This is a feature story published by the U.S. Department of Energy (DOE) Office of Science and shared with permission.
For decades, scientists have debated the impact of human-made and environmental particles in the atmosphere, called aerosols, on severe weather. Climate studies suggest aerosols may help shape and even strengthen elements of storms such as rainfall and lightning.
However, studying aerosols in the atmosphere is difficult. There are many types, and the particles are small. Their chemical and physical processes can also be subtle or short-lived. Scientists have voiced the need for more detailed data on aerosols. New data are especially needed to improve the representation of clouds and storms in climate models.
To provide these important data for scientists, policymakers, and the public, the DOE Office of Science is supporting a team of researchers who are scanning clouds in the Texas sky at high resolution. By tracking aerosols and clouds in this way, the team hopes to better understand the relationship between the particles, clouds, and storms.
DOE’s Mobile Atmospheric Observatory
A new project called TRACER—TRacking Aerosol Convection interactions ExpeRiment—is using a DOE mobile observatory from the Atmospheric Radiation Measurement (ARM) user facility to record micro processes happening in clouds. The experiment runs from October 2021 to September 2022 in the Houston, Texas, area.
The ARM observatory consists of portable shelters outfitted with instruments and communications equipment. The observatory site may look inconspicuous—but it is one of the world’s most advanced facilities for collecting atmospheric data.
The Office of Science’s Biological and Environmental Research (BER) program manages several ARM observatories as a multi-laboratory user facility. For over 30 years, research campaigns have taken these mobile stations to the frontiers of climate and atmospheric science—from the South Pole to the North Pole to the tropics. The data collected from these field expeditions help improve climate model predictions.
Advancing Our Understanding of Aerosols
[perfectpullquote align=”left” bordertop=”false” cite=”Michael Jensen, TRACER principal investigator” link=”” color=”” class=”” size=””]“Convective clouds act as the elevators of the atmosphere. They’re vertically developed and tend to transport water vapor, heat, momentum, and particles from the surface up to the atmosphere.”[/perfectpullquote]
Aerosols are human-made and natural particles that make their way into the atmosphere. Human-made aerosols may include pollutants emitted from automobiles or industrial plants. Natural aerosols may include sea salt, dust, wildfire smoke, and other particles from the environment, either nearby or carried hundreds of miles by wind and weather.
“One of the major questions of the TRACER campaign is the extent to which atmospheric aerosols can make storms more severe,” said Shaima Nasiri, BER Atmospheric System Research (ASR) program manager.
Connecting the dots between small particles and storms is a complex problem. Fortunately, solving multiscale problems such as this one, spanning fundamental chemistry to global climate modeling, is a specialty of the Office of Science.
TRACER is led by DOE’s Brookhaven National Laboratory principal investigator Michael Jensen, with many co-investigators across other DOE national laboratories, the University of Houston, and scientists around the globe. The one-year campaign will focus on aerosols found in deep convective clouds—a common type of storm cloud.
“Convective clouds act as the elevators of the atmosphere,” Jensen said. “They’re vertically developed and tend to transport water vapor, heat, momentum, and particles from the surface up to the atmosphere.”