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!
NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center
The melting ice makes the sea around Greenland less saline
16.10.2017 | Aarhus University
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
18.10.2017 | Materials Sciences
18.10.2017 | Physics and Astronomy
18.10.2017 | Physics and Astronomy