HOUSTON, June 7 (UPI) -- U.S. researchers say widespread urban development alters weather patterns in a way that can increase warm-weather pollutant levels.
The study, focusing on Houston and led by the National Center for Atmospheric Research, suggests a proliferation of strip malls, subdivisions and other paved areas may interfere with breezes needed to clear away smog and other pollution, with implications for air quality in fast-growing U.S. coastal cities and other mid-latitude regions overseas, a release from the National Science Foundation reported Tuesday.
Because pavement soaks up heat and keeps land areas relatively warm overnight, the contrast between land and sea temperatures is reduced during the summer, which in turn causes a reduction in nighttime winds that would otherwise blow pollutants out to sea, the researchers said. Built-up areas interfere with local winds and contribute to relatively stagnant afternoon conditions, they found.
The researchers focused on the Houston area and combined extensive atmospheric measurements with computer simulations to examine the impact of pavement on breezes in that city.
"The developed area of Houston has a major impact on local air pollution," said NCAR scientist Fei Chen, lead author of the new study. "If the city continues to expand, it's going to make the winds even weaker in the summertime, and that will make air pollution much worse."
Houston, known for its abundance of petrochemical facilities, sprawling suburbs and traffic jams that stretch for miles, has some of the highest levels of ground-level ozone and other air pollutants in the United States, the study said.
