Airborne In-Situ Measurements of Formaldehyde Over California: One Year of Results from the Compact Formaldehyde Fluorescence Experiment (COFFEE) Instrument

Formaldehyde (HCHO) is one of the most abundant oxygenated volatile organiccompounds (VOCs) in the atmosphere, playing a role in multiple atmosphericprocesses, such as ozone (O3) production in polluted environments. Due toits short lifetime of only a few hours in daytime, HCHO also serves astracer of recent photochemical activity. While photochemical oxidation ofnon-methane hydrocarbons is the dominant source, HCHO can also be emitteddirectly from fuel combustion, vegetation, and biomass burning. The CompactFormaldehyde FluorescencE Experiment (COFFEE) instrument was built forintegration onto the Alpha Jet Atmospheric eXperiment (AJAX) payload, basedout of NASAs Ames Research Center (Moffett Field, CA). Using Non-ResonantLaser Induced Fluorescence (NR-LIF), trace concentrations of HCHO can bedetected with a sensitivity of 200 parts per trillion.Since its first research flight in December 2015, COFFEE has successfullyflown on more than 20 science missions throughout California and Nevada.Presented here are results from these flights, including boundary layermeasurements and vertical profiles throughout the tropospheric column.Californias San Joaquin Valley is a primary focus, as this region is knownfor its elevated levels of HCHO as well as O3. Measurements collected inwildfire plumes, urban centers, agricultural lands, and on and off shorecomparisons will be presented. In addition, the correlation of HCHO to othertrace gases also measured by AJAX, including O3, methane, carbon dioxide,and water vapor will also be shown. Lastly, the implications of these HCHOmeasurements on calibration and validation of remote sensing data collectedby NASAs OMI (Aura) and OMPS (SuomiNPP) satellites will be addressed

Airborne In-Situ Measurements of Formaldehyde Over California: First Results from the Compact Formaldehyde Fluorescence Experiment (COFFEE) Instrument

Formaldehyde (HCHO) is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere, playing a role multiple atmospheric processes. Measurements of HCHO can be used to help quantify convective transport, the abundance of VOCs, and ozone production in urban environments. The Compact Formaldehyde FluorescencE Experiment (COFFEE) instrument uses Non-Resonant Laser Induced Fluorescence (NR-LIF) to detect trace concentrations of HCHO as part of the Alpha Jet Atmospheric eXperiment (AJAX) payload. Developed at NASA GSFC, COFFEE is a small, low maintenance instrument with a sensitivity of 100 pptv and a quick response time (1 sec). The COFFEE instrument has been customized to fit in an external wing pod on the Alpha Jet aircraft based at NASA ARC. The instrument can operate over a broad range of altitudes, from boundary layer to lower stratosphere, making it well suited for the Alpha Jet, which can access altitudes from the surface up to 40,000 ft. Results of the first COFFEE science flights preformed over the California's Central Valley will be presented. Boundary layer measurements and vertical profiles in the tropospheric column will both be included. This region is of particular interest, due to its elevated levels of HCHO, revealed in satellite images, as well as its high ozone concentrations. In addition to HCHO, the AJAX payload includes measurements of atmospheric ozone, methane, and carbon dioxide. Formaldehyde is one of the few urban pollutants that can be measured from space. Plans to compare in-situ COFFEE data with satellite-based HCHO observations such as those from OMI (Aura) and OMPS (SuomiNPP) will also be presented

Outcomes of 7 Years of Airborne Trace Gas Measurements over California and Nevada: The Alpha Jet Atmospheric eXperiment (AJAX)

The Alpha Jet Atmospheric eXperiment (AJAX) has been flying a scientific payload since January 2011 measuring ozone, carbon dioxide, methane, formaldehyde and meteorological parameters up to 9 kilometers. AJAX is located and operated from the San Francisco Bay Area and has flown a total of 229 flights, on a regular basis (approximately 3 per month) over all seasons cataloguing a long-term record of trace gas concentrations over California and Nevada. The AJAX project focuses on science questions which benefit from routine, frequent observations with flexible scheduling. This presentation will provide an overview of AJAX activities including a discussion of airborne measurements for: Long-Range Transport (LRT) and Stratosphere-to-Troposphere Transport (STT). Regular sampling by AJAX has aided identification of LRT and evidence of STT, which during spring and summer months are visible as elevated O3 laminae within airborne profiles. Some laminae have the ability to impact surface level air quality; Satellite validation - Regular AJAX missions include flights to Railroad Valley, NV in coordination with GOSAT (Greenhouse Gases Observing Satellite) and OCO-2 (Carbon Observatory-2) observations, and more recently to provide coincident measurements under TROPOMI (TROPOspheric Monitoring Instrument); The AJAX project is uniquely flexible to incorporate specialized flights with limited planning notice, such as sampling emissions from California wildfires. Nine wildfires have been sampled, with some more than once allowing to observe emission changes as the fire progresses; Pandora validation - Future work will include development of flight strategies for validation of ground based Pandora spectrometers

Characterization of Volatile Organic Compounds from Oil and Natural Gas Emissions in North America

Emissions of hydrocarbons associated with oil and natural gas infrastructure are of current significant interest to atmospheric scientists. Studies aim to address the local and regional air quality impacts of oil and gas operations throughout North America. In Fort McMurray, multiple facilities mine and upgrade crude bitumen. The “Industrial Heartland” in Fort Saskatchewan, Alberta is Canada’s largest hydrocarbon processing center, home to over 40 chemical and petrochemical facilities. Ambient samples collected in both regions during the summer of 2010 revealed significant enhancements in over 40 VOCs. Many of these measured values were similar to or greater than some of the world’s largest urban and industrial centers. The primary sources of these VOCs included propene fractionation, diluent separation, and bitumen processing facilities. Hydroxyl radical reactivity (ROH) was calculated in each region as a measure of ozone formation potential. On average, background samples had a ROH of 4.4 s-1, while industrial plumes averaged 9.2 s-1, with reactivity reaching up to 60 s-1 in the most concentrated plumes. Acetaldehyde, propene, and 1,3-butadiene had the largest contributions to the ROH values.The Barnett Shale of northern Texas is one of the most developed and active natural gas shale plays in the United States. Emissions from the many oil and gas system components in the region have not been fully characterized. Whole air samples were collected throughout the region in October 2013, targeting known methane sources. Hydrocarbon mixing ratios, correlation plots, and stable isotopes were used to discern emission signatures for thermogenic (oil and gas) versus biogenic sources of methane. Ratios of ethane and propane to methane were distinct for each source type, although highly variable, and used to characterize natural gas as either wet or dry. Integration of these ratios into a bottom-up methane emissions inventory for the region predicted a median ethane flux of 5500 kg C2H6 hr-1, which was consistent with top-down estimates. Lastly, the impact of emissions on local photochemistry and a statistical source apportionment suggested that thermogenic sources are responsible for nearly 70% of hydroxyl reactivity, matching the 64-72% predicted by the CH4 inventory. Overall, oil and natural gas activities were the dominant source of CH4 in the Barnett Shale region.In addition to their influence on air quality and climate, VOCs emitted from oil and natural gas operations are of concern because of their potential health risks. Compounds such as 1,3-butadiene and benzene are hazardous air pollutants and known cancer-causing agents. In the communities closest to the Industrial Heartland, a 13-year record revealed a higher rate of male hematopoietic cancers than other communities in Alberta. The industrial emissions cannot directly be linked to cancer rates, but the elevated VOC concentrations in the region warrant further monitoring and research. In the Barnett Shale, oil and wet natural gas emit increased amounts of potentially harmful gases, including benzene. Using two methods, benzene emission estimates were calculated for the region, and ranged from 48 ± 16 to 84 ± 26 kg C6H6 hr-1