Trailer-sized AMOLITE lidar station reads atmosphere to 10 km altitudes
Canadian researchers developed AMOLITE to obtain atmospheric profiles using lidar.
IMAGE: A photograph shows the Autonomous Mobile Ozone Lidar Instrument for Tropospheric Experiments (AMOLITE) mounted in a climate-controlled mobile trailer. (Image credit: SPIE Newsroom)
Researchers from the Air Quality Processes Research Section, Environment and Climate Change Canada (ECCC; Toronto, Canada), have developed the Autonomous Mobile Ozone Lidar Instrument for Tropospheric Experiments (AMOLITE) to obtain atmospheric profiles from near to the ground to altitudes of more than 10 km.
Lidar (light detection and ranging) technology has rapidly advanced over the past several decades. From a number of different platforms, this technique can now be used to measure a variety of atmospheric constituents with ever increasing accuracy and at ever finer scales, but typically require an operator to control the complex equipment. To overcome the need for a lidar operator, a team at Environment and Climate Change Canada (ECCC) has previously designed several autonomous aerosol lidar systems to support a number of research objectives.
The AMOLITE system builds upon the successes of their earlier autonomous lidars, but now uses a synergistic approach to simultaneously measure the vertical profiles of tropospheric ozone, aerosols, and water vapor. The design combines a dual laser for redundancy purposes and a dual lidar design; that is, the tropospheric ozone Differential Absorption lidar (DIAL) and an aerosol lidar with three backscatter channels, two Raman channels, and one cross-polarization channel (‘3+2+1’ configuration). In addition, a water vapor channel--arising from the Raman-shifted 355 nm output (407 nm)--has been added to provide nighttime water vapor profiles. The final product of the system is lidar profiles (near-ground to 10-15km altitude) at minute-long intervals. The system is operated remotely 24 hours a day, seven days a week (except during precipitation events). Furthermore, data is updated hourly to a website, thus enabling near-real-time analysis.
The team was able to evaluate the performance of its AMOLITE ozone lidar through an intercomparison study--with four other tropospheric ozone lidar systems, all of which are part of the Tropospheric Ozone Lidar Network(TOLNet). They conducted this study--known as the Southern California Ozone Observation Project (SCOOP)--at the Jet Propulsion Laboratory's Table Mountain Facility in Wrightwood, CA. The results show a good level of agreement between AMOLITE and other lidar systems.