TOLNet Lidar Measurements for Air Quality Applications

The air-quality research community has a long legacy of using space-based observations (e.g., GOME, OMI, TROPOMI) to observe day-to-day and year-to-year changes in atmospheric constituents. However, they have not been able to capture the diurnal variability of pollution with enough temporal or spatial fidelity and a low enough latency for regular use by operational decision makers. As a result, the operational AQ community has traditionally relied on ground-based and airborne observing systems to study tropospheric chemistry. The Tropospheric Ozone Lidar Network (TOLNet) has matured into a credible scientific group of six ozone lidars (with a modeling group and data center) that is capable of accurate, high-spatio-temporal-resolution measurement of tropospheric ozone and aerosol structures and morphology. These profiling measurements can fill the upper-air gap between the surface monitoring network and global satellite observations to support air-quality decision making. With the TOLNet lidar measurements, we have investigated many scientific phenomena including stratosphere-to-troposphere exchange, fire smoke transport, Front-range-ozone morphology, urban outflow, land/sea interactions, et al. These processes are usually short-term, but impose large variability on tropospheric background ozone and surface air quality. Currently, we are also providing daily lidar profiles to support the TROPOMI validation. The experiences will be beneficial to provide routine lidar measurements in the future to improve the accuracy of the TEMPO lower-tropospheric ozone observations.