If you find the summer heat hard to take, cities are the worst places to be. Artist-researcher Nickolay Lamm has turned his attention to mapping New York City's heat with a thermal camera.

The side of a skyscraper: Sunlight is incident from the right and leads the right-facing wall (red) to be warmer than the front-facing wall (mainly light green). Windows of the front-facing wall are relatively cool (dark green), probably due to contact with air conditioners. The metallic roof reflects sunlight and remains relatively cool, almost invisible in this image.

The Freedom Tower.

The south-facing wall of the Freedom Tower receives direct sunlight, and is warmer (green) than the other vertical surfaces of the building (mainly blue). However, the south-facing walls of the older buildings tend to be warmer (red) than the south-facing wall of the Freedom Tower. Highly reflecting materials on the surface of buildings reduce the urban heat island effect.

The Empire State Building.

Structural materials in vertical walls of the Empire State Building become warm when exposed to sunlight (red) while windows in contact with an air-conditioned interior remain cooler (blue). The background sky is cold and appears black.

A New York City crosswalk.

The white strips of the crosswalk reflect sunlight and are therefore cooler (yellow, orange) than the street’s dark surface (red). Contact with the air keeps the sewer grate cool (green).

The direct release of heat to the air in cities is called “anthropogenic heat release.”

The area near the engine at the rear of the bus is relatively warm (green) compared to the street and the passenger area (blue). The warmest regions are near the vents (red) that release heat from the engine.

The Statue of Liberty.

The water remains relatively cool (blue) all day while the Statue of Liberty warms when exposed to the sun. A haze layer exists near the ground, and the particles and droplets in this layer emit “longwave thermal radiation” in the far infrared portion of the spectrum. The haze nearest to the ground is relatively warm while the temperature decreases with altitude.


Visualizing How New York City Heats Up In The Summertime

There's something about the sticky, humid (and smelly) heat in cities that makes people want to run for the hills. Using a thermal camera, these graphics explain how a city gets hot and stays hot.

If you find the summer heat hard to take, cities are the worst places to be. Studies show that urban spaces can be up to three degrees hotter than surrounding areas. That's because of the "heat island effect"—which is what you get from paving every available surface with heat-absorbing asphalt and concrete.

We've featured some of the work of artist-researcher Nickolay Lamm before (for example, these epic visualizations of New York's inequality problem). Here, he turns his attention to New York's heat.

Lamm snapped these images with a thermal camera on a five-hour whirlwind trip from Pittsburgh (which he talks about here). He teamed up with John Frederick, a heat island expert at the University of Chicago, who explained exactly why some parts of the city are hotter than others (see the slide show for more information on that).

All this heat we're trapping isn't merely an uncomfortable inconvenience. Each extra degree adds to air conditioning bills and increases energy consumption; it also raises health risks for the elderly and vulnerable. Painting more roofs white would help, as would more trees. Cities should also think about new colors for pavements, as we discussed here.

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  • Anthony Reardon

    Yeah. Interesting subject. Now I heard I think it was Chicago experimenting with different kinds of paving materials to allow more natural heat and fluid transfers rather than absorption and channeling.

    I've been a big fan of the idea of energy entropy- that if you use some kind of energy, you get another kind of energy. I saw that done in the Prius braking system, for instance, where power that normally gets wasted when applied actually can end up getting recycled back in.

    Take for instance these graphics of temperature differences. I bet systems could be built to turn that into power and thus mitigate the negative impacts. It's basic physics and engineering really. With heating and air conditioning, for example, you use power to create a separation or difference of temperature in an area. It just makes sense that if you have such a difference, you should be able to convert that back to power.

    Best, Anthony