Mapping Urban Heat From the Ground Up

Published: 30 August 2022

Team supporting ARM’s TRACER campaign develops technique to map urban heat islands at unprecedented scales

The following is based on a story by Stephanie Kossman, Brookhaven National Laboratory.

With her back to the camera, Brookhaven National Laboratory scientist Katia Lamer lifts her arm to release a mini radiosonde balloon in downtown Houston, Texas.
Brookhaven National Laboratory scientist Katia Lamer prepares to release a mini radiosonde balloon in Houston, Texas, as part of a new observational technique to map the city’s urban heat island.

One year ago, scientists at Brookhaven National Laboratory in New York assembled a unique mobile observatory for surveying the climate in urban environments.

The completely off-the-grid platform maintained by Brookhaven Lab’s Center for Multiscale Applied Sensing (CMAS) employs a suite of instruments to measure atmospheric conditions at fixed locations in individual neighborhoods or while moving across entire cities.

A truck loaded with atmospheric instruments turns right onto a street in downtown Houston, Texas.
This mobile observatory, seen operating in Houston in June 2022, measures atmospheric conditions at fixed locations in individual neighborhoods or while moving across entire cities. The platform is maintained by Brookhaven Lab’s Center for Multiscale Applied Sensing (CMAS).

Now, researchers have taken the mobile observatory on a 1,700-mile journey from Upton, New York, to Houston, Texas, where they measured air temperature and relative humidity using a new observational technique.

Their work—recently featured by Wired, Popular Science, and New York’s TBR News Media—could help improve climate prediction models and address infrastructure and energy needs across the nation.

The mobile observatory was initially deployed to Houston to support two field campaigns aimed at studying deep convective clouds.

The U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) user facility is conducting the yearlong TRacking Aerosol Convection interactions ExpeRiment (TRACER) through September 2022.

The CMAS observatory also went to Houston to collect data for the Experiment of Sea Breeze Convection, Aerosols, Precipitation and Environment (ESCAPE), funded by the National Science Foundation.

Getting Creative

In the video above, Lamer, director of operations at CMAS, gives an overview of the mobile observatory’s work in Houston and her team’s new technique for mapping urban heat islands.

When scientists descended on the typically stormy city of Houston for TRACER’s summertime intensive operational period, the storms they came to study fizzled out.

Following the mobile observatory’s successful first deployment in Manhattan, New York, where researchers measured surface temperature and wind patterns to investigate the impact of solar heating on airflow around skyscrapers, the team sought to collect new data on the horizontal and vertical variability of urban heat.

Led by Katia Lamer, director of operations at CMAS and a scientist at Brookhaven Lab, the team developed and employed a measurement approach involving the release of 32 miniature radiosonde balloons from the suburbs through downtown Houston.

As the balloons rose, they began transmitting climate data back to antennas installed on two mobile observatories.

The new measurement approach enabled the team to map Houston’s urban heat island—a phenomenon thought to be associated with a dome of hotter air centered around the densest development in a city—at an unprecedented scale.

Despite the lack of storms during its time in Houston, the CMAS observatory gathered data that will benefit ESCAPE and TRACER.

“The measurements collected by the CMAS truck will also contribute to TRACER science objectives by helping to characterize the regional variability, including within the urban center, of the environment in which clouds and convection form,” says TRACER’s lead scientist, Michael Jensen, a meteorologist at Brookhaven Lab. “This is an important contribution to the interpretation of TRACER observations and as a constraint for high-resolution modeling studies.”

To learn more about the CMAS team’s work in Houston, read the full Brookhaven Lab feature story.

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ARM is a DOE Office of Science user facility operated by nine DOE national laboratories.