There is an important new article on the role of urban temperatures in the January-February 2010 issue of NASA’s The Earth Observer.
The 2010 article is on page 36-37 and is titled
Ecosystem, Vegetation Affect Intensity of Urban Heat Island Effect by Mike Carlowicz, ofNASA’s Earth Science News Team. The Earth Observer. Volume 22 Issue 1. pages 36-37.
Excerpts from the article are
“Goddard researchers including [Marc] Imhoff, Lahouari Bounoua, Ping Zhang, and Robert Wolfe presented their findings at the Fall Meeting of the American Geophysical Union in San Francisco, CA on December 16.”
“When examining cities in arid and semi-arid regions —such as North Africa and the American Southwest—scientists found that they are only slightly warmer than surrounding areas in summer and sometimes cooler than surrounding areas in winter. In the U.S., the summertime urban heat island (UHI) for desert cities like Las Vegas was 0.83°F (0.46°C) lower than surrounding areas, compared to 18°F (10°C) higher for cities like Baltimore. Globally, the differences were not as large, with a summertime UHI of -0.38°F (-0.21°C) for desert cities compared to +6.8°F (+3.8°C) for cities in forested regions.”
“The open question is: do changes in land cover and urbanization affect global temperatures and climate?” Imhoff [Marc Imhoff added. “Urbanization is perceived as a relatively small effect, and most climate models focus on how the oceans and atmosphere store and balance heat. Urban heat islands are a lot of small, local changes, but do they add up? Studies of the land input are still in early stages.”