Two-dimensional cloud-top and surface brightness temperature with 1 Hz temporal resolution derived at flight altitude from VELOX during the HALO-(AC)³ field campaign ...

• Main Authors: Schäfer, Michael, Rosenburg, Sophie, Ehrlich, André, Röttenbacher, Johannes, Wendisch, Manfred
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2023
• Subjects: HALO; HALO-AC³; Arctic Amplification AC3; Atmospheric and Earth System Research with HALO – High Altitude and Long Range Research Aircraft SPP1294; Arctic; Fram Strait; Sea ice
• Online Access: https://dx.doi.org/10.1594/pangaea.963401; https://doi.pangaea.de/10.1594/PANGAEA.963401

During the HALO-(AC)³ campaign in March-April 2022 airborne observations were performed with the High Altitude and LOng range research aircraft (HALO) covering the Fram Strait and north polar regions. The flight tracks covered open ocean areas, the marginal sea ice zone, and closed sea ice cover. Furthermore, cloud conditions were observed during air mass transformation events as marine cold air outbreaks and warm air intrusions. The thermal-infrared imager VELOX (Video airbornE Longwave Observations within siX channels) onboard HALO provided two-dimensional (2D) cloud-top or surface brightness temperature (BT) fields. The imager has a field of view of 35.5° by 28.7° (640 by 512 spatial pixels) yielding a spatial resolution of 10 m at a target distance of 10 km. The brightness temperature was measured in six spectral bands (BT1 to BT6) in the thermal-infrared wavelength range from 7.7 to 12.0 µm. Currently, BT1 and BT4 provide redundant broadband measurements for this full spectral range. The remaining four ...