Why can it get so hot at times

Why can it get so hot at times?

UC expert weighs in on the science that makes Cincinnati swelter

Cincinnati is experiencing more days of extreme heat this summer than in previous decades, largely due to warmer global temperatures. But as The Cincinnati Enquirer recently reported, explanations for these higher temperatures also involve regional factors, including the city's location in a river valley and its large proportion of built environment.

Located in the Ohio River Valley, Cincinnati and the surrounding areas create ideal conditions for warm, moist air to become trapped. As reported, this leads to longer-lasting, more intense heat domes that prevent hot air from moving out of the valley.

But as the planet warms, its capacity to hold moisture increases. Moist air is much harder to cool than dry air. While the heat accumulated during the day is supposed to radiate into the atmosphere at night, increased moisture from warmer temperatures instead traps that heat, leading to warmer nights and even hotter days.

This trapped, hot air also creates problems for air quality, said George Leikauf, PhD, co-director of the University of Cincinnati's Center for Collaboration on Climate & Community for Health and professor in the Division of Pulmonary, Critical Care and Sleep Medicine within the College of Medicine's Department of Internal Medicine.

He said that when people start their cars in the morning, for example, the fuel in the engine combines with oxygen during combustion, but not all of it burns completely. This process releases nitrogen oxides and volatile organic hydrocarbons, which - when exposed to sunlight - trigger a chemical reaction that produces ozone.

Ozone, along with other particulates, such as those from the Canadian wildfires, is also trapped in the valley.

Another factor is that, like any metropolitan area, Cincinnati has continued to replace green spaces and trees with impermeable surfaces, such as roads, parking lots, and sidewalks. These surfaces absorb heat.

In areas with more built infrastructure and industrialization, temperature differences between neighborhoods during the warmer months range from 5 to 10 degrees because of more impermeable surfaces and less green space.

Read the full story from The Cincinnati Enquirer.

Featured image at top: iStock/piyaset.

Related Stories