Validation of the TOLNet Lidars: The Southern California Ozone Observation Project (SCOOP)

Abstract

Abstract. The North-America-based Tropospheric Ozone Lidar Network (TOLNet) was recently established to provide high spatio-temporal vertical profiles of ozone, to better understand physical processes driving tropospheric ozone variability, and to validate the tropospheric ozone measurements of upcoming space-borne missions such as Tropospheric Emissions:Monitoring Pollution (TEMPO). The network currently comprises six tropospheric ozone lidars, four of which are mobile 25 instruments deploying to the field a few times per year, based on campaign and science needs. In August 2016, all four mobile TOLNet lidars were brought to the fixed TOLNet site of JPL-Table Mountain Facility for the one-week-long Southern California Ozone Observation Project (SCOOP). This intercomparison campaign, which included 400 hours of lidar measurements and 18 ozonesondes launches, allowed for the unprecedented simultaneous validation of five of the six TOLNet lidars. For measurements between 3 and 10 km above sea level, a mean difference of 0.7 ppbv (1.7%), with a root-30 mean-square deviation of 1.6 ppbv or 2.4% was found between the lidars and ozonesondes, which is well within the combined uncertainties of the two measurement techniques. The few minor differences identified were typically associated with the known limitations of the lidars at the profiles altitude extremes (i.e., first 1 km above ground and at the instruments highest retrievable altitude). As part of a large homogenization and quality control effort within the network, many aspects of the TOLNet in-house data processing algorithms were also standardized and validated. This thorough validation of both the 35 2 measurements and retrievals builds confidence in the high quality and reliability of the TOLNet ozone lidar profiles for many years to come, making TOLNet a valuable ground-based reference network for tropospheric ozone profiling.

A method for quantifying near range point source induced O3 titration events using Co-located Lidar and Pandora measurements

“…As part of these efforts, TOLNet lidar teams have collectively developed rigorous instrument procedures and processing algorithms to ensure consistency in O 3 data products and associated uncertainties between instruments (Leblanc et al, 2016a, b). Crosscomparison studies conducted between TOLNet lidar systems (Leblanc et al, 2018;Wang et al, 2017;Sullivan et al, 2015) showed that O 3 profile concentrations typically agree within ±5%, consistent with system specific propagated errors.…”

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

“…Although the CABOTS ozonesondes were launched too far away from the VMA to allow quantitative comparisons with the lidar, TOPAZ was relocated to the NASA Jet Propulsion Laboratory (JPL) (Leblanc et al, 2018). The results from the SCOOP intercomparison and those presented here complete the inter-validation of the CABOTS lidar, aircraft, and ozonesonde profile measurements.…”

“…In this paper, we compare O3 measurements from the NOAA ESRL Tropospheric Optical Profiler for Aerosol and oZone (TOPAZ) lidar with in-situ measurements from nearby regulatory and research surface monitors, and from instruments flown aboard the UC Davis/Scientific Aviation Mooney (Trousdell et al, 2016) and Alpha Jet research aircraft based at NASA's Ames Research Center (Hamill et al, 2016;Yates et al, 2015). These comparisons, together with those from the multi-lidar (including TOPAZ) and ozonesonde Southern California Ozone Observation Project (SCOOP) intercomparison conducted by the NASA-sponsored Tropospheric Ozone Lidar Network (TOLNet) immediately after CABOTS (Leblanc et al, 2018) provide this validation.…”

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

“…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).…”