Intercomparison of lidar, aircraft, and surface ozone measurements in the San Joaquin Valley during the California Baseline Ozone Transport Study (CABOTS)

Langford, A. O.; Alvarez, R. J.; Kirgis, Guillaume; Senff, Christoph J.; Caputi, Dani; Conley, Stephen; Faloona, I. C.; Iraci, L. T.; Marrero, Josette E.; McNamara, M. E.; Ryoo, Ju‐Mee; Yates, E. L.

doi:10.5194/amt-12-1889-2019

Cited by 17 publications

(14 citation statements)

References 35 publications

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“…Ozone, CO 2 , CH 4 , and other species were also sampled by single-engine Mooney TLS Bravo and Ovation 2 research aircraft operated by the University of California, Davis (UC Davis) and Scientific Aviation (SciAv) (Trousdell et al, 2019) and by the NASA Alpha Jet Atmospheric eXperiment (AJAX) research aircraft (Yates et al, 2015). Details of the sampling techniques and intercomparisons between the lidar and airborne O 3 measurements are described in Leblanc et al (2018) and Langford et al (2019).…”

Section: The California Baseline Ozone Transport Studymentioning

confidence: 99%

Ozone Production in the Soberanes Smoke Haze: Implications for Air Quality in the San Joaquin Valley During the California Baseline Ozone Transport Study

et al. 2020

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The Soberanes Fire burned 53,470 ha (132,127 acres) along the central California coast between 22 July and 12 October 2016, generating dense smoke and a variety of gaseous compounds that drifted eastward into the San Joaquin Valley Air Basin (SJVAB), an “extreme” nonattainment area for ozone (O3). These gases included nitrogen oxides (NOx) and volatile organic compounds, the photochemical precursors of O3. The fire started during the California Baseline Ozone Transport Study, a field campaign that brought aircraft, surface, and remote sensing measurements of O3 and related species to central California. In this paper, we use the California Baseline Ozone Transport Study measurements to assess the impact of the Soberanes Fire on ozone and particulate air quality in the SJVAB. We focus our analysis on 27 July to 2 August when the smoke haze was heaviest and the highest O3 concentrations in the SJVAB during 2016 were recorded. Our analyses suggest that while 40 to 60 ppbv of fire‐generated O3 was transported to the eastern SJVAB in the 1‐ to 3‐km‐altitude range, relatively little smoke or fire‐generated O3 reached the surface in the Visalia area.

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Section: The California Baseline Ozone Transport Studymentioning

confidence: 99%

Ozone Production in the Soberanes Smoke Haze: Implications for Air Quality in the San Joaquin Valley During the California Baseline Ozone Transport Study

et al. 2020

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“…The flight domain focused on the region of the SJV between Fresno and Visalia, with approximately two-thirds of the data collected below ∼ 1 km and missed approaches executed at each airport in order to sample to within a few meters of the ground. The flight days were selected in coordination with a team from NOAA's Earth System Research Laboratory operating a tunable optical profiler for aerosol and ozone (TOPAZ) lidar in Visalia, California, who have shown excellent agreement between the ozone data collected by the aircraft and lidar (Langford et al, 2019). Periodically the airplane would make deep vertical profiles from ∼ 3 m to 3 km in addition to two or three other profiling legs in order to diagnose the ABL top, its growth, and vertical profiles of the measured scalars.…”

Section: Flight Strategiesmentioning

confidence: 99%

Photochemical production of ozone and emissions of NOx and CH4 in the San Joaquin Valley

et al. 2019

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Abstract. Midday summertime flight data collected in the atmospheric boundary layer (ABL) of California's San Joaquin Valley (SJV) are used to investigate the scalar budgets of NOx, O3, and CH4, in order to quantify the individual processes that control near-surface concentrations, yet are difficult to constrain from surface measurements alone: these include, most importantly, horizontal advection and entrainment mixing from above. The setting is a large mountain–valley system with a small aspect ratio, where topography and persistent temperature inversions impose strong restraints on ABL ventilation. In conjunction with the observed time rates of change this airborne budgeting technique enables us to deduce net photochemical ozone production rates and emission fluxes of NOx and CH4. Estimated NOx emissions from our principal flight domain averaged 216 (±33) t d−1 over six flights in July and August, which is nearly double the California government's NOx inventory for the surrounding three-county region. We consider several possibilities for this discrepancy, including the influence of wildfires, the temporal bias of the airborne sampling, instrumental interferences, and the recent hypothesis presented by Almaraz et al. (2018) of localized high soil NO emissions from intensive agricultural application of nitrogen fertilizers in the region and find the latter to be the most likely explanation. The methane emission average was 438 Gg yr−1 (±143), which also exceeds the emissions inventory for the region by almost a factor of 2. Measured ABL ozone during the six afternoon flights averaged 74 ppb (σ=9.8 ppb). The average midafternoon ozone rise of 2.8 ppb h−1 was found to be comprised of −0.8 ppb h−1 due to horizontal advection of lower O3 levels upwind, −2.5 ppb h−1 from dry deposition loss, −0.5 ppb h−1 from dilution by entrainment mixing, and 6.9 ppb h−1 net in situ photochemical production. The O3 production rates exhibited a dependence on NO2 concentrations (r2=0.35) and no discernible dependence on methane concentrations (r2∼0.02), which are correlated with many of the dominant volatile organic compounds in the region, suggesting that the ozone chemistry was predominantly NOx-limited on the flight days. Additionally, in order to determine the heterogeneity of the different scalars, autocorrelation lengths were calculated for potential temperature (18 km), water vapor (18 km), ozone (30 km), methane (27 km), and NOx (28 km). The spatially diffuse patterns of CH4 and NOx seem to imply a preponderance of broad areal sources rather than localized emissions from cities and/or highway traffic within the SJV.

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“…Some ozone lidars have an aerosol channel available, either independently or sharing receiving optics with the ozone channel (e.g., Browell et al, 1994;De Young et al, 2017;Gronoff et al, 2019;Kovalev and McElroy, 1994;Uchino and Tabata, 1991). For most of the traditional two-wavelength ozone lidars without an aerosol channel, although there has been some discussion about the aerosol retrieval algorithm (e.g., Eisele and Trickl, 2005;Langford et al, 2019;Papayannis et al, 1999;Sullivan et al, 2014), the evaluation of the aerosol retrieval product and its error budget have rarely been addressed. Due to a significant wavelength difference with aerosol lidars, several aspects of the aerosol retrieval using an ozone lidar are worth noting.…”

Section: S Kuang Et Al: Evaluation Of Uv Aerosol Retrievals From Anmentioning

confidence: 99%

Evaluation of UV aerosol retrievals from an ozone lidar

Kuang

Newchurch

et al. 2020

Atmos. Meas. Tech.

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Abstract. Aerosol retrieval using ozone lidars in the ultraviolet spectral region is challenging but necessary for correcting aerosol interference in ozone retrieval and for studying the ozone–aerosol correlations. This study describes the aerosol retrieval algorithm for a tropospheric ozone lidar, quantifies the retrieval error budget, and intercompares the aerosol retrieval products at 299 nm with those at 532 nm from a high spectral resolution lidar (HSRL) and with those at 340 nm from an AErosol RObotic NETwork radiometer. After the cloud-contaminated data are filtered out, the aerosol backscatter or extinction coefficients at 30 m and 10 min resolutions retrieved by the ozone lidar are highly correlated with the HSRL products, with a coefficient of 0.95 suggesting that the ozone lidar can reliably measure aerosol structures with high spatiotemporal resolution when the signal-to-noise ratio is sufficient. The actual uncertainties of the aerosol retrieval from the ozone lidar generally agree with our theoretical analysis. The backscatter color ratio (backscatter-related exponent of wavelength dependence) linking the coincident data measured by the two instruments at 299 and 532 nm is 1.34±0.11, while the Ångström (extinction-related) exponent is 1.49±0.16 for a mixture of urban and fire smoke aerosols within the troposphere above Huntsville, AL, USA.

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Intercomparison of lidar, aircraft, and surface ozone measurements in the San Joaquin Valley during the California Baseline Ozone Transport Study (CABOTS)

Cited by 17 publications

References 35 publications

Ozone Production in the Soberanes Smoke Haze: Implications for Air Quality in the San Joaquin Valley During the California Baseline Ozone Transport Study

Ozone Production in the Soberanes Smoke Haze: Implications for Air Quality in the San Joaquin Valley During the California Baseline Ozone Transport Study

Photochemical production of ozone and emissions of NO<sub><i>x</i></sub> and CH<sub>4</sub> in the San Joaquin Valley

Evaluation of UV aerosol retrievals from an ozone lidar

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Intercomparison of lidar, aircraft, and surface ozone measurements in the San Joaquin Valley during the California Baseline Ozone Transport Study (CABOTS)

Cited by 17 publications

References 35 publications

Ozone Production in the Soberanes Smoke Haze: Implications for Air Quality in the San Joaquin Valley During the California Baseline Ozone Transport Study

Ozone Production in the Soberanes Smoke Haze: Implications for Air Quality in the San Joaquin Valley During the California Baseline Ozone Transport Study

Photochemical production of ozone and emissions of NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; in the San Joaquin Valley

Evaluation of UV aerosol retrievals from an ozone lidar

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Photochemical production of ozone and emissions of NO<sub><i>x</i></sub> and CH<sub>4</sub> in the San Joaquin Valley