Advancing our understanding of atmospheric composition and climate

The Chemical Sciences Laboratory (CSL) is one of ten NOAA Research Laboratories located throughout the United States organized under the office of Oceanic & Atmospheric Research (OAR). CSL is one of four individual OAR labs located within the David Skaggs Research Center (DSRC) in Boulder, Colorado. The research conducted at CSL aims to advance scientific understanding of the chemical and physical processes that affect Earth's atmospheric composition and climate.

Researchers from NOAA CSL and CIRES, along with numerous federal and academic partners, have begun a coordinated set of nationwide, atmospheric field campaigns that will span the summer of 2023. The field campaigns, collectively known as AGES+, bring together a series of individual airborne and ground-based projects led by NOAA, NASA, NCAR, DoE, and several universities with the joint goal of applying next-generation measurement capabilities to investigating our modern-day mix of urban air pollution.

The NOAA effort is headlined by CSL’s Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) and Coastal Urban Plume Dynamics Study (CUPiDS) airborne campaigns, alongside coordinated NOAA CPO AC4-funded ground sites, deploying state-of-the-art instruments and models to investigate how the mix of air pollution sources in urban environments have shifted over recent decades and have affected near-surface ozone production and particulate matter formation.

The AEROMMA campaign was the first to launch, with research flights beginning in late June off the coast of California. The project is using NASA’s DC-8 research aircraft, loaded with instruments specially designed to measure an array of important trace gases, including ozone, volatile organic compounds, and sulfur compounds, as well as aerosol properties, such as size distribution, chemical composition, and reflectivity. The first week of flights are targeting marine emissions of sulfur compounds that react in the air to produce sulfate aerosols. Sulfate aerosols can scatter or reflect sunlight and can also lead to formation of marine clouds–properties that make them an important factor for climate.

After the marine flights, the NASA DC-8 and AEROMMA scientists will shift their focus to East Coast urban air quality research, where it will join CUPiDS and the other AGES+ campaigns to investigate the causes of persistent air quality problems over New York City, Chicago, and Toronto. The airborne measurements are also of vital importance for validating the recently-launched TEMPO geostationary atmospheric composition satellite instrument, which is serving as a proving ground for NOAA’s next-generation GeoXO mission.

The summer of 2021 was a smoky one for Denver and northeastern Colorado.

Smoky haze from wildfires in Arizona, California, and the Pacific Northwest shrouded the Front Range mountains and cast a gray pallor over the sky on a near-daily basis. The typical pattern of monsoon-driven summer thunderstorms that normally flush out stagnant air in July and August largely failed to materialize, allowing smog cooked under the summer sun in 90-degree heat to pool along the base of the foothills to the west.

All that added up to a record number of days when ground-level ozone, which has long bedeviled the “Queen City of the Plains,” exceeded the 2015 National Ambient Air Quality Standard (NAAQS) of 70 parts per billion averaged over 8 hours set by the US Environmental Protection Agency. In 2022, the U.S. Environmental Protection Agency proposed to downgrade the northern Front Range from a “serious” to “severe” violator of the 2008 federal ozone standard.

So how bad was it?

“The smoke was unpleasant to be sure,” said Andrew Langford, a research chemist with NOAA’s Chemical Sciences Laboratory, and lead author of a paper published today in the Journal of Geophysical Research: Atmospheres. ”Particulates, which you can see, only exceeded the air quality standard a few times that summer. Ozone exceeded the standard on more than half the days. But you can’t see ozone, so this was a much more insidious problem.”

Two Cooperative Institute researchers at CSL received Outstanding Performance Awards at the annual CIRES Rendezvous in May. The CIRES Outstanding Performance Award (OPA) recognizes Cooperative Institute for Research in Environmental Sciences (CIRES) employees who have uncommon initiative, resourcefulness, and/or scientific creativity conducting research with potential to expand or change the direction of a particular field or discipline. It also recognizes participation in collaborative and/or multidisciplinary research that engages a broader cross-section than the researcher's typical scientific or engineering community.

Max Holloway received an OPA in the Science and Engineering category for extraordinary support of the Atmospheric Remote Sensing group's instrument development and field deployments, including the CalFiDE wildfire research campaign. Max Holloway's impressive skills in hardware design, CAD, mechanical fabrication, assembly and modification, as well as his extensive knowledge and skill in electronics, have propelled the group's instrument development and field campaign successes.

Lizzy Asher received an OPA in the Science and Engineering category for pioneering deployment of aerosol instrumentation for long-duration flights in the stratosphere – work that has produced illuminating new data. Lizzy Asher is a key contributor to NOAA's Balloon Baseline Stratospheric Aerosol Profiles (B2SAP) project where she has pioneered the deployment of Portable Optical Particle Spectrometers (POPS) at multiple locations and at critical times to measure key episodes, such as the Raikoke (2019) and Hunga-Tonga (2022) volcanic eruptions, as well as the 2022 Australian New Year's fires.