Abstract
Abstract. From 23 January to 13 February 2020, 20 manned research flights were conducted over the tropical Atlantic, off the coast of Barbados (13∘30′ N, 58∘30′ W), to characterize the trade-wind clouds generated by shallow convection. These flights were conducted as part of the international EUREC4A (Elucidating the role of cloud–circulation coupling in climate) field campaign. One of the objectives of these flights was to characterize the trade-wind cumuli at their base for a range of meteorological conditions, convective mesoscale organizations and times of the day, with the help of sidewards-staring remote sensing instruments (lidar and radar). This paper presents the datasets associated with horizontal lidar measurements. The lidar sampled clouds from a lateral window of the aircraft over a range of about 8 km, with a horizontal resolution of 15 m, over a rectangle pattern of 20 km by 130 km. The measurements made possible the characterization of the size distribution of clouds near their base and the presence of dust-like aerosols within and above the marine boundary layer. This paper presents the measurements and the different levels of data processing, ranging from the raw Level 1 data (https://doi.org/10.25326/57; Chazette et al., 2020c) to the Level 2 and Level 3 processed data that include a horizontal cloud mask (https://doi.org/10.25326/58; Chazette et al., 2020b) and aerosol extinction coefficients (https://doi.org/10.25326/59; Chazette et al., 2020a). An intermediate level, companion to Level 1 data (Level 1.5), is also available for calibrated and geolocalized data (https://doi.org/10.25326/57; Chazette et al., 2020c).
Highlights
Subtropical regions play a major role in the radiation balance of the Earth due to their dry free troposphere and their ability to emit a large amount of heat to space (Pierrehumbert, 1995)
The sidewayspointing lidar ALIAS allowed the characterization of the variability of aerosol-related extinction within the High Altitude and Long-Range Research Aircraft (HALO) circle in cloud-free conditions, or was used to obtain a cloud mask and further statistics on the properties of stratiform clouds, whenever they were present at the altitude of the flight
An airborne sidewards-staring lidar was implemented on board the ATR-42 for the EUREC4A field campaign
Summary
Subtropical regions play a major role in the radiation balance of the Earth due to their dry free troposphere and their ability to emit a large amount of heat to space (Pierrehumbert, 1995). 2020 over the western tropical Atlantic, west of Barbados (Stevens et al, 2020) This experiment was originally designed to test our understanding of low-cloud feedbacks (Bony et al, 2017), especially the physical processes that control the cloud fraction around cloud base, where climate models predict the largest changes in cloudiness with warming. To increase the areal sampling of the cloud field and observe the cloud distribution at cloud base, EUREC4A introduced a new sampling approach, consisting in using an aircraft carrying a sidewards-staring lidar This strategy was realized by implementing the Airborne Lidar for Atmospheric Studies (ALiAS) (Chazette et al, 2012b) with a horizontal line of sight in the ATR-42 of SAFIRE (the Service des Avions Français Instrumentés pour la Recherche en Environnment), using a modified lateral window on the aircraft.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
