains unclear. This study examined the effect of snow cover in urban canopy on energy budget in urban areas of Sapporo, north Japan by 1km mesh WRF experiments. The modified urban canopy model permits snow cover in urban canopy by the modification of surface albedo, surface emissivity, and thermal conductivity for roof and road according to snow depth and snow water equivalent. The experiments revealed that snow cover in urban canopy decreases urban air temperature more strongly for daily maximum temperature (0.4-0.6 K) than for daily minimum temperature (0.1-0.3 K). The high snow albedo reduces the net radiation at building roof, leading to decrease in sensible heat flux. Interestingly, the cooling effect of snow cover compensates the warming effect by anthropogenic heat release in Sapporo, suggesting the importance of snow cover treatment in urban canopy model as well as estimating accurate anthropogenic heat distributions. In addition, the effect of road snow clearance tends to increase nocturnal surface air temperature in urban areas. A possible role of snow cover on urban heat island intensity was evaluated by two experiments with snow cover (i.e., realistic condition) and without snow cover in entire numerical domain. The snow cover decreases surface air temperature more in rural areas than in urban areas, which was commonly seen throughout a day, with stronger magnitude during nighttime than daytime, resulting in intensifying urban heat island by 4.0 K for daily minimum temperature.

  19. Secondary effects of urban heat island mitigation measures on air quality

    NASA Astrophysics Data System (ADS)

    Fallmann, Joachim; Forkel, Renate; Emeis, Stefan

    2016-01-01

    This study presents numerical simulations analysing the effect of urban heat island (UHI) mitigation measures on the chemical composition of the urban atmosphere. The mesoscale chemical transport model WRF-Chem is used to investigate the impact of urban greening and highly reflective surfaces on the concentrations of primary (CO, NO) as well as secondary pollutants (O3) inside the urban canopy. In order to account for the sub-grid scale heterogeneity of urban areas, a multi-layer urban canopy model is coupled to WRF-Chem. Using this canopy model at its full extend requires the introduction of several urban land use classes in WRF-Chem. The urban area of Stuttgart serves as a test bed for the modelling of a case scenario of the 2003 European Heat Wave. The selected mitigation measures are able to reduce the urban temperature by about 1 K and the mean ozone concentration by 5-8%. Model results however document also negative secondary effects on urban air quality, which are closely related to a decrease of vertical mixing in the urban boundary layer. An increase of primary pollutants NO and CO by 5-25% can be observed. In addition, highly reflective surfaces can increase peak ozone concentration by up to 12% due to a high intensity of reflected shortwave radiation accelerating photochemical reactions.

  20. 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.

  1. The use of a vegetation index for assessment of the urban heat island effect

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Mcnab, A. L.; Karl, T. R.; Brown, J. F.; Hood, J. J.; Tarpley, J. D.

    1993-01-01

    A vegetation index and radiative surface temperature were derived from NOAA-11 Advanced Very High Resolution Radiometer (AVHRR) data for the Seattle, WA region from 28 June through 4 July 1991. The vegetation index and surface temperature values were computed for locations of weather observation stations within the region and compared to observed minimum air temperatures. These comparisons were used to evaluate the use of AVHRR data to assess the influence of the urban environment on observed minimum air temperatures (the urban heat island effect). AVHRR derived normalized difference vegetation index (NDVI) and radiant surface temperature data from a one week composite product were both related significantly to observed minimum temperatures, however, the vegetation index accounted for a greater amount of the spatial variation observed in mean minimum temperatures. The difference in the NDVI between urban and rural regions appears to be an indicator of the difference in surface properties (i.e., evaporation and heat storage capacity) between the two environments that are responsible for differences in urban and rural minimum temperatures.

  2. 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

  3. Examinations on the Meteorologic Factors of Urban Heat Island Development in Small and Medium-sized Towns of Hungary

    NASA Astrophysics Data System (ADS)

    Szegedi, S.; Gyarmati, R.; Kapocska, L.; Toth, T.

    2010-09-01

    EXAMINATIONS ON THE METEOROLOGICAL FACTORS OF URBAN HEAT ISLAND DEVELOPMENT IN SMALL AND MEDIUM-SIZED TOWNS OF HUNGARY Sandor Szegedi, Renata Gyarmati, Laszlo Kapocska and Tamas Toth University of Debrecen Department of Meteorology, 4032 Debrecen Egyetem tér 1. The thermal difference between the settlements and their environment is called urban heat island (UHI). Potential UHI intensities are mainly determined by the size, population and built-up structure of settlements. Meteorological conditions have a determinant impact on the development of the heat island at a certain moment. International and Hungarian studies usually deal with metropolises and big cities; much less attention is paid to medium-sized and small towns. Consequently this study has been focused on the development of UHI in such Hungarian urbanized areas as mentioned above. Settlements, located near the city of Debrecen (ca. 220,000 inhabitants) in East Hungary, with population of about 30000, 20000 10000 and 1000 were chosen for the research. Car-mounted digital thermometers with data loggers were used. Twenty four measurements were carried out during a one-year-long campaign in 2003-2004. Synoptic conditions, especially cloudiness, wind direction and wind speed were taken to consideration as determinant factors. Spatial characteristics of UHI have been described. Results have proved the existence of UHI even in the smallest settlement under suitable weather conditions. The non-heating season proved to be more advantageous for the development of UHI due to stronger irradiance and frequent anticyclonic synoptic conditions. Effects of cloudiness and wind speed have been revealed as well. St type clouds have proved to be most effective in preventing the formation of UHI. A 90-100% St cover could completely eliminate the thermal differences between natural and artificial surfaces. Ci type clouds had the weakest impact, they could prevent the formation of the heat island only in the smallest

  4. Urban Heat Island Versus Air Quality - a Numerical Modelling Study for a European City

    NASA Astrophysics Data System (ADS)

    Fallmann, J.; Forkel, R.; Emeis, S.

    2014-12-01

    In 2050 70% of the global population is expected to live in urban areas. Climate change will render these areas more vulnerable to heat waves, which often are accompanied by severe air pollution problems. The Urban Heat Island (UHI) is a feature that adds to the general temperature increase that is expected. Decreasing the UHI can impact air quality as well, because heat influences atmospheric dynamics and accelerates air chemical processes and often also increases the emission of primary pollutants due to increased demand of energy. The goal of this study is to investigate the effect of, e.g., high reflective surfaces and urban greening on mitigating the UHI and the related impact on air quality. A multi-layer urban canopy model is coupled to the mesoscale model WRF-Chem and the urban area of Stuttgart (South-West Germany) is taken as one example. Different scenario runs are executed for short time periods and are compared to a control run. The results show that the UHI effect can be substantially reduced when changing the albedo of roof surfaces, whereas the effect of urban greening is minor. Both scenarios have in common, that they evoke changes in secondary circulation patterns. The effects of these mitigation strategies on chemical composition of the urban atmosphere are complex, attributed to both chemical and dynamical features. Increasing the reflectivity of roof surfaces in the model results in a net decrease of the surface ozone concentration, because ozone formation is highly correlated to temperature. With regard to primary pollutants, e.g. NO, CO and PM10 concentrations are increased when increasing reflectivity. This effect primarily can be ascribed to a reduction of turbulent motion, convection and a decrease of the boundary layer height, coming along with lower temperatures in the urban canopy layer due to increased reflectivity. The table below shows the effect on grid cell mean concentrations for different chemical species and scenarios.

  5. 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.

  6. 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

    2016-03-01

    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

  7. 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

  8. Assessing the impacts of the urban heat island effect on streamflow patterns in Ottawa, Canada

    NASA Astrophysics Data System (ADS)

    Adamowski, Jan; Prokoph, Andreas

    2013-07-01

    Due to a variety of commercial and residential activities, large metropolitan areas in mid-to-high latitudinal ranges are experiencing rising air temperatures compared to their surrounding rural areas. This study investigated how this urban heat island effect (UHIE) may influence the streamflow of rivers crossing large urban areas on annual and multi-decadal time-scales. In order to detect, link, and quantify differences in meteorological and streamflow patterns between rural and large urban areas, this study developed a methodology based on the continuous wavelet transform (CWT), cross-wavelet transform (XWT), linear regression, as well as the Mann-Kendall (MK) test. A case study was carried out for the city of Ottawa, Canada as the metropolitan centre, along with three surrounding rural locations (Angers, Arnprior, Russell), with pristine rivers crossing these locations. From roughly 1970 to 2000, air temperature in Ottawa increased at a rate exceeding 0.035 °C/year, while parallel changes in rural areas were relatively stable, and varied by less than 0.025 °C/year. The urban warming that occurred during these decades was accompanied by a significant drop in the amplitude of annual temperatures (i.e. warmer winters). Precipitation in both urban and rural areas showed no significant trends, although the variability in the precipitation amount decreased in both settings. Concurrently, streamflow showed decreasing trends in both urban and rural areas. Annual amplitudes in urban streamflow (Rideau River through Ottawa, ON) correlated positively with annual air temperature amplitudes (i.e., less severe annual flooding with a decreasing winter/summer temperature contrast), whereas such a relationship was not apparent for the rural stations. Moreover, the timing of the annual daily minimum temperature cycle correlated significantly with the streamflow pattern in the urban area, i.e., early annual warming corresponded to earlier annual streamflow maxima. The

  9. 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

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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

  11. Urban Heat Island Modeling in Conjunction with Satellite-Derived Surface/Soil Parameters.

    NASA Astrophysics Data System (ADS)

    Hafner, Jan; Kidder, Stanley Q.

    1999-04-01

    Although it has been studied for over 160 years, the urban heat island (UHI) effect is still not completely understood, yet it is increasingly important. The main purpose of this work is to improve UHI modeling by using AVHRR (Advanced Very High Resolution Radiometer) satellite data to retrieve the surface parameters (albedo, as well as soil thermal and moisture properties). In this study, a hydrostatic three-dimensional mesoscale model was used to perform the numerical modeling. The Carlson technique was applied to retrieve the thermal inertia and moisture availability using the thermal AVHRR channels 4 and 5. The net urban effect was determined as the difference between urban and nonurban simulations, in which urban parameters were replaced by rural parameters.Two winter days were each used for two numerical simulations: a control and an urban-to-rural replacement run. Moisture availability values on the less windy day showed generally a south to north gradient downwind of the city and urban values less than rural values (the urban dry island day). Moisture availability was higher on the windy day, with uniform values in the rural and urban areas (uniform soil moisture day). The only exceptions were variations in the rural hills north of the city and the low rural values under the polluted urban plume downwind of the city.While thermal inertia values showed no urban-rural differences on the uniform soil moisture day, they exhibited larger values over Atlanta than in surrounding rural area on the (less moist) dry island day. Two puzzling facts exist in the data: 1) lack of a north-south thermal inertia gradient on the dry soil day to correspond to its above-mentioned moisture availability gradient and 2) rural thermal inertia values do not change between both days in spite of their large difference in soil moisture. The observed lack of corresponding urban change is expected, as its thermal inertia values depend more on urban building materials than on moisture of

  12. Climate Change, Pacific Ocean and Land Use Influences on Los Angeles' Urban Heat Islands

    NASA Astrophysics Data System (ADS)

    Gamelin, B.; Hsu, F.; LaDochy, S.; Ramirez, P. C.; Ye, H.; Sequera, P.; Gonzalez, J.; McDonald, K.; Patzert, W. C.

    2013-12-01

    The Los Angeles urban heat island (UHI) is a complex entity that is changing in time, space and intensity. The major influences on its characteristics appear to be population, landuse, and Pacific Ocean variability. Since 1950, the city of Los Angeles has nearly tripled in population from 1,333,300 to 3,792,621 in 2010. The downtown skyline has also changed as more high-rises replace lower density buildings and parking lots. Downtown average temperatures have increased rapidly, rising over 3oC in the last century. Tmin values have increased faster than Tmax similar to other UHI cities. However the Los Angeles UHI is unique among most cities, with its complex terrain and dominant land/sea breeze circulations. Also, the city is part of a regional megalopolis, where the surrounding rural areas are distant and ill-defined, in contrast to most UHIs. Our study looks at the diurnal and seasonal patterns in the urban thermal regime and how they have changed over recent decades. Temporal changes in land use, particularly vegetation, coastal sea surface temperatures, Pacific climatic indices such as the Pacific Decadal Oscillation (PDO) and coastal upwelling all seem to contribute to the changes in city temperatures. The PDO especially correlates well with Los Angeles temperatures. The spatial changes in an UHI are described combining surface met data and aircraft remote sensing, using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and the MODIS/ASTER Airborne Simulator (MASTER) sensors at spatial resolutions of 30 and 50 m, respectively. In our study recent sea breeze enhancement will be investigated in its influence on coastal cooling. Implications of the role of the intensifying UHI in the increases in Los Angeles heat waves will also be discussed.

  13. Maximum urban heat island intensity in a medium-sized coastal Mediterranean city

    NASA Astrophysics Data System (ADS)

    Papanastasiou, Dimitris K.; Kittas, Constantinos

    2012-02-01

    This paper studies the maximum intensity of the urban heat island (UHI) that develops in Volos urban area, a medium-sized coastal city in central Greece. The maximum temperature difference between the city center and a suburb is 3.4°C and 3.1°C during winter and summer, respectively, while during both seasons the average maximum UHI intensity is 2.0°C. The UHI usually starts developing after sunset during both seasons. It could be attributed to the different nocturnal radiative cooling rate and to the different anthropogenic heat emission rate that are observed at the city center and at the suburb, as well as to meteorological conditions. The analysis reveals that during both seasons the daily maximum hourly (DMH) UHI intensity is positively correlated with solar radiation and with previous day's maximum hourly UHI intensity and negatively correlated with wind speed. It is also negatively correlated with relative humidity during winter but positively correlated with it during summer. This difference could be attributed to the different mechanisms that mainly drive humidity levels (i.e., evaporation in winter and sea breeze (SB) in summer). Moreover, it is found that SB development triggers a delay in UHI formation in summer. The impact of atmospheric pollution on maximum UHI intensity is also examined. An increase in PM10 concentration is associated with an increase in maximum UHI intensity during winter and with a decrease during summer. The impact of PM10 on UHI is caused by the attenuation of the incoming and the outgoing radiation. Additionally, this study shows that the weekly cycle of the city activities induces a weekly variation in maximum UHI intensity levels. The weekly range of DMH UHI intensity is not very large, being more pronounced during winter (0.4°C). Moreover, a first attempt is made to predict the DMH UHI intensity by applying regression models, whose success is rather promising.

  14. The effectiveness of cool and green roofs as urban heat island mitigation strategies

    NASA Astrophysics Data System (ADS)

    Li, Dan; Bou-Zeid, Elie; Oppenheimer, Michael

    2014-05-01

    Mitigation of the urban heat island (UHI) effect at the city-scale is investigated using the Weather Research and Forecasting (WRF) model in conjunction with the Princeton Urban Canopy Model (PUCM). Specifically, the cooling impacts of green roof and cool (white/high-albedo) roof strategies over the Baltimore-Washington metropolitan area during a heat wave period (7 June-10 June 2008) are assessed using the optimal set-up of WRF-PUCM described in the companion paper by Li and Bou-Zeid (2014). Results indicate that the surface UHI effect (defined based on the urban-rural surface temperature difference) is reduced significantly more than the near-surface UHI effect (defined based on urban-rural 2 m air temperature difference) when these mitigation strategies are adopted. In addition, as the green and cool roof fractions increase, the surface and near-surface UHIs are reduced almost linearly. Green roofs with relatively abundant soil moisture have comparable effect in reducing the surface and near-surface UHIs to cool roofs with an albedo value of 0.7. Significant indirect effects are also observed for both green and cool roof strategies; mainly, the low-level advection of atmospheric moisture from rural areas into urban terrain is enhanced when the fraction of these roofs increases, thus increasing the humidity in urban areas. The additional benefits or penalties associated with modifications of the main physical determinants of green or cool roof performance are also investigated. For green roofs, when the soil moisture is increased by irrigation, additional cooling effect is obtained, especially when the ‘unmanaged’ soil moisture is low. The effects of changing the albedo of cool roofs are also substantial. These results also underline the capabilities of the WRF-PUCM framework to support detailed analysis and diagnosis of the UHI phenomenon, and of its different mitigation strategies.

  15. Spatio-temporal variance and meteorological drivers of the urban heat island in a European city

    NASA Astrophysics Data System (ADS)

    Arnds, Daniela; Böhner, Jürgen; Bechtel, Benjamin

    2015-12-01

    Urban areas are especially vulnerable to high temperatures, which will intensify in the future due to climate change. Therefore, both good knowledge about the local urban climate as well as simple and robust methods for its projection are needed. This study has analysed the spatio-temporal variance of the mean nocturnal urban heat island (UHI) of Hamburg, with observations from 40 stations from different suppliers. The UHI showed a radial gradient with about 2 K in the centre mostly corresponding to the urban densities. Temporarily, it has a strong seasonal cycle with the highest values between April and September and an inter-annual variability of approximately 0.5 K. Further, synoptic meteorological drivers of the UHI were analysed, which generally is most pronounced under calm and cloud-free conditions. Considered were meteorological parameters such as relative humidity, wind speed, cloud cover and objective weather types. For the stations with the highest UHI intensities, up to 68.7 % of the variance could be explained by seasonal empirical models and even up to 76.6 % by monthly models.

  16. 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.

  17. 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.

  18. Study on the urban heat island effect based on quantitative remote sensing technology

    NASA Astrophysics Data System (ADS)

    Nie, Yunju; Tong, Chengzhuo; Cheng, Penggen; Chen, Xiaoyong; Zhou, Mengyu

    2015-12-01

    In recent years, the effect of urban heat island (UHI) is increasingly obvious with moving forward in further urbanization process, which has become one of the prominent issues of environment. The image data of Nanchang city supplied by Landsat 5 Thematic Mapper (TM) in September 2006 is used in this paper, and the land surface temperature (LST) over the same period has been retrieved by using a mono-window algorithm based on remote sensing technology. The classification of LST is subsequently fulfilled by the method of proper density cutting. Characteristics of intensity and spatial distribution of UHI effect in Nanchang, as well as its relationships with land use type and vegetation coverage degree (VCD) are discussed in detail. The result shows that the phenomena of UHI are significantly presented in urban area with an inhomogeneous distribution, and the degree of influence of UHI depends on types of land uses. The intensity of UHI effect has a significant negative linear correlation with normalized difference vegetation index (NDVI). It is deduced that suitably optimizing land use types and raising VCR are obvious and effective ways to reduce UHI.

  19. The summer surface urban heat island of Bucharest (Romania) retrieved from MODIS images

    NASA Astrophysics Data System (ADS)

    Cheval, Sorin; Dumitrescu, Alexandru

    2015-08-01

    The summer surface urban heat island (SUHI) of the city of Bucharest (Romania) is investigated in terms of its shape, intensity, extension and links to land cover. The study employs land surface temperature (LST) data retrieved by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard the Terra (EOS AM-1) and Aqua (EOS PM-1) NASA satellites, between 2000 and 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 SUHI's limits. The thermal difference between the SUHI and several surrounding buffers defines the SUHI's intensity. The night-time SUHI's geometry is more regular, and its intensity is slightly lower than during the day, while the land cover exerts a strong influence on Bucharest's LST. In summary, the study proposes a methodology to delimit and quantify the average SUHI based on the statistical significance of the shift between the urban area and its surroundings, and the limitations of the method are mentioned.

  20. Modeling and measuring neighborhood scale flow, turbulence, and temperature within Chicago heat island

    NASA Astrophysics Data System (ADS)

    Conry, Patrick; Sharma, Ashish; Leo, Laura; Fernando, H. J. S.; Potosnak, Mark; Hellmann, Jessica

    2013-11-01

    The modeling of urban heat island (UHI) requires a multi-scale approach as it involves numerous physical phenomena spanning a range of scales. We have performed a comprehensive study of Chicago's UHI via coupling of mesoscale Weather Research and Forecasting (WRF) and micro-scale ENVI-met models. The application of the latter model to a Lincoln Park neighborhood and a parallel observational campaign will be the primary focus of this presentation. ENVI-met employs a computational fluid dynamics model to represent heterogeneity of urban areas, providing fine resolution output of UHI dynamics. In the field campaign, two stations located on rooftops of DePaul University buildings were each equipped with a sonic anemometer and vertical array of thermocouples, allowing investigations of spatial variability of flow, turbulent fluxes, and temperature profiles in an urban roughness sublayer. One of these was located above a rooftop garden and the other above a conventional rooftop. Downscaled output from the WRF model or a set of observational data served as initial and boundary conditions for the ENVI-met model. The model's predicative capabilities were assessed through comparison with another set of observational data, and dynamical causes for the model's poor behavior were identified. Funded by NSF Grant No. 0934592 and ND-ECI.

  1. Nocturnal urban heat island in Lisbon (Portugal): main features and modelling attempts

    NASA Astrophysics Data System (ADS)

    Alcoforado, M.-J.; Andrade, H.

    2006-02-01

    In recent years, several studies have examined the Lisbon urban climate. A central conclusion is the existence of a nocturnal urban heat island (mean ΔTu-r = 2.5 °C). The aim of this paper is to summarise several attempts carried out in the last decade to interpolate nocturnal air temperatures across Lisbon, in order to be able to draw thermal maps as accurately as possible. This study refers only to clear nights. Stepwise multiple regression and a Geographic Information System were used to model the relation between air temperature and parameters related to land-use and topography. The different regression models (coefficients of determination between 0.68 and 0.92) show that canopy layer air temperature depends on sky-view factor, building height and percentage of built-up area, but also to a great extend on mesoclimatic geographic factors such as altitude, topography and distance from the Tagus River. Examples of four frequently encountered nocturnal air temperature patterns are presented, each corresponds to a different weather type. This method employed could prove useful in drawing climatic maps that may be of use in master plans of urban municipalities.

  2. Air quality influenced by urban heat island coupled with synoptic weather patterns.

    PubMed

    Lai, Li-Wei; Cheng, Wan-Li

    2009-04-01

    Few studies have discussed the association between the urban heat island (UHI) phenomenon and air quality under synoptic weather patterns conducive to UHI. In this study, the authors used statistical analyses to study this association in the Taichung metropolis region. The air quality data obtained from government-owned observation stations and wind field profiles obtained from tethersonde monitoring (performed during 21-29 October 2004) were combined with the simulations of the horizontal wind fields at different heights by the air pollution model (TAPM). The results show that certain specific synoptic weather patterns worsen the air quality and induce the UHI phenomenon: Taichung's UHI appears clearly under the synoptic weather patterns featuring light air or breezes (0.56 m/s < or =wind speed <2.2 m/s) mainly from the north and west. Furthermore, under these weather patterns, the concentrations of air pollutants (NO2, CO2 and CO) increase significantly (P<0.05) with the UHI intensity. The convergence usually associated with nocturnal UHI causes the accumulation of O3 precursors, as well as other air pollutants, thereby worsening the air quality at that time and also during the following daytime period. PMID:19200584

  3. Effects of Urban Heat Island Mitigation Strategies on Current and Future Meteorology of Atlanta, Georgia

    NASA Astrophysics Data System (ADS)

    Crosson, W. L.; Lapenta, W. M.; Griggs, L.; Kenna, G.; Johnson, H.; Dembek, S.

    2004-05-01

    The characterization of land use/land cover is an integral component of an ongoing air quality modeling project focused on evaluating strategies for reducing the Urban Heat Island (UHI) and improving air quality in Atlanta, Georgia. The `UHI mitigation strategies' applied in this project involve `Cool Communities' principles of high albedo pavement and roofing as well as increased urban tree canopy. These strategies have been developed based on input from local stakeholders and represent conditions that are attainable assuming broad-based support from local government and the community. In order to evaluate the impact of these strategies on urban meteorology (principally near-surface air temperature) and ultimately on air quality, mesoscale model simulations have been performed for the Atlanta region based on land use for 1999 and projected to 2030 using the Spatial Growth Model assuming `Business as Usual' development. Significant land use change associated with continuing urban sprawl is expected from now until 2030. Model simulations based on identical synoptic forcing were performed to evaluate the effects of local land use change on local and regional meteorology. For the 2030 case, results from `Business as Usual' and `UHI mitigation strategies' simulations will be compared. The impacts of higher urban albedo and increased tree cover will be examined separately and in combination.

  4. 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. PMID:26372336

  5. Identifying the Local Surface Urban Heat Island Through the Morphology of the Land Surface Temperature

    NASA Astrophysics Data System (ADS)

    Wang, Jiong; Zhan, Qingming; Xiao, Yinghui

    2016-06-01

    Current characterization of the Land Surface Temperature (LST) at city scale insufficiently supports efficient mitigations and adaptations of the Surface Urban Heat Island (SUHI) at local scale. This research intends to delineate the LST variation at local scale where mitigations and adaptations are more feasible. At the local scale, the research helps to identify the local SUHI (LSUHI) at different levels. The concept complies with the planning and design conventions that urban problems are treated with respect to hierarchies or priorities. Technically, the MODerate-resolution Imaging Spectroradiometer satellite image products are used. The continuous and smooth latent LST is first recovered from the raw images. The Multi-Scale Shape Index (MSSI) is then applied to the latent LST to extract morphological indicators. The local scale variation of the LST is quantified by the indicators such that the LSUHI can be identified morphologically. The results are promising. It can potentially be extended to investigate the temporal dynamics of the LST and LSUHI. This research serves to the application of remote sensing, pattern analysis, urban microclimate study, and urban planning at least at 2 levels: (1) it extends the understanding of the SUHI to the local scale, and (2) the characterization at local scale facilitates problem identification and support mitigations and adaptations more efficiently.

  6. Surface urban heat island effect and its relationship with urban expansion in Nanjing, China

    NASA Astrophysics Data System (ADS)

    Tu, Lili; Qin, Zhihao; Li, Wenjuan; Geng, Jun; Yang, Lechan; Zhao, Shuhe; Zhan, Wenfeng; Wang, Fei

    2016-04-01

    Nanjing, a typical megacity in eastern China, has undergone dramatic expansion during the past decade. The surface urban heat island (SUHI) effect is an important indicator of the environmental consequences of urbanization and has rapidly changed the dynamics of Nanjing. Accurate measurements of the effects and changes resulting from the SUHI effect may provide useful information for urban planning. Index, centroid transfer, and correlation analyses were conducted to measure the dynamics of the SUHI and elucidate the relationship between the SUHI and urban expansion in Nanjing over the past decade. Overall, the results indicated that (1) the region affected by the SUHI effect gradually expanded southward and eastward from 2000 to 2012; (2) the centroid of the SUHI moved gradually southeastward and then southward and southwestward, which is consistent with the movement of the urban centroid; (3) the trajectory of the level-3 SUHI centroid did not correspond with the urban mass or SUHI centroids during the study period and (4) the SUHI intensity and urban fractal characteristics were negatively correlated. In addition, we presented insights regarding the minimization of the SUHI effect in cities such as Nanjing, China.

  7. The effects of Sao Paulo urban heat island on lightning activity: Decadal analysis (1999-2009)

    NASA Astrophysics Data System (ADS)

    Bourscheidt, Vandoir; Pinto, Osmar; Naccarato, Kleber P.

    2016-05-01

    Eleven years of lightning data from the Brazilian Integrated National Lightning Detection Network were used to analyze the effects of the urban heat island (UHI) of Sao Paulo on lightning activity, extending the investigation of previous works. Cloud-to-ground lightning data were analyzed in both spatial and temporal perspectives, using different approaches: flash density, flash rate, thunderstorm hours (TH), and the cell initiation technique (CIT), which aims to identify the onset of thunderstorms. Land surface temperature (LST) from MODIS (Moderate Resolution Imaging Spectroradiometer) was used to analyze the UHI evolution over the years. MODIS data were validated using ground stations, distributed within the urban area. Different time intervals (seasonal and intraday) were used in an attempt to separate local convective systems from synoptic-scale events. The results indicate significant effects of the UHI (using LST) on THs and CIT. The CIT showed a nearly ring pattern, especially during the afternoon (14:00-18:00 LT) of summer months, reinforcing temperature contrast as a condition for storm initiation. The results also suggest an amplification of the UHI effects on thunderstorm activity by local factors (sea and country breeze, synoptic events, and terrain). Higher flash rates were also observed throughout the urban region, which influences the lightning density. Temporal analysis indicates that minimum temperature and lightning activity increase in wintertime. In summary, the results agree with previous studies about the UHI and indicate its importance on lightning occurrence, especially by increasing the temperature contrast and the instability in these regions.

  8. Urban Heat Island Adaptation Strategies are not created equal: Assessment of Impacts and Tradeoffs

    NASA Astrophysics Data System (ADS)

    Georgescu, Matei

    2014-05-01

    Sustainable urban expansion requires an extension of contemporary approaches that focus nearly exclusively on reduction of greenhouse gas emissions. Researchers have proposed biophysical approaches to urban heat island mitigation (e.g., via deployment of cool or green roofs) but little is known how these technologies vary with place and season and what impacts are beyond those of near surface temperature. Using a suite of continuous, multi-year and multi-member continental scale numerical simulations for the United States, we examine hydroclimatic impacts for a variety of U.S. urban expansion (to the year 2100) and urban adaptation futures and compare those to contemporary urban extent. Adaptation approaches include widespread adoption of cool roofs, green roofs, and a hypothetical hybrid approach integrating properties of both cool and green roofs (i.e., reflective green roofs). Widespread adoption of adaptation strategies exhibits hydroclimatic impacts that are regionally and seasonally dependent. For some regions and seasons, urban-induced warming of 3°C can be completely offset by the adaptation approaches examined. For other regions and seasons, widespread adoption of some adaptation strategies can result in significant reduction in precipitation. Finally, implications of large-scale urbanization for seasonal energy demand will be examined.

  9. 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

  10. Based on Landsat8 multi-resolution remote sensing image fusion of urban heat-island difference analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Zhou, Guoqing; Wang, Yuefeng; Ye, Siqi; Han, Caiyun

    2015-12-01

    Over the years, with the accelerating of city construction, urban heat-island effect has become increasingly significant.According to meteorological data of nearly ten years, some parts of the regional land surface temperature is higher, and then it influence people's introduction and living directly. At the same time it also affect the ecological environment of the earth.This article bases on the Landsat8 remote sensing image of 2014, through the different resolution of image fusion to analyze the differences surface temperature of the study area and forecast the future development tendency. Research finding: in different resolution, due to details of the objects reflecting obviously differences, affected by it, the surface temperature also exists obvious difference. The lower resolution, the surface temperature difference is smaller; on the contrary,the higher resolution makes surface temperature difference more significant. This shows that with the expansion of cities and the change of vegetation, water, the regional differences of heat-island effect is more obvious. In future development, how to coordinate and plan buildings, factories, vegetation, water, etc will affect the distribution of urban heat-island effect.

  11. Results of the DUE Thermopolis Campaign with Regard to the Urban Heat Island (UHI) Effect in Athens

    NASA Astrophysics Data System (ADS)

    Daglis, Ioannis A.; Rapsomanikis, Spyridon; Kourtidis, Konstantinos; Melas, Dimitrios; Papayannis, Alexandros; Keramitsoglou, Iphigenia; Giannaros, Theodoros; Amiridis, Vassilis; Petropoulos, Georgios; Georgoulias, Aristeidis; Sobrino, Jose Antonio; Manunta, Paolo; Grobner, Julian; Paganini, Marc; Bianchi, Remo

    2010-12-01

    The Urban Heat Island (UHI) effect is a typical phenomenon of urban climate, where the temperature of central urban locations is several degrees higher than that of surrounding rural areas of similar elevation; the temperature difference is especially pronounced during night-time. Although the UHI effect has long been studied through ground-based observations, the possibility of thermal remote sensing using spacecraft and/or airborne platforms has become available only relatively recently, providing innovative ways for the observation and study of the UHI effect. Following an initiative of the European Space Agency (ESA) to improve our understanding of the complexities of how urban heat islands arise, a relevant project entitled "Urban Heat Islands and Urban Thermography" has been under way to study the UHI effect in major European cities through the combination of ground-based observations and spacecraft remote sensing. In this paper we report preliminary results of this project pertaining to the metropolitan area of Athens, Greece, where also airborne remote sensing observations became available through the ESA-funded Thermopolis 2009 campaign, coordinated by the Democritus University of Thrace and implemented by a wide consortium

  12. 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

  13. 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.

  14. Native, Arid Green Design: Strategies to Combat Urban Heat Island Effect

    NASA Astrophysics Data System (ADS)

    Tepler, S. K.; Pavao-Zuckerman, M.; Livingston, M.; Smith, S. E.; Stoltz, R.

    2010-12-01

    The heat island effect has one of the greatest impacts on the biogeochemistry of urban microclimates. As cities grow hotter from climate change and increased energy consumption, the effect on urban ecosystem function will likely intensify. One strategy for ameliorating local elevated temperatures is to use green design to alter energy balances and reduce energy demands for cooling. In arid environments, however, little is known about how to balance needs for energy reduction with water costs associated with green roof installations in cities. We are conducting a pilot study to investigate strategies to implement green roofs in arid cities that are environmentally ‘responsible’ with respect to water consumption. In this study we ask, (a) is green roof technology appropriate for a desert city, (b) if native plants and environmentally responsible watering regimes are used, will ecosystem services we seek from green roofs be supported, and (c) would such an installation meet building code requirements. Small-plot model green roofs are constructed on the campus of Biosphere 2, near Oracle, AZ. The study design crosses two artificial soil types (a heavy and light mix made of different proportions of sand, organic materials, and a lightweight porous material [SOILMatrixTM], two irrigation regimes (ambient and drip irrigated), and three plant species (succulent: Hesparaloe parviflora; shrub: Calliandra eriophylla; grass: Cathestecum erectum) in initial tests. To address the questions we are posing, we compare energy balance of the plots, water status and health of the plants, and soil water contents. EPA MIST models indicate that plant cover has the potential to reduce average temperatures by 4 to 8°C, resulting in energy savings of 3 - 6% kWhr/ft2. In preliminary tests we found that the dry weights of our environmentally accurate rocky soil mixes were well under 40 lbs per sq. ft., the building code limit. Preliminary results from the first season of data collection

  15. 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

  16. "Urban heat island" effect on tree growth at several cities of Northern Europe

    NASA Astrophysics Data System (ADS)

    Shumilov, O. I.; Kasatkina, E. A.; Timonen, M.; Herva, H.; Kirtsideli, I.; Kanatjev, A. G.

    2010-05-01

    We investigated growth of larches being planted at several cities of Northern Europe: St. Petersburg (59°57'N, 30°19'E), Rovaniemi (66°30'N, 25°44'E), Apatity (67°34'N, 33°23'E). The data were collected at several sites inside of each city, and at one site in the rural area outside of each cities (about 50 km apart). Totally we studied 10 series. The longest chronology was about 190 years (in St. Petersburg). However, the most others were not very long (about 50 - 70 years). Firstly, it was shown that tree-rings of planted (not typical) larch trees don't reflect the influence of external (solar) factors in contrast with natural species. That is it could not be possible to detect some warming for the 1930-1960 period and some cooling later on. This effect was observed for both series inside the cities and outside of them. Secondly, it was revealed that for both northern cities (Apatity and Rovaniemi) variability of tree-ring indexes was more pronounced in series collected inside of them. Another situation was found for St. Petersburg. Growth of larch trees was stable inside of this megapolis. The preliminary interpretation of the results obtained seems to be connected to different influence of "urban heat island" effect on planted trees inside and outside of the cities for megapolis and relatively small towns. This work is financially supported by the Russian Foundation for Basic Research (grant No. 09-04-98801), by the Program of the Russian Academy and by the Regional Scientific Program of Murmansk region.

  17. [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. PMID:22919847

  18. The impact of green areas in mitigation of urban heat island

    NASA Astrophysics Data System (ADS)

    Zaninovic, Ksenija

    2016-04-01

    In the framework of the project REPUBLICMED (REtroffiting PUBLic spaces in Intelligent MEDiterranean Cities) co-financed by the European Union, the changes in urban structure have to be proposed in order to mitigate the urban heat island in Zadar, Croatia. The intention is to compare thermal perception for selected locations in Zadar in the present situation and after proposed changes in different parts of the year. For that purpose, four days in different seasons were selected. For winter and summer, the days with extreme minimum and maximum temperatures were selected, whilst for spring and autumn the days in the middle of seasons (April and October) with mean temperatures similar to the corresponding mean seasonal temperatures were selected. All selected days were mainly clear or with small cloudiness resulting with maximum solar radiation. The thermal perception was calculated by means of biometeorological index based on energy equilibrium between human body and environment - physiologically equivalent temperature (PET). In the first analysis, daily courses of biometeorological index for selected situations based on hourly data were compared. During warmest parts of the day in summer the thermal perception differs up to 5°C under the tree shadow, while the differences in other seasons are smaller. The second analysis included the differences in the distribution of frequencies of thermal perception in the warmest part of the day (2 p.m.) throughout the year for selected locations. It is performed using meteorological data measured at the meteorological station Zadar in the 30-year climate period 1981-2010. The results have revealed the reduction in the frequency of sensations of hot and very hot (PET > 35°C or 41°C) under the shadow of the trees during summer, at the rate of up to 25% comparing to the situation before modification (without trees).

  19. Seasonal Co-Variation in Surface Properties and the Urban Heat Island in Boston

    NASA Astrophysics Data System (ADS)

    Cheek, L.; Friedl, M. A.; Wang, J.

    2015-12-01

    Understanding the drivers behind the urban heat island (UHI) effect - the phenomenon of elevated temperatures in urban areas - is an important goal in urban climatology, particularly in the context of an increasingly urbanized and warming planet. Remote sensing offers a useful source of information for UHI studies by providing spatially explicit measures of both temperature and surface properties over time. However, key questions remain, particularly regarding what controls spatio-temporal dynamics in the UHI in and around cities. The objective of this study is to characterize seasonality in the daytime and nighttime UHI over Boston for the period 2001-2010, paying special attention to the roles of (1) green leaf phenology and (2) urban land use and shading in urban canyons as explanatory variables. We use 1 km 8-day land surface temperature (LST) data from MODIS to characterize temperature variability. Initial results are consistent with previously described UHI characteristics, with the highest daytime urban-rural temperature difference occurring during the summer. However, seasonal hysteresis for Boston is apparent in an enhanced UHI signature in the spring versus the fall, even when rural temperatures are equivalent during the two time periods. To characterize how surface cover variations control surface temperatures over the course of the year, we use spectral mixture analysis (SMA) applied to 30 m multi-temporal Landsat data. SMA is particularly well suited for studies of spatially heterogeneous urban areas because unlike classification methods or traditional vegetation indices, SMA takes explicit advantage of sub-pixel compositional variability. Preliminary results for 2010 suggest that spatio-temporal patterns in surface properties, and by extension land surface temperatures, in and around Boston are well explained as combinations of (a) green vegetation, (b) substrate/soil, (c) urban impervious, and (d) shade derived from SMA of multi-temporal Landsat data.

  20. New Perspectives on Longwave Imaging of Urban Heat Islands: Middle Infrared to Microwaves

    NASA Astrophysics Data System (ADS)

    Henebry, G. M.; Krehbiel, C. P.; Zheng, B.; Nguyen, L. H.; de Beurs, K.; Owsley, B.

    2015-12-01

    Urban populations are projected to increase throughout the century. As urban areas expand and increase in density as a result of population pressures, urban heat islands (UHIs) will grow and intensify. Characterization of UHIs using remote sensing has focused primarily on the use of thermal infrared (TIR) sensors. Remote sensing of TIR measures, at 1 km spatial resolution or coarser, land surface or skin temperatures to reveal the surface UHI (sUHI) in contrast to in situ approaches that measure air temperature at points in networks or along transects. The city, its suburbs, and rural matrix all emit longwave electromagnetic radiation at wavelengths both shorter and longer than TIR. Here we introduce the use of two other wavelength regions for UHI characterization. Our prior work has shown that the middle infrared (MIR) in the atmospheric window from 3-5 microns offers some advantages to imaging urban areas. We demonstrate a new method for characterizing the intensity and the seasonality of sUHI in the MIR for selected cities in North America and Europe using MODIS band 23. In contrast to MIR and TIR sensors, microwave radiometers (MWR) can retrieve both air temperature and water vapor, albeit at coarse spatial resolution (~25 km) relative to most urban areas. Using the AMSR-E/AMSR2 product time series, we show both the advantages and limitations of using MWR data to characterize UHIs in the megacities and major conurbations of North and South America. These new approaches to UHI characterization complement the traditional TIR methods to reveal other impacts of cities on their environment.

  1. Examining the impact of urban biophysical composition and neighboring environment on surface urban heat island effect

    NASA Astrophysics Data System (ADS)

    Song, Yang; Wu, Changshan

    2016-01-01

    Due to atmospheric and surface modifications associated with urbanization, surface urban heat island (SUHI) effects have been considered essential in examining urban ecological environments. With remote sensing technologies, numerous land cover type related variables, including spectral indices and land cover fractions, have been applied to estimate land surface temperature (LST), thereby further examining SUHI. This study begins with the reexamination of the commonly used indicators of LST using Landsat Enhanced Thematic Mapper Plus (ETM+) and Landsat Thematic Mapper (TM) images which cover four counties of Wisconsin, United States. Origin of the large variation of LST found in urban areas is then investigated by discriminating soil and impervious surfaces. Except land cover types, neighboring environment is another key factor which may affect LST in urban areas. Thus, a neighboring effect considered method is proposed at the end of the study to better understand the relationship between impervious surfaces fraction (%ISA) and LST by taking the influence of neighboring environment into account. Results indicate that spectral indices have better performance in predicting LST than land cover fractions do within the study area. However, the result remains arguable due to the complexity and uncertainty of spectral mixture analysis. Impervious surfaces are found responsible for the large variation of LST in urban areas, which indicates that impervious surfaces should not be simply considered as a single land cover type has stable negative correlation with LST. Moreover, a better relationship is found between %ISA and LST when neighboring effect is considered, when compared to the traditional method which ignores the neighboring effect.

  2. Impact of Megacity Shanghai on the Urban Heat-Island Effects over the Downstream City Kunshan

    NASA Astrophysics Data System (ADS)

    Kang, Han-Qing; Zhu, Bin; Zhu, Tong; Sun, Jia-Li; Ou, Jian-Jun

    2014-09-01

    The impact of upstream urbanization on the enhanced urban heat-island (UHI) effects between Shanghai and Kunshan is investigated by analyzing seven years of surface observations and results from mesoscale model simulations. The observational analysis indicates that, under easterly and westerly winds, the temperature difference between Shanghai and Kunshan increases with wind speed when the wind speed 5 m s. The Weather Research and Forecasting (WRF) numerical model, coupled with a one-layer urban canopy model (UCM), is used to examine the UHI structure and upstream effects by replacing the urban surface of Shanghai and/or Kunshan with cropland. The WRF/UCM modelling system is capable of reproducing the surface temperature and wind field reasonably well. The simulated urban canopy wind speed is a better representation of the near-surface wind speed than is the 10-m wind speed at the centre of Shanghai. Without the urban landscape of Shanghai, the surface air temperature over downstream Kunshan would decrease by 0.2-0.4 C in the afternoon and 0.4-0.6 C in the evening. In the simulation with the urban landscape of Shanghai, a shallow cold layer is found above the UHI, with a minimum temperature of about to 0.5 C during the afternoon hours. Strong horizontal divergence is found in this cold layer. The easterly breeze over Shanghai is strengthened at the surface by strong UHI effects, but weakened at upper levels. With the appearance of the urban landscape specific humidity decreases by 0.5-1 g kg within the urban area because of the waterproof property of an urban surface. On the other hand, the upper-level specific humidity is increased because of water vapour transferred by the strong upward vertical motions.

  3. Using MODIS Skin Temperature to Assess Urban Heat Island Effect and Biosphere-Atmosphere-Land Interactions

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Two surface temperatures have been used in global change studies - 2-m surface air temperature (Tair) and skin temperature (Tskin). Skin temperature provides additional new information about the Earth surface because its physical meaning and magnitude differ from Tair. We will present two examples to reveal the advantages of using Tskin in studying land-atmosphere-biosphere interactions: an urban system and a Tibetan system. Ten-years of NASA MODIS skin temperature observations reveal new features related to the urban heat island effect (UHI). For example, the UHI is evident in both daytime and nighttime instead of being a nocturnal phenomenon traditionally referred from Tair. UHI is partially due to both albedo and emissivity reduction and partially due to soil moisture modification by urban surfaces (i.e., a change in Bowen ratio). Furthermore, urban aerosols affect surface insloation, which leads to a reduction in surface skin temperature. In summary, clearly the UHI is a result of land-atmosphere-biosphere interactions. Skin temperatures also provide detailed information for remote regions that are difficult to access, in particular, the Tibetan Plateau. Tskin shows a slight increase during 2000-2010, nevertheless, such an increase is only statistically significant for summer urban regions. Different land covers have varying patterns and seasonality of skin temperature. In particular, skin temperature and vegetation index (NDVI) have close relationships for their extremes. Such extremes are also a function of season and land cover. In conclusion, skin temperature is very useful in our understanding on biosphere-land-and atmosphere interactions. Further work is needed to examine the implications of these finding for scientific research and societal applications.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. Mitigating the Urban Heat Island under Climate Change through Urban Management

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Lee, X.; Oleson, K. W.; Schultz, N. M.; Smith, R. B.

    2015-12-01

    The urban heat island (UHI) represents ubiquitous urban warmth compared to surrounding rural areas. This phenomenon, when compounded with future climate warming, will exacerbate heat stress on urban residents who will comprise 70% of the world's population by 2070. At the same time, urban climate adaptation plans have shown great potential for reducing the impacts of global change. In this study, we assess three mitigation strategies, including reflective roofs, green roofs, and street trees, to ameliorate the warming under climate change through both "online" and "offline" methods. The "online" method compares modeling results from a modified urban roof albedo configuration (ALB-MOD) where the roof albedo is raised to a high reflective value to the modeling results from the default configuration (CTRL), both using the Community Earth System Model (CESM). Three pairs of simulations under current climate forcing and two future scenarios (RCP4.5 and RCP8.5) are conducted. The "offline" method uses a surface temperature attribution solution derived previously for partitioning the UHI intensity to assess the efficacy of the mitigation strategies. The "offline" method supplements the "online" method in assessing green roof and street tree strategies, because the current design of CESM does not have explicit vegetation in the urban canopy configuration. The excellent agreement between the "online" and "offline" results confirms the validity of the offline scheme, supporting that the "offline" method can be used to predict the impacts of various urban adaptation strategies for development planning. Results show that albedo management is the most effective and viable way to mitigate UHIs, whereas although green roof and street trees strategies have evaporative cooling effects, the cooling is compensated by vegetation's lower albedo, showing much less effectiveness on UHI mitigation. Although convection efficiency associated with the surface roughness is an important

  9. Actual Performance Prediction of Split-type Room Air Conditioner which Considered Unsteady Operation Concerning Heat Island Problem

    NASA Astrophysics Data System (ADS)

    Shinomiya, Naruaki; Nishimura, Nobuya; Iyota, Hiroyuki; Nomura, Tomohiro

    Split type air conditioners are operated actually in the situation unlike the condition that was described in a product catalog. On the other hand, exhaust heat from air conditioner is considered as one of the causes of heat island problem in urban area, and the air conditioner performance and heat load affect exhaust heat amount. In this study, air conditioner performances in both standard summer day and severe hot day were examined by dynamic simulation which considered outdoor weather changes. As a result, actual performances of the air conditioner were demonstrated as a function of outdoor temperature, heat load and indoor temperature. The higher the outdoor temperature and heat load rise, the smaller influences of indoor temperature against COP became. In standard summer day, relative performance exceeded by 15 to 45% than that of JIS operating condition. Also, COP in severe hot day decreased about 6% at the peak time than that of standard day. As a result, the air conditioner exhaust heat during one day which was predicted by the proposed simulation model became about 16% smaller than the conventional prediction model.

  10. Monitoring the urban heat island of Bucharest (Romania) through a network of automatic meteorological sensors - first results

    NASA Astrophysics Data System (ADS)

    Cheval, Sorin; Lucaschi, Bogdan; Ioja, Cristian; Dumitrescu, Alexandru; Manea, Ancuta; Radulescu, Adrian; Dumitrache, Catalin; Tudorache, George; Vanau, Gabriel; Onose, Diana

    2015-04-01

    Extreme warm temperatures and heat waves represent one of the major climate hazards which impact the city of Bucharest (Romania), favoured by the climate background and by the urban characteristics. Previous studies based either on sparse ground sensors or satellite remote sensing indicate that the average differences between the monthly temperature of the built area and the neighbouring rural buffers of Bucharest can reach 3-4°C, but instantaneous values are certainly higher. Since the city shelters about 2 million residents, as well as the major administrative and economic facilities of the country, the hazard management should receive a vivid attention. The meteorological monitoring of the city is currently performed in a systematic manner by the National Meteorological Administration (NMA) through 3 ground-based stations following the standards of the World Meteorological Organization, and through radar and satellite remote sensing. In 2014, NMA set up 7 automatic sensors in specific urban conditions, while the University of Bucharest deployed 30 mobile sensors in a joint effort for enhancing the accuracy of the urban heat island monitoring. Both sensor devices are designed for continuous monitoring (24/7). This presentation focuses on the technical characteristics of the recently implemented network (1), and brings to the public the first results of the monitoring (2), including the implementation experience, the observed benefits and plans for development and applications. The data obtained are compared with the existing data sets from meteorological stations and satellite products, and they are currently integrated in a common database, providing valuable information about the Bucharest's urban heat island. 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-Development-Innovation for Space Technology and

  11. 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. PMID:26520258

  12. 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

  13. 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

  14. Urban Heat Island in the city of Bari (Italy) ant its relationship with morphological features

    NASA Astrophysics Data System (ADS)

    Ceppi, C.; Balena, P.; Loconte, P.; Mancini, F.

    2012-04-01

    The investigation of an Urban Heat Island (UHI) and its relationship with the wide range of factors able to explain its behavior is a very difficult task: the main trouble is represented by the spatial variability of the urban temperature due to the extreme heterogeneousness of the urban coverage and morphological features. In literature it is known that the local surface temperatures are influenced by the changing characteristics in urban surface and modification of land surface processes affecting the surface energy balance and the shape of boundary layer. The whole processes could lead to distinct urban climates. This work is mainly focused on the mechanisms which are actually connecting the urban morphology with the surface temperature as derived by satellite data provided from the ASTER sensor. Urban morphology could be described by several factors depending on the selected scale of analysis. At the macroscale the UHI is more related to the land-use, environmental context and boundary conditions. At the microscale the surface characteristics, urban density, ratio between green and built areas and, construction and built typology are more involved in addition to the composite indicators such as the Sky View factor and the elevation of the built texture. The case study of the city of Bari is faced. It is a medium sized city in the southern Italy, characterized by the presence of a pervasive waterfront and presence of "lame", a natural erosive furrows shallow that are typical of the Apulia country side. Such ephemeral streams convey the stormwater from the plateau of the hilly Murgia areas to the sea. Moreover, the urban complexity of the city exacerbates the spatial variability of the phenomenon. The first step aim at the investigating of the relationship between the thermal behavior and the above mentioned factors by the construction of a set of homogeneous morphological units. The classification is built both in the urban and rural zone. The second step

  15. 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

  16. Interactions between urban vegetation and surface urban heat islands: a case study in the Boston metropolitan region

    NASA Astrophysics Data System (ADS)

    Melaas, Eli K.; Wang, Jonathan A.; Miller, David L.; Friedl, Mark A.

    2016-05-01

    Many studies have used thermal data from remote sensing to characterize how land use and surface properties modify the climate of cities. However, relatively few studies have examined the impact of elevated temperature on ecophysiological processes in urban areas. In this paper, we use time series of Landsat data to characterize and quantify how geographic variation in Boston’s surface urban heat island (SUHI) affects the growing season of vegetation in and around the city, and explore how the quality and character of vegetation patches in Boston affect local heat island intensity. Results from this analysis show strong coupling between Boston’s SUHI and vegetation phenology at the scale of both individual landscape units and for the region as a whole, with significant detectable signatures in both surface temperature and growing season length extending 15 km from Boston’s urban core. On average, land surface temperatures were about 7 °C warmer and the growing season was 18–22 days longer in Boston relative to adjacent rural areas. Within Boston’s urban core, patterns of temperature and timing of phenology in areas with higher vegetation amounts (e.g., parks) were similar to those in adjacent rural areas, suggesting that vegetation patches provide an important ecosystem service that offsets the urban heat island at local scales. Local relationships between phenology and temperature were affected by the intensity of urban land use surrounding vegetation patches and possibly by the presence of exotic tree species that are common in urban areas. Results from this analysis show how species composition, land cover configuration, and vegetation patch sizes jointly influence the nature and magnitude of coupling between vegetation phenology and SUHIs, and demonstrate that urban vegetation provides a significant ecosystem service in cities by decreasing the local intensity of SUHIs.

  17. Scale effect analysis of the relationships between urban heat island and impact factors: case study in Chongqing

    NASA Astrophysics Data System (ADS)

    Luo, Xiaobo; Li, Weisheng

    2014-01-01

    Several indices, including the normalized difference vegetation index (NDVI), normalized difference build-up index (NDBI), and normalized difference water index (NDWI), were retrieved from the Landsat 5 Thematic Mapper (TM) images, and the land surface temperature (LST) was reversed by the thermal radiation transfer model. Next, with the help of the thermal field variance index from LST, characteristics of spatial distribution of urban heat island were analyzed. Then, the regression models between LST and the three indices were formed by the least-squares method after they were aggregated from 30 to 120, 240, 480, 960, and 1200 m, and the relationships between the accuracies of the regression models and spatial scales were analyzed quantitatively. Finally, results from the experiment exemplified by Chongqing show that at all these spatial scales, both NDVI and NDWI are negatively correlated with LST and NDBI is positively correlated with LST. At the same spatial scale, cooling effect by NDWI acting upon LST is superior to that by NDVI, while inferior to that by NDBI to enhance LST. The fitting determination coefficients (R) of the regression models of LST and NDVI, NDBI, and NDWI increase from 0.23 (30 m) to 0.57 (1200 m), from 0.34 (30 m) to 0.70 (1200 m), and from 0.31 (30 m) to 0.68 (1200 m), respectively. Further, the R of all of the regression models and spatial scales have positive logarithmic function relations, while the standard deviation and spatial scale have negative logarithmic function relations correspondingly, and the R of all of the logarithmic models are >0.95. The heat islands of Chongqing are roughly along northeast-southwest directions, while the heat islands of the urban core area, such as Yuzhong district, are not obvious due to the influence of the Yangtze River and the Jialing River.

  18. 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.

  19. Energy impacts of heat island reduction strategies in the Greater Toronto Area, Canada

    SciTech Connect

    Konopacki, Steven; Akbari, Hashem

    2001-11-30

    In 2000, the Toronto Atmospheric Fund (TAF) embarked on an initiative to quantify the potential benefits of Heat Island Reduction (HIR) strategies (shade trees, reflective roofs and pavements) in reducing cooling energy use in buildings, lowering the ambient air temperature and improve air quality. This report summarizes the efforts of Lawrence Berkeley National Laboratory (LBNL) to assess the impacts of HIR measures on building cooling- and heating-energy use. We discuss our efforts to calculate annual energy savings and peak-power avoidance of HIR strategies in the building sector of the Greater Toronto Area. The analysis is focused on three major building types that offer most saving potentials: residence, office and retail store. Using an hourly building energy simulation model, we quantify the energy saving potentials of (1) using cool roofs on individual buildings [direct effect], (2) planting deciduous shade trees near south and west walls of building [direct effect], (3) planting coniferous wind-shielding vegetation near building [direct effect], (4) ambient cooling by a large-scale program of urban reforestation with reflective building roofs and pavements [indirect effect], (5) and the combined direct and indirect effects. Results show potential annual energy savings of over $11M (with uniform residential and commercial electricity and gas prices of $0.084/kWh and $5.54/GJ) could be realized by ratepayers from the combined direct and indirect effects of HIR strategies. Of that total, about 88 percent was from the direct impact roughly divided equally among reflective roofs, shade trees and wind-shielding, and the remainder (12 percent) from the indirect impact of the cooler ambient air temperature. The residential sector accounts for over half (59 percent) of the total, offices 13 percent and retail stores 28 percent. Savings from cool roofs were about 20 percent, shade trees 30 percent, wind shielding of tree 37 percent, and indirect effect 12 percent

  20. An Observational Study of the Urban Heat Island in the Greater Thessaloniki Area: Preliminary Results and Development of a Forecasting Service

    NASA Astrophysics Data System (ADS)

    Giannaros, T. M.; Melas, D.; Kontogianni, P.

    2010-01-01

    The present paper investigates the characteristics of the Urban Heat Island (UHI) in the Greater Thessaloniki Area (GTA). The study is carried out by using and analyzing hourly air temperature data covering the period from June through September 2008. It was found that the urban zone of the city is heated faster and more effectively than the suburban surroundings, especially in early morning hours. Two measuring sites were selected as representative of "urban" and "suburban" areas and the hourly air temperature differences were calculated and classified by magnitude. The analysis of the percentage of occurrences for each class revealed that the city of Thessaloniki is subject to a rather moderate UHI. It was also found that the heat island can be more clearly observed during overnight hours, reaching, however, its maximum magnitude in early morning hours. Last but not least, the current paper introduces the development of an Urban Heat Island Forecasting Service (UHI-FS).

  1. Experimental and Numerical Studies of the Effects of Water Sprinkling on Urban Pavement on Heat Island Mitigation

    NASA Astrophysics Data System (ADS)

    Yoshioka, M.; Tosaka, H.; Nakagawa, K.

    2007-12-01

    One of the main causes of 'heat island phenomeno' is thought to be the artificial covers of the ground surface with asphalt or concrete which reduce greatly inherent cooling effect of water evaporation from soil surface. In this study, as a candidate method of mitigating the heat island the effects of the 'water sprinkling' on the pavements are discussed from field experiments and numerical studies. Three field experiments of water sprinkling on the asphalt/concrete pavements were performed in hot summer days in 2004-2006. For detecting the change in temperatures, the authors developed and used a 3-D measurements system which consists of two vertical planes with 6m high and 16m wide, and has network arrays of 102 thermistors distributed spatially in the planes. The temperatures measured in and around the water sprinkled area indicated that the ground surface temperature decreased 5 to 15 degrees uniformly in the water sprinkled area compared with those in the un-sprinkled area, while the relative decrease of atmospheric temperature was approximately up to 1 degree. The subsurface temperature at a depth of 14cm under the pavement decreased significantly and kept lower than that at the same depth in un-sprinkled area over the next morning. A numerical model was developed and applied to interpret the experimental results. It deals with the heat balance of radiation, sensible/latent heat transfer at the ground surface and heat conduction through the artificial and natural soil layer under ground. temperature and vapor conditions changes at and near ground surface were modeled by using the bulk formula.Good agreements between the calculated time-temperature profiles and the experimental ones were obtained by assuming adequate physical parameters and meteorological conditions. The model could be improved in order to evaluate the changes of temperature and vapor contents in atmosphere near the ground surface caused by aerodynamic turbulent diffusion.

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

    NASA Astrophysics Data System (ADS)

    Aggarwal, Rimjhim M.; Guhathakurta, Subhrajit; Grossman-Clarke, Susanne; Lathey, Vasudha

    2012-06-01

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

  3. WRF Model Evaluation for the Urban Heat Island Assessment under Varying Land Use/Land Cover and Reference Site Conditions

    NASA Astrophysics Data System (ADS)

    Bhati, S.

    2015-12-01

    Urban heat island effect has been assessed using Weather Research and Forecasting model (WRF v3.5) coupled with urban canopy model (UCM) focusing on air temperature and surface skin temperature in the sub-tropical urban Indian megacity of Delhi. The estimated heat island intensities for different land use/land cover (LULC) have been compared with those derived from in-situ and satellite observations. There is a significant improvement in model performance with inclusion of UCM both for meteorological parameters (T and RH) and the UHIs. Overall, RMSEs for near surface temperature improved from 1.63°C to 1.13°C for urban areas and from 2.89°C to 2.75°C for non-urban areas with inclusion of urban canopy model in WRF. Similarly, index of agreement and RMSEs for mean urban heat island intensities (UHI) improved from 0.77 to 0.88 and 1.91°C to 1.60°C respectively with WRF-UCM. Hit rate from the model simulated mean heat island intensities using WRF model are 72 % for urban areas and 58 % for non-urban areas such as green areas and riverside areas. The corresponding values improved in WRF-UCM with a hit rate of 75% for urban areas and 72 % for non-urban areas. In general, model is able to capture the magnitude of UHI well though it performs better during night than during the daytime. High UHI zones and top 3 hotspots are captured well by the model. The relevance of selecting a rural reference point for UHI estimation near the urban area is examined in the context of rapidly growing cities where nearby rural areas are transforming fast into built-up areas themselves and reference site may not be appropriate for future years. Both WRF and WRF-UCM simulated UHI shows satisfactory performance against benchmarks for the statistical measures with classical methodology using rural site as a reference point. Using an alternate methodology of considering a green area within the city having minimum temperature as a reference site worked satisfactorily only with WRF- UCM. In

  4. Investigation of temporal-spatial parameters of an urban heat island on the basis of passive microwave remote sensing

    NASA Astrophysics Data System (ADS)

    Khaikine, M. N.; Kuznetsova, I. N.; Kadygrov, E. N.; Miller, E. A.

    2006-02-01

    Quantitative measurements of the impact of an urban environment on the thermal state of the atmospheric boundary layer are presented. Temperature profiles up to the height of 600 m were obtained in a continuous series of measurements by three microwave profilers MTP-5 located in different areas of Moscow. The influence of this large city on urban heat island (UHI) parameters was estimated on occasions with stationary atmospheric processes and during cases with frontal passage. Two types of UHI were identified: one with a dome of urban warmth at all levels, and another with a low warm dome in combination with a lens of cold air above.

  5. 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.

  6. The role of magnetic islands in modifying long range temporal correlations of density fluctuations and local heat transport

    NASA Astrophysics Data System (ADS)

    van Milligen, B. Ph.; Estrada, T.; García, L.; López Bruna, D.; Carreras, B. A.; Xu, Y.; Ochando, M.; Hidalgo, C.; Reynolds-Barredo, J. M.; López Fraguas, A.; the TJ-II Team

    2016-01-01

    This work explores the relation between magnetic islands, long range temporal correlations and heat transport. A low order rational surface ({\\rlap- \\iota}=3/2 ) was purposely scanned outward through an electron cyclotron resonance heated (ECRH) plasma in the TJ-II stellarator. Density turbulence and the poloidal flow velocity were characterized using a two channel Doppler reflectometer. Simultaneously, the ECRH power was modulated to characterize heat transport, using measurements from a 12 channel electron cyclotron emission diagnostic. A systematic variation of the poloidal velocity was found to be associated with the {\\rlap- \\iota}=3/2 rational surface. Near the rational surface, the Hurst exponent, quantifying the nature of long-range correlations, was reduced below 0.5 (indicating subdiffusion), while at radii smaller than that of the rational surface, it was found to be significantly enhanced (superdiffusion). In the latter region, heat transport was enhanced as well, thus establishing a link between density fluctuations and anomalous heat transport. The observed variation of the Hurst exponent was consistent with a magnetohydrodynamic turbulence simulation.

  7. Mapping a Wind-Modified Urban Heat Island in Tucson, Arizona (with Comments on Integrating Research and Undergraduate Learning).

    NASA Astrophysics Data System (ADS)

    Comrie, Andrew C.

    2000-10-01

    Tucson, Arizona, is an example of the many cities in the southwestern United States experiencing rapid growth and urban sprawl over the last several decades. The accompanying extensive modification of land use and land cover leads to many environmental impacts, including urban heat islands. The primary aim of this paper is to expand knowledge of the phenomenon for Tucson, by quantifying the amount of urban warming, and by mapping temperature patterns over the city and examining related aspects of the local-scale atmospheric circulation. The secondary aim is to document how an applied empirical research project was integrated into an introductory undergraduate climatology class via active learning. The paper begins and concludes with general and practical comments on combining the research and educational aspects of the project. An analysis of 30-yr temporal trends in urban and nonurban minimum temperatures across the region shows the rate of urban warming to be about three-quarters of the general regional warming. Tucson's urban heat island is ~3°C over the last century, with >2°C of this warming in the last 30 years. The annual average urban warming trend over the last three decades is 0.071°C yr-1 with the strongest effect in March and the weakest effect in November. There is evidence that the latter is caused by strong, near-surface winds under stable conditions. A case study is presented comprising field measurements and map analysis of urban temperatures and supporting variables for 13 February 1999. Measurements include comprehensive mapping using vehicle-mounted thermistors and numerous local meteorological observations from around the city. Wind speeds during the field measurements were somewhat stronger than is typical of heat island studies, up to 12 m s-1. Nonetheless, because of terrain-induced flows and land surface heterogeneity, complex temperature patterns were observed. Several transient katabatic flows off surrounding mountain ranges were

  8. The influence of atmospheric circulation on the intensity of urban heat island and urban cold island in Poznań, Poland

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    The study has analyzed influence of an atmospheric circulation on urban heat island (UHI) and urban cold island (UCI) in Poznań. Analysis was conducted on the basis of temperature data from two measurement points situated in the city center and in the Ławica airport (reference station) and the data concerning the air circulation (Niedźwiedź's calendar of circulation types and reanalysis of National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR)). The cases with UHI constitute about 85 % of all data, and UCI phenomena appear with a frequency of 14 % a year. The intensity of UHI phenomenon is higher in the anticyclonic circulation types. During the year in anticyclonic circulation, intensity of UHI is 1.2 °C on average while in cyclonic is only 0.8 °C. The occurring of UHI phenomena is possible throughout all seasons of the year in all hours of the day usually in anticyclonic circulation types. The cases with highest UHI intensity are related mostly to nighttime. The cases of UCI phenomena occurred almost ever on the daytime and the most frequently in colder part of the year together with cyclonic circulation. Study based on reanalysis data indicates that days with large intensity of UHI (above 4, 5, and 6 °C) are related to anticyclonic circulation. Anticyclonic circulation is also promoting the formation of the strongest UCI. Results based on both reanalysis and the atmospheric circulation data (Niedźwiedź's circulation type) confirm that cases with the strongest UHI and UCI during the same day occur in strong high-pressure system with the center situated above Poland or central Europe.

  9. Photovoltaic canopies: thermodynamics to achieve a sustainable systems approach to mitigate the urban heat island hysteresis lag effect

    NASA Astrophysics Data System (ADS)

    Golden, Jay S.

    2006-03-01

    At a time of greater attention to global climate change and increased costs of energy, our planet is rapidly urbanizing and transitioning regions from the natural rural vegetation to man-made urban engineered infrastructure. The anthropogenic-induced change has manifested itself in micro-scale and meso-scale increase in temperatures in comparison to adjacent rural regions which is known as the urban heat island effect ? Tu- r; (Oke 1987, Brazel 2003) and results in the increased need of electricity for mechanical cooling as well as various adverse environmental, social, and economic consequences for local and global communities (Golden 2004). Prior research has documented that between 29% and 45% of the urban fabric comprised paved surfaces to support mobility (Akbari et al. 1999). The increase in paved surfaces as a function of thermodynamics alters the urban energy budget due to changes in albedo, thermal mass as well as conduction, convection, and evapotranspiration. An emerging engineering option to reduce the significant role that surface pavements play in adding to the urban heat island is to capitalize on the capturing and shading of incident solar energy by means of utilization of photovoltaic panels to provide covered parking for this large portion of the urban fabric.

  10. Two decades of urban climate research: a review of turbulence, exchanges of energy and water, and the urban heat island

    NASA Astrophysics Data System (ADS)

    Arnfield, A. John

    2003-01-01

    Progress in urban climatology over the two decades since the first publication of the International Journal of Climatology is reviewed. It is emphasized that urban climatology during this period has benefited from conceptual advances made in microclimatology and boundary-layer climatology in general. The role of scale, heterogeneity, dynamic source areas for turbulent fluxes and the complexity introduced by the roughness sublayer over the tall, rigid roughness elements of cities is described. The diversity of urban heat islands, depending on the medium sensed and the sensing technique, is explained. The review focuses on two areas within urban climatology. First, it assesses advances in the study of selected urban climatic processes relating to urban atmospheric turbulence (including surface roughness) and exchange processes for energy and water, at scales of consideration ranging from individual facets of the urban environment, through streets and city blocks to neighbourhoods. Second, it explores the literature on the urban temperature field. The state of knowledge about urban heat islands around 1980 is described and work since then is assessed in terms of similarities to and contrasts with that situation. Finally, the main advances are summarized and recommendations for urban climate work in the future are made.

  11. Evaluating Spatial Patterns of Land Use and urban Heat Island in The Fast Growing Metropolitan Shanghai, China

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Ma, W.; Li, J.; Wang, X.

    2007-12-01

    Remotely sensed data (Landsat TM5) were used to quantitatively characterize the patterns of land use and urban heat island (UHI) in the fast growing Metropolitan Shanghai, China. Results showed that, with dramatic change in land use and land cover driven by substantial economic growth since the 1990s, rapid expansion of the urbanized and urbanizing areas occurred at regional level during 1997 and 2004. Similarly, both the extent and magnitude of UHI in Shanghai have undergone a significant increase, though some newly emerging cooling patches were detected in the central urban area. On small and meso scales, a significant spatial patterning was present in UHI as indicated by land surface temperature (LST). Moreover, based on the satellite images, the Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Normalized Difference Bareness Index (NDBaI), and Normalized Difference Build-up Index (NDBI) were produced to explore the relationship between land use and UHI effect. Although these indices were effective in characterizing the spatial and temporal patterns of UHI, there were some unexplainable factors due to the complexity in ecological process. As a whole, it can be predicted that the ongoing urban sprawl in the satellite towns will adversely cause a long term effect on regional atmospheric environment. Keywords Spatial pattern; Urban heat island (UHI); Land surface temperature (LST);urban sprawl ;Shanghai; China.

  12. 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.

  13. Enumeration of Thermophilic Heterotrophs in Geothermally Heated Soils from Mount Erebus, Ross Island, Antarctica

    PubMed Central

    Hudson, J. Andrew; Daniel, Roy M.

    1988-01-01

    Soil samples with temperatures up to 64°C were collected from Mount Erebus, an active volcano located on Ross Island, Antarctica. Acridine orange direct counts and most probable number counts of soil samples stored at 4°C for 2 months showed a wide variation in the number of thermophilic microorganisms in different soils. Organisms similar to Clostridium thermohydrosulfuricum, Bacillus schlegelii, and Bacillus acidocaldarius, as well as neutrophilic Bacillus strains, were isolated. PMID:16347573

  14. Enumeration of thermophilic heterotrophs in geothermally heated soils from mount erebus, ross island, antarctica.

    PubMed

    Hudson, J A; Daniel, R M

    1988-02-01

    Soil samples with temperatures up to 64 degrees C were collected from Mount Erebus, an active volcano located on Ross Island, Antarctica. Acridine orange direct counts and most probable number counts of soil samples stored at 4 degrees C for 2 months showed a wide variation in the number of thermophilic microorganisms in different soils. Organisms similar to Clostridium thermohydrosulfuricum, Bacillus schlegelii, and Bacillus acidocaldarius, as well as neutrophilic Bacillus strains, were isolated. PMID:16347573

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

    SciTech Connect

    Kolokotroni, Maria; Bhuiyan, Saiful; Davies, Michael; Croxford, Ben; Mavrogianni, Anna

    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 that 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)

  16. 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. PMID:27424113

  17. WRF model evaluation for the urban heat island assessment under varying land use/land cover and reference site conditions

    NASA Astrophysics Data System (ADS)

    Bhati, Shweta; Mohan, Manju

    2015-08-01

    Urban heat island effect in Delhi has been assessed using Weather Research and Forecasting (WRF v3.5) coupled with urban canopy model (UCM) focusing on air temperature and surface skin temperature. The estimated heat island intensities for different land use/land cover (LULC) have been compared with those derived from in situ and satellite observations. The model performs reasonably well for urban heat island intensity (UHI) estimation and is able to reproduce trend of UHI for urban areas. There is a significant improvement in model performance with inclusion of UCM which results in reduction in root mean-squared errors (RMSE) for temperatures from 1.63 °C (2.89 °C) to 1.13 °C (2.75 °C) for urban (non-urban) areas. Modification of LULC also improves performance for non-urban areas. High UHI zones and top 3 hotspots are captured well by the model. The relevance of selecting a reference point at the periphery of the city away from populated and built-up areas for UHI estimation is examined in the context of rapidly growing cities where rural areas are transforming fast into built-up areas, and reference site may not be appropriate for future years. UHI estimated by WRF model (with and without UCM) with respect to reference rural site compares well with the UHI based on observed in situ data. An alternative methodology is explored using a green area with minimum temperature within the city as a reference site. This alternative methodology works well with observed UHIs and WRF-UCM-simulated UHIs but has poor performance for WRF-simulated UHIs. It is concluded that WRF model can be applied for UHI estimation with classical methodology based on rural reference site. In general, many times WRF model performs satisfactorily, though WRF-UCM always shows a better performance. Hence, inclusion of appropriate representation of urban canopies and land use-land cover is important for improving predictive capabilities of the mesoscale models.

  18. 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. PMID:22154211

  19. 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

    2016-02-01

    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.

  20. Remote-sensing evaluation of the relationship between urban heat islands and urban biophysical descriptors in Jinan, China

    NASA Astrophysics Data System (ADS)

    Meng, Fei; Shan, Baoyan; Liu, Min

    2014-01-01

    Global warming and climate change have gained more and more attention because the global mean surface temperature has increased since the late 19th century. With the progress of rapid urbanization, Jinan city has witnessed a significant urban thermal environment change. To investigate the relationship between urban heat islands and urban biophysical descriptors, the city's biophysical properties along with land surface temperature (LST) in 1992 and 2011 were retrieved from the Landsat TM images. Additionally, three thematic indices were employed to extract the features of the impervious surface, water, and vegetation, respectively. The correlation and spatial overlay of these land surface features were then analyzed. The results show that the Jinan region has witnessed very fast urban sprawl. The total impervious surface area of the region in 2011 was 134.7% more than that in 1992. This increase significantly reduced the vegetation and open water coverage in the urban area. Simultaneously, the expansion of impervious surfaces was accompanied by an increased urban heat island (UHI) ratio index, which increased from 0.43 in 1992 to 0.55 in 2011, showing that the UHI in Jinan has developed from a weak level to a significant level over the 19-year period. The quantitative analysis between LST and indices revealed that impervious surfaces have a positive exponential relationship with LST, while the water and vegetation are both negatively correlated with temperature. A multifactor analysis also indicated that the contribution of impervious surfaces to the LST could equal or even exceed that of the sum of vegetation and water.

  1. Assessment of the canopy urban heat island of a coastal arid tropical city: The case of Muscat, Oman

    NASA Astrophysics Data System (ADS)

    Charabi, Yassine; Bakhit, Abdelhamid

    2011-07-01

    The spatio-temporal variability of the canopy-level urban heat island (UHI) of Muscat is examined on the basis of meteorological observations and mobile measurements during a span of 1 year. The results indicate that the peak UHI magnitude occurs from 6 to 7 hours after sunset and it is well developed in the summer season. The warm core of the UHI is located in the Highland zone of Muscat, along a narrow valley characterized by low ventilation, high business activities, multi-storied buildings and heavy road traffic. Topographically, this valley is surrounded by mountains formed of dark-colored rocks such Ophiolites that can absorb short wave radiation and contribute, herewith, to the emergence of this warm urban core. In addition, this mountainous terrain tends to isolate this location from the cooling effect of the land-sea breeze circulation during the day time. In this warm valley the hottest temperature is encountered in the compact districts of old Muscat. In comparison, the urban thermal pattern in Lowland zone of Muscat is fragmented and the urban-rural thermal difference is reduced because of the lower urban density of the residential quarters. In addition, the flat alluvial terrain on which these residential quarters are located is consistently exposed to the land breeze circulation. Also, the study illuminates and emphasizes the importance giving due consideration to the nature of the rural baseline when assessing the urban effect on an area's climate. For Muscat City, irrespective of the rural baseline used, a significant difference in the value of the urban heat island is registered.

  2. 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.

  3. From urban to national heat island: The effect of anthropogenic heat output on climate change in high population industrial countries

    NASA Astrophysics Data System (ADS)

    Murray, John; Heggie, Douglas

    2016-06-01

    The project presented here sought to determine whether changes in anthropogenic thermal emission can have a measurable effect on temperature at the national level, taking Japan and Great Britain as type examples. Using energy consumption as a proxy for thermal emission, strong correlations (mean r2 = 0.90 and 0.89, respectively) are found between national equivalent heat output (HO) and temperature above background levels Δt averaged over 5- to 8-yr periods between 1965 and 2013, as opposed to weaker correlations for CMIP5 model temperatures above background levels Δmt (mean r2 = 0.52 and 0.10). It is clear that the fluctuations in Δt are better explained by energy consumption than by present climate models, and that energy consumption can contribute to climate change at the national level on these timescales.

  4. 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. PMID:26828171

  5. Satellite-Supported Modeling of the Relationships between Urban Heat Island and Land Use/Cover Changes

    NASA Astrophysics Data System (ADS)

    Vahmani, P.; Ban-Weiss, G. A.

    2015-12-01

    Reliable assessment of the primary causes of urban heat island (UHI) and the efficiency of various heat mitigation strategies requires accurate prediction of urban temperatures and realistic representation of land surface physical characteristics in models. In this study, we expand the capabilities of the Weather Research and Forecasting (WRF) model and the Urban Canopy Model (UCM) by implementing high-resolution real-time satellite observations of green vegetation fraction (GVF), leaf area index (LAI), and albedo. We use MODIS-based GVF, LAI, and albedo to replace constant values that are assumed for urban pixels and climatological values that are used for non-urban pixels in the default WRF-UCM. Utilizing the improved model, summertime climate of Los Angeles is simulated over the span of three years (2010-2012). Next, thermal sensitivity of urban climate to anthropogenic land use/cover is assessed via replacing current urban cover with pre-development vegetation cover, consisting of shrubland and grassland. Surrounding undeveloped areas and inverse distance weighting method are utilized to estimate GVF and LAI of pre-development vegetation cover. Our analysis of diurnal and nocturnal surface and air temperatures shows cooling effects of urbanization in neighborhoods with high fractions of irrigated vegetation. However, urban warming is consistently detected over industrial/commercial and high-intensity residential areas. In addition to well-known mechanisms such as a shift in surface energy partitioning, high heat storage in urban material, and inefficiency of urban surfaces in transferring convective heat from the surface to the boundary layer, our results show decreased wind speed and sea breeze also contribute to the UHI intensity. We further evaluate the interactions between UHI and replacing irrigated and imported vegetation with non-irrigated native vegetation as a water conservation strategy in water-stressed Los Angeles metropolitan area.

  6. 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

  7. The effect of urban heat islands on geothermal potential: examples from Quaternary aquifers in Finland

    NASA Astrophysics Data System (ADS)

    Arola, Teppo; Korkka-Niemi, Kirsti

    2014-12-01

    The use of renewable energy can be enhanced by utilising groundwater reservoirs for heating and cooling purposes. The urbanisation effect on the peak heating and peak cooling capacity of groundwater in a cold groundwater region was investigated. Groundwater temperatures were measured and energy potentials calculated from three partly urbanised aquifers situated between the latitudes of 60° 25'N and 60° 59'N in Finland. The average groundwater temperature below the zone of seasonal temperature fluctuations was 3-4 °C higher in the city centres than in the rural areas. The study demonstrated that due to warmer groundwater, approximately 50-60 % more peak heating power could be utilized from populated areas compared with rural areas. In contrast, approximately 40-50 % less peak cooling power could be utilised. Urbanisation significantly increases the possibility of utilising local heat energy from groundwater within a wider region of naturally cold groundwater. Despite the warming in urban areas, groundwater still remains attractive as a source of cooling energy. More research is needed in order to determine the long-term energy capacity of groundwater, i.e. the design power, in urbanised areas of cold regions.

  8. 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

  9. Unraveling the heat island effect observed in urban groundwater bodies - Definition of a potential natural state

    NASA Astrophysics Data System (ADS)

    Epting, Jannis; Huggenberger, Peter

    2013-09-01

    A superposition of several thermal processes leads to an elevation of groundwater temperatures of up to 9 °C above the natural state in the city of Basel, Switzerland. The urban thermal groundwater regime is influenced by: (1) urbanization and annual heating periods; (2) thermal groundwater use; (3) seasonal trends; (4) river-groundwater interaction; and (5) climate change and consequences thereof. The combination of short- and long-term data analysis, including conventional and high-resolution multilevel groundwater temperature monitoring, as well as 3D numerical groundwater flow and heat-transport modeling allowed quantifying the thermal influences on the investigated urban groundwater body. Results facilitate to describe the “present state” of the urban thermal groundwater regime and to derive a “potential natural state” of the investigated groundwater body. The study originated from a request of the executive council to provide a basis for cost estimates of infrastructure adaptation measures necessary to mitigate the impact of climate change. It is shown that the principal trigger for the observed thermal development is not climate change but that local and regional anthropogenic factors are dominating. Although in urban areas, groundwater is increasingly used for cooling purposes; the geothermal potential, resulting from elevated groundwater temperatures, is generally not exploited. The presented approach provides a basis for the setup of combined and thermally balanced heating and cooling systems.

  10. 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.

  11. Evolution of the Urban Heat Island of the city of Bologna (Italy) in the last 30 years

    NASA Astrophysics Data System (ADS)

    Ventura, Francesca; Gaspari, Nicola; Piana, Stefano; Rossi Pisa, Paola

    2010-05-01

    The Urban Heat Island (UHI) phenomenon is the air temperature difference between the urban area and the surrounding agricultural area of a city, due to the anthropic activities and different surfaces typical of the town. This phenomenon has been documented for many cities with different population, topography and climate (Chandler, 1962 and Oke, 1982 among the first), and has been quantified in many areas (see as an example for Italy Agnese et al, 2008). Many causes contribute to the UHI, such as different heat capacities of vegetated surfaces as compared to buildings and paving materials; different absorption due to canopy geometry; anthropogenic heat sources and so on. (for example see Camilloni and Barros, 1997) What is not so easy to find in literature is the study of the evolution of this phenomenon with time. UHI could be improved by changes in the town behaviour (increase in car traffic or winter-heating/summer-cooling), reduced by the enlargement of the suburb area, arriving to include the rural meteorological stations, or mitigated by the general growth of air temperature due to global warming. In this work, results from the analysis of two 30 years time series air temperature data are presented. The first data set comes from an agrometeorological station sited in the Botanical garden of the University of Bologna, in the centre of the town (44° 30' 05"N, 11° 21' 18" E). The second agrometeorological station is sited in the experimental farm of the University of Bologna in Cadriano (44° 33' 03" N, 11° 24' 36" E), 9 km from the first and outside of the town boundaries. Both data series range from 1978 to 2007 and are measured by mechanical thermoigrometers. Detailed information about instruments and data treatment are available in Matzneller et al. (2009). Results show an increasing trend in both stations for air maximum (Tmax) and minimum (Tmin) temperatures, more evident in the rural data. The mean UHI is of about 1.3 ± 0.7 °C as an average on the 30

  12. Long-term changes of meteorological conditions of urban heat island development in the region of Debrecen, Hungary

    NASA Astrophysics Data System (ADS)

    László, Elemér; Bottyán, Zsolt; Szegedi, Sándor

    2016-04-01

    Meteorological conditions have a remarkable impact on urban climate similarly to other local and microscale climates. Clear skies and calm weather are advantageous for the development of the urban heat island (UHI). There are numerous studies on the spatial and temporal features of the phenomenon. Much less attention is paid, however, to the meteorological conditions of UHI development. The aim of the present paper is to reveal the characteristics of the changes in the frequencies of advantageous and disadvantageous meteorological conditions for UHI development on the basis of a 50-year-long time series. Meteorological condition categories of UHI development have been established on the basis of wind speed values, cloudiness, and precipitation ranging from advantageous to disadvantageous conditions. Frequencies of occurrence of condition categories of UHI development were determined first. Advantageous and moderately advantageous conditions were found to be dominant in the time series. Linear trend analysis revealed a significant increasing trend in the time series of advantageous conditions. Increase of the frequencies of advantageous conditions was analyzed for the years, seasons, and months of the study period as well. Spring and summer (April and June) produced significant increasing trends of frequencies of advantageous conditions, while winter (with the exception of February) and autumn did not show significant increase of those frequencies. Change-point analyses detected a significant increase in the frequency of advantageous conditions in the time series at the turn of 1981/1982 especially in the summer and spring months. Detected tendencies have negative effects on urban energy consumption: they contribute to the increase of air conditioning energy demand in the summer and do not decrease the energy demand of heating in the winter significantly.

  13. 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.

  14. Influence of diversified relief on the urban heat island in the city of Kraków, Poland

    NASA Astrophysics Data System (ADS)

    Bokwa, Anita; Hajto, Monika J.; Walawender, Jakub P.; Szymanowski, Mariusz

    2015-10-01

    In cities located in concave landforms, urban heat island (UHI) is an element of a complicated thermal structure and occurs due to the common impact of urban built-up areas and orography-induced processes like katabatic flows or air temperature inversions. Kraków, Poland (760,000 inhabitants) is located in a large valley of the river Vistula. In the years 2009-2013, air temperature was measured with the 5-min sampling resolution at 21 urban and rural points, located in various landforms. Cluster analysis was used to process data for the night-time. Sodar and synoptic data analysis provided results included in the definition of the four types of night-time thermal structure representing the highest and the lowest spatial air temperature variability and two transitional types. In all the types, there are three permanent elements which show the formation of the inversion layer, the cold air reservoir and the UHI peak zone. As the impact of land use and relief on air temperature cannot be separated, a concept of relief-modified UHI (RMUHI) was proposed as an alternative to the traditional UHI approach. It consists of two steps: (1) recognition of the areal thermal structure taking into consideration the city centre as a reference point and (2) calculation of RMUHI intensity separately for each vertical zone.

  15. Establishing a correlation between the Urban Heat Island (UHI) effect in New York City and the land cover

    NASA Astrophysics Data System (ADS)

    Sossa, A. S.; Curtis, C.; Karimi, M.; vant-Hull, B.; Khanbilvardi, R.; Nazari, R.

    2013-12-01

    Urban areas experience a higher temperature compared to their rural surroundings and this phenomenon is called Urban Heat Island (UHI) effect. Surface temperature varies in different areas of a city. This study's objective is to characterize the variation of the temperature at the street level in different area of New York City and to explain why those variations occur. The method used consisted on collecting climatic data on sixteen routes in New York City on June and July 2013. The instrument used is a mobile data logger equipped with three different sensors which measures the temperature, the relative humidity and the luminosity at the street level. The data are compared with the Central Park weather station data. The results reveal that Central park has the lowest temperature varies in the space throughout the City and depends on the land cover. Further studies must be done in order to find a correlation between the observation on the horizontal and vertical routes. This work is a step toward a more accurate prediction on the pattern of temperature at the street level, and therefore an enhancement of the characterization and mitigation of the UHI in New York City.

  16. 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. PMID:25523076

  17. [Spatiotemporal distribution characteristics and causes of sunny days' heat island effect in Chengdu City of Southwest China].

    PubMed

    Zhang, Shun-Qian; Zhou, Chang-Yan

    2013-07-01

    Based on 99 clear sky Terra satellite images of Chengdu City in 2005-2010, and by using a novel automatic extraction method of suburb temperature, i. e., each city-circle temperature jump, this paper studied the spatiotemporal variation characteristics of the urban heat island (UHI) effect in the City in 2005-2010, and analyzed the causes of the variation characteristics. In the study period, the central area of the largest and strongest UHI was in the Jinhua Town located in the southwest of Chengdu. The UHI effect had no significant spatial variation, but the range and intensity of the UHI effect tented to be decreased. The intra-annual UHI intensity and area within the ring roads showed a three-peak distribution pattern, with the peak values appeared in April, July, and October, and the intensity reached the maximum in July. The UHI intensity in Chengdu was attenuated by the decrease of air temperature and the increase of precipitation and urban vegetation cover. PMID:24175528

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

    SciTech Connect

    Pomerantz, M.; Akbari, H.; Chang, S.-C.; Levinson, R.; Pon, B.

    2003-04-30

    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 the 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.

  19. Do we need full mesoscale models to simulate the urban heat island? A study over the city of Barcelona.

    NASA Astrophysics Data System (ADS)

    García-Díez, Markel; Ballester, Joan; De Ridder, Koen; Hooyberghs, Hans; Lauwaet, Dirk; Rodó, Xavier

    2016-04-01

    As most of the population lives in urban environments, the simulation of the urban climate has become an important part of the global climate change impact assessment. However, due to the high resolution required, these simulations demand a large amount of computational resources. Here we present a comparison between a simplified fast urban climate model (UrbClim) and a widely used full mesoscale model, the Weather Research and Forecasting (WRF) model, over the city of Barcelona. In order to check the advantages and disadvantages of each approach, both simulations were compared with station data and with land surface temperature observations retrieved by satellites, focusing on the urban heat island. The effect of changing the UrbClim boundary conditions was studied too, by using low resolution global reanalysis data (70 km) and a higher resolution forecast model (15 km). Finally, a strict comparison of the computational resources consumed by both models was carried out. Results show that, generally, the performance of the simple model is comparable to or better than the mesoscale model. The exception are the winds and the day-to-day correlation in the reanalysis driven run, but these problems disappear when taking the boundary conditions from a higher resolution global model. UrbClim was found to run 133 times faster than WRF, using 4x times higher resolution and, thus, it is an efficient solution for running long climate change simulations over large city ensembles.

  20. 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.

  1. 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.

  2. Correlation analysis of the urban heat island effect and the spatial and temporal distribution of atmospheric particulates using TM images in Beijing.

    PubMed

    Xu, L Y; Xie, X D; Li, S

    2013-07-01

    This study combines the methods of observation statistics and remote sensing retrieval, using remote sensing information including the urban heat island (UHI) intensity index, the normalized difference vegetation index (NDVI), the normalized difference water index (NDWI), and the difference vegetation index (DVI) to analyze the correlation between the urban heat island effect and the spatial and temporal concentration distributions of atmospheric particulates in Beijing. The analysis establishes (1) a direct correlation between UHI and DVI; (2) an indirect correlation among UHI, NDWI and DVI; and (3) an indirect correlation among UHI, NDVI, and DVI. The results proved the existence of three correlation types with regional and seasonal effects and revealed an interesting correlation between UHI and DVI, that is, if UHI is below 0.1, then DVI increases with the increase in UHI, and vice versa. Also, DVI changes more with UHI in the two middle zones of Beijing. PMID:23558302

  3. 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

  4. A study of the hourly variability of the urban heat island effect in the Greater Athens Area during summer.

    PubMed

    Kourtidis, K; Georgoulias, A K; Rapsomanikis, S; Amiridis, V; Keramitsoglou, I; Hooyberghs, H; Maiheu, B; Melas, D

    2015-06-01

    Measurements of air temperature and humidity in the urban canopy layer during July 2009 in 26 sites in Athens, Greece, allowed for the mapping of the hourly spatiotemporal evolution of the urban heat island (UHI) effect. City districts neighboring to the mountains to the east were the hottest during the afternoon, while being among the coolest during the early morning hours. While during the early morning some coastal sites were the hottest, the warm air plume slowly moved to the densely urbanized center of the city until 14:00-15:00, moving then further west, to the Elefsis industrial area in the afternoon. Results from the UrbClim model agree fairly well with the observations. Satellite-derived land surface temperature (LST) data from AATSR, ASTER, AVHRR and MODIS, for pixels corresponding to ground stations measuring Tair, showed that LST can be up to 5K lower than the respective Tair during nighttime, while it can be up to 15K higher during the rest of the day. Generally, LST during late afternoon as acquired from AATSR is very near to Tair for all stations and all days, i.e., the AATSR LST afternoon retrieval can be used as a very good approximation of Tair. The hourly evolution of the spatial Tair distribution was almost the same during days with NE Etesian flow as in days with sea breeze circulation, indicating that the mean wind flow was not the main factor controlling the diurnal UHI evolution, although it influenced the temperatures attained. No unambiguous observation of the urban moisture excess (UME) phenomenon could be made. PMID:25727673

  5. The Urban Heat Island and its spatial scale dependent impact on survival and development in butterflies of different thermal sensitivity.

    PubMed

    Kaiser, Aurélien; Merckx, Thomas; Van Dyck, Hans

    2016-06-01

    Climate alteration is one of the most cited ecological consequences of urbanization. However, the magnitude of this impact is likely to vary with spatial scale. We investigated how this alteration affects the biological fitness of insects, which are especially sensitive to ambient conditions and well-suited organisms to study urbanization-related changes in phenotypic traits. We monitored temperature and relative air humidity in wooded sites characterized by different levels of urbanization in the surroundings. Using a split-brood design experiment, we investigated the effect of urbanization at the local (i.e., 200 × 200 m) and landscape (i.e., 3 × 3 km) scale on two key traits of biological fitness in two closely related butterfly species that differ in thermal sensitivity. In line with the Urban Heat Island concept, urbanization led to a 1°C increase in daytime temperature and an 8% decrease in daytime relative humidity at the local scale. The thermophilous species Lasiommata megera responded at the local scale: larval survival increased twofold in urban compared to rural sites. Urbanized sites tended to produce bigger adults, although this was the case for males only. In the woodland species Pararge aegeria, which has recently expanded its ecological niche, we did not observe such a response, neither at the local, nor at the landscape scale. These results demonstrate interspecific differences in urbanization-related phenotypic plasticity and larval survival. We discuss larval pre-adaptations in species of different ecological profiles to urban conditions. Our results also highlight the significance of considering fine-grained spatial scales in urban ecology. PMID:27516869

  6. Pseudovertical Temperature Profiles and the Urban Heat Island Measured by a Temperature Datalogger Network in Phoenix, Arizona

    SciTech Connect

    Fast, Jerome D.; Torcolini, Joel C.; Redman, Randy

    2005-01-01

    As part an air quality field campaign conducted in Phoenix during the summer of 2001, a network of temperature dataloggers and surface meteorological stations were deployed across the metropolitan area for a 61-day period. The majority of the dataloggers were deployed along two intersecting lines across the city to quantify characteristics of the urban heat island (UHI). To obtain pseudo-vertical temperature profiles, some of the instrumentation was also deployed along a mountain slope that rose to 480 m above the valley floor. The instrumentation along the mountain slope provided a reasonable approximation of the vertical temperature profile of the free atmosphere over the valley center during the night and a few hours after sunrise. Mean differences of 0.63 and 0.92o K and standard deviations of 1.33 and 1.45o K were obtained when compared with the in situ radiosonde and remote radio acoustic sounding system measurements, respectively. The vertical temperature gradients associated with temperature inversions within 200 m of the surface during the morning were also close to those obtained from the radiosondes. The average UHI during the measurement period was between 2.5 and 3.5oC; however, there was significant day-to-day variability and it was as large as 10oC during one evening. The peak UHI usually occurred around midnight; however, a strong UHI was frequently observed 2-3 hours after sunrise that coincided with the persistence of strong temperature inversions obtained from the radiosonde and the pseudo-vertical temperature profiles. The nocturnal horizontal temperature gradient was somewhat different than reported for other large cities and the UHI did not decrease with increasing wind speeds until the wind speeds exceeded 7 m s-1.

  7. The Effect of Urban Heat Island on Climate Warming in the Yangtze River Delta Urban Agglomeration in China.

    PubMed

    Huang, Qunfang; Lu, Yuqi

    2015-08-01

    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

  8. Quantifying urban heat island effects and human comfort for cities of variable size and urban morphology in the Netherlands

    NASA Astrophysics Data System (ADS)

    Steeneveld, G. J.; Koopmans, S.; Heusinkveld, B. G.; van Hove, L. W. A.; Holtslag, A. A. M.

    2011-10-01

    This paper reports on the canopy layer urban heat island (UHI) and human comfort in a range of small to large cities and villages in the Netherlands. To date, this subject has not been substantially studied in the Netherlands, since it has a relatively mild oceanic (Cfb) climate and impact was assumed to be minor. To fill this knowledge gap, this paper reports on observations of a selected network of reliable hobby meteorologists, including several in The Hague and Rotterdam. A number of alternative measures were also used to quantify UHI, i.e., the generalized extreme value distribution and return periods of UHI and adverse human comfort; its uncertainties were estimated by the statistical method of bootstrapping. It appeared essential to distinguish observations made at roof level from those made within the urban canyon, since the latter related more closely to exposure at pedestrian level and to urban canyon properties in their close neighborhood. The results show that most Dutch cities experience a substantial UHI, i.e., a mean daily maximum UHI of 2.3 K and a 95 percentile of 5.3 K, and that all cities experience a shadow effect in the morning when cities remain cooler than the rural surroundings. Also, an evident relation between the median of the daily maximum UHI and its 95 percentile was discovered. Furthermore, the 95 percentile of the UHI appears well correlated with population density. In addition, we find a significant decrease of UHI and the percentage of surface area covered by green vegetation, but the relation with open water remains unclear.

  9. Climate–vegetation control on the diurnal and seasonal variations of surface urban heat islands in China

    NASA Astrophysics Data System (ADS)

    Zhou, Decheng; Zhang, Liangxia; Li, Dan; Huang, Dian; Zhu, Chao

    2016-07-01

    Remotely sensed surface urban heat islands (UHIs) have gained considerable interest in recent decades due to the easy access and the wall-to-wall coverage of satellite products. The magnitude or intensity of surface UHIs have been well documented at regional and global scales, yet a systematic evaluation of the temporal variability over large areas is still lacking. In this study, the diurnal and seasonal cycles of surface UHI intensities (SUHIIs) in China are examined using Aqua/Terra MODIS data from 2008 to 2012. Results show that the mean annual SUHIIs varied greatly in a diurnal cycle, characterized by a positive day-night difference (DND) in Southeast China and the opposite in Northeast and Northwest China. Also, the SUHIIs differed dramatically in a seasonal cycle, indicated by a positive summer-winter difference (SWD) in the day and a negative SWD at night, accompanied by the highly diverse DNDs across seasons and geographic regions. Northwest and Northeast China overall showed the largest DND and SWD (>3 °C), respectively. These diurnal and seasonal variations depend strongly on local climate-vegetation regimes, as indicated by a strong positive correlation between DND and precipitation (and air temperature) and a negative relationship between DND and vegetation activity across cities and seasons. In particular, SHUIIs were quadratically correlated with the mean annual precipitation across space, suggesting that there might be a threshold in terms of the effects induced by local background climate. Our findings highlight the importance of considering the temporal variability of UHIs for more accurate characterization of the associated ecological and social-economic consequences.

  10. Urban Heat Islands

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey C.; Quattrochi, Dale A.; Rickman, Doug L.; Estes, Maury G.

    2011-01-01

    It is estimated that by the year 2025, 80% of the world's population will live in cities. This conversion of the natural landscape vegetation into man-made urban structures such as roads and buildings drastically alter the regional surface energy budgets, hydrology, precipitation patterns, and meteorology. Research studies from many cities have documented these effects range from decreases in air quality, increased energy consumption and alteration of regional climate to direct effects on human health.

  11. Urban Heat Island Growth Modeling Using Artificial Neural Networks and Support Vector Regression: A case study of Tehran, Iran

    NASA Astrophysics Data System (ADS)

    Sherafati, Sh. A.; Saradjian, M. R.; Niazmardi, S.

    2013-09-01

    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. Therefore, to achieve a model which is able to simulate UHI growth, urban expansion should be concerned first. Considerable researches on urban expansion modeling have been done based on cellular automata. Accordingly the objective of this paper is to implement CA method for trend detection of Tehran UHI spatiotemporal growth based on urban sprawl parameters (such as Distance to nearest road, Digital Elevation Model (DEM), Slope and Aspect ratios). It should be mentioned that UHI growth modeling may have more complexities in comparison with urban expansion, since the amount of each pixel's temperature should be investigated instead of its state (urban and non-urban areas). The most challenging part of CA model is the definition of Transfer Rules. Here, two methods have used to find appropriate transfer Rules which are Artificial Neural Networks (ANN) and Support Vector Regression (SVR). The reason of choosing these approaches is that artificial neural networks and support vector regression have significant abilities to handle the complications of such a spatial analysis in comparison with other methods like Genetic or Swarm intelligence. In this paper, UHI change trend has discussed between 1984 and 2007. For this purpose, urban sprawl parameters in 1984 have calculated and added to the retrieved LST of this year. In order to achieve LST, Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) night-time images have exploited. The reason of implementing night-time images is that UHI phenomenon is more obvious during night hours. After that multilayer feed-forward neural networks and support vector regression have used separately to find the relationship between this data and the retrieved LST in 2007. Since the transfer rules might not be the same in different regions, the satellite image of the city has

  12. 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

  13. 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

    SciTech Connect

    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 temperature 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.

  14. A Remote Sensing-based Characterization of the Urban Heat Island and its Implications for Modeled Estimates of Urban Biogenic Carbon Fluxes in Boston, MA.

    NASA Astrophysics Data System (ADS)

    Wang, J.; Friedl, M. A.; Hutyra, L.; Hardiman, B. S.

    2015-12-01

    Urban land use occupies a small but critical proportion of global land area for the carbon cycle, and in the coming decades, urban land area is expected to nearly double. Conversion of natural land cover to urban land cover imposes myriad ecological effects, including increased land surface and air temperatures via the urban heat island effect. In this study, we characterize the seasonal and spatial characteristics of the urban heat island over Boston, MA and estimate its consequences on biogenic carbon fluxes with a remote sensing-based model. Using a 12-year time series of emissivity- and atmospherically-corrected land surface temperatures from Landsat TM and ETM+ imagery, we find a high degree of spatial heterogeneity and consistent seasonal patterns in the thermal properties of Boston, controlled mainly by variations in vegetative cover. Field measurements of surface air temperature across an urbanization gradient show season- and vegetation-dependent patterns consistent with those observed in the Landsat data. With a fused data set that combines surface air temperature, MODIS, and Landsat observations, we modify and run the Vegetation Photosynthesis and Respiration Model (VPRM) to explore 1) how elevated temperatures affect diurnal and seasonal patterns of hourly urban biogenic carbon fluxes in Massachusetts in 2013 and 2014 and 2) to what extent these fluxes follow spatial patterns found in the urban heat island. Model modifications simulate the ecological effects of urbanization, including empirical adjustments to reanalysis-driven air temperatures (up to 5 K) and ecosystem respiration reduced by impervious surface area. Model results reveal spatio-temporal patterns consistent with strong land use and vegetation cover controls on biogenic carbon fluxes, with non-trivial biogenic annual net ecosystem exchange occurring in urban and suburban areas (up to -2.5 MgC/ha/yr). We specifically consider the feedbacks between Boston's urban heat island and landscape

  15. Urban Heat Island Connections to Neighborhood Microclimates in Phoenix, Arizona: Defining the Influences of Land Use and Social Variables on Temperature

    NASA Astrophysics Data System (ADS)

    Prashad, L. C.; Stefanov, W. L.; Brazel, A.; Harlan, S.

    2003-12-01

    Phoenix, AZ is known to have an urban heat island that significantly increases minimum and maximum temperatures, which continue to climb as the city grows and becomes denser. We present a study that investigates "neighborhood" scale (1 square km) microclimate and its potential connections to the regional heat island. The purpose of our study is to: 1) identify social factors/ behaviors that influence temperature on a neighborhood scale and relate fluctuations to the overall heat island; 2) determine the effect of land use on temperature at the neighborhood and regional scales; 3) evaluate a range of thermal infrared (TIR) remotely sensed (RS) data and compare the RS surface temperatures to air temperature. Neighborhoods in both the urban core and fringe were delineated within Phoenix for our study. The neighborhoods represent a range of income levels and ethnicities. Daytime TIR data from Landsat sensors (TM, ETM+) and the airborne MASTER sensor were used to obtain surface temperatures for the neighborhoods. Nighttime surface temperature data were obtained from the ASTER sensor. Vegetation indices (SAVI) were created from Landsat and MASTER imagery. Climate monitors installed in each neighborhood recorded air temperature and dew point readings every 5 minutes. Land use was obtained from an expert systems classification of Landsat imagery and from aerial photos. Our results indicate surface temperatures correlate strongly with air temperatures. The 12.5m/pixel MASTER and 30m/pixel Landsat thermal data can highlight surface temperature gradients within a neighborhood while nighttime ASTER data provides better mean surface temperature discrimination between neighborhoods, and allows for quantification of local diurnal temperature variation. Neighborhoods with a low mean income, high percentage of Hispanics, and low educational attainment are significantly hotter than their high-income, non-Hispanic, highly educated counterparts. Urban core neighborhoods with high

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

    SciTech Connect

    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, 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-conditioned buildings in

  17. Mapping urban heat islands of arctic cities using combined data on field measurements and satellite images based on the example of the city of Apatity (Murmansk Oblast)

    NASA Astrophysics Data System (ADS)

    Konstantinov, P. I.; Grishchenko, M. Y.; Varentsov, M. I.

    2015-12-01

    This article presents the results of a study of the urban heat island (UHI) in the city of Apatity during winter that were obtained according to the data of field meteorological measurements and satellite images. Calculations of the surface layer temperature have been made based on the surface temperature data obtained from satellite images. The experimental data on air temperature were obtained as a result of expeditionary meteorological observations, and the experimental data on surface temperature were obtained based on the data of the space hyperspectral Moderate-Resolution Imaging Spectroradiometer (MODIS) system, channels 31 and 32 (10.78-11.28 and 11.77-12.27 micrometers, respectively). As a result of the analysis of temperature fields, an intensive heat island (up to 3.2°C) has been identified that was estimated based on the underlying surface temperature, and its mean intensity over the observation period significantly exceeds the representative data for European cities in winter. It has also been established that the air temperature calculated according to the MODIS data is systematically higher under winter conditions than the air temperature from direct measurement data.

  18. Identification of a Gene within a Pathogenicity Island of Enterotoxigenic Escherichia coli H10407 Required for Maximal Secretion of the Heat-Labile Enterotoxin

    PubMed Central

    Fleckenstein, James M.; Lindler, Luther E.; Elsinghorst, Eric A.; Dale, James B.

    2000-01-01

    Studies of the pathogenesis of enterotoxigenic Escherichia coli (ETEC) have largely centered on extrachromosomal determinants of virulence, in particular the plasmid-encoded heat-labile (LT) and heat-stable enterotoxins and the colonization factor antigens. ETEC causes illnesses that range from mild diarrhea to severe cholera-like disease. These differences in disease severity are not readily accounted for by our current understanding of ETEC pathogenesis. Here we demonstrate that Tia, a putative adhesin of ETEC H10407, is encoded on a large chromosomal element of approximately 46 kb that shares multiple features with previously described E. coli pathogenicity islands. Further analysis of the region downstream from tia revealed the presence of several candidate open reading frames (ORFs) in the same transcriptional orientation as tia. The putative proteins encoded by these ORFs bear multiple motifs associated with bacterial secretion apparatuses. An in-frame deletion in one candidate gene identified here as leoA (labile enterotoxin output) resulted in marked diminution of secretion of the LT enterotoxin and lack of fluid accumulation in a rabbit ileal loop model of infection. Although previous studies have suggested that E. coli lacks the capacity to secrete LT, our studies show that maximal release of LT from the periplasm of H10407 is dependent on one or more elements encoded on a pathogenicity island. PMID:10768971

  19. 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.

  20. Differences between satellite- and ground-based urban heat island effect - Case study for the Budapest agglomeration area

    NASA Astrophysics Data System (ADS)

    Pongracz, R.; Bartholy, J.; Lelovics, E.; Dezso, Z. S.; Dobi, I.

    2012-04-01

    Urban heat island (UHI) is defined as the positive temperature anomaly occurring between built-in areas and their surroundings. For detailed analysis of UHI in a particular area, different approaches can be used. Here, two different techniques (ground-based and satellite-based) are applied to the Budapest agglomeration area and the results are compared. (1) Hourly recorded air temperature observations are available from six automatically operating climatological stations of the Hungarian Meteorological Service. Two stations are located in the downtown of Budapest (Kitaibel Pál street and Lágymányos); two stations can be found in the suburbs (Újpest and Pestszentlőrinc); and two stations are in the rural region (Penc - located to the northeast from the capital, and Kakucs - to the southeast from Budapest). These ground-based observations at the Budapest weather stations provide air temperature data at standard 2 m height above surface. However, due to the limited station number, this approach is not suitable for detailed evaluation of spatial UHI distribution. (2) Remotely sensed surface temperature values are available from seven thermal infrared channel measurements of the multi-spectral radiometer sensor called MODIS (Moderate Resolution Imaging Spectroradiometer), which is one of the sensors on-board satellites Terra and Aqua. They were launched to polar orbit as part of the NASA's Earth Observing System in December 1999, and in May 2002, respectively. Satellite Terra (Aqua) provides surface temperature fields around 09-10 UTC (12-13 UTC) and 20-21 UTC (02-03 UTC) with 1 km spatial resolution. The whole agglomeration has been divided into urban and rural pixels using the MODIS Land Cover Product categories, distance from the city centre, satellite images of the Google Earth, and GTOPO-30 global digital elevation model. However, the main disadvantage of this method is that for UHI analysis, data can be used only in case of clear sky conditions, which occurs

  1. Investigation of detailed spatial structure of the Moscow urban heat island with application of the newest meteorological observations and regional climate modelling

    NASA Astrophysics Data System (ADS)

    Varentsov, Mikhail; Pavel, Konstantinov; Timofey, Samsonov

    2016-04-01

    During the last years, the network of metrological observation in Moscow megacity and its neighborhoods, forming the biggest urban agglomeration in Europe, was significantly extended. Several new weather stations and completely new dense network of air-quality monitoring appears during the last decade. In addition, several microwave meteorological profilers MTP 5, which are available to measure temperature at the heights from 0 to 1000 meters with 50-m resolution, were installed in the city and its surrounding. All these measurements allow revealing undiscovered features of Moscow urban climate and urban heat island (UHI). In our research, bases on this data, we covered several topics related to urban climatology: - Investigation of detailed spatial structure of Moscow UHI and its relationships with building features, such as land use and morphology of the street canyons, obtained by GIS-algorithms according (Samsonov et. al, 2015); - Investigation of three-dimensional structure of the UHI, including its vertical extend and influence on the stratification of the atmosphere, and three-dimensional structure of the urban heat island advection and urban heat plumes; - Application of the newest data for validation of the regional climate model COSMO-CLM, coupled with TEB urban scheme (Masson, 2000; Trusilova et. al., 2013), launched for Moscow region with 1-km spatial resolution. References: 1. Masson V. A. Physically-Based Scheme for the Urban Energy Budget in Atmospheric models. Bound. Layer Meteor. 2000. V. 94 (3). P. 357-397. 2. Trusilova K., Früh B., Brienen S., Walter A., Masson V., Pigeon G., Becker P. Implementation of an Urban Parameterization Scheme into the Regional Climate Model COSMO-CLM. J. Appl. Meteor. Climatol. V. 52. P. 2296-2311. 3. Samsonov T.E., Konstantinov P.I., Varentsov M.I. Object-oriented approach to urban canyon analysis and its applications in meteorological modeling. Urban Climate. 2015. Vol. 13. P. 122-139.

  2. The state of permafrost surrounding "Gabriel de Castilla" Spanish Antarctic Station (Deception Island, Antarctica): Studying the possible degradation due to the infrastructures heating effect.

    NASA Astrophysics Data System (ADS)

    Recio, Cayetana; Ángel de Pablo, MIguel; Ramos, MIguel; Molina, Antonio

    2015-04-01

    Permafrost degradation is one of the effects of the global warming. Many studies reveal the increase of active layer and reduction on permafrost table thickness, also in Antarctica. However, these trends on permafrost can be accelerated by the human activities, as the heating produced by the Antarctic stations infrastructures when they are not properly isolated from the ground. In Deception island, South Shetland Archipelago, we started 3 years ago a monitoring program at the 26 years old "Gabriel de Castilla" Spanish Antarctic Station (SAS), It is focused on charactering the state of permafrost, since in the coastal scarps at tens of meters from the station an increase on erosion had been detected. Although the main cause of the erosion of this coastal volcanoclastic materials is the 2 meters thick icefield which forms during the winter in the inner sea of this volcanic island, we want to detect any possible contribution to the coastal erosion caused by the permafrost degradation related to the SAS presence. We present our preliminary analysis based on three years of continuous ground temperature data, monitored at a shallow borehole (70 cm deep) in the SAS edge, together with the active layer thickness measured around the station and their vicinities in two thawing seasons. We complete this study with the analysis of the continuous temperature data taken inside the SAS and the air and ground temperatures below the station, acquired during the last Antarctic Campaign (December 2014-February 2015). These preliminary results are fundamental 1) to discard any contribution from the SAS presence, and to help to improve its thermal isolation, 2) to help improve our knowledge about the thermal state of permafrost in the area, and 3) to help to understand the causes of the coastal erosion in the volcanic Deception Island.

  3. 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.

  4. An Evaluation of the Complex Age Progression along the Cook-Austral Islands Using High-resolution 40Ar/39Ar Incremental Heating Ages

    NASA Astrophysics Data System (ADS)

    Rose, J.; Koppers, A. A. P.

    2014-12-01

    Until recently, the hotspot hypothesis has been generally accepted to explain the presence of linear volcanic chains. The hypothesis predicts a linear age progression along each chain, as well as consistent angular rotation velocities for all chains on a single plate. While such age progressions have been observed at places such as Hawaii and Louisville, several young (0-30 Ma) volcanic chains that formed on the Pacific plate show age progressions and associated angular velocities that are in disagreement with one another. The Cook-Austral island chain has age distributions that are particularly difficult to resolve based on the hotspot hypothesis, due to its location on the "hotspot highway" (Jackson et al. 2010) and a wide geographic range of recent volcanism. Several of these islands were previously studied by Turner and Jarrard (1982) who interpreted this age progression to suggest the presence of three active hotspots positioned along a "hot line" above a sheet-like upwelling area in the mantle as opposed to a singular "hot spot". However, this study was performed using the K/Ar dating method, and it has been shown that K and/or Ar loss (and addition of K) due to weathering and alteration can have significant effects on the age and uncertainty of samples dated with this technique. Here we present high-resolution 40Ar/39Ar incremental heating ages for several of the same samples previously analyzed in this study, as well as some unpublished samples. Analyses were conducted using the ARGUS-VI multicollector mass spectrometer, employing incremental heating procedures that provide more precise and more accurate ages compared to K/Ar and total fusion 40Ar/39Ar measurements. These new data will be used in conjunction with existing plate motion models and geochemical data to assess whether they support a point source or line source hypothesis. This in turn will allow us to improve our overall knowledge of mantle anomaly geometry and absolute plate motion.

  5. 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.

  6. 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

  7. Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy

    NASA Astrophysics Data System (ADS)

    Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.

    2015-04-01

    The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping

  8. 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.

  9. Turning up the Heat: Increasing Temperature and Coral Bleaching at the High Latitude Coral Reefs of the Houtman Abrolhos Islands

    PubMed Central

    Abdo, David A.; Bellchambers, Lynda M.; Evans, Scott N.

    2012-01-01

    Background Coral reefs face increasing pressures particularly when on the edge of their distributions. The Houtman Abrolhos Islands (Abrolhos) are the southernmost coral reef system in the Indian Ocean, and one of the highest latitude reefs in the world. These reefs have a unique mix of tropical and temperate marine fauna and flora and support 184 species of coral, dominated by Acropora species. A significant La Niña event during 2011 produced anomalous conditions of increased temperature along the whole Western Australian coastline, producing the first-recorded widespread bleaching of corals at the Abrolhos. Methodology/ Principal Findings We examined long term trends in the marine climate at the Abrolhos using historical sea surface temperature data (HadISST data set) from 1900–2011. In addition in situ water temperature data for the Abrolhos (from data loggers installed in 2008, across four island groups) were used to determine temperature exposure profiles. Coupled with the results of coral cover surveys conducted annually since 2007; we calculated bleaching thresholds for monitoring sites across the four Abrolhos groups. Conclusions/ Significance In situ temperature data revealed maximum daily water temperatures reached 29.54°C in March 2011 which is 4.2°C above mean maximum daily temperatures (2008–2010). The level of bleaching varied across sites with an average of ∼12% of corals bleached. Mortality was high, with a mean ∼50% following the 2011 bleaching event. Prior to 2011, summer temperatures reached a mean (across all monitoring sites) of 25.1°C for 2.5 days. However, in 2011 temperatures reached a mean of 28.1°C for 3.3 days. Longer term trends (1900–2011) showed mean annual sea surface temperatures increase by 0.01°C per annum. Long-term temperature data along with short-term peaks in 2011, outline the potential for corals to be exposed to more frequent bleaching risk with consequences for this high latitude coral reef system at the

  10. High Spatial Resolution Thermal 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)

    2002-01-01

    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.

  11. 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.

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

    SciTech Connect

    Akbari, Hashem; Xu, Tengfang; Taha, Haider; Wray, Craig; Sathaye, Jayant; Garg, Vishal; Tetali, Surekha; Babu, M. Hari; Reddy, K. Niranjan

    2011-05-25

    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.

  13. 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

  14. 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

  15. Modeling urban heat islands in heterogeneous land surface and its correlation with impervious surface area by using night-time ASTER satellite data in highly urbanizing city, Delhi-India

    NASA Astrophysics Data System (ADS)

    Mallick, Javed; Rahman, Atiqur; Singh, Chander Kumar

    2013-08-01

    The present study is an assessment and identification of urban heat island (UHI) in the environment of one of the fastest urbanizing city of India, Delhi Metropolis, employing satellite image of ASTER and Landsat 7 ETM+ in the thermal infrared region 3-14 μm. Temporal (2001 and 2005) ASTER datasets were used to analyze the spatial structure of the thermal urban environment subsequently urban heat island (UHI) in relation to the urban surface characteristics and land use/land cover (LULC). The study involves derivation of parameters governing the surface heat fluxes, constructing statistics of ASTER thermal infrared images along with validation through intensive in situ measurements. The average images reveal spatial and temporal variations of land surface temperature (LST) of night-time and distinct microclimatic patterns. Central Business District (CBD) of Delhi, (Connaught Place, a high density built up area), and commercial/industrial areas display heat islands condition with a temperature greater than 4 °C compared to the suburbs. The small increase in surface temperature at city level is mainly attributed to cumulative impact of human activities, changes in LULC pattern and vegetation density. In this study the methodology takes into account spatially-relative surface temperatures and impervious surface fraction value to measure surface UHI intensity between the urban land cover and rural surroundings. Both the spatial and temporal variation in surface temperature associated with impervious surface area (ISA) has been evaluated to assess the effect of urbanization on the local climate.

  16. Green and cool roofs to mitigate urban heat island effects in the Chicago metropolitan area: evaluation with a regional climate model

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Conry, P.; Fernando, H. J. S.; Hamlet, Alan F.; Hellmann, J. J.; Chen, F.

    2016-06-01

    The effects of urban heat islands (UHIs) have a substantial bearing on the sustainability of cities and environs. This paper examines the efficacy of green and cool roofs as potential UHI mitigation strategies to make cities more resilient against UHI. We have employed the urbanized version of the Weather Research and Forecasting (uWRF) model at high (1 km) resolution with physically-based rooftop parameterization schemes (conventional, green and cool), a first-time application to the Chicago metropolitan area. We simulated a hot summer period (16–18 August 2013) and assessed (i) UHI reductions for different urban landuse with green/cool roofs, (ii) the interaction of lake breeze and UHI, and (iii) diurnal boundary layer dynamics. The performance of uWRF was evaluated using sensible heat flux and air temperature measurements from an urban mini-field campaign. The simulated roof surface energy balance captured the energy distribution with respective rooftop algorithms. Results showed that daytime roof temperature reduced and varied linearly with increasing green roof fractions, from less than 1 °C for the case of 25% green roof to ∼3 °C during peak daytime for 100% green roof. Diurnal transitions from land to lake breeze and vice versa had a substantial impact on the daytime cycle of roof surface UHI, which had a 3–4 hour lag in comparison to 2 m UHI. Green and cool roofs reduced horizontal and vertical wind speeds and affected lower atmosphere dynamics, including reduced vertical mixing, lower boundary layer depth, and weaker convective rolls. The lowered wind speeds and vertical mixing during daytime led to stagnation of air near the surface, potentially causing air quality issues. The selection of green and cool roofs for UHI mitigation should therefore carefully consider the competing feedbacks. The new results for regional land-lake circulations and boundary layer dynamics from this study may be extended to other urbanized areas, particularly to coastal

  17. 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).

  18. Dynamics and controls of urban heat sink and island phenomena in a desert city: Development of a local climate zone scheme using remotely-sensed inputs

    NASA Astrophysics Data System (ADS)

    Nassar, Ahmed K.; Blackburn, G. Alan; Whyatt, J. Duncan

    2016-09-01

    This study aims to determine the dynamics and controls of Surface Urban Heat Sinks (SUHS) and Surface Urban Heat Islands (SUHI) in desert cities, using Dubai as a case study. A Local Climate Zone (LCZ) schema was developed to subdivide the city into different zones based on similarities in land cover and urban geometry. Proximity to the Gulf Coast was also determined for each LCZ. The LCZs were then used to sample seasonal and daily imagery from the MODIS thermal sensor to determine Land Surface Temperature (LST) variations relative to desert sand. Canonical correlation techniques were then applied to determine which factors explained the variability between urban and desert LST. Our results indicate that the daytime SUHS effect is greatest during the summer months (typically ∼3.0 °C) with the strongest cooling effects in open high-rise zones of the city. In contrast, the night-time SUHI effect is greatest during the winter months (typically ∼3.5 °C) with the strongest warming effects in compact mid-rise zones of the city. Proximity to the Arabian Gulf had the largest influence on both SUHS and SUHI phenomena, promoting daytime cooling in the summer months and night-time warming in the winter months. However, other parameters associated with the urban environment such as building height had an influence on daytime cooling, with larger buildings promoting shade and variations in airflow. Likewise, other parameters such as sky view factor contributed to night-time warming, with higher temperatures associated with limited views of the sky.

  19. Remote Sensing of the Surface Urban Heat Island and Land Architecture in Phoenix, Arizona: Combined Effects of Land Composition and Configuration and Cadastral-Demographic-Economic Factors

    NASA Astrophysics Data System (ADS)

    Middel, A. C.; LI, X.

    2015-12-01

    This study seeks to determine the role of land architecture—the composition and configuration of land cover—as well as cadastral-demographic-economic factors on land surface temperature (LST) and the surface urban heat island (SUHI) effect of Phoenix, Arizona. It employs 1 m National Agricultural Imagery Program data of land-cover with 120 m Landsat-derived land surface temperature decomposed to 30m, a new measure of configuration, the normalized moment of inertia, and U.S. Census data to address the question for two randomly selected samples comprising 523 and 545 residential neighborhoods (census blocks) in the city. The results indicate that, contrary to most other studies, land configuration maintains as strong a role in LST as does land composition. In addition, land architecture combined with cadastral, demographic and economic data, captures a significant amount of explained variance in LST. The results indicate that attention to land architecture in the development of or reshaping of neighborhoods may ameliorate the summer extremes in LST.

  20. A Satellite Time Slots Climatology of the Urban Heat Island of Guadalajara Megacity in Mexico from NOAA ¡/AVHRR THERMAL Infrared Monitoring (TIR)

    NASA Astrophysics Data System (ADS)

    Galindo, I.

    2009-04-01

    The urban heat island (UHI) of the metropolitan area of the second megacity of Mexico, named Guadalajara in Mexico is studied using thermal infrared data (TIR) (10 £ l £ 12 mm) obtained from the Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA polar orbitters whose signals are received on real time at our ground station for the period 1996-2006. The TIR data are selected by means of a software, since they depend on natural causes (e.g., atmospheric transparency, surface temperature, spectral emissivity and topography) and observational (time and incidence angle of the satellite pass, season of the year, etc.). The above conditions have a variable contribution to the measurements which it can be so high that they simulate the temporal-space fluctuations considered as thermal anomalies. Using a Geographic Information System and spatial analysis techniques temperatures are obtained for diofferent times of the day (satellite slots) and dropped into a grid with a 2.5 km distance between points (latitude, longitude). The temperatures obtained for each satellite pass slot (four per day) are monthly averaged and the temperature anomalies are represented in thermal isolines for the study area. The temperature difference usually is larger at night than during the day, reaching a thermal gradient of 9 °C.

  1. 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)

  2. Thermal island destabilization and the Greenwald limit

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    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. 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. 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.

  3. Thermal island destabilization and the Greenwald limit

    SciTech Connect

    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 saturated 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.

  4. Thermal island destabilization and the Greenwald limit

    SciTech Connect

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

    2015-02-15

    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. 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. 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.

  5. Thermal island destabilization and the Greenwald limit

    DOE PAGESBeta

    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

  6. Exploring the Influence of Impervious Surface Density and Shape on Urban Heat Islands in the Northeast USA Using MODIS and Landsat

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    Impervious surface area (ISA) from the National Land Cover Database (NLCD) 2001 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 and its relationship to settlement size and shape, development intensity distribution, and land cover composition for 42 urban settlements embedded in forest biomes in the Northeastern United States. Development intensity zones, based on percent ISA, are defined for each urban area emanating outward from the urban core to nearby rural areas and are used to stratify land surface temperature. The stratification is further constrained by biome type and elevation to insure objective intercomparisons between urban zones within an urban settlement and between settlements. Stratification based on ISA allows the definition of hierarchically ordered urban zones that are consistent across urban settlements and scales. In addition to the surrounding ecological context, we find that the settlement size and shape as well as the development intensity distribution significantly influence the amplitude of summer daytime UHI. Within the Northeastern US temperate broadleaf mixed forest, UHI magnitude is positively related to the logarithm of the urban area size. Our study indicates that for similar urban area sizes, the development intensity distribution is one of the major drivers of UHI. In addition to urban area size and development intensity distribution, this analysis shows that both the shape of the urban area and the land cover composition in the surrounding rural area play an important role in modulating the UHI magnitude in different urban settlements. Our results indicate that remotely sensed urban area size and shape as well as the development intensity distribution influence UHI amplitude across regional scales.

  7. Dense Community of Hyperthermophilic Sulfur-Dependent Heterotrophs in a Geothermally Heated Shallow Submarine Biotope near Kodakara-Jima Island, Kagoshima, Japan

    PubMed Central

    Hoaki, T.; Nishijima, M.; Miyashita, H.; Maruyama, T.

    1995-01-01

    Microbial communities in marine hydrothermal sediments (0 to 30 cm deep) in an inlet of Kodakara-Jima Island, Kagoshima, Japan, were studied with reference to environmental factors, especially the presence of amino acids. The study area was shallow, and the sea floor was covered with sand through which hot volcanic gas bubbled and geothermally heated water seeped out. The total bacterial density increased with depth in the sediments in parallel with a rise in the ambient temperature (80(deg)C at the surface and 104(deg)C at a depth of 30 cm in the sediments). As estimated by most-probable-number studies, hyperthermophilic sulfur-dependent heterotrophs growing at 90(deg)C dominated the microbial community (3 x 10(sup7) cells (middot) g of sediment(sup-1) at a depth of 30 cm in the sediments), followed in abundance by hyperthermophilic sulfur-dependent facultative autotrophs (3.3 x 10(sup2) cells (middot) g of sediment(sup-1)). The cooler sandy or rocky floor surrounding the hot spots was covered with white bacterial mats which consisted of large Beggiatoa-like filaments. Both the total organic carbon content, most of which was particulate (75% in the surface sediments), and the amino acid concentration in void seawater in the sediments decreased with depth. Amino acids, both hydrolyzable and free, constituted approximately 23% of the dissolved organic carbon in the surface sediments. These results indicate that a lower amino acid concentration is probably due to consumption by dense populations of hyperthermophilic sulfur-dependent heterotrophs, which require amino acids for their growth and thus create a gradient of amino acid concentration in the sediments. The role of primary producers, which supply essential amino acids to sustain this microbial community, is also discussed. PMID:16535029

  8. Simulation of Urban Heat Island Mitigation Strategies in Atlanta, GA Using High-Resolution Land Use/Land Cover Data Set to Enhance Meteorological Modeling

    NASA Technical Reports Server (NTRS)

    Crosson, William L.; Dembek, Scott; Estes, Maurice G., Jr.; Limaye, Ashutosh S.; Lapenta, William; Quattrochi, Dale A.; Johnson, Hoyt; Khan, Maudood

    2006-01-01

    The specification of land use/land cover (LULC) and associated land surface parameters in meteorological models at all scales has a major influence on modeled surface energy fluxes and boundary layer states. In urban areas, accurate representation of the land surface may be even more important than in undeveloped regions due to the large heterogeneity within the urban area. Deficiencies in the characterization of the land surface related to the spatial or temporal resolution of the data, the number of LULC classes defined, the accuracy with which they are defined, or the degree of heterogeneity of the land surface properties within each class may degrade the performance of the models. In this study, an experiment was conducted to test a new high-resolution LULC data set for meteorological simulations for the Atlanta, Georgia metropolitan area using a mesoscale meteorological model and to evaluate the effects of urban heat island (UHI) mitigation strategies on modeled meteorology for 2030. Simulation results showed that use of the new LULC data set reduced a major deficiency of the land use data used previously, specifically the poor representation of urban and suburban land use. Performance of the meteorological model improved substantially, with the overall daytime cold bias reduced by over 30%. UHI mitigation strategies were projected to offset much of a predicted urban warming between 2000 and 2030. In fact, for the urban core, the cooling due to UHI mitigation strategies was slightly greater than the warming associated with urbanization over this period. For the larger metropolitan area, cooling only partially offset the projected warming trend.

  9. An assessment of urban heat island effect adopting urban parameterizations in COSMO-CLM simulations over big cities in Northern Italy

    NASA Astrophysics Data System (ADS)

    Montesarchio, Myriam; Rianna, Guido; Mercogliano, Paola; Castellari, Sergio; Schiano, Pasquale

    2015-04-01

    In Europe, about 80% of people live in urban areas, which most of them can be particularly vulnerable to climate impacts (e.g. high air temperatures along with heat waves, flooding due to intense precipitation events, water scarcity and droughts). In fact, the density of people and assets within relatively small geographic areas, such as an urban settlements, mean more risk exposure than in rural areas. Therefore, reliable numerical climate models are needed for elaborating climate risk assessment at urban scale. These models must take into account the effects of the complex three-dimensional structure of urban settlements, combined with the mixture of surface types with contrasting radiative, thermal and moisture characteristics. In this respect, previous studies (e.g. Trusilova et al., 2013) have already assessed the importance to consider urban properties in very high resolution regional climate modeling to better reproduce the features of urban climate, especially in terms of urban heat island effect. In this work, two different configurations of the regional climate model COSMO-CLM at the horizontal resolution of 0.02° (about 2.2km), one including urban parameterization scheme and another without including them, have been applied in order to perform two different climate simulations covering the entire northern Italy. In particular, the present study is focused on large urban settlements such as Milan and Turin. Due to high computational cost required to run very high resolution simulations, the results of the two simulations have been compared over a period of ten years, from 1980 to 1989. Preliminary results indicate that the modification of climate conditions, due to the presence of urban areas, is present mainly in the areas covered by big cities and surrounding them, or rather the presence of urban areas induces modification mainly in their local climate. Other evidences are that the simulation including urban parameterization scheme shows, in general

  10. Mechanisms of Air Pollution Transport in Urban Valleys as a Result of the Interplay Between the Temperature Inversion and the Urban Heat Island Effect

    NASA Astrophysics Data System (ADS)

    Rendón, A.; Wirth, V.; Salazar, J. F.; Palacio, C. A.; Brötz, B.

    2014-12-01

    Urban valleys can experience serious air pollution problems of concern for public health. The venting of pollution out of an urban valley is limited by the topography and can be further restricted by low-level temperature inversions and/or local circulations such as those induced by the Urban Heat Island (UHI) effect. The combined effects of a temperature inversion and a UHI on the dynamics of the atmospheric boundary layer and the associated mechanisms of air pollution transport in urban valleys were studied through idealized simulations performed with the EULAG model. Three different aspects were considered: the expansion of the urban area, variations in surface heating owing to topographic shading, and variations of the topography. The results show that different mechanisms of air pollution transport may arise in urban valleys as a result of the interplay between the temperature inversion, the slope flows, and the UHI. Three types of interrelated mechanisms of air pollution transport were identified. Type A describes the transport of pollutants by the slope winds, which can reduce pollution in the lower levels or reinforce the trapping of pollutants below the inversion layer depending on the UHI effect on weakening or reversing the upslope winds. Type B describes closed slope-flow circulations that are likely to occur below an inversion layer near the base of the sidewalls of valleys where an urban area is concentrated on the valley floor. These circulations can develop when upslope winds are detrained toward the center due to the inversion layer, or when the UHI forces downslope winds linked to ascending flows that are also restricted by the inversion layer. Pollutants can remain trapped within these circulation cells that have been termed smog traps. Type C describes a low-level UHI-induced circulation that tends to concentrate pollutants in the valley center and may cause the development of elevated polluted layers below the inversion layer. The persistence

  11. 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

  12. Spatio-temporal variability of the atmospheric boundary layer depth over the Paris agglomeration: An assessment of the impact of the urban heat island intensity

    NASA Astrophysics Data System (ADS)

    Pal, S.; Xueref-Remy, I.; Ammoura, L.; Chazette, P.; Gibert, F.; Royer, P.; Dieudonné, E.; Dupont, J.-C.; Haeffelin, M.; Lac, C.; Lopez, M.; Morille, Y.; Ravetta, F.

    2012-12-01

    Within the framework of a French nationally funded project (CO2-MEGAPARIS) for quantifying the CO2 emissions of the Paris area, a lidar-based experimental investigation of the variability of the atmospheric boundary layer (ABL) depths was performed over four days in March 2011 under clear sky conditions. The prevailing synoptic settings were mainly characterized by anti-cyclonic situations with low wind. The key aim of this paper is to assess the impact of the urban heat island intensity (UHII) on the spatio-temporal variability of the ABL depths over the Paris megacity. A network of fixed aerosol lidars was deployed inside the city and in the vicinity of sub-urban and rural areas. Additionally, the spatial heterogeneity of the nocturnal boundary layer (NBL) depths over greater Paris area is addressed, thanks in particular, to the deployment of a 355-nm elastic lidar in a mobile van to measure the aerosol distributions. Radiosonde-derived profiles (twice a day) of thermodynamic variables over the sub-urban site helped investigate the temperature inversion above ground and hence to compare the lidar-derived ABL depths. Comparing these two results, an excellent concordance was found with a correlation coefficient of 0.994. Five important factors closely related to the ABL circulation, namely, spatio-temporal variability of the ABL depths, growth rate of the ABL depths, entrainment zone thickness, and near-surface temperature fields including resultant UHII were considered to infer the urban-rural contrasts. The mean NBL depth over the urban area was on average 63 m (45%) higher than its adjacent sub-urban area which was, on occasion, as much as (74 m) 58% higher mainly due to the effect of UHII. Daytime well-mixed convective boundary layer and associated strong turbulent mixing near its top over the urban area showed higher entrainment zone thickness (326 m) than over sub-urban (234 m) and rural (200 m) areas. Temperature growth rates during sunrise increased up to

  13. Analysis of seasonal variation in urban heat island effect for West Mediterranean Region of Turkey using Landsat 8 OLI/TIRS data

    NASA Astrophysics Data System (ADS)

    Aslan, Nagihan; KOC-SAN, Dilek

    2016-07-01

    Technological developments are accelerating day by day in 21st century which has brought social and economic developments. Besides, the word population is increasing rapidly and the majority of population lives in city center. Large and crowded cities, industrial areas and shopping centers are being built for providing human needs and wishes. For these purposes, natural resources are destroyed and urban climate is affected. The temperatures of urban areas can be warmer than the rural areas and differences in temperature between urban and surrounding rural areas were defined as Urban Heat Island (UHI). The objectives of this study are (i) to calculate Land Surface Temperatures (LST) for urban and vegetation areas in the selected cities, (ii) to determine the UHI effects and its change between seasons, (iii) to examine the relationship between city size and UHI effect magnitude. In this study, Landsat 8 OLI/TIRS imageries for winter (23 December 2013), summer (17 June 2014) and autumn (7 October 2014) seasons were used. The Antalya, Burdur and Isparta provinces that are placed in West Mediterranean Region of Turkey were selected as study areas. These three provinces have different characteristics. Antalya is the fifth biggest city of Turkey and its population growth is quite high. In addition, the summer population of this city increases severely, because of its tourism potential. On the other hand, Isparta and Burdur are relatively small cities when compared to Antalya with respect to population and urban area. In this study, firstly, the brightness temperatures and LST values are calculated from Landsat 8 thermal images. Secondly, urban areas are identified by an approach that combines emissivity image, Defense Meteorological Satellite Program - Operational Linescan System (DMSP/OLS) nighttime lights data and ASTER Global Digital Elevation Model (GDEM). In addition, the vegetation areas are defined by using emissivity image. Finally, the UHI effect is determined

  14. 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

  15. Island Hopping

    ERIC Educational Resources Information Center

    Bennett, Gayle

    2009-01-01

    At some institutions, it may feel as though faculty live on one island and advancement staff on another. The islands form part of an archipelago, and they exchange ambassadors and send emissaries occasionally, but interactions are limited. It may even seem as though the two groups speak different languages, deal in different currencies, and abide…

  16. Siberian Islands

    Atmospheric Science Data Center

    2013-04-16

    ... Distinguishing Clouds from Ice over the East Siberian Sea, Russia     View Larger Image ... clouds from snow and ice. The central portion of Russia's East Siberian Sea, including one of the New Siberian Islands, Novaya ...

  17. Island of Okinawa, Japan

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The island of Okinawa, (26.5N, 128.0E) largest of the Ryukyu Islands, Japan. The Ryukyu island group lies south of the main home islands of Japan in an arc towards the Chinese island Republic of Taiwan. As is typical throughout the Japanese home islands, intense urban development can be observed all over the island in this near vertical view.

  18. Devon Island

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mars Researchers Rendezvous on Remote Arctic Island   ... equipment and technology that may be deployed during a human mission to Mars. One of the many objectives of the project scientists is to ... Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's ...

  19. Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Multiangle Imaging Spectro-Radiometer (MISR) image of five Hawaiian Islands was acquired by the instrument's vertical- viewing (nadir) camera on June 3, 2000. The image shows the islands of Oahu, Molokai, Lanai, Maui, and Kahoolawe. The prevailing Pacific trade winds bring higher levels of rainfall to the eastern slopes of the islands, leading to a greater abundance of vegetation on the windward coasts. The small change in observation angle across the nadir camera's field-of- view causes the right-hand portion of the image to be more affected by Sun glint, making the ocean surface appear brighter. Oahu is the westernmost of the islands seen in this image. Waikiki Beach and the city of Honolulu are located on the southern shore, to the west of Diamond Head caldera. MISR is one of several Earth-observing instruments on the Terra satellite, launched in December 1999. The Terra spacecraft, the flagship of a fleet of satellites dedicated to understanding our global environment, is part of NASA's Earth Sciences Enterprise, a long-term research program dedicated to understanding how human-induced and natural changes affect our world. Image courtesy NASA/GSFC/JPL, MISR Team

  20. Anatahan Island

    Atmospheric Science Data Center

    2013-04-19

    ... Snorkelers around this island are likely to encounter the fish Achilles Tang and the Moorish Idol (Acanthurus achilles and Zanclus ... Terra circles the Earth in the same orbit as Landsat 7, flying at an altitude of about 700 kilometers above the Earth's surface. ...

  1. A comparison of urban heat islands mapped using skin temperature, air temperature, and apparent temperature (Humidex), for the greater Vancouver area.

    PubMed

    Ho, Hung Chak; Knudby, Anders; Xu, Yongming; Hodul, Matus; Aminipouri, Mehdi

    2016-02-15

    Apparent temperature is more closely related to mortality during extreme heat events than other temperature variables, yet spatial epidemiology studies typically use skin temperature (also known as land surface temperature) to quantify heat exposure because it is relatively easy to map from satellite data. An empirical approach to map apparent temperature at the neighborhood scale, which relies on publicly available weather station observations and spatial data layers combined in a random forest regression model, was demonstrated for greater Vancouver, Canada. Model errors were acceptable (cross-validated RMSE=2.04 °C) and the resulting map of apparent temperature, calibrated for a typical hot summer day, corresponded well with past temperature research in the area. A comparison with field measurements as well as similar maps of skin temperature and air temperature revealed that skin temperature was poorly correlated with both air temperature (R(2)=0.38) and apparent temperature (R(2)=0.39). While the latter two were more similar (R(2)=0.87), apparent temperature was predicted to exceed air temperature by more than 5 °C in several urban areas as well as around the confluence of the Pitt and Fraser rivers. We conclude that skin temperature is not a suitable proxy for human heat exposure, and that spatial epidemiology studies could benefit from mapping apparent temperature, using an approach similar to the one reported here, to better quantify differences in heat exposure that exist across an urban landscape. PMID:26706765

  2. Streamlined Island

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-514, 15 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture shows a streamlined island in Marte Vallis, a large outflow channel system that crosses the 180oW meridian between the Elysium and Amazonis regions of Mars. The flow patterns on the floor of Marte Vallis might be the remains of lava flows or mud flows. Marte is the Spanish word for Mars. Most of the largest valleys on the red planet are named for 'Mars' in various languages. This island is located near 21.8oN, 175.3oW. The picture covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the lower left.

  3. Impact of remotely sensed albedo and vegetation fraction on simulation of urban climate in WRF-urban canopy model: A case study of the urban heat island in Los Angeles

    NASA Astrophysics Data System (ADS)

    Vahmani, P.; Ban-Weiss, G. A.

    2016-02-01

    Modeling the climate of urban areas is of interest for studying urban heat islands (UHIs). Reliable assessment of the primary causes of UHIs and the efficacy of various heat mitigation strategies requires accurate prediction of urban temperatures and realistic representation of land surface physical characteristics in models. In this study, we expand the capabilities of the Weather Research and Forecasting (WRF) model by implementing high-resolution, real-time satellite observations of green vegetation fraction (GVF) and albedo. Satellite-based GVF and albedo replace constant values that are assumed for urban pixels in the default version of WRF. Simulations of urban meteorology in Los Angeles using the improved model show marked improvements relative to the default model. The largest improvements are for nocturnal air temperatures, with a reduction in root-mean-square deviation between simulations and observations from 3.8 to 1.9°C. Utilizing the improved model, we quantify relationships between surface and 2 m air temperatures versus urban fraction, GVF, albedo, distance from the ocean, and elevation. Distance from the ocean is found to be the main contributor to variations in temperatures around Los Angeles. After conditionally sampling pixels to minimize the influence of distance from the ocean and elevation, we find that variations in GVF and urban fraction are responsible for up to 58 and 27% of the variance in temperatures. The satellite-supported meteorological modeling framework reported here can be used for studying UHIs in other cities and can serve as a foundation for testing the efficacy of various heat mitigation strategies.

  4. Classifying Pacific islands

    NASA Astrophysics Data System (ADS)

    Nunn, Patrick D.; Kumar, Lalit; Eliot, Ian; McLean, Roger F.

    2016-12-01

    An earth-science-based classification of islands within the Pacific Basin resulted from the preparation of a database describing the location, area, and type of 1779 islands, where island type is determined as a function of the prevailing lithology and maximum elevation of each island, with an island defined as a discrete landmass composed of a contiguous land area ≥1 ha (0.01 km2) above mean high-water level. Reefs lacking islands and short-lived (<20 years) transient islands are not included. The principal aim of the classification is to assess the spatial diversity of the geologic and geomorphic attributes of Pacific islands. It is intended to be valid at a regional scale and based on two attributes: five types of lithology (volcanic, limestone, composite, continental, surficial) and a distinction between high and low islands. These attributes yielded eight island types: volcanic high and low islands; limestone high and low islands; composite high and low islands; reef (including all unconsolidated) islands; and continental islands. Most common are reef islands (36 %) and volcanic high islands (31 %), whereas the least common are composite low islands (1 %). Continental islands, 18 of the 1779 islands examined, are not included in maps showing the distribution of island attributes and types. Rationale for the spatial distributions of the various island attributes is drawn from the available literature and canvassed in the text. With exception of the few continental islands, the distribution of island types is broadly interpretable from the proximity of island-forming processes. It is anticipated the classification will become the basis for more focused investigation of spatial variability of the climate and ocean setting as well as the biological attributes of Pacific islands. It may also be used in spatial assessments of second-order phenomena associated with the islands, such as their vulnerability to various disasters, coastal erosion, or ocean pollution as

  5. Solomon Islands.

    PubMed

    1988-06-01

    The Solomon Islands, which form an archipelago in the Southwest Pacific about 1900 km northeast of Australia, are described. Included are brief descriptions about such points as geography, people, history, type of government, political conditions, economy, and foreign relations. In 1987 the population was 301,180 (49% under age 14); the annual growth rate was 3.67%. The infant mortality rate is 46/1000; the life expectancy, 54 years. Health conditions in the Solomons generally are adequate, and the country does not suffer from serious endemic diseases other than malaria, in both the vivax and falsiparum strains. Hospitals and pharmacies are limited to population centers and missions. PMID:12177986

  6. The electron heating rate and ion chemistry in the thermosphere above Wallops Island during the solar eclipse of 7 March 1970.

    NASA Technical Reports Server (NTRS)

    Brace, L. H.; Mayr, H. G.; Pharo, M. W., III; Scott, L. R.; Spencer, N. W.; Carignan, G. R.

    1972-01-01

    Measurement of the N2 concentration and temperature, the ion composition and concentrations, and the electron temperature up to 290 km about 30 and 5 min before totality during the Mar. 7, 1970, eclipse. The rockets traveled similar trajectories, thus permitting the purely temporal changes between flights to be resolved. The neutral temperature and N2 concentration changed little, but the electron temperature decreased by as much as 20% in the lower F region. The ion concentration decreased by about 30% in the F region and about 50% in the E region, with little change in relative ion composition. The electron cooling rates decreased by a factor of 6 in the lower F region, approximately in proportion to the change in the visible solar disk. A smaller than expected decrease in the cooling rate below 150 km between the two flights indicates a hardening of the solar spectrum and suggests a significant heat contribution from the solar corona near totality. The ion composition measurements were consistent with solutions of the ion continuity equations. A proper fit required a factor-of-three enhancement of the flux below 200 A, an amount also consistent with the electron heat balance analysis. Reactions involving the minor ions N(+) and N2(+) were found to be important for the ion chemistry of the major ions O2(+) and NO(+), especially at the time of eclipse.-

  7. Estimating seasonal changes of land cover, surface wetness and latent heat flux of wet polygonal tundra (Samoylov Island, Lena-Delta, Siberia) with high-resolution aerial and hyperspectral CHRIS Proba satellite imagery

    NASA Astrophysics Data System (ADS)

    Muster, S.; Langer, M.; Boike, J.

    2009-12-01

    Vegetation cover, land cover and surface wetness are few of the many factors exerting control on the partitioning of energy to latent, sensible and ground heat flux. Spatial estimates of these factors can be inferred from remote sensing data. The fractionated polygonal tundra landscape of Samoylov Island of wet and dry surfaces induces strong spatial variations of resistance to evapotranspiration. The development of low-centered ice-wedge polygons results in a prominent microrelief that is the most important factor for small-scale differences in vegetation type and near surface soil moisture. Depressed polygon centers alternate with elevated polygon rims with elevation differences of up to 0.5 m over a few meters distance. In the depressed polygon centers, drainage is strongly impeded due to the underlying permafrost resulting in water-saturated soils or small ponds. A process-based understanding of the surface energy balance, however, needs to consider both the temporal and the spatial variations of the surface. In the course of the summer season, the surface wetness changes significantly since the water table falls about 5 cm below the surface. This change in surface wetness is likely to be associated with changing evapotranspiration rates. We consider the effect of seasonal changes in land cover, vegetation cover and surface wetness on latent heat flux by investigating a time-series of high-resolution aerial and hyperspectral satellite imagery and comparing them to ground-based measurements of near-surface soil moisture and latent heat flux. Two sets of aerial images from August 15 and September 11, 2008 in the VNIR provide detailed information of the polygonal landscape with a resolution of 0.3m. CHRIS Proba imagery provides hyperspectral data with 18 spectral bands in the VNIR range (400 - 1050 nm) and a resolution of 17 m. Acquisition dates are June 21, July 23 and September 10, 2008. Daily point-based measurements of near-surface soil moisture and latent

  8. Electron energization during magnetic island coalescence

    SciTech Connect

    Le, A.; Egedal, J.; Karimabadi, H.; Roytershteyn, V.; Daughton, W.

    2012-07-15

    Radio emission from colliding coronal mass ejection flux ropes in the interplanetary medium suggested the local generation of superthermal electrons. Inspired by those observations, a fully kinetic particle-in-cell simulation of magnetic island coalescence models the magnetic reconnection between islands as a source of energetic electrons. When the islands merge, stored magnetic energy is converted into electron kinetic energy. The simulation demonstrates that a mechanism for electron energization originally applied to open field line reconnection geometries also operates near the reconnection site of merging magnetic islands. The electron heating is highly anisotropic, and it results mainly from an electric field surrounding the reconnection site that accelerates electrons parallel to the magnetic field. A detailed theory predicts the maximum electron energies and how they depend on the plasma parameters. In addition, the global motion of the magnetic islands launches low-frequency waves in the surrounding plasma, which induce large-amplitude, anisotropic fluctuations in the electron temperature.

  9. 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…

  10. A Case Study of Urbanization Impact on Summer Precipitation in the Greater Beijing Metropolitan Area. Urban Heat Island Versus Aerosol Effects

    SciTech Connect

    Zhong, Shi; Qian, Yun; Zhao, Chun; Leung, Lai-Yung R.; Yang, Xiuqun

    2015-10-23

    Convection-resolving ensemble simulations using the WRF-Chem model coupled with a single-layer Urban Canopy Model (UCM) are conducted to investigate the individual and combined impacts of land use and anthropogenic pollutant emissions from urbanization on a heavy rainfall event in the Greater Beijing Metropolitan Area (GBMA) in China. The simulation with the urbanization effect included generally captures the spatial pattern and temporal variation of the rainfall event. An improvement of precipitation is found in the experiment including aerosol effect on both clouds and radiation. The expanded urban land cover and increased aerosols have an opposite effect on precipitation processes, with the latter playing a more dominant role, leading to suppressed convection and rainfall over the upstream (northwest) area, and enhanced convection and more precipitation in the downstream (southeast) region of the GBMA. In addition, the influence of aerosol indirect effect is found to overwhelm that of direct effect on precipitation in this rainfall event. Increased aerosols induce more cloud droplets with smaller size, which favors evaporative cooling and reduce updrafts and suppress convection over the upstream (northwest) region in the early stage of the rainfall event. As the rainfall system propagates southeastward, more latent heat is released due to the freezing of larger number of smaller cloud drops that are lofted above the freezing level, which is responsible for the increased updraft strength and convective invigoration over the downstream (southeast) area.

  11. A case study of urbanization impact on summer precipitation in the Greater Beijing Metropolitan Area: Urban heat island versus aerosol effects

    NASA Astrophysics Data System (ADS)

    Zhong, Shi; Qian, Yun; Zhao, Chun; Leung, Ruby; Yang, Xiu-Qun

    2015-10-01

    Convection-resolving ensemble simulations using the WRF-Chem model coupled with a single-layer Urban Canopy Model are conducted to investigate the individual and combined impacts of land use and anthropogenic pollutant emissions from urbanization on a heavy rainfall event in the Greater Beijing Metropolitan Area (GBMA) in China. The simulation with the urbanization effect included generally captures the spatial pattern and temporal variation of the rainfall event. An improvement of precipitation is found in the experiment including aerosol effect on both clouds and radiation. The expanded urban land cover and increased aerosols have an opposite effect on precipitation processes, with the latter playing a more dominant role, leading to suppressed convection and rainfall over the upstream (northwest) area, and enhanced convection and more precipitation in the downstream (southeast) region of the GBMA. In addition, the influence of aerosol indirect effect is found to overwhelm that of direct effect on precipitation in this rainfall event. Increased aerosols lead to more cloud droplets with smaller size, which favor evaporative cooling and reduce updrafts and suppress convection over the upstream (northwest) region in the early stage of the rainfall event. As the rainfall system propagates southeastward, more latent heat is released due to the freezing of larger number of smaller cloud drops that are lofted above the freezing level, which is responsible for the increased updraft strength and convective invigoration over the downstream (southeast) area.

  12. 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

  13. Simulation and analytic analysis of radiation driven islands at the density limit

    NASA Astrophysics Data System (ADS)

    Brennan, D. P.; Liu, C.; Gates, D. A.; Delgado-Aparicio, L.; White, R.

    2014-10-01

    The effect of radiative cooling on the onset and evolution of magnetic islands is investigated with nonlinear resistive MHD simulations and reduced theoretical analysis. The configuration is a cylindrical tokamak with a m/n = 2/1 island and includes three dimensional resistivity and anisotropic heat conduction in the simulations. The radiative cooling is implemented as a temperature perturbation inside the island, which modifies the island structure and drives the island more unstable. Analytic reduction of the saturated island size and structure supports the simulation results. The results offer intuitive understanding of experimental observations of radiation driven magnetic islands, which may explain density limit disruptions.

  14. Development, Testing, and Application of a Coupled Hydrodynamic Surface-Water/Groundwater Model (FTLOADDS) with Heat and Salinity Transport in the Ten Thousand Islands/Picayune Strand Restoration Project Area, Florida

    USGS Publications Warehouse

    Swain, Eric D.; Decker, Jeremy D.

    2009-01-01

    A numerical model application was developed for the coastal area inland of the Ten Thousand Islands (TTI) in southwestern Florida using the Flow and Transport in a Linked Overland/Aquifer Density-Dependent System (FTLOADDS) model. This model couples a two-dimensional dynamic surface-water model with a three-dimensional groundwater model, and has been applied to several locations in southern Florida. The model application solves equations for salt transport in groundwater and surface water, and also simulates surface-water temperature using a newly enhanced heat transport algorithm. One of the purposes of the TTI application is to simulate hydrologic factors that relate to habitat suitability for the West Indian Manatee. Both salinity and temperature have been shown to be important factors for manatee survival. The inland area of the TTI domain is the location of the Picayune Strand Restoration Project, which is designed to restore predevelopment hydrology through the filling and plugging of canals, construction of spreader channels, and the construction of levees and pump stations. The effects of these changes are simulated to determine their effects on manatee habitat. The TTI application utilizes a large amount of input data for both surface-water and groundwater flow simulations. These data include topography, frictional resistance, atmospheric data including rainfall and air temperature, aquifer properties, and boundary conditions for tidal levels, inflows, groundwater heads, and salinities. Calibration was achieved by adjusting the parameters having the largest uncertainty: surface-water inflows, the surface-water transport dispersion coefficient, and evapotranspiration. A sensitivity analysis did not indicate that further parameter changes would yield an overall improvement in simulation results. The agreement between field data from GPS-tracked manatees and TTI application results demonstrates that the model can predict the salinity and temperature

  15. Hawaiian Island Archipelago

    NASA Technical Reports Server (NTRS)

    1985-01-01

    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.

  16. Barrier Island Hazard Mapping.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.; Neal, William J.

    1980-01-01

    Describes efforts to evaluate and map the susceptibility of barrier islands to damage from storms, erosion, rising sea levels and other natural phenomena. Presented are criteria for assessing the safety and hazard potential of island developments. (WB)

  17. Urban Surfaces and Heat Island Mitigation Potentials

    SciTech Connect

    Akbari, Hashem; Akbari, Hashem; Shea Rose, Leanna

    2007-06-14

    Data on materials and surface types that comprise a city, i.e. urban fabric, are needed in order to estimate the effects of light-colored surfaces (roofs and pavements) and urban vegetation (trees, grass, shrubs) on the meteorology and air quality of a city. We discuss the results of a semi-automatic statistical approach used to develop data on surface-type distribution and urban-fabric makeup using aerial color orthophotography, for four metropolitan areas of Chicago, IL, Houston, TX, Sacramento, CA, and Salt Lake City, UT. The digital high resolution (0.3 to 0.5-m) aerial photographs for each of these metropolitan areas covers representative urban areas ranging from 30 km{sup 2} to 52 km{sup 2}. Major land-use types examined included: commercial, residential, industrial, educational, and transportation. On average, for the metropolitan areas studied, vegetation covers about 29-41% of the area, roofs 19-25%, and paved surfaces 29-39%. For the most part, trees shade streets, parking lots, grass, and sidewalks. At ground level, i.e., view from below the tree canopies, vegetation covers about 20-37% of the area, roofs 20-25%, and paved surfaces 29-36%.

  18. Urban Heat Island ın Ankara

    NASA Astrophysics Data System (ADS)

    Yılmaz, Erkan

    2016-04-01

    In this study, the seasonal variation of the surface temperature of Ankara urban area and its enviroment have been analyzed by using Landsat 7 image. The Landsat 7 images of each month from 2007 to 2011 have been used to analyze the annually changes of the surface temperature. The land cover of the research area was defined with supervised classification method on the basis of the satellite image belonging to 2008 July. After determining the surface temperatures from 6-1 bands of satellite images, the monthly mean surface temperatures were calculated for land cover classification for the period between 2007 and 2011. According to the results obtained, the surface temperatures are high in summer and low in winter from the airtemperatures. all satellite images were taken at 10:00 am, it is found that urban areas are cooler than rural areas at 10:00 am. Regarding the land cover classification, the water surfaces are the coolest surfaces during the whole year.The warmest areas are the grasslands and dry farming areas. While the parks are warmer than the urban areas during the winter, during the summer they are cooler than artificial land covers. The urban areas with higher building density are the cooler surfaces after water bodies.

  19. 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.

  20. Arctic ice islands

    SciTech Connect

    Sackinger, W.M.; Jeffries, M.O.; Lu, M.C.; Li, F.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) 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.

  1. 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.

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

    PubMed Central

    Ida, K.; Kobayashi, T.; Evans, T. E.; Inagaki, S.; Austin, M. E.; Shafer, M. W.; Ohdachi, S.; Suzuki, Y.; Itoh, S.-I.; Itoh, K.

    2015-01-01

    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 a repeating cycle of island states. These two states are interpreted as a bifurcation of magnetic island with high and low heat pulse accessibility. This report describes the discovery of a bifurcation in the coupled dynamics between the transport and topology of magnetic islands in tokamak plasmas. PMID:26530273

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

    DOE PAGESBeta

    Ida, K.; Kobayashi, T.; Evans, T. E.; Inagaki, S.; Austin, M. E.; Shafer, M. W.; Ohdachi, S.; Suzuki, Y.; Itoh, S. -I.; Itoh, K.

    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

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

    SciTech Connect

    Ida, K.; Kobayashi, T.; Evans, T. E.; Inagaki, S.; Austin, M. E.; Shafer, M. W.; Ohdachi, S.; Suzuki, Y.; Itoh, S. -I.; Itoh, K.

    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 a 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.

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

    PubMed

    Ida, K; Kobayashi, T; Evans, T E; Inagaki, S; Austin, M E; Shafer, M W; Ohdachi, S; Suzuki, Y; Itoh, S-I; Itoh, K

    2015-01-01

    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 a repeating cycle of island states. These two states are interpreted as a bifurcation of magnetic island with high and low heat pulse accessibility. This report describes the discovery of a bifurcation in the coupled dynamics between the transport and topology of magnetic islands in tokamak plasmas. PMID:26530273

  6. Summer Heat Waves - Extreme Years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The performance of four heat stress indices was compared for response to known events. A 12-yr period of weather data was analyzed for occurrence of heat wave events at each of three locations--Grand Island and Concord, NE and Rockport, MO. Numerous events were detected at each location. The Temp...

  7. Energy Transition Initiative, Island Energy Snapshot - Turks & Caicos (Fact Sheet)

    SciTech Connect

    Not Available

    2015-02-01

    This profile presents a snapshot of the electricity generation and reduction technologies, including solar hot water heating, available to Turks and Caicos - a British overseas territory consisting of two groups of islands located southeast of the Bahamas. Heating and transportation fuels are not addressed.

  8. Energy Transition Initiative: Island Energy Snapshot - St. Lucia (Fact Sheet)

    SciTech Connect

    Not Available

    2015-02-01

    This profile provides a snapshot of the electricity generation or reduction technologies, including solar hot water heating, available to Saint Lucia, one of six Caribbean countries that make up the Windward Islands - the southern arc of the Lesser Antilles chain - at the eastern end of the Caribbean Sea. Heating and transportation fuels are not addressed.

  9. Energy Transition Initiative, Island Energy Snapshot - Bahamas (Fact Sheet)

    SciTech Connect

    Not Available

    2015-02-01

    This profile provides a snapshot of the electricity generation or reduction technologies, including solar hot water heating, available to the Commonwealth of the Bahamas - a country consisting of more than 700 islands, cays, and islets - of which only 30 are actually inhabited. Heating and transportation fuels are not addressed.

  10. 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

  11. Channel Islands rare plants

    USGS Publications Warehouse

    McEachern, K.

    1999-01-01

    Database contains information on 65 rare plant taxa on six islands from archive searches and field surveys, including population location, size and extent 1920-1999, population and habitat conditions, census data, phenological information, associated species. USGS-BRD, Channel Islands Field Station, Ventura, CA.

  12. Pine Island Bay

    Atmospheric Science Data Center

    2013-04-16

    ... article title:  Birth of a Large Iceberg in Pine Island Bay, Antarctica     View ... iceberg (42 kilometers x 17 kilometers) broke off Pine Island Glacier, West Antarctica (75°S latitude, 102°W longitude) sometime ...

  13. Marine and Island Ecology.

    ERIC Educational Resources Information Center

    Stephens, Lawrence J.; And Others

    1988-01-01

    Describes an ecology course which provides students with an opportunity to observe aquatic and terrestrial life in the Bahamas. States that students learn scientific methodology by measuring physical and chemical aspects of the island habitats. Provides information on the island, course description and objectives, transportation, facilities, and…

  14. Basaltic island sand provenance

    SciTech Connect

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  15. Back to Treasure Island

    ERIC Educational Resources Information Center

    Shriki, Atara

    2011-01-01

    In this article, the author presents the Treasure Island problem and some inquiry activities derived from the problem. Trying to find where pirates buried a treasure leads to a surprising answer, multiple solutions, and a discussion of problem solving. The Treasure Island problem is an example of an inquiry activity that can be implemented in…

  16. Island Natural Science School.

    ERIC Educational Resources Information Center

    Toronto Board of Education (Ontario).

    Prepared for students in grade six attending the Island Natural Science School, Toronto, Ontario, Canada, this booklet offers information and suggests activities in the areas of ecology, conservation, natural resources, and outdoor recreation. Introductory material describes island lore, its formation and significant features, followed by units of…

  17. Transport properties of interacting magnetic islands in tokamak plasmas

    SciTech Connect

    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 coefficient 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.

  18. Heat pipe array heat exchanger

    DOEpatents

    Reimann, Robert C.

    1987-08-25

    A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

  19. 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

  20. Cognitive Constraints and Island Effects

    ERIC Educational Resources Information Center

    Hofmeister, Philip; Sag, Ivan A.

    2010-01-01

    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…

  1. Organic maturation and thermal history of Queen Charlotte Islands

    SciTech Connect

    Bustin, R.M.; Vellutini, D. )

    1989-09-01

    The level of organic maturation and thermal history of Mesozoic and Tertiary strata of the Queen Charlotte Islands have been determined with vitrinite reflectance (R{sub 0}), numerical modeling (modified Arrhenius model), and Rock-Eval Pyrolysis. The level of organic maturation increases from northern Graham to southern Moresby Island, which primarily reflects high heat flow resulting from Middle to Late Jurassic and Eocene to Oligocene plutonism and cospatial dyking. Upper Triassic-Lower Jurassic and most Cretaceous strata are overmature on Moresby Island, with R{sub 0} values ranging from 2.40 to 5.80%. Jurassic, Cretaceous, and Tertiary strata are immature to overmature on Graham Island, with R{sub 0} values ranging from 0.15% (Skonun Formation) to 2.4% (Haida Formation). Locally, R{sub 0} values up to 3.2% on Graham Island and 8.3% on Moresby Island occur adjacent to igneous intrusives. Modeling measured levels of organic maturation suggests that elevated geothermal gradients ranging from 83{degree} to 150{degree}C/km existed during Yakoun (183-178 Ma) and Masset (35-10 Ma) volcanism on Graham Island. Numerical modeling further suggests that Triassic strata on Fredrick Island and Kennecott Point (Graham Island) entered the oil window during the early Miocene, whereas Jurassic strata at Rennell Junction and Cumshewa Inlet entered the oil window during the Bajocian. Cretaceous strata on north and south Graham Island entered the oil window during the early Miocene and are currently within the oil window. The Tertiary Skonun Formation is generally immature except for strata on west and northeast Graham Island, which entered the oil window in the late Miocene.

  2. Drift-tearing magnetic islands in tokamak plasmas

    SciTech Connect

    Fitzpatrick, R.; Waelbroeck, F. L.

    2008-01-15

    A systematic fluid theory of nonlinear magnetic island dynamics in conventional low-{beta}, large aspect-ratio, circular cross-section tokamak plasmas is developed using an extended magnetohydrodynamics model that incorporates diamagnetic flows, ion gyroviscosity, fast parallel electron heat transport, the ion sound wave, the drift wave, and average magnetic field-line curvature. The model excludes the compressible Alfven wave, geodesic field-line curvature, neoclassical effects, and ion Landau damping. A collisional closure is used for plasma dynamics parallel to the magnetic field. Two distinct branches of island solutions are found, namely the 'sonic' and 'hypersonic' branches. Both branches are investigated analytically, using suitable ordering schemes, and in each case the problem is reduced to a relatively simple set of nonlinear differential equations that can be solved numerically via iteration. The solution determines the island phase velocity, relative to the plasma, and the effect of local currents on the island stability. Sonic islands are relatively wide, flatten both the temperature and density profiles, and tend to propagate close to the local ion fluid velocity. Hypersonic islands, on the other hand, are relatively narrow, only flatten the temperature profile, radiate drift-acoustic waves, and tend to propagate close to the local electron fluid velocity. The hypersonic solution branch ceases to exist above a critical island width. Under normal circumstances, both types of island are stabilized by local ion polarization currents.

  3. 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.

  4. Lost island found

    NASA Astrophysics Data System (ADS)

    An abandoned ll-by-5-km kidney-shaped chunk of freshwater ice, used as a research station for 25 years, was rediscovered after the National Oceanic and Atmospheric Administration (NOAA) lost track of the island for 6 months. The recent find may foreshadow another loss, however: The island is drifting through the Greenland Sea and into the North Atlantic where it should melt within several months and d u m p its cargo of oil drums, equipment, and a wrecked plane into the ocean.Known as Fletcher's Ice Island—after Joseph O. Fletcher, a member of the first team of researchers to inhabit the island and a recently retired NOAA climate researcher—the ice chunk has already melted to a third of its original 49 m thickness. A pilot flying over the area to measure annual pollution buildup in the Arctic located the drifting island 242 km from the North Pole near the International Date Line.

  5. The Island Approach.

    ERIC Educational Resources Information Center

    Schroder, Peter C.

    1994-01-01

    Proposes the study of islands to develop a method of integrating sustainable development with sound resource management that can be extrapolated to more complex, highly populated continental coastal areas. (MDH)

  6. Island Watershed Activity.

    ERIC Educational Resources Information Center

    Benson, Rod

    2003-01-01

    Describes a 90-minute "Island Watershed" activity to help earth science students understand the concept of the water cycle. Introduces a surface waters unit appropriate for students in grades 7-10. Includes watershed project guidelines. (Author/KHR)

  7. Small islands adrift

    NASA Astrophysics Data System (ADS)

    Petherick, Anna

    2015-07-01

    With the charismatic former president of the Maldives, Mohamed Nasheed, behind bars on a widely derided terrorism charge, Anna Petherick asks whether small island states can really make themselves heard in Paris.

  8. Melville Island, Australia

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Melville Island, just off the coast of Darwin, Northern Territory, Australia (11.5S, 131.0E) is a sparsely inhabited tropical island with heavy woodland concentrations. The widespread and prominant smoke plumes were most likely set to renew pasture under open canopy woodland. Soil erosion is almost non- existant as can be seen by the clear and clean river flow. The offshore sediments are coastal current borne deposits from King Sound to the west.

  9. Quantification of the Impact of Nauru Island on ARM Measurements

    SciTech Connect

    Long, Charles N.; McFarlane, Sally A.

    2012-03-23

    Nauru Island at times generates low clouds that impact low-level cloud statistics and downwelling shortwave radiation measurements made at the Atmospheric Radiation Measurement Program (ARM) site. This study uses five years of Nauru data to quantify the island impact on the site measurements. The results indicate that the solar-heating-produced Nauru island effect occurs about 11% of the time during daylight hours. The island effect increases the 500-1000-m cloud base occurrence by 15%-20% when clouds occur, but because the island effect only occurs 11% of the time the overall increase in daylight low-cloud statistics is 2%, or 1% for 24-h statistics. In a similar way, the island effect produces a reduction of about 17% in the downwelling shortwave (SW) radiation across the daylight hours during the 11% of the time it occurs, an overall 2% daylight (or 1% for 24 h) average reduction. The island effect produces frequent positive downwelling SW cloud effects, in particular during the morning, which tend to somewhat mitigate the overall decrease in downwelling SW radiation that is due to clouds. This produces 17 W m22 less daylight average SW cloud effect relative to non-island-effect times, in particular for the convectively suppressed regime that typifies island-effect-producing conditions. For long-term overall statistical studies such as model and satellite comparisons, the2%daylight (or1%per 24 h) average increase in low-level cloud occurrence and decrease in downwelling SW are not of large concern as long as researchers are aware of them. For shorter-term studies, however, or those that separate data by conditions such as convectively active/suppressed regimes, the Nauru island effect can have significant impacts.

  10. 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.

  11. 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.

  12. 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

  13. 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). PMID:27122558

  14. Heat Waves

    MedlinePlus

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and spasms due ... that the body is having trouble with the heat. If a heat wave is predicted or happening… - ...

  15. Heat emergencies

    MedlinePlus

    Heat emergencies or illnesses are caused by exposure to extreme heat and sun. Heat illnesses can be prevented by ... to regulate the temperature, and make a heat emergency more likely: Drinking alcohol before or during exposure ...

  16. Archaeoastronomy of Easter Island

    NASA Astrophysics Data System (ADS)

    Edwards, Edmundo

    Astronomer priests or "skywatchers" on Easter Island lived in stone towers that were used as observatories and built stone markers in the periphery that indicated the heliacal rising of certain stars that served to indicate the arrival of marine birds, turtles, the offshore fishing season, and times for planting and harvest. Petroglyphs related to such sites depict outriggers, fishhooks, pelagic fish, and turtles and supposedly represented a star map. In this chapter, we analyze a set of such skywatchers dwellings, and stone markers located upon the North coast of Easter Island that have astronomic orientations, its related petroglyphs, and the relations between these directions with their yearly activities and their ritual calendar.

  17. Sakhalin Island terrain intelligence

    USGS Publications Warehouse

    U.S. Geological Survey Military Geology Branch

    1943-01-01

    This folio of maps and explanatory tables outlines the principal terrain features of Sakhalin Island. Each map and table is devoted to a specialized set of problems; together they cover the subjects of terrain appreciation, climate, rivers, water supply, construction materials, suitability for roads, suitability for airfields, fuels and other mineral resources, and geology. In most cases, the map of the island is divided into two parts: N. of latitude 50° N., Russian Sakhalin, and south of latitude 50° N., Japanese Sakhalin or Karafuto. These maps and data were compiled by the United States Geological Survey during the period from March to September, 1943.

  18. Long Island Solar Farm

    SciTech Connect

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  19. 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

  20. Island Ecology in Bermuda.

    ERIC Educational Resources Information Center

    Wulff, Barry L.; And Others

    1981-01-01

    Reports on an island ecology course offered by Eastern Connecticut State College providing opportunities for students to study the ecology and natural history of organisms found in a variety of subtropical habitats in Bermuda. Explains student selection criteria, trip preparation, evaluation criteria, daily programs, and habitats studied on the…

  1. Christmas Island birds returning

    NASA Astrophysics Data System (ADS)

    Six months after their mass exodus, birds are beginning to return to Christmas Island. Roughly 17 million birds, almost the entire adult bird population, either perished or fled their mid-Pacific atoll home last autumn, leaving behind thousands of nestlings to starve (Eos, April 5, 1983, p. 131). It is believed that the strong El Niño altered the ecology of the surrounding waters and forced the birds to flee. Christmas Island is the world's largest coral atoll.“Ocean and atmosphere scientists are unsure of future directions for the El Niño conditions and cannot now predict what will happen to the birds in the coming months,” said Ralph W. Schreiber, curator of ornithology at the Natural History Museum of Los Angeles County in California. Heisthe ornithologist who discovered the disappearance. “The recovery of the bird populations depends on the food supply in the waters surrounding the island.” The island's birds feed exclusively on small fish and squid.

  2. Hawaii's Sugar Islands.

    ERIC Educational Resources Information Center

    Hawaiian Sugar Planters' Association, Aiea, HI.

    A warm and sunny subtropical climate helps make Hawaii an important sugar producer. History records that sugarcane was already present when Captain James Cook discovered the islands in 1778, and that the first successful sugarcane plantation was started in 1835 by Ladd and Company at Koloa. The first recorded export of Hawaiian sugar was in 1837,…

  3. Kiritimati, Kiribati (Christmas Island)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Pronounced 'Ki-ris-mas,' Kiritimati Island has a large infilled lagoon that gives it the largest land area (125 square miles, 321 square km) of any atoll in the world. Captain Cook named the atoll Christmas Island when he arrived on Christmas Eve in 1777. Used for nuclear testing in the 1950s and 1960s, the island is now valued for its marine and wildlife resources. It is particularly important as a seabird nesting site-with an estimated 6 million birds using or breeding on the island, including several million Sooty Terns. Rainfall on Kiritimati is linked to El Nino patterns, with long droughts experienced between the wetter El Nino years. This image is based on a mosaic of four digital photographs taken on 16 January 2002 from the Space Station Alpha as part of the Crew Earth Observations Project. The underlying data have 10 meter spatial resolution. Coral reefs are one of the areas selected as a scientific theme for this project (see also the recent Earth Observatory article, Mapping the Decline of Coral Reefs. The mosaic, based on images ISS004-ESC-6249 to 6252, was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  4. The Flores Island tsunamis

    NASA Astrophysics Data System (ADS)

    Yeh, Harry; Imamura, Fumihiko; Synolakis, Costas; Tsuji, Yoshinobu; Liu, Philip; Shi, Shaozhong

    On December 12, 1992, at 5:30 A.M. GMT, an earthquake of magnitude Ms 7.5 struck the eastern region of Flores Island, Indonesia (Figure 1), a volcanic island located just at the transition between the Sunda and Banda Island arc systems. The local newspaper reported that 25-m high tsunamis struck the town of Maumere, causing substantial casualties and property damage. On December 16, television reports broadcast in Japan via satellite reported that 1000 people had been killed in Maumere and twothirds of the population of Babi Island had been swept away by the tsunamis.The current toll of the Flores earthquake is 2080 deaths and 2144 injuries, approximately 50% of which are attributed to the tsunamis. A tsunami survey plan was initiated within 3 days of the earthquake, and a cooperative international survey team was formed with four scientists from Indonesia, nine from Japan, three from the United States, one from the United Kingdom, and one from Korea.

  5. 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.

  6. Magnetic island induced bootstrap current on island dynamics in tokamaks

    SciTech Connect

    Shaing, K.C.; Spong, D.A.

    2006-02-15

    When a magnetic island is embedded in toroidally symmetric tokamaks, the toroidal symmetry in |B| is broken [K. C. Shaing, Phys. Rev. Lett. 87, 245003 (2001)]. Here, B is the magnetic field. This broken symmetry induces an additional bootstrap current density in the vicinity of the island. It is illustrated that this island induced bootstrap current density modifies the island evolution equation and imposes a lower limit on the absolute value of the tearing mode stability parameter {delta}{sup '} for the island to be unstable. This lower limit depends on the local poloidal plasma beta {beta}{sub p}, the ratio of the plasma pressure to the poloidal magnetic field pressure. If {beta}{sub p} is high enough, the magnetic island is stable. This mechanism provides an alternative route to stabilize the island.

  7. Magnetic Island Induced Bootstrap Current on Island Dynamics in Tokamaks

    SciTech Connect

    Spong, Donald A; Shaing, K. C.

    2006-02-01

    When a magnetic island is embedded in toroidally symmetric tokamaks, the toroidal symmetry in |B| is broken [K. C. Shaing, Phys. Rev. Lett. 87, 245003 (2001)] . Here, B is the magnetic field. This broken symmetry induces an additional bootstrap current density in the vicinity of the island. It is illustrated that this island induced bootstrap current density modifies the island evolution equation and imposes a lower limit on the absolute value of the tearing mode stability parameter |{Delta}{prime}| for the island to be unstable. This lower limit depends on the local poloidal plasma beta {beta}{sub p}, the ratio of the plasma pressure to the poloidal magnetic field pressure. If {beta}{sub p} is high enough, the magnetic island is stable. This mechanism provides an alternative route to stabilize the island.

  8. Response of microscale turbulence and transport to the evolution of resistive magnetohydrodynamic magnetic island

    SciTech Connect

    Li, Jiquan Kishimoto, Y.; Wang, Z. X.

    2014-02-15

    Nonlinear evolution of microscale turbulence interacting with a naturally growing MHD magnetic island is simulated based on a Landau-fluid model. Here, we report on a new short wavelength magnetic-island-induced ion temperature gradient (ITG) instability triggered by a critical threshold of magnetic island width in multiscale turbulence, which is referred to as sw-MITG mode. The sw-MITG mode is characterized by a substantially low stability threshold and a global structure propagating along the ion diamagnetic drift direction. Its generation results from the response of microscale fluctuations to turbulent cross-field heat transport associated with increasing boundary layer width about the island separatrix. An intermittency of heat transport is caused by the sw-MITG mode interacting with dynamical magnetic island and microturbulence.

  9. 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

    ... Register on August 14, 2007 (72 FR 45444), announcing our intent to complete a CCP/EA and inviting public... Fish and Wildlife Service Protection Island and San Juan Islands National Wildlife Refuges, Jefferson, Island, San Juan, Skagit, and Whatcom Counties, WA AGENCY: Fish and Wildlife Service, Interior....

  10. LOUISIANA BARRIER ISLAND EROSION STUDY.

    USGS Publications Warehouse

    Sallenger,, Asbury H., Jr.; Penland, Shea; Williams, S. Jeffress; Suter, John R.

    1987-01-01

    During 1986, the U. S. Geological Survey and the Louisiana Geological Survey began a five-year cooperative study focused on the processes which cause erosion of barrier islands. These processes must be understood in order to predict future erosion and to better manage our coastal resources. The study area includes the Louisiana barrier islands which serve to protect 41% of the nation's wetlands. These islands are eroding faster than any other barrier islands in the United States, in places greater than 20 m/yr. The study is divided into three parts: geological development of barrier islands, quantitative processes of barrier island erosion and applications of results. The study focuses on barrier islands in Louisiana although many of the results are applicable nationwide.

  11. Heat Without Heat

    NASA Astrophysics Data System (ADS)

    Lubkin, Elihu

    1997-04-01

    Logic of the Second Law of Thermodynamics demands acquisition of naked entropy. Accordingly, the leanest liaison between systems is not a diathermic membrane, it is a purely informational tickler, leaking no appreciable energy. The subsystem here is a thermodynamic universe, which gets `heated' entropically, yet without gaining calories. Quantum Mechanics graciously supports that(Lubkin, E. and Lubkin, T., International Journal of Theoretical Physics,32), 933-943 (1993) (at a cost of about 1 bit) through entanglement---across this least permeable of membranes---with what is beyond that universe. Heat without heat(Also v. forthcoming Proceedings of the 4th Drexel University Conference of September 1994) is the aspirin for Boltzmann's headache, conserving entropy in mechanical isolation, even while increasing entropy in thermodynamic isolation.

  12. FLANDERS FIELDS MEMORIAL IN TRAFFIC ISLAND ON EAST DRIVE. VIEW ...

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

    FLANDERS FIELDS MEMORIAL IN TRAFFIC ISLAND ON EAST DRIVE. VIEW TO NORTHEAST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

  13. 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.

  14. 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. PMID:27447234

  15. Real-Time Detection for Magnetic Island of Neoclassical Tearing Mode in EAST Plasma Control System

    NASA Astrophysics Data System (ADS)

    Liang, Shaoyong; Xiao, Bingjia; Zhang, Yang; Wang, Linfang; Yuan, Qiping; Luo, Zhengping; Shi, Tonghui; Ti, Ang

    2016-02-01

    Accurate detection of a magnetic island in real time is one of the important issues for the tearing mode (TM) and neoclassical tearing mode (NTM) control. This paper presents a real-time detection system for the magnetic island of NTM control in the EAST Plasma Control System (PCS). Diagnosis is based on magnetic periodic perturbation and electron temperature fluctuation caused by the magnetic island. Therefore, a Mirnov measurement has been selected to calculate the island's parameters, such as island width, frequency of island rotation, and toroidal number. The electron cyclotron emission (ECE) system can detect the island position, which is calculated by two fast detection algorithms called correlation analysis and Hilbert transform. For future NTM control, real-time equilibrium reconstruction (rt-EFIT) is needed to locate the rational q-surface where the island is detected. This fast detection system is able to detect an island within 3 ms. It can be integrated into PCS to provide effective parameters of the island for NTM control by using EC resonance heating (ECRH) in the next experiment of EAST. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2014GB103000, 2012GB103000, and 2012GB103002), National Natural Science Foundation of China (No. 11205200)

  16. Charge Islands Through Tunneling

    NASA Technical Reports Server (NTRS)

    Robinson, Daryl C.

    2002-01-01

    It has been recently reported that the electrical charge in a semiconductive carbon nanotube is not evenly distributed, but rather it is divided into charge "islands." This paper links the aforementioned phenomenon to tunneling and provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive. This paper also provides a basis for calculating the charge profile over the length of the tube so that nanoscale devices' conductive properties may be fully exploited.

  17. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  18. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  19. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  20. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  1. 32 CFR 935.62 - Island Attorney.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Island Attorney. 935.62 Section 935.62 National... WAKE ISLAND CODE Judiciary § 935.62 Island Attorney. There is an Island Attorney, appointed by the General Counsel as needed. The Island Attorney shall serve at the pleasure of the General Counsel....

  2. Asthma and Native Hawaiians/Pacific Islanders

    MedlinePlus

    ... Other Pacific Islander > Asthma Asthma and Native Hawaiians/Pacific Islanders Native Hawaiians/Pacific Islanders are 70 percent more likely to have ... being told they had asthma, 2014 Native Hawaiian/Pacific Islander Non-Hispanic White Native Hawaiian/Pacific Islander/ ...

  3. Adaptation and diversification on islands.

    PubMed

    Losos, Jonathan B; Ricklefs, Robert E

    2009-02-12

    Charles Darwin's travels on HMS Beagle taught him that islands are an important source of evidence for evolution. Because many islands are young and have relatively few species, evolutionary adaptation and species proliferation are obvious and easy to study. In addition, the geographical isolation of many islands has allowed evolution to take its own course, free of influence from other areas, resulting in unusual faunas and floras, often unlike those found anywhere else. For these reasons, island research provides valuable insights into speciation and adaptive radiation, and into the relative importance of contingency and determinism in evolutionary diversification. PMID:19212401

  4. 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. PMID:25254475

  5. 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

  6. Electron thermal transport within magnetic islands in the reversed-field pinch

    SciTech Connect

    Stephens, H. D.; Reusch, J. A.; Den Hartog, D. J.; Hegna, C. C.

    2010-05-15

    Tearing mode induced magnetic islands have a significant impact on the thermal characteristics of magnetically confined plasmas such as those in the reversed-field pinch (RFP). New Thomson scattering diagnostic capability on the Madison Symmetric Torus (MST) RFP has enabled measurement of the thermal transport characteristics of islands. Electron temperature (T{sub e}) profiles can now be acquired at 25 kHz, sufficient to measure the effect of an island on the profile as the island rotates by the measurement point. In standard MST plasmas with a spectrum of unstable tearing modes, remnant islands are present in the core between sawtoothlike reconnection events. Associated with these island remnants is flattening of the T{sub e} profile inside the island separatricies. This flattening is characteristic of rapid parallel heat conduction along helical magnetic field lines. In striking contrast, a temperature gradient within an m=1, n=5 island is observed in these same plasmas just after a sawtooth event when the m=1, n=5 mode may briefly come into resonance near the magnetic axis. This suggests local heating and relatively good confinement within the island. Local power balance calculations suggest reduced thermal transport within this island relative to the confinement properties of standard MST discharges between reconnection events. The magnetic field and island structure is modeled with three-dimensional nonlinear resistive magnetohydrodynamic simulations (DEBS code) with Lundquist numbers matching those in MST during standard discharges. During improved confinement plasmas with reduced tearing mode activity, temperature fluctuations correlated with magnetic signals are small with characteristic fluctuation amplitudes of order T-tilde{sub e}/T{sub e}approx2%.

  7. Spray-ice islands evaluated for Arctic-drilling structures

    SciTech Connect

    Juvkam-Wold, H.C.

    1986-04-21

    Comparisons of spray-ice drilling structures for the Beaufort Sea with drilling structures presently in use there show that over a wide range of water depths drilling from spray-ice islands offers significant benefits over the existing alternatives. Both technical and economic comparisons were made. In a water depth of 50 ft, a gravel island for drilling an exploration hole would likely cost between $40 and $60 million. A spray-ice island in the same location would cost less than $10 million. ''Spray-ice'' as used in this article refers to ice made by pumping sea water high up into the air for rapid heat transfer and freezing. The resulting ice has a granular structure and is quite porous.

  8. 19. New York Connecting Railroad: Randalls Island Viaduct. Randalls Island, ...

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

    19. New York Connecting Railroad: Randalls Island Viaduct. Randalls Island, New York Co., NY. Sec. 4207, MP 8.54. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  9. 15. New York Connecting Railroad: Wards Island Viaduct. Wards Island, ...

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

    15. New York Connecting Railroad: Wards Island Viaduct. Wards Island, New York Co., NY. Sec. 4207, MP 7.65. - Northeast Railroad Corridor, Amtrak Route between New Jersey/New York & New York/Connecticut State Lines, New York County, NY

  10. Islands and Non-islands in Native and Heritage Korean

    PubMed Central

    Kim, Boyoung; Goodall, Grant

    2016-01-01

    To a large extent, island phenomena are cross-linguistically invariable, but English and Korean present some striking differences in this domain. English has wh-movement and Korean does not, and while both languages show sensitivity to wh-islands, only English has island effects for adjunct clauses. Given this complex set of differences, one might expect Korean/English bilinguals, and especially heritage Korean speakers (i.e., early bilinguals whose L2 became their dominant language during childhood) to be different from native speakers, since heritage speakers have had more limited exposure to Korean, may have had incomplete acquisition and/or attrition, and may show significant transfer effects from the L2. Here we examine islands in heritage speakers of Korean in the U.S. Through a series of four formal acceptability experiments comparing these heritage speakers with native speakers residing in Korea, we show that the two groups are remarkably similar. Both show clear evidence for wh-islands and an equally clear lack of adjunct island effects. Given the very different linguistic environment that the heritage speakers have had since early childhood, this result lends support to the idea that island phenomena are largely immune to environmental influences and stem from deeper properties of the processor and/or grammar. Similarly, it casts some doubt on recent proposals that islands are learned from the input. PMID:26913017

  11. IslandViewer update: Improved genomic island discovery and visualization.

    PubMed

    Dhillon, Bhavjinder K; Chiu, Terry A; Laird, Matthew R; Langille, Morgan G I; Brinkman, Fiona S L

    2013-07-01

    IslandViewer (http://pathogenomics.sfu.ca/islandviewer) is a web-accessible application for the computational prediction and analysis of genomic islands (GIs) in bacterial and archaeal genomes. GIs are clusters of genes of probable horizontal origin and are of high interest because they disproportionately encode virulence factors and other adaptations of medical, environmental and industrial interest. Many computational tools exist for the prediction of GIs, but three of the most accurate methods are available in integrated form via IslandViewer: IslandPath-DIMOB, SIGI-HMM and IslandPick. IslandViewer GI predictions are precomputed for all complete microbial genomes from National Center for Biotechnology Information, with an option to upload other genomes and/or perform customized analyses using different settings. Here, we report recent changes to the IslandViewer framework that have vastly improved its efficiency in handling an increasing number of users, plus better facilitate custom genome analyses. Users may also now overlay additional annotations such as virulence factors, antibiotic resistance genes and pathogen-associated genes on top of current GI predictions. Comparisons of GIs between user-selected genomes are now facilitated through a highly requested side-by-side viewer. IslandViewer improvements aim to provide a more flexible interface, coupled with additional highly relevant annotation information, to aid analysis of GIs in diverse microbial species. PMID:23677610

  12. Islands and Non-islands in Native and Heritage Korean.

    PubMed

    Kim, Boyoung; Goodall, Grant

    2016-01-01

    To a large extent, island phenomena are cross-linguistically invariable, but English and Korean present some striking differences in this domain. English has wh-movement and Korean does not, and while both languages show sensitivity to wh-islands, only English has island effects for adjunct clauses. Given this complex set of differences, one might expect Korean/English bilinguals, and especially heritage Korean speakers (i.e., early bilinguals whose L2 became their dominant language during childhood) to be different from native speakers, since heritage speakers have had more limited exposure to Korean, may have had incomplete acquisition and/or attrition, and may show significant transfer effects from the L2. Here we examine islands in heritage speakers of Korean in the U.S. Through a series of four formal acceptability experiments comparing these heritage speakers with native speakers residing in Korea, we show that the two groups are remarkably similar. Both show clear evidence for wh-islands and an equally clear lack of adjunct island effects. Given the very different linguistic environment that the heritage speakers have had since early childhood, this result lends support to the idea that island phenomena are largely immune to environmental influences and stem from deeper properties of the processor and/or grammar. Similarly, it casts some doubt on recent proposals that islands are learned from the input. PMID:26913017

  13. Pine Island Glacier, Antarctica

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This pair of MISR images of the Pine Island Glacier in western Antarctica was acquired on December 12, 2000 during Terra orbit 5246. At left is a conventional, true-color image from the downward-looking (nadir) camera. The false-color image at right is a composite of red band data taken by the MISR forward 60-degree, nadir, and aftward 60-degree cameras, displayed in red, green, and blue colors, respectively. Color variations in the left (true-color) image highlight spectral differences. In the multi-angle composite, on the other hand, color variations act as a proxy for differences in the angular reflectance properties of the scene. In this representation, clouds show up as light purple. Blue to orange gradations on the surface indicate a transition in ice texture from smooth to rough. For example, the bright orange 'carrot-like' features are rough crevasses on the glacier's tongue. In the conventional nadir view, the blue ice labeled 'rough crevasses' and 'smooth blue ice' exhibit similar coloration, but the multi-angle composite reveals their different textures, with the smoother ice appearing dark purple instead of orange. This could be an indicator of different mechanisms by which this ice is exposed. The multi-angle view also reveals subtle roughness variations on the frozen sea ice between the glacier and the open water in Pine Island Bay.

    To the left of the 'icebergs' label are chunks of floating ice. Additionally, smaller icebergs embedded in the frozen sea ice are visible below and to the right of the label. These small icebergs are associated with dark streaks. Analysis of the illumination geometry suggests that these streaks are surface features, not shadows. Wind-driven motion and thinning of the sea ice in the vicinity of the icebergs is one possible explanation.

    Recently, Robert Bindschadler, a glaciologist at the NASA Goddard Space Flight Center discovered in Landsat 7 imagery a newly-formed crack traversing the Pine Island Glacier. This crack

  14. Fire Island National Seashore

    USGS Publications Warehouse

    Brock, John C.; Wright, C. Wayne; Patterson, Matt; Nayagandhi, Amar; Patterson, Judd

    2007-01-01

    These lidar-derived topographic maps were produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, the National Park Service (NPS), Northeast Coastal and Barrier Network, Inventory and Monitoring Program, and the National Aeronautics and Space Administration (NASA) Wallops Flight Facility. The aims of the partnership that created this product are to develop advanced survey techniques for mapping barrier island geomorphology and habitats, and to enable the monitoring of ecological and geological change within National Seashores. This product is based on data from an innovative airborne lidar instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Advanced Airborne Research Lidar (EAARL).

  15. Heat Illness in Hawai‘i

    PubMed Central

    2014-01-01

    Heat illness is a commonly encountered health problem in the Hawaiian Islands. Year round warm temperatures, proximity to the equator, and high humidity combined with a plethora of opportunities for outdoor activities put many individuals at risk. This paper will focus on the physiology, identification, and treatment of varying forms of heat illness. Severe heat illness can be life threatening. All outdoor enthusiasts should have a basic understanding of how to recognize this potentially life-threatening condition and employ preventive measures. We will discuss appropriate management in pre-hospital and hospital settings. Early recognition and cooling are the most crucial aspects of the management of heat illness. PMID:25478301

  16. Profile: Native Hawaiians and Pacific Islanders

    MedlinePlus

    ... Hawaiian/Other Pacific Islander Profile: Native Hawaiians and Pacific Islanders (Map of the US with the states that have significant Native Hawaiian/Pacific Islander populations according to the Census Bureau) HI - ...

  17. Infant Mortality and Asians and Pacific Islanders

    MedlinePlus

    ... Infant Heath & Mortality Infant Mortality and Asians and Pacific Islanders Among Asian/Pacific Islanders, Sudden Infant Death Syndrome (SIDS) is the fourth leading cause of infant mortality. Asian/Pacific Islanders women generally have lower infant mortality rates ...

  18. Heart Disease and Asians and Pacific Islanders

    MedlinePlus

    ... American > Heart Disease Heart Disease and Asians and Pacific Islanders Overall, Asian American adults are less likely ... Disease Death Rates per 100,000 (2013) Asians/Pacific Islanders Non-Hispanic White Asians/Pacific Islanders /Non- ...

  19. Immunizations and Asians and Pacific Islanders

    MedlinePlus

    ... Profiles > Asian American > Immunizations Immunizations and Asians and Pacific Islanders Asian/Pacific Islander adults are 10% less likely to ever ... to non-Hispanic white adults. In 2014, Asian/Pacific Islander adults aged 65 years and older were ...

  20. Diabetes and Native Hawaiians/Pacific Islanders

    MedlinePlus

    ... Other Pacific Islander > Diabetes Diabetes and Native Hawaiians/Pacific Islanders Asian Americans, in general, have the same ... However, there are differences within the Native Hawaiian/Pacific Islander population. From a national survey, Native Hawaiians/ ...

  1. [Heat stroke and the elderly].

    PubMed

    Takamatsu, Noriko

    2012-06-01

    Recently, the heat stroke in the elderly who often remains at home during the day increases due to high temperatures in summer by urban heat island effect. We have examined how the elderly were influenced by the high summer temperatures. We explained the patients or the caregivers at home while showing the checklist of six items. In addition, we checked and interviewed time of visits, patients' room temperature, with or without air conditioning fan etc., and filled out their histories of summer heat. If some items of the checklist were not improved, we explained the care points again every time we visited. 10 people out of the 72 patients were identified as summer heat illness at home. We need to work together with medical cares and welfare services and the other organizations of each region. PMID:22690611

  2. Acanthamoeba genotypes T2, T4, and T11 in soil sources from El Hierro island, Canary Islands, Spain.

    PubMed

    Reyes-Batlle, María; Zamora-Herrera, Jonadab; Vargas-Mesa, Alejandro; Valerón-Tejera, Marco Antonio; Wagner, Carolina; Martín-Navarro, Carmen Ma; López-Arencibia, Atteneri; Sifaoui, Ines; Martínez-Carretero, Enrique; Valladares, Basilio; Piñero, José E; Lorenzo-Morales, Jacob

    2016-08-01

    The genus Acanthamoeba includes pathogenic strains which are causative agents of keratitis and encephalitis that often may end fatal in humans and other animals. In the present study, forty soil samples were collected in the island of El Hierro, Canary Islands, Spain, and checked for the presence of Acanthamoeba. Samples were cultivated onto 2 % non-nutrient agar plates seeded with a layer of heat killed Escherichia coli. Amplification by PCR and sequencing of the DF3 region of the 18S rDNA of Acanthamoeba was carried out in order to confirm morphological identification of the amoebae. Furthermore, Acanthamoeba spp. was isolated from 47.5 % of soil samples. Moreover, genotypes T2, T4, and T11 were identified in these samples. To the best of our knowledge, this is the first study to establish genotypes T2, T4, and T11 in soil sources from El Hierro island. PMID:27075307

  3. Opportunity at 'Cook Islands'

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,825th Martian day, or sol, of Opportunity's surface mission (March 12, 2009). North is at the top.

    The rover had driven half a meter (1.5 feet) earlier on Sol 1825 to fine-tune its location for placing its robotic arm onto an exposed patch of outcrop including a target area informally called 'Cook Islands.' On the preceding sol, Opportunity turned around to drive frontwards and then drove 4.5 meters (15 feet) toward this outcrop. The tracks from the SOl 1824 drive are visible near the center of this view at about the 11 o'clock position. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). Opportunity had previously been driving backward as a strategy to redistribute lubrication in a wheel drawing more electrical current than usual.

    The outcrop exposure that includes 'Cook Islands' is visible just below the center of the image.

    The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

    This view is presented as a cylindrical projection with geometric seam correction.

  4. Volcanic Island Appears Near Tonga

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    2006-11-01

    A volcano known as Home Reef is now believed to be the source of a small island that appeared recently in Tonga, accordingto scientists from the Smithsonian Institution's Global Volcanism Program who had initially placed the location of the eruption and resulting island at nearby Metis Shoal. Mariners onboard the yacht Maiken

  5. An Island Effect in Japanese.

    ERIC Educational Resources Information Center

    Richards, Norvin

    2000-01-01

    Develops an argument for a pied-piping approach to the apparent absence of island effects in Japanese, along the lines of Nishigauchi (1986, 1990). Investigates the nature of pied-piping, developing a theory that accounts for the fact that wh-islands cannot be pied-piped. (Author/VWL)

  6. Island Divertor Plate Modeling for the Compact Toroidal Hybrid Experiment

    NASA Astrophysics Data System (ADS)

    Hartwell, G. J.; Massidda, S. D.; Ennis, D. A.; Knowlton, S. F.; Maurer, D. A.; Bader, A.

    2015-11-01

    Edge magnetic island divertors can be used as a method of plasma particle and heat exhaust in long pulse stellarator experiments. Detailed power loading on these structures and its relationship to the long connection length scrape off layer physics is a new Compact Toroidal Hybrid (CTH) research thrust. CTH is a five field period, l = 2 torsatron with R0 = 0 . 75 m, ap ~ 0 . 2 m, and | B | <= 0 . 7 T. For these studies CTH is configured as a pure stellarator using a 28 GHz, 200 kW gyrotron operating at 2nd harmonic for ECRH. We report the results of EMC3-EIRENE modeling of divertor plates near magnetic island structures. The edge rotational transform is varied by adjusting the ratio of currents in the helical and toroidal field coils. A poloidal field coil adjusts the shear of the rotational transform profile, and width of the magnetic island, while the phase of the island is rotated with a set of five error coils producing an n = 1 perturbation. For the studies conducted, a magnetic configuration with a large n = 1 , m = 3 magnetic island at the edge is generated. Results from multiple potential divertor plate locations will be presented and discussed. This work is supported by U.S. Department of Energy Grant No. DE-FG02-00ER54610.

  7. Effects of Kuroshio Intrusions on the atmosphere northeast of Taiwan Island

    NASA Astrophysics Data System (ADS)

    Chow, Chun Hoe; Liu, Qinyu; Xie, Shang-Ping

    2015-03-01

    The Kuroshio loses bathymetric support off northeast Taiwan Island, causing large variability in its path. The resultant covariability of sea surface temperature (SST) and the lower atmosphere is investigated using satellite observations. In winter and spring off northeast Taiwan Island, the intrusions of warm Kuroshio water onto the continental shelf cause a large increase in local SST, intensify the northeasterly monsoonal winds, and lead to the increases in water vapor and rainfall. Key to this air-sea interaction is the existence of anomalous heat advection by the Kuroshio intrusions. The Kuroshio intrusions are partly due to westward propagating ocean eddies east of Taiwan Island with a lead time of 3 weeks, hinting at the possibility of improved weather prediction near northeast Taiwan Island by considering ocean variability east of Taiwan Island.

  8. Measured data from the Avery Island Site C heater test

    SciTech Connect

    Waldman, H.; Stickney, R.G.

    1984-05-01

    Over the past six years, a comprehensive field testing program was conducted in the Avery Island salt mine. Three single canister heater tests were included in the testing program. Specifically, electric heaters, which simulate canisters of heat-generating nuclear waste, were placed in the floor of the Avery Island salt mine, and measurements were made of the response of the salt to heating. These tests were in operation by June, 1978. One of the three heater tests, Site C, operated for a period of 1858 days and was decommissioned during July and August, 1983. This data report presents the temperature and displacement data gathered during the operation and decommissioning of the Site C heater test. The purpose of this data report is to transmit the data to the scientific community. Rigorous analysis and interpretation of the data are considered beyond the scope of a data report. 8 refs., 21 figs., 1 tab.

  9. Measured data from the Avery Island Site C heater test

    SciTech Connect

    Waldman, H.; Stickney, R.G.

    1984-11-01

    Over the past six years, a comprehensive field testing program was conducted in the Avery Island salt mine. Three single canister heater tests were included in the testing program. Specifically, electric heaters, which simulate canisters of heat-generating nuclear waste, were placed in the floor of the Avery Island salt mine, and measurements were made of the response of the salt to heating. These tests were in operation by June 1978. One of the three heater tests, Site C, operated for a period of 1858 days and was decommissioned during July and August 1983. This data report presents the temperature and displacement data gathered during the operation and decommissioning of the Site C heater test. The purpose of this data report is to transmit the data to the scientific community. Rigorous analysis and interpretation of the data are considered beyond the scope of a data report. 6 references, 21 figures, 1 table.

  10. 2. Light tower, view west towards Squirrel Island, south and ...

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

    2. Light tower, view west towards Squirrel Island, south and east sides - Ram Island Light Station, Ram Island, south of Ocean Point & just north of Fisherman Island, marking south side of Fisherman Island Passage, Ocean Point, Lincoln County, ME

  11. Underground Temperature Measurements as a Tool for Volcanic Activity Monitoring in the Island of Tenerife, Canary Islands

    NASA Astrophysics Data System (ADS)

    Eff-Darwich, A.; Coello, J.; Viñas, R.; Soler, V.; Martin-Luis, M. C.; Farrujia, I.; Quesada, M. L.; de La Nuez, J.

    2008-01-01

    The spatial distribution of groundwater temperatures in the volcanic island of Tenerife, Canary Islands, has been inferred through measurements of water temperatures collected in the vast network of wells and subhorizontal tunnels, locally called “galleries,” which constitutes the main water supply of the island. The spatial coverage of the network of galleries allows us to reach from depth almost any geological feature of the island. The complex spatial distribution of temperatures in the interior of Tenerife is the result of the complex geological evolution of the island. Groundwater temperatures are greatly affected by groundwater flow and are considerably warmer in those galleries located in areas where water circulation is reduced due to the low permeability of materials and/or to the low infiltration rate of cooling meteoric water. In this sense, groundwater temperature should be characterized in quiescent conditions (background level), in order to facilitate monitoring changes in heat flow, such as those induced by ascending gases expected with an increase in volcanic activity.

  12. Heat Stress

    MedlinePlus

    ... Stress Learn some tips to protect workers including: acclimatization, rest breaks, and fluid recommendations. NIOSH Workplace Solution: ... Blog: Adjusting to Work in the Heat: Why Acclimatization Matters The natural adaptation to the heat takes ...

  13. Heating Safety

    MedlinePlus

    ... from heating equipment, such as the furnace, fireplace, wood stove, or portable heater. • Only use heating equipment ... into the room and burn only dry, seasoned wood. Allow ashes to cool before disposing in a ...

  14. 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.

  15. 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.

  16. Anatahan Volcano, Mariana Islands

    NASA Technical Reports Server (NTRS)

    2008-01-01

    In the early hours of February 7, ASTER captured this nighttime thermal infrared image of an eruption of Anatahan Volcano in the central Mariana Islands. The summit of the volcano is bright indicating there is a very hot area there. Streaming to the west is an ash plume, visible by the red color indicating the presence of silicate-rich particles. Dark grey areas are clouds that appear colder than the ocean. Anatahan is a stratovolcano that started erupting in May 2003, forming a new crater.

    The image covers an area of 56.3 x 41.8 km, and is located 16 degrees north latitude and 145.6 degrees east 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.

  17. SRTM Anaglyph: Fiji Islands

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Sovereign Democratic Republic of the Fiji Islands, commonly known as Fiji, is an independent nation consisting of some 332 islands surrounding the Koro Sea in the South Pacific Ocean. This topographic image shows Viti Levu, the largest island in the group. With an area of 10,429 square kilometers (about 4000 square miles), it comprises more than half the area of the Fiji Islands. Suva, the capital city, lies on the southeast shore. The Nakauvadra, the rugged mountain range running from north to south, has several peaks rising above 900 meters (about 3000 feet). Mount Tomanivi, in the upper center, is the highest peak at 1324 meters (4341 feet). The distinct circular feature on the north shore is the Tavua Caldera, the remnant of a large shield volcano that was active about 4 million years ago. Gold has been mined on the margin of the caldera since the 1930s. The Nadrau plateau is the low relief highland in the center of the mountain range. The coastal plains in the west, northwest and southeast account for only 15 percent of Viti Levu's area but are the main centers of agriculture and settlement.

    This shaded relief anaglyph image was generated using preliminary topographic data from the Shuttle Radar Topography Mission. A computer-generated artificial light source illuminates the elevation data from the top (north) to produce a pattern of light and shadows. Slopes facing the light appear bright, while those facing away are shaded. The stereoscopic effect was created by first draping the shaded relief image back over the topographic data and then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

    This image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar

  18. Heat exchanger

    DOEpatents

    Daman, Ernest L.; McCallister, Robert A.

    1979-01-01

    A heat exchanger is provided having first and second fluid chambers for passing primary and secondary fluids. The chambers are spaced apart and have heat pipes extending from inside one chamber to inside the other chamber. A third chamber is provided for passing a purge fluid, and the heat pipe portion between the first and second chambers lies within the third chamber.

  19. 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

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission 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...

  20. Global Collembola on Deception Island.

    PubMed

    Greenslade, Penelope; Potapov, Mikhail; Russell, David; Convey, Peter

    2012-01-01

    Three new non-indigenous springtail species are recorded in recent collections made on Deception Island, South Shetland Islands, maritime Antarctic: Deuteraphorura (Deuteraphorura) cebennaria (Gisin) (Collembola: Onychiuridae), Mesaphorura macrochaeta Rusek (Tullbergiidae), and Proisotoma minuta Axelson (Isotomidae). One of these, D. (D.) cebennaria, is described. Additionally, two new indigenous species, Mesaphorura macrochaeta Rusek and Proisotoma minuta Axelson, are also recorded. The total number of Collembola species now known from the island is 14, comprised of eight native species and six non-indigenous species. This number of non-indigenous species recorded at Deception Island compares with only a single non-indigenous springtail recorded at any other maritime or continental Antarctic location. The reason underlying this high level of occurrence of non-indigenous species on Deception Island is likely to be a combination of the island's high level of human visitation and the presence of relatively benign terrestrial habitats associated with areas of geothermal activity. Two of the new records represent species recently assessed as being of the highest risk to become invaders in the less extreme environments of the subantarctic, thereby emphasising the importance and urgency of adopting and applying effective biosecurity measures to protect the unique and vulnerable ecosystems of this region. Also documented are the impacts on the soil fauna of the island from human trampling, which drastically reduced densities of both native and non-indigenous species to 1% of the abundance typical of non-trampled sites. PMID:23438196

  1. GIPSy: Genomic island prediction software.

    PubMed

    Soares, Siomar C; Geyik, Hakan; Ramos, Rommel T J; de Sá, Pablo H C G; Barbosa, Eudes G V; Baumbach, Jan; Figueiredo, Henrique C P; Miyoshi, Anderson; Tauch, Andreas; Silva, Artur; Azevedo, Vasco

    2016-08-20

    Bacteria are highly diverse organisms that are able to adapt to a broad range of environments and hosts due to their high genomic plasticity. Horizontal gene transfer plays a pivotal role in this genome plasticity and in evolution by leaps through the incorporation of large blocks of genome sequences, ordinarily known as genomic islands (GEIs). GEIs may harbor genes encoding virulence, metabolism, antibiotic resistance and symbiosis-related functions, namely pathogenicity islands (PAIs), metabolic islands (MIs), resistance islands (RIs) and symbiotic islands (SIs). Although many software for the prediction of GEIs exist, they only focus on PAI prediction and present other limitations, such as complicated installation and inconvenient user interfaces. Here, we present GIPSy, the genomic island prediction software, a standalone and user-friendly software for the prediction of GEIs, built on our previously developed pathogenicity island prediction software (PIPS). We also present four application cases in which we crosslink data from literature to PAIs, MIs, RIs and SIs predicted by GIPSy. Briefly, GIPSy correctly predicted the following previously described GEIs: 13 PAIs larger than 30kb in Escherichia coli CFT073; 1 MI for Burkholderia pseudomallei K96243, which seems to be a miscellaneous island; 1 RI of Acinetobacter baumannii AYE, named AbaR1; and, 1 SI of Mesorhizobium loti MAFF303099 presenting a mosaic structure. GIPSy is the first life-style-specific genomic island prediction software to perform analyses of PAIs, MIs, RIs and SIs, opening a door for a better understanding of bacterial genome plasticity and the adaptation to new traits. PMID:26376473

  2. Heat Pipes

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Phoenix Refrigeration Systems, Inc.'s heat pipe addition to the Phoenix 2000, a supermarket rooftop refrigeration/air conditioning system, resulted from the company's participation in a field test of heat pipes. Originally developed by NASA to control temperatures in space electronic systems, the heat pipe is a simple, effective, heat transfer system. It has been used successfully in candy storage facilities where it has provided significant energy savings. Additional data is expected to fully quantify the impact of the heat pipes on supermarket air conditioning systems.

  3. Heat Pipes

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Heat Pipes were originally developed by NASA and the Los Alamos Scientific Laboratory during the 1960s to dissipate excessive heat build- up in critical areas of spacecraft and maintain even temperatures of satellites. Heat pipes are tubular devices where a working fluid alternately evaporates and condenses, transferring heat from one region of the tube to another. KONA Corporation refined and applied the same technology to solve complex heating requirements of hot runner systems in injection molds. KONA Hot Runner Systems are used throughout the plastics industry for products ranging in size from tiny medical devices to large single cavity automobile bumpers and instrument panels.

  4. The Cambrian of Bennett Island (New Siberian Islands)

    NASA Astrophysics Data System (ADS)

    Danukalova, M. K.; Kuzmichev, A. B.; Korovnikov, I. V.

    2014-07-01

    The paper presents new data on the Cambrian stratigraphy of Bennett Island, one of the least explored East Arctic islands. The section, about 500 m of total thickness, comprises four lithological units that store a record of the deposition history: (1) clastic sediments including storm sandstones; (2) shallow-marine mudstone; (3) lagoonal variegated mudstone and limestone; (4) black shale. It is suggested to classify the units as formations with their proper names. The section spans all epoches of the Cambrian stratigraphy constrained by trilobite fossils. In the Cambrian, territory of the island belonged to Siberia rather than to some exotic terrane, judging by abundant endemic Siberian trilobite species in the Bennett section. This inference is supported by synchronicity in recorded deposition events of Bennett Island and northeastern Siberia (Kharaulakh Mountains). The Cambrian sediments of the two areas were deposited in different parts of a single shallow sea which extended as far as Taimyr.

  5. A numerical investigation of tropical island thunderstorms

    SciTech Connect

    Golding, B.W. )

    1993-05-01

    A version of the United Kingdom Meteorological Office mesoscale weather prediction model is used to simulate cases of deep tropical convection from the Island Thunderstorm Experiment off the north coast of Australia. Selected cases contrast rather isolated storm development in a dry basic state, with widespread precipitation from a moist basic state. Excellent agreement is found between the simulations and the observed early shower development on both occasions. Initiation of convection occurs along the sea-breeze front, which is then reinforced by downdraft outflows. Merging of simulated cells occurs where the outflows meet, producing cells with cloud tops above 18 km and updraft speeds of 60 m s[sup [minus]1]. The later movement of the storms is less well represented, probably due to weakness in the storm-mean flow interaction. Comparison of the cases shows that differences in the timing of initiation and intensity of subsequent convection are well captured, and relate to differences in the initial sounding. Mean budgets of heat. moisture, and momentum are presented, and sensitivity of the simulations to resolution, island shape, and model microphysics is explored. 48 refs., 12 figs.

  6. 21 CFR 808.89 - Rhode Island.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Rhode Island. 808.89 Section 808.89 Food and Drugs... and Local Exemptions § 808.89 Rhode Island. The following Rhode Island medical device requirements are... from preemption under section 521(b) of the act: Rhode Island General Laws, Section 5-49-2.1,...

  7. 21 CFR 808.89 - Rhode Island.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Rhode Island. 808.89 Section 808.89 Food and Drugs... and Local Exemptions § 808.89 Rhode Island. The following Rhode Island medical device requirements are... from preemption under section 521(b) of the act: Rhode Island General Laws, Section 5-49-2.1,...

  8. 21 CFR 808.89 - Rhode Island.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Rhode Island. 808.89 Section 808.89 Food and Drugs... and Local Exemptions § 808.89 Rhode Island. The following Rhode Island medical device requirements are... from preemption under section 521(b) of the act: Rhode Island General Laws, Section 5-49-2.1,...

  9. 21 CFR 808.89 - Rhode Island.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rhode Island. 808.89 Section 808.89 Food and Drugs... and Local Exemptions § 808.89 Rhode Island. The following Rhode Island medical device requirements are... from preemption under section 521(b) of the act: Rhode Island General Laws, Section 5-49-2.1,...

  10. 21 CFR 808.89 - Rhode Island.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Rhode Island. 808.89 Section 808.89 Food and Drugs... and Local Exemptions § 808.89 Rhode Island. The following Rhode Island medical device requirements are... from preemption under section 521(b) of the act: Rhode Island General Laws, Section 5-49-2.1,...

  11. Stroke and Native Hawaiians/Pacific Islanders

    MedlinePlus

    ... Other Pacific Islander > Stroke Stroke and Native Hawaiians/Pacific Islanders Native Hawaiians/Pacific Islanders were four times more likely than non- ... a stroke in 2010. In general, Native Hawaiian/Pacific Islander adults have developed several of the high ...

  12. 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 southernmost extremity of Savannah Beach on Tybee Island 255° true across Tybee Inlet to the shore of...

  13. Diameter distribution of thermally evaporated indium metal islands on silicon substrates

    NASA Astrophysics Data System (ADS)

    Balch, Joleyn; Tsakalakos, Loucas; Huber, William; Grande, James; Knussman, Michael; Cale, Timothy S.

    2007-09-01

    Although many groups have studied the initial growth stages of various metals, including indium, there is little information in literature on diameter distributions of indium in relation to film thickness or annealing conditions. This paper reports island size distributions of thermally evaporated In islands on Si (100) and Si (111) substrates for nominal film thicknesses ranging from 5 to 50 nm. Because indium has a low melting temperature, and therefore a high homologous temperature at room temperature, 3-dimensional islands form during deposition with no subsequent heat treatments needed. Island diameters were calculated using commercial image analysis software in conjunction with SEM images of the samples. It is found that there is a bimodal island diameter distribution for nominal indium thicknesses greater than 5 nm. While the diameters of the larger islands increase exponentially with nominal thickness, those of the smaller islands increase linearly, and therefore more slowly, with nominal thickness. For nominal thickness of 50 nm, the average diameters of the small and large islands differ by almost an order of magnitude. Anneal conditions were studied in an attempt to narrow diameter distributions. Samples of each nominal thickness were annealed at temperatures ranging from 360°C to 550°C and the diameters again measured. The range of island diameters become narrower with 360°C anneal and volume average island diameter increases by ~30-50%. This narrowing of the distribution occurs due to smaller islands being absorbed by the larger in a process akin to Ostwald ripening, which is facilitated by higher surface diffusivities at higher homologous temperatures.

  14. 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.

  15. Synthesizing knowledge of ocean islands

    NASA Astrophysics Data System (ADS)

    Jefferson, Anne J.; Lees, Jonathan M.; McClinton, Tim

    2011-11-01

    AGU Chapman Conference on the Galápagos as a Laboratory for the Earth Sciences; Puerto Ayora, Galápagos, Ecuador, 25-30 July 2011 An inspiration for Darwin's theory of evolution, the Galápagos Islands and surrounding waters are a natural laboratory for a wide range of Earth science topics. The Galápagos are perfectly situated for geophysical and geochemical investigations of deep-Earth processes at a hot spot, and proximity to a spreading center allows exploration of hot spot-ridge interactions. Several highly active volcanoes show rapid deformation facilitating investigation of melt transport paths and volcanic structure. The islands exhibit a range of ages, eruptive styles, and climatic zones that allow analysis of hydrogeologic and geomorphic processes. The Galápagos Islands are a World Heritage Site and are an ideal setting for developing an integrated biological and geological understanding of ocean island evolution.

  16. Upolu Island, Western Samoa

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Island nations in the South Pacific Ocean experience natural disasters associated with typhoons, and with their proximity to the Pacific Ocean's 'Ring of Fire.' This radar image shows the western end of the island of Upolu in the nation of Western Samoa. Disaster managers use digital elevation models (DEMs) generated from radar data to assist in research toward disaster mitigation and management. Geologists also use DEM data of volcanic features, such as the circular craters in this image, to study eruption rates and volumes, and volcanic landform evolution.

    Black areas near the top of the image are areas where steep topography causes holes in the data; these holes can be filled in by collecting data at other look directions. Color represents topography and intensity represents across-section of the radar backscatter. Since rough areas return more of the incident signal, they appear brighter on the image than relatively smooth areas, such as the ocean surface at the top of the image.

    This image was acquired by the AIRborne Synthetic Aperture (AIRSAR) radar instrument aboard a DC-8 aircraft operated out of NASA's Dryden Flight Research Center. AIRSAR collects fully polarimetric data at three wavelengths; C-band (0.057 meter), L-band (0.25 meter) and P-band (0.68 meter). AIRSAR also collects cross-track and along track interferometric data that results in topographic measurements and motion detection, respectively.

    This image was collected during the Pacific Rim mission, a three-month mission from July to October 2000 that collected data at over 200 sites in eighteen countries and territories around the Pacific Rim. AIRSAR is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, D.C.

    Size: 10 km (6.2 miles) x 10 km (6.2 miles) Location: 14.02 deg. North lat., 171.52 deg. West Orientation: North at top Date Acquired: August 10, 2000

  17. Upolu Island, Western Samoa

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Island nations in the South Pacific Ocean experience natural disasters associated with typhoons, and with their proximity to the Pacific Ocean's 'Ring of Fire.' This radar image shows most of the northern coast of the island of Upolu in the nation of Western Samoa. Disaster managers use digital elevation models (DEMs) generated from radar data to assist in research toward disaster mitigation and management. Geologists also use DEM data of volcanic features, such as the line of circular craters in this image, to study eruption rates and volumes, and volcanic landform evolution. The capital of Western Samoa, Apia, is in the lower left of the image.

    Angular black areas in the image are areas where steep topography causes holes in the data; these holes can be filled in by collecting data at other look directions. Color represents topography and intensity represents across-section of the radar backscatter. Since rough areas return more of the incident signal, they appear brighter on the image than relatively smooth areas, such as the ocean surface , along the left side of the image.

    This image was acquired by the AIRborne Synthetic Aperture (AIRSAR) radar instrument aboard a DC-8 aircraft operated out of NASA's Dryden Flight Research Center. AIRSAR collects fully polarimetric data at three wavelengths; C-band (0.057 meter), L-band (0.25 meter) and P-band (0.68 meter). AIRSAR also collects cross-track and along track interferometric data that results in topographic measurements and motion detection, respectively.

    This image was collected during the Pacific Rim mission, a three-month mission from July to October 2000 that collected data at over 200 sites in eighteen countries and territories around the Pacific Rim. AIRSAR is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, D.C.

    Size: 10 km (6.2 miles) x 63 km (37.3 miles) Location: 14.16 deg. North lat., 171.75 deg. West Orientation: North towards

  18. Glacial migrations of plants: island biogeographical evidence.

    PubMed

    Simpson, B B

    1974-08-23

    Analyses of the floras of the high north Andean habitat islands (paramos) and the Galápagos Islands show that plant species diversity conforms to the MacArthur and Wilson model of island biogeography but that immigration occurred primarily during glacial periods. Modern plant species diversity is more significantly correlated with area and distance measures of the glacial forms of the islands than with similar measures of the present-day islands. PMID:17736375

  19. Magnetic island formation in tokamaks

    SciTech Connect

    Yoshikawa, S.

    1989-04-01

    The size of a magnetic island created by a perturbing helical field in a tokamak is estimated. A helical equilibrium of a current- carrying plasma is found in a helical coordinate and the helically flowing current in the cylinder that borders the plasma is calculated. From that solution, it is concluded that the helical perturbation of /approximately/10/sup /minus/4/ of the total plasma current is sufficient to cause an island width of approximately 5% of the plasma radius. 6 refs.

  20. Circulation around a "skirted" island

    NASA Astrophysics Data System (ADS)

    Iacono, R.; Napolitano, E.; Pedlosky, J.; Helfrich, K.

    2009-04-01

    Assessing the role of planetary scale islands in the dynamics of the ocean circulation is both of intrinsic fluid mechanical interest and of practical importance. Until now, investigations of this problem have idealized the island as an interior "hole" in the oceanic basin whose boundaries are vertical walls. Here we take up the question of the effect of topography in the region bounding the island. We represent topography as a simple continental slope "skirt" in which the depth of the ocean linearly varies from zero at the island to the full (and constant) ocean depth at some distance both east and west of the island, which we otherwise idealize as a thin linear barrier oriented north-south. In addition to providing a possibly more realistic representation of the island topography, the presence of the skirt also introduces fundamental changes in the dynamics. When the depth change is strong enough the isolines of potential vorticity will tend to wrap around the island and close on themselves. When this closure happens a free geostrophic mode is possible in which the motion can freely circulate along the closed potential vorticity contours and the nature of the circulation alters dramatically. We study the circulation around the "skirted" island with a forced, dissipative shallow water numerical model, whose results are compared to those of laboratory experiments made with the sliced-cylinder device. We also develop an approximate analytic theory, in the linear limit, that to a large measure clarifies and explains key features of the numerical experiments with weak and moderate forcing. We conclude with a survey of results from strongly nonlinear experiments that exhibit rich time-dependent dynamics.

  1. Invasive rodent eradication on islands.

    PubMed

    Howald, Gregg; Donlan, C Josh; Galván, Juan Pablo; Russell, James C; Parkes, John; Samaniego, Araceli; Wang, Yiwei; Veitch, Dick; Genovesi, Piero; Pascal, Michel; Saunders, Alan; Tershy, Bernie

    2007-10-01

    Invasive mammals are the greatest threat to island biodiversity and invasive rodents are likely responsible for the greatest number of extinctions and ecosystem changes. Techniques for eradicating rodents from islands were developed over 2 decades ago. Since that time there has been a significant development and application of this conservation tool. We reviewed the literature on invasive rodent eradications to assess its current state and identify actions to make it more effective. Worldwide, 332 successful rodent eradications have been undertaken; we identified 35 failed eradications and 20 campaigns of unknown result. Invasive rodents have been eradicated from 284 islands (47,628 ha). With the exception of two small islands, rodenticides were used in all eradication campaigns. Brodifacoum was used in 71% of campaigns and 91% of the total area treated. The most frequent rodenticide distribution methods (from most to least) are bait stations, hand broadcasting, and aerial broadcasting. Nevertheless, campaigns using aerial broadcast made up 76% of the total area treated. Mortality of native vertebrates due to nontarget poisoning has been documented, but affected species quickly recover to pre-eradication population levels or higher. A variety of methods have been developed to mitigate nontarget impacts, and applied research can further aid in minimizing impacts. Land managers should routinely remove invasive rodents from islands <100 ha that lack vertebrates susceptible to nontarget poisoning. For larger islands and those that require nontarget mitigation, expert consultation and greater planning effort are needed. With the exception of house mice (Mus musculus), island size may no longer be the limiting factor for rodent eradications; rather, social acceptance and funding may be the main challenges. To be successful, large-scale rodent campaigns should be integrated with programs to improve the livelihoods of residents, island biosecurity, and reinvasion response

  2. Heat Island and Smog Reduction Act of 2011

    THOMAS, 112th Congress

    Rep. Connolly, Gerald E. [D-VA-11

    2011-01-05

    02/08/2011 Referred to the Subcommittee on Government Organization, Efficiency, and Financial Management . (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  3. Heated Goggles

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The electrically heated ski goggles shown incorporate technology similar to that once used in Apollo astronauts' helmet visors, and for the same reason-providing fogfree sight in an activity that demands total vision. Defogging is accomplished by applying heat to prevent moisture condensation. Electric heat is supplied by a small battery built into the h goggles' headband. Heat is spread across the lenses by means of an invisible coating of electrically conductive metallic film. The goggles were introduced to the market last fall. They were designed by Sierracin Corporation, Sylmar, California, specialists in the field of heated transparent materials. The company produces heated windshields for military planes and for such civil aircraft as the Boeing 747, McDonnell Douglas DC-10 and Lockheed L-1011 TriStar.

  4. Radiometric evidence for involvement of floating islands in the formation of Florida Everglades tree islands

    NASA Astrophysics Data System (ADS)

    Gleason, Patrick J.; Piepgras, Donald; Stone, Peter A.; Stipp, Jerry

    1980-04-01

    Inversions of radiocarbon dates were determined on samples from the peat profiles of two small extant tree islands in the northeastern Everglades, Florida. These reversals were predicted from the theory that such tree islands developed on laterally displaced floating islands.

  5. 33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-westernmost point on Sapelo Island to Wolf Island. (h) A north-south line (longitude 81°17.1′ W.) drawn from the south-easternmost point of Wolf Island to the northeasternmost point on Little St. Simons...

  6. 33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-westernmost point on Sapelo Island to Wolf Island. (h) A north-south line (longitude 81°17.1′ W.) drawn from the south-easternmost point of Wolf Island to the northeasternmost point on Little St. Simons...

  7. 33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-westernmost point on Sapelo Island to Wolf Island. (h) A north-south line (longitude 81°17.1′ W.) drawn from the south-easternmost point of Wolf Island to the northeasternmost point on Little St. Simons...

  8. 33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-westernmost point on Sapelo Island to Wolf Island. (h) A north-south line (longitude 81°17.1′ W.) drawn from the south-easternmost point of Wolf Island to the northeasternmost point on Little St. Simons...

  9. 33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-westernmost point on Sapelo Island to Wolf Island. (h) A north-south line (longitude 81°17.1′ W.) drawn from the south-easternmost point of Wolf Island to the northeasternmost point on Little St. Simons...

  10. 46 CFR 7.80 - Tybee Island, GA to St. Simons Island, GA.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... southernmost extremity of Savannah Beach on Tybee Island 255° true across Tybee Inlet to the shore of Little... extremity of Little Tybee Island at Beach Hammock to the easternmost extremity of Wassaw Island. (c) A...

  11. Mars Researchers Rendezvous on Remote Arctic Island

    NASA Technical Reports Server (NTRS)

    2002-01-01

    ice.

    The data were captured on June 28, 2001, during the early part of the arctic summer, when sea ice becomes thinner and begins to move depending upon localized currents and winds. In winter the entire region is locked with several meters of nearly motionless sea ice, which acts as a thermodynamic barrier to the loss of heat from the comparatively warm ocean to the colder atmosphere. Summer melting of sea ice can be observed at the two large, dark regions of open water; one is present in the Jones Sound (near the top to the left of center), and another appears in the Wellington Channel (left-hand edge). A large crack caused by tidal heaving has broken the ice cover over the Parry Channel (lower right-hand corner). A substantial ice cap permanently occupies the easternmost third of the island (upper right). Surface features such as dendritic meltwater channels incised into the island's surface are apparent. The Haughton-Mars project site is located slightly to the left and above image center, in an area which appears with relatively little surface ice, near the island's inner 'elbow.'

    The images were acquired during Terra orbit 8132 and cover an area of about 334 kilometers x 229 kilometers. They utilize data from blocks 27 to 31 within World Reference System-2 path 42.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  12. 46 CFR 7.85 - St. Simons Island, GA to Little Talbot Island, FL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 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... Island Light. (b) A line drawn from the southernmost extremity of Amelia Island to latitude 30°29.4′...

  13. 46 CFR 7.85 - St. Simons Island, GA to Little Talbot Island, FL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 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... Island Light. (b) A line drawn from the southernmost extremity of Amelia Island to latitude 30°29.4′...

  14. 46 CFR 7.85 - St. Simons Island, GA to Little Talbot Island, FL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 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... Island Light. (b) A line drawn from the southernmost extremity of Amelia Island to latitude 30°29.4′...

  15. 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... Island Light. (b) A line drawn from the southernmost extremity of Amelia Island to latitude 30°29.4′...

  16. 46 CFR 7.85 - St. Simons Island, GA to Little Talbot Island, FL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 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... Island Light. (b) A line drawn from the southernmost extremity of Amelia Island to latitude 30°29.4′...

  17. 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.

  18. Genetic determinants of heat resistance in Escherichia coli

    PubMed Central

    Mercer, Ryan G.; Zheng, Jinshui; Garcia-Hernandez, Rigoberto; Ruan, Lifang; Gänzle, Michael G.; McMullen, Lynn M.

    2015-01-01

    Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR). This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli. PMID:26441869

  19. Energy Conservation Measures for the Charles E. Shea Senior High School, Pawtucket, Rhode Island. Public Service Report.

    ERIC Educational Resources Information Center

    New England Innovation Group, Providence, RI.

    Presented is a study of energy conservation opportunities in a Rhode Island high school. With the aid of an infrared camera system, researchers documented heat losses that were not evident to the naked eye. Each infrared thermogram obtained showed one or more types of heat loss and identified the specific sections of the building where the…

  20. Heat stroke.

    PubMed

    Leon, Lisa R; Bouchama, Abderrezak

    2015-04-01

    Heat stroke is a life-threatening condition clinically diagnosed as a severe elevation in body temperature with central nervous system dysfunction that often includes combativeness, delirium, seizures, and coma. Classic heat stroke primarily occurs in immunocompromised individuals during annual heat waves. Exertional heat stroke is observed in young fit individuals performing strenuous physical activity in hot or temperature environments. Long-term consequences of heat stroke are thought to be due to a systemic inflammatory response syndrome. This article provides a comprehensive review of recent advances in the identification of risk factors that predispose to heat stroke, the role of endotoxin and cytokines in mediation of multi-organ damage, the incidence of hypothermia and fever during heat stroke recovery, clinical biomarkers of organ damage severity, and protective cooling strategies. Risk factors include environmental factors, medications, drug use, compromised health status, and genetic conditions. The role of endotoxin and cytokines is discussed in the framework of research conducted over 30 years ago that requires reassessment to more clearly identify the role of these factors in the systemic inflammatory response syndrome. We challenge the notion that hypothalamic damage is responsible for thermoregulatory disturbances during heat stroke recovery and highlight recent advances in our understanding of the regulated nature of these responses. The need for more sensitive clinical biomarkers of organ damage is examined. Conventional and emerging cooling methods are discussed with reference to protection against peripheral organ damage and selective brain cooling. PMID:25880507

  1. Heat Problems.

    ERIC Educational Resources Information Center

    Connors, G. Patrick

    Heat problems and heat cramps related to jogging can be caused by fluid imbalances, medications, dietary insufficiency, vomiting or diarrhea, among other factors. If the condition keeps reoccurring, the advice of a physician should be sought. Some preventive measures that can be taken include: (1) running during the cooler hours of the day; (2)…

  2. 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.

  3. Photosymbiotic ascidians from Pari Island (Thousand Islands, Indonesia).

    PubMed

    Hirose, Euichi; Iskandar, Budhi Hascaryo; Wardiatno, Yusli

    2014-01-01

    Photosymbiotic ascidian fauna were surveyed in the subtidal zone off Pari Island in the Thousand Islands (Java Sea, Indonesia). Nine species were recorded: Didemnum molle, Trididemnum miniatum, Lissoclinum patella, L. punctatum, L. timorense, Diplosoma gumavirens, D. simile, D. simileguwa, and D. virens. All of these species have been previously recorded in the Ryukyu Archipelago, Japan. Diplosoma gumavirens and D. simileguwa were originally described from the Ryukyu Archipelago in 2009 and 2005, respectively, and all of the observed species are potentially widely distributed in Indo-West Pacific coral reefs. PMID:25061385

  4. Possible NASA Contributions to HEAT

    NASA Technical Reports Server (NTRS)

    Shepherd, J. M.

    2004-01-01

    A four-year experiment (HEAT) has been proposed (one summer in the field, 2005) to determine the sources and causes for the enhanced cloud-to-ground lightning over Houston, Texas, in association with simultaneous experiments by the Environmental Protection Agency (EPA) and the Texas Natural Resource Conservation Commission (TNRCC). Houston is the third most populous city in the United States and the region contains 50% of the petroleum refining capacity of the United States. Recent studies covering the period 1989-2000 document a 50% increase of cloud-to-ground lightning in the Houston area as compared to background values, which is second in flash density only to the Tampa Bay, Florida area. It is suggested that the elevated flash densities could result from several factors, including, 1) the convergence due to the urban heat island effect and complex sea breeze, and 2) the increasing levels of air pollution from anthropogenic sources producing numerous small droplets and thereby suppressing mean droplet size. The latter effect would enable more cloud water to reach the mixed phase region where it is involved in the formation of precipitation and the separation of electric charge, leading to an enhancement of lightning. The primary goals of HEAT are to examine the effects of (1) pollution, (2) the urban heat island, and (3) the complex coastline, on storms and lightning characteristics in the Houston area. The project is a multi- agency effort and will employ numerous observing capabilities and expertise. Dr. Shepherd has been asked to serve as a possible co- investigator to contribute expertise in areas related to urban impacts on precipitation variability. Dr. Shepherd is also a key NASA representative in the interagency effort. This presentation will provide an overview of recent NASA research focused on urban rainfall in Houston and offer potential NASA capabilities that could contribute to HEAT.

  5. Modelled trends in oceanic conditions of Pine Island Bay between 1991 and 2014

    NASA Astrophysics Data System (ADS)

    Kimuras, Satoshi; Holland, Paul; Regan, Heather; Jenkins, Adrian; Van Wessem, Melchior

    2016-04-01

    Two ice shelves in Pine Island Bay, Pine Island Glacier and its neighbour Thwaites Glacier, have been highlighted as major drainage pathways for the West Antarctic Ice Sheet. We quantify the melting of these ice shelves and oceanic conditions between 1991 and 2014 using a general circulation model. Two different atmospheric forcing scenarios (RACMO2.3 and ERA-Interim) are used as a surface boundary. The ocean heat content of the Pine Island Bay from the simulations shows periodic decrease in the late 1990s and 2012-2014, but the magnitude of cooling is different between RACMO2.3 and ERA-Interim forced simulations. The brine rejection of the sea ice production causes enhanced overturning and cools the water north of Pine Island Glacier Ice Shelf. This cold water flows southward along the coastline, resulting in lower melt rate in the late 1990s and 2012-2014.

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

    SciTech Connect

    Matthews, Stuart; Hacker, Jorg M.; Cole, Jason N.; Hare, Jeffrey; Long, Charles N.; Reynolds, R. M.

    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 the 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.

  7. Identification of an Island-induced Alfvén Eigenmode in MST plasmas

    NASA Astrophysics Data System (ADS)

    Anderson, J. K.; Cook, C. R.; Hegna, C. C.; Boguski, J.; Feng, R.; McCollam, K. M.; Sears, S. H.; Spong, D. A.; Hirshman, S. P.

    2015-11-01

    Recent theoretical work analytically computes the effect of a magnetic island on the shear Alfvén continuum and may explain unresolved Alfvénic activity observed in neutral beam-heated MST plasmas. Consideration of the previously-ignored core-localized n=5 island leads to theoretical Alfvén continua that provide a gap in which the observed n=4 Alfvénic bursts reside. Numerical simulations using the STELLGAP/AE3D codes, as well as a new code called SIESTAlfvén have identified the bursts as the first observation of an Island-induced Alfvén Eigenmode (IAE). The IAE arises from a helical coupling of mode numbers, similar to the helicity-induced Alfvén eigenmode, but occurs in the core of an island. The observed frequency of bursting n=4 Alfvénic modes fall within the island-induced gap over a wide range of MST operating parameters. Characteristics such as mode frequency, width and damping rate are measured as a function of experimentally-varied magnetic island width. Coincident bursts with toroidal mode number n=1 may exhibit frequency scaling of an Alfvénic eigenmode; the possibility of an island induced extremum mode is explored as an explanation. Work supported by US DoE under grants DE-FG02-99ER54546, DE-SC0006103 and DE-FC02-05ER54814.

  8. 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

  9. Late Quaternary climate change shapes island biodiversity.

    PubMed

    Weigelt, Patrick; Steinbauer, Manuel Jonas; Cabral, Juliano Sarmento; Kreft, Holger

    2016-04-01

    Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration-extinction dynamics, or as geologically dynamic with biodiversity resulting from immigration-speciation-extinction dynamics influenced by changes in island characteristics over millions of years. Present climate and spatial arrangement of islands, however, are rather exceptional compared to most of the Late Quaternary, which is characterized by recurrent cooler and drier glacial periods. These climatic oscillations over short geological timescales strongly affected sea levels and caused massive changes in island area, isolation and connectivity, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory. Consequences of these oscillations for present biodiversity remain unassessed. Here we analyse the effects of present and Last Glacial Maximum (LGM) island area, isolation, elevation and climate on key components of angiosperm diversity on islands worldwide. We find that post-LGM changes in island characteristics, especially in area, have left a strong imprint on present diversity of endemic species. Specifically, the number and proportion of endemic species today is significantly higher on islands that were larger during the LGM. Native species richness, in turn, is mostly determined by present island characteristics. We conclude that an appreciation of Late Quaternary environmental change is essential to understand patterns of island endemism and its underlying evolutionary dynamics. PMID:27027291

  10. Yaws in the Solomon Islands.

    PubMed

    Fegan, D; Glennon, M; Macbride-Stewart, G; Moore, T

    1990-02-01

    Yaws is a chronic, relapsing, non-venereally transmitted disease caused by Treponema pertenue. As a result of the WHO mass treatment campaign of the late 1950s, the prevalence in the Solomon Islands fell dramatically. Here the disease was thought to have been eradicated until an outbreak occurred in 1981. In 1984 a mass treatment survey following modified WHO guidelines was carried out. Subsequent to this campaign, yaws recurred and in 1987 a further treatment survey was required. Two observations were made as a result of our recent experience in controlling yaws in the Solomon Islands. (1) The disease appears to be attenuated. (2) WHO control policy may now be an inappropriate method for dealing with yaws in the Solomon Islands and should be replaced by a method which is integrated into the existing primary health care (PHC) structure. PMID:2304133

  11. Dust Storm Hits Canary Islands

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A thick pall of sand and dust blew out from the Sahara Desert over the Atlantic Ocean yesterday (January 6, 2002), engulfing the Canary Islands in what has become one of the worst sand storms ever recorded there. In this scene, notice how the dust appears particularly thick in the downwind wake of Tenerife, the largest of the Canary Islands. Perhaps the turbulence generated by the air currents flowing past the island's volcanic peaks is churning the dust back up into the atmosphere, rather than allowing it to settle toward the surface. This true-color image was captured by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite, on January 7, 2002. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  12. Recharge Data for Hawaii Island

    DOE Data Explorer

    Nicole Lautze

    2015-01-01

    Recharge data for Hawaii Island in shapefile format. The data are from the following sources: Whittier, R.B and A.I. El-Kadi. 2014. Human Health and Environmental Risk Ranking of On-Site Sewage Disposal systems for the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final, Prepared for Hawaii Dept. of Health, Safe Drinking Water Branch by the University of Hawaii, Dept. of Geology and Geophysics. Oki, D. S. 1999. Geohydrology and Numerical Simulation of the Ground-Water Flow System of Kona, Island of Hawaii. U.S. Water-Resources Investigation Report: 99-4073. Oki, D. S. 2002. Reassessment of Ground-water Recharge and Simulated Ground-Water Availability for the Hawi Area of North Kohala, Hawaii. U.S. Geological Survey Water-Resources Investigation report 02-4006.

  13. Hawaii Island Groundwater Flow Model

    DOE Data Explorer

    Nicole Lautze

    2015-01-01

    Groundwater flow model for Hawaii Island. Data is from the following sources: Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume II – Island of Hawaii Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2008; and Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014.

  14. Heat collector

    DOEpatents

    Merrigan, M.A.

    1981-06-29

    A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

  15. Heat collector

    DOEpatents

    Merrigan, Michael A.

    1984-01-01

    A heat collector and method suitable for efficiently and cheaply collecting solar and other thermal energy are provided. The collector employs a heat pipe in a gravity-assist mode and is not evacuated. The collector has many advantages, some of which include ease of assembly, reduced structural stresses on the heat pipe enclosure, and a low total materials cost requirement. Natural convective forces drive the collector, which after startup operates entirely passively due in part to differences in molecular weights of gaseous components within the collector.

  16. 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.