Summer land surface temperatures of cities in the Northeast were an average of 13°F to 16°F (7°C to 9°C) warmer than surrounding rural areas over a three year period, the new research shows. The complex phenomenon that drives up temperatures of cities such as Boston, Philadelphia, and Washington D.C. is called the urban heat island effect.
By comparing 42 cities in the Northeast, the researchers have demonstrated that a city's development pattern can have a significant impact on the strength of a city's heat island. They found that densely-developed cities with compact urban cores are more apt to produce strong urban heat islands than more sprawling, less intensely-developed cities.
The new research relating development patterns and heat islands is part of a broader effort by scientists at NASA's Goddard Space Flight Center in Greenbelt, Md. to study urban heat islands all around the globe. By analyzing data from thousands of settlements, the Goddard team has pinpointed a set of key city characteristics that drive the development of strong heat islands.
"This, at least to our knowledge, is the first time that anybody has systematically compared the heat islands of a large number of cities at continental and global scales," said Ping Zhang, a researcher at Goddard and the lead author of the research.
The largest cities, their analysis shows, usually have the strongest heat islands. Cities located in forested regions, such as the northeastern United States, also have stronger heat islands than cities situated in grassy or desert environments.
"The urban heat island is a relative measure comparing the temperature of the urban core to the surrounding area," said Marc Imhoff, the leader of the NASA Goddard research group. "As a result, the condition of the rural land around the city matters a great deal."
The method used to compare the cities, which the team of scientists has honed for about two years, involves the use of maps of impervious surface area produced by the United States Geological Survey-operated Landsat satellite, and surface temperature data from the Moderate-resolution Imaging Spectroradiometer (MODIS), an instrument aboard NASA's Aqua and Terra satellites.
Development produces heat islands by replacing vegetation, particularly forests, with pavement, buildings, and other infrastructure. This limits plant transpiration, an evaporative process that helps cool plant leaves and results in cooler air temperatures, explained Robert Wolfe, one of the Goddard scientists who conducted the new research.
Dark city infrastructure, such as black roofs, also makes urban areas more apt to absorb and retain heat. Heat generated by motor vehicles, factories, and homes also contributes to the development of urban heat islands.
Of the 42 northeastern U.S. cities most-recently analyzed, Providence, R.I.; Washington, D.C.; Philadelphia, Pa.; Baltimore, Md.; Boston, Mass.; and Pittsburgh, Pa. had some of the strongest heat islands.For more information about this topic, please visit this page:
Sarah DeWitt | EurekAlert!
UCI and NASA document accelerated glacier melting in West Antarctica
26.10.2016 | University of California - Irvine
Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union
Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.
So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
28.10.2016 | Power and Electrical Engineering
28.10.2016 | Physics and Astronomy
28.10.2016 | Life Sciences