| Popis: |
In 2014, the National Research Council (NRC) and Environment and Climate Change Canada (ECCC) acquired two Airborne Elastic Cloud Lidar (AECL) systems produced by Alpenglow Instruments LLC, for the purposes of retrieving in-flight vertical profiles of clouds and aerosols. In May 2015, the AECLs were deployed on board the NRC Convair-580 aircraft during the HAIC-HIWC (High Altitude Ice Crystals – High Ice Water Content) campaign in French Guiana, where they were used to acquire nearly 40 hours of measurements of various atmospheric features, including liquid and mixed phase clouds as well as ice crystals in HIWC regions. The present report has a twofold objective. First, we describe the AECL operating principle, technical specifications as well as data processing chain. Particular attention is given to the problem of incomplete overlap between the laser and the receiving telescope fields of view. A Klett backward inversion method is also described and is used to convert the raw lidar return into the backscatter and extinction coefficients based on several assumptions, including an assumed extinction-to-backscatter ratio. The second objective of the report is to showcase some of the AECL cloud characterization capabilities based on representative test cases from the HAIC-HIWC campaign. |
