The earth’s crust is a leaky geofluid system where surface trace gas emissions relate to open migration pathways and the presence of subsurface source(s). Seismic activity can open sealed migration pathways leading to trace gas emissions from the surface intersection of the active fault, which may not relate to observable surface fault rupture or offset. After the M7.1 Ridgecrest earthquake, we collected mobile surface trace gas and meteorology data with AMOG (AutoMObile trace Gas) Surveyor, a mobile atmospheric chemistry and meteorology lab, in the Death Valley Park and Searles Valley within 24 hours of the quake, the following week, and after several weeks with air samples also were collected for detailed later laboratory analysis. We found widespread highly elevated CO2 emissions along Panamint Valley including overall elevated SO2 and H2S with strong enhancements around Manly Pass, where aftershocks occurred at the northern edge of the Slate Range and along a trend parallel to Water Canyon. This is in contrast to AMOG data collected in Death and Panamint Valleys in 2014, where concentrations were typical of California desert levels–near ambient and uniform. Significant sulfur trace gas emissions were discovered escaping from the rim of Ubehebe Volcano, last active ~2500 B.P., 115-km north of the Slate Range. Faults appear to play an important role in these geogas emissions, activated by the major earthquake and aftershocks. Further investigations are planned to characterize the system’s return towards quiescence.

COVID-19’s impact on society and our daily habits has been unprecedented. With a decrease in vehicular traffic and industrial production, a decrease in local emissions was expected to occur. In order to capture any trends in ambient trace gas concentrations, approximately one thousand whole air samples were collected in intervals across the United States from April to July 2020 as part of the NASA Student Airborne Research Program (SARP). These samples were then analyzed by the UCI Rowland-Blake Lab using multi-column gas chromatography for over one hundred unique trace gases, including methane, non-methane hydrocarbons, and halocarbons, as described in Colman et al. (2001) and Barletta et al. (2002). Initial samples collected in April coincided with the peak of stay-at-home/social distancing orders in most states while samples collected later in the spring and early summer reflect the easing of these measures and initial state reopenings. Overall trends in emissions over time in select metropolitan areas will be discussed and compared to trends observed across the entire United States.

The 2020 COVID-19 pandemic provided a unique opportunity to sample atmospheric gases during a period of very low industrial/human activity. Over 1000 Whole Air Samples were collected in over 30 cities and towns across the United States from April through July 2020 as part of the NASA Student Airborne Research Program (SARP). Sample locations leveraged the geographic distribution across the United States of the undergraduate and graduate students, faculty, and NASA personnel associated with the internship program (44 people total). Each person collected approximately 24 air samples in their city/town with the goal of characterizing local emissions with time during the pandemic. Samples were collected in 2-Liter stainless steel evacuated canisters at approximately 2 meters above ground level. The canisters were shipped to the Rowland/Blake Laboratory at the University of California Irvine and analyzed for methane, carbon dioxide, carbon monoxide, non-methane hydrocarbons, and halocarbons using the gas chromatographic system described in Colman et al. (2001) and Barletta et al. (2002). Initial samples collected in April coincided with the peak of stay-at-home/social distancing orders across most of the United States while samples collected later in the spring and early summer reflect the easing of these measures in most locations. Overall trends in emissions with time across the United States during the pandemic (in several large metro areas as well as rural locations) will be discussed.

Organic nitrates (RONO) are an important NO sink.  In rural environments dominated by biogenic emissions, nocturnal NO-initiated production of RONO is competitive with daytime OH-initiated RONO production.  However, in urban areas, OH-initiated production of RONO has been assumed dominant and NO-initiated production considered negligible.  We show evidence for nighttime RONO production similar in magnitude to daytime production during three aircraft campaigns in chemically-distinct environments: SEACRS in the rural Southeastern US, FRAPPÉ in the Colorado Front Range, and KORUS-AQ around the megacity of Seoul.  During each campaign, morning observations show RONO enhancements at constant, near-background Ox (≡ O + NO), indicating that the RONO are from a non-photochemical source, whereas afternoon observations show a strong correlation between RONO and O resulting from photochemical production.  We show there are sufficient precursors for nighttime RONO formation during all three campaigns.  This evidence impacts our understanding of the nighttime lifetime and fate of NO.

The Satellite Coastal and Oceanic Atmospheric Pollution Experiment (SCOAPE) cruise in the Gulf of Mexico (GOM) was conducted in May 2019 by NASA and the Bureau of Ocean Energy Management to determine the feasibility of using satellite data to measure air quality (AQ) in a region of concentrated oil and natural gas (ONG) operations. SCOAPE featured nitrogen dioxide (NO2) instrumentation (Pandora, Teledyne API analyzer) at Cocodrie, LA (29.26°, -90.66°), and on the Research Vessel Point Sur operating off the Louisiana coast with measurements of ozone, carbon monoxide (CO) and volatile organic compounds (VOC). The findings: (1) both satellite and Pandora NO2 observations revealed two AQ regimes over the GOM, the first influenced by tropical air in 10-14 May, the second influenced by flow from urban areas on 15-17 May; (2) Comparisons of OMI v4 and TROPOMI v1.3 TC (total column) NO2 data with all Pandora NO2 column observations on the Point Sur averaged 13% agreement with the largest difference during 15-17 May (~20%). At Cocodrie, LA, at the same time, the satellite-Pandora agreement was ~5%. (3) Three new-model Pandora instruments displayed a TC NO2 precision of 0.01 Dobson Units (~5%); (4) Regions of smaller and older operations displayed high methane (CH4) readings, presumably from leakage; VOC were also detected at high concentrations. Given an absence of regular AQ data in and near the GOM, SCOAPE data constitute a baseline against which future observations can be compared.