Over the past several years, the JPL Lidar Group has been working on the development of Small Mobile Ozone lidar (SMOL) instruments, a new compact, and affordable (<$100k) class of ozone differential absorption lidars. The SMOL systems provide high-resolution tropospheric ozone profiles between near the surface and 7-8 km above the surface at a low cost, becoming an important new measurement capability for air quality studies and for the validation of the NASA TEMPO ozone products. Following the successful field deployment of the first three SMOL instruments in 2023 and 2024 [Chouza et al., 2024], a SMOL system with extended capability (SMOL-X) was developed for the measurement of ozone in the stratosphere, representing a new affordable measurement capability for long-term monitoring and campaign-basis deployment at NDACC sites. The main difference between SMOL-X and its tropospheric SMOL counterpart is the use of slightly longer wavelengths to accommodate stronger ozone absorption in the stratosphere, the use of a larger telescope and a more powerful laser. The full system can be built for under $120k, i.e., considerably cheaper than the Excimer laser-based ozone DIAL systems current used at the NDACC stations of Mauna Loa, Table Mountain, Observatoire de Haute-Provence, Hohenpeissenberg and Lauder.
By summer 2024, the UV transmitter/receiver, dedicated to ozone profiling, was optimized and tested at the JPL Table Mountain Facility. The ozone precision up to 38 km altitude is better than 10% for 4 hours integration (Figure 1). The system can provide high-resolution ozone profiles in the Upper Troposphere Lower Stratosphere (UTLS, 7-20 km) at 1-hr time resolution or better. The lidar covers altitudes comprised between 4.5 km above the surface to about 40 km.
Figure 1: Results from the final UV receiver tests performed in late summer 2024 (7 nights ozone comparison between SMOL-X and TMSOL at JPL Table Mountain Facility)
Testing of the visible (532 nm) transmitter/receiver intended for Polar Stratospheric Cloud (PSC) measurement is now ongoing. The entire lidar’s integration and testing is expected to be completed by the end of Spring 2025. At that point, the system will be shipped to the NDACC site of Lauder, New Zealand for field testing and validation during several months. SMOL-X will then travel to Arrival Heights, Antarctica (February 2026) as part of a multi-year polar ozone research in support of NDACC. During that time, it will provide systematic profiles of PSC and ozone over the altitude range 4-35 km, capturing springtime ozone depletion development and documenting its evolution as Antarctic spring will progress. This project constitutes the first polar deployment of an ozone DIAL in several decades, allowing to partially fill one of the many data gaps expected as a result of the end of the Aura-MLS mission.
Cost disclaimer: The cost information contained in this news article is of a budgetary and planning nature and is intended for informational purposes only. It does not constitute a commitment on the part of JPL and/or Caltech.
Chouza, F., Leblanc, T., Wang, P., Brown, S.S., Zuraski, K., Chace, W., Womack, C.C., Peischl, J., Hair, J., Shingler, T., Sullivan, J., (2025), The Small Mobile Ozone Lidar (SMOL): instrument description and first results, Atmos. Meas. Tech., 18, 405–419, 2025, https://doi.org/10.5194/amt-2024-154.