$12 Million NSF Grant Will Establish Nationwide Atmospheric Measurement Network

Professor Nga Lee “Sally” Ng has earned a $12 million grant from the National Science Foundation (NSF) Mid-Scale Research Infrastructure program to provide high time-resolution (every 1 to 15 minutes), long-term measurements of the properties of atmospheric particulates known as aerosols, which have significant effects on health and climate change.

The award will establish a network of 12 sites around the United States, including locations in national parks, rural areas, and some of the country’s largest cities. Each will be outfitted with state-of-the-art instruments for characterizing the properties of aerosols. These sites will form what is officially called the Atmospheric Science and mEasurement NeTwork (ASCENT).

Data from ASCENT will allow researchers to address a variety of questions about how the composition and abundance of aerosols are changing, such as how the modernization of electrical production (coal to natural gas to renewable) and transportation (gasoline to electric vehicles) affect air pollution and climate-relevant variables.

“This is an incredibly exciting opportunity,” said Ng. “ASCENT represents a key advancement in atmospheric measurement infrastructure in the U.S. For the first time, we will be able to acquire comprehensive, high time-resolution, long-term characterization of aerosols over a wide range of geographical regions. ASCENT will provide the critical, fundamental knowledge for informing science-based decisions on climate change, air quality, and minimizing inequalities in air pollution exposure.”

ASCENT will also advance understanding of the adverse health impacts of PM2.5 (particulate matter with a diameter smaller than 2.5 micrometers). Exposure to PM2.5 has been associated with cardiopulmonary diseases and millions of deaths per year.

“ASCENT's long-term, advanced chemical composition and particle size measurements will facilitate transformative studies to unravel specific aerosol types and properties responsible for their adverse health effects.” - Sally Ng

“ASCENT will contribute to building a foundation to define future regulations in the U.S. for protecting public health, as aerosol sources and properties continue to evolve in a changing world.”

Aerosols impact climate by changing the Earth’s energy balance via direct absorption or scattering of solar radiation and altering the albedo (surface reflection), formation of clouds, and precipitation. The Intergovernmental Panel on Climate Change assessment established that the aerosol effects represent the single largest source of uncertainty in understanding climate change.

Competitive Edge

According to NSF, ASCENT will also allow U.S. researchers to remain competitive in a global research environment. The 2016 National Academies report on The Future of Atmospheric Chemistry Research emphasized the critical need for long-term atmospheric chemistry measurements, recommending that the NSF take the lead.

Currently, several aerosol monitoring networks exist in the United States, but none have the capability of measuring aerosol chemical and physical properties at high timeresolution (highly regular intervals of measurement).

The ASCENT network’s 12 sites across the United States are strategically located in rural, urban, and remote sites that have pre-existing infrastructure for atmospheric monitoring.

Each site will be equipped with four advanced instruments: an Aerosol Chemical Speciation Monitor (ACSM, non-refractory aerosols), Xact (trace metals), Aethalometer (black/brown carbon), and Scanning Mobility Particle Sizer (SMPS, aerosol number size distribution and concentration).

The sites include: Delta Junction, Alaska; Cheeka Peak/Makah, Washington; Los Angeles/Pico Rivera, California; Rubidoux, California; Joshua Tree National Park, California; Yellowstone National Park, Wyoming; Denver, Colorado; Houston, Texas; Pittsburgh, Pennsylvania; New York City; Atlanta, Georgia; and Great Smoky Mountain National Park, Tennessee.