Aircraft measurements of aerosol optical depth in the Arctic during the AFLUX campaign 2019 ...

• Main Author: Herber, Andreas
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2022
• Subjects: aerosol optical depth; airborne photometer; Arctic; Arctic Amplification AC3
• Online Access: https://dx.doi.org/10.1594/pangaea.946923; https://doi.pangaea.de/10.1594/PANGAEA.946923

The presented spectral aerosol optical depth (AOD) data are measured with an active tracking Sun photometer SPTA. The system was installed under a quartz dome of Polar 5 to derive this mentioned AOD. It operates a filter wheel with ten selected wavelengths in the spectral range from 367 to 1024 nm. To measure the direct solar irradiance, the optics of the SPTA use an aperture with a field of view of 1°. With knowledge of the extraterrestrial signal, the spectral optical depth of the atmosphere as well as spectral optical depth of aerosol was derived. The extraterrestrial signal was calculated based on a Langley calibration, which are performed regularly in a high mountain area (Izana, Tenerife). The data were screened for contamination by clouds to minimize an artificial enhancement of the AOD. The cloud screening algorithm applied a threshold of measured irradiance and made use of the higher temporal and spatial variability of clouds compared to the rather smooth changes of aerosols properties. ...