Even though America faces natural emergencies like tornadoes, floods, and hurricanes, it is the excessive heat that harms more people than all aforementioned hazards combined. A meteorological phenomenon that has been catapulted into the foray thanks to global warming now stands right in the faces of the American people. The question of action becomes imminent, and the first step that looks to explain the problem stops at heat mapping.
What are heat Islands?
Due to the expansive construction of buildings with concrete, roads, and the production of anthropogenic warmth inside big cities, extreme heat can be trapped on surfaces. This creates Urban Heat Island effect, where cities tend to be hotter than surrounding rural areas that have more green space and trees. The effect is intensified as cities grow and in areas with little vegetation.
How is mapping an area beneficial?
Mapping the heat in different areas and counties of the country can be the answer to many complications, one of them is to understand why the heat is disproportionately spread even in close areas. By measuring temperatures in thousands of locations across cities, this heat mapping effort can reveal the areas within the city that are warmest and why these patterns in temperatures occur. Further, knowledge of heat distribution will help inform heat mitigation efforts to avoid adverse impacts on natural and built environments and human health, while addressing the inequitable distribution of urban heat risk and vulnerability.
In Nashville, Tennessee, a total of 142 volunteers signed up when local experts, nonprofits, and researchers teamed up to measure temperatures and humidity across Davidson County during a one-day heat mapping campaign on Sunday, August 14. The data will reveal the warmest and coolest neighborhoods in our city and help inform heat mitigation efforts by city public health and environmental officials, nonprofits, urban planners, urban foresters, and researchers once processed.
The initiative is headed by the National Oceanic and Atmospheric Administration (NOAA), which for six years has made it possible to study some 70 counties across the country, with the help of residents.
The volunteers, who were also called ‘community scientists,’ drove around Nashville along pre-determined routes in their cars. They were given three-time slots; 6 am, 3 pm, and 7 pm on a hot and dry day. A specially designed sensor that looked like a hammer was placed out of the window of the passenger side at all times to collect the data along the route. Once turned on, the device records the temperature, humidity, time, and its exact position every second.
Similarly, a campaign was also launched in Silver Spring, a suburb in Washington. In total, more than a hundred people took part in the experiment in a day: 57 teams of two traveled 19 different routes, covering around 200 square miles. The temperature was measured along each route three times during the day: at 6:00 am, 3:00 pm, and 7:00 pm.
Urban heat islands form because the sun’s heat is absorbed more by impervious surfaces such as concrete, roads, and buildings, than by grass or water, for example. Planting trees is therefore essential, but other solutions are also being developed, such as ultra-reflective paints.
Today, the number of days above 90F in Montgomery County is about 19 per year. In 2050, it will be 70 days, according to Ken Graham, director of the National Weather Center, which is part of NOAA.
Thanks to the mapping campaigns carried out in recent years, “there’s been parks that have been built in some of these communities, there have been changes in roofing, a dark roof versus a light roof,” said Graham. That’s just a taste of the future we need to prepare for, he said. “It’s going to take all of us to be a climate-ready nation. And if we work together, we can do it,” French publication RFI reported.
