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A newly upgraded German Weather Service (DWD) ozone and temperature lidar (HOH) located at the Hohenpeißenberg Meteorological Observatory (47.8° N, 11.0° E) has been evaluated through comparison with the travelling standard lidar operated by NASA's Goddard Space Flight Center (NASA STROZ), satellite overpasses from the Microwave Limb Sounder (MLS), the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), the Ozone Mapping and Profiler Suite (OMPS), meteorological radiosondes launched from München (65 km north-east), and locally launched ozonesondes. The blind evaluation was conducted under the framework of the Network for the Detection of Atmospheric Composition Change (NDACC) using 10 clear nights of measurements in 2018 and 2019. This campaign was conducted within the larger context of NDACC validation activities for European lidar stations. The previous 2017-2018 validation campaign took place at the French Observatoire de Haute Provence and and showed a high degree of fidelity between participating instruments. The results are reported in the companion article (Wing et al., 2020). There was good agreement between all ozone lidar measurements in the range of 15 to 41 km with relative differences between co-located ozone profiles of less than ±;10 %. Differences in the measured ozone numbers densities between the lidars and the locally launched ozone sondes were also generally less than 5 % below 30 km. The satellite ozone profiles demonstrated some differences with respect to the ground based lidars which are due to sampling differences and geophysical variation. Temperatures differences for all instruments were less than ±;5 K below 60 km, with larger differences present in the lidar-satellite comparisons above this region. Temperature differences between the lidars met the NDACC accuracy requirements of ±;1 K between 17 and 78 km. The NASA lidar exhibited slightly colder temperatures, between 5 and 10 K, than the other instruments below 20 km and slightly warmer temperatures, 5 to 10 K, above 70 km. These differences are likely due to algorithm initialisation choices and photon count saturation corrections. [ABSTRACT FROM AUTHOR]

A two-part inter-comparison campaign was conducted at L'Observatoire de Haute Provence (OHP) for the validation of lidar ozone and temperature profiles using the mobile NASA Stratospheric Ozone Lidar (NASA STROZ), satellite overpasses from the Microwave Limb Sounder (MLS), the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER), meteorological radiosondes launched from Nimes, and locally launched ozonesondes. All the data were submitted and compared blind, before the group could see results from the other instruments. There was good agreement between all ozone measurements between 20 and 40 km with differences of generally less than 5 % throughout this region. Below 20 km SABER and MLS measured significantly more ozone than the lidars or ozone sondes. Temperatures for all lidars were in good agreement between 30 and 60 km with differences on the order of ±1 to 3 K. Below 30 km, the OHP lidar operating at 532 nm has a significant cool bias due to contamination by aerosols. Systematic, altitude varying bias up to ±5 K compared to the lidars was found for MLS at many altitudes. SABER temperature profiles are generally closer to the lidar profiles, with up 3 K negative bias near 50 km. Uncertainty estimates for ozone and temperature appear to be realistic for nearly all systems. However, it does seem that the very low estimated uncertainties of lidars between 30 and 50 km, between 0.1 and 1 K, are not achieved during LidAr VAlidation NDacc Experiment (LAVANDE). These estimates might have to be increased to 1 to 2 K. [ABSTRACT FROM AUTHOR]

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 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 inter-comparison 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-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 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. [ABSTRACT FROM AUTHOR]

The Tropospheric Ozone Lidar Network (TOLNet) is a unique network of lidar systems that measure high-resolution atmospheric profiles of ozone. The accurate characterization of these lidars is necessary to determine the uniformity of cross-instrument calibration. From July to August 2014, three lidars, the TROPospheric OZone (TROPOZ) lidar, the Tunable Optical Profiler for Aerosol and oZone (TOPAZ) lidar, and the Langley Mobile Ozone Lidar (LMOL), of TOLNet participated in the "Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality" (DISCOVER-AQ) mission and the "Front Range Air Pollution and Photochemistry Éxperiment" (FRAPPÉ) to measure ozone variations from the boundary layer to the top of the troposphere. This study presents the analysis of the intercomparison between the TROPOZ, TOPAZ, and LMOL lidars, along with comparisons between the lidars and other in situ ozone instruments including ozonesondes and a P-3B airborne chemiluminescence sensor. In terms of the range-resolving capability, the TOLNet lidars measured vertical ozone structures with an accuracy generally better than ±15% within the troposphere. Larger differences occur at some individual altitudes in both the near-field and far-field range of the lidar systems, largely as expected. In terms of column average, the TOLNet lidars measured ozone with an accuracy better than ±5% for both the intercomparison between the lidars and between the lidars and other instruments. These results indicate very good measurement accuracy for these three TOLNet lidars, making them suitable for use in air quality, satellite validation, and ozone modeling efforts. [ABSTRACT FROM AUTHOR]