Ground-based remote sensing of aerosol properties using high-resolution infrared emission and lidar observations in the High Arctic

• Published in: Atmospheric Measurement Techniques
• Main Authors: Ji, Denghui, Palm, Mathias, Ritter, Christoph, Richter, Philipp, Sun, Xiaoyu, Buschmann, Matthias, Notholt, Justus
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2023
• Subjects: article; Verlagsveröffentlichung; Arctic; Ny-Ålesund; Paul-Emile Victor; Alfred Wegener Institute; black carbon; Ny Ålesund; Spitsbergen
• Online Access: https://doi.org/10.5194/amt-16-1865-2023; https://noa.gwlb.de/receive/cop_mods_00065843; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00064353/amt-16-1865-2023.pdf; https://amt.copernicus.org/articles/16/1865/2023/amt-16-1865-2023.pdf

Arctic amplification, the phenomenon that the Arctic is warming faster than the global mean, is still not fully understood. The Transregional Collaborative Research Centre “TRR 172: ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms (AC)3” program, funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), contributes towards this research topic. For the purpose of measuring aerosol components, a Fourier transform infrared spectrometer (FTIR), for measuring downwelling emission (in operation since 2019), and a Raman lidar are operated at the joint Alfred Wegener Institute for Polar and Marine Research and Paul Emile Victor Institute (AWIPEV) research base in Ny-Ålesund, Spitsbergen (79∘ N, 12∘ E). To carry out aerosol retrieval using measurements from the FTS, the LBLDIS retrieval algorithm, based on a combination of the Line-by-Line Radiative Transfer Model (LBLRTM) and the DIScrete Ordinate Radiative Transfer (DISORT) algorithm, is modified for different aerosol types (dust, sea salt, black carbon, and sulfate), aerosol optical depth (AOD), and effective radius (Reff). Using lidar measurement, an aerosol and cloud classification method is developed to provide basic information about the distribution of aerosols or clouds in the atmosphere and is used as an indicator to perform aerosol or cloud retrievals with the FTS. Therefore, a two-instrument joint-observation scheme is designed and subsequently used on the data measured from 2019 to the present. In order to introduce this measurement technique in detail, an aerosol-only case study is presented using data from 10 June 2020. In the aerosol-only case, the retrieval results show that sulfate is the dominant aerosol throughout the day ( τ900cm-1 = 0.007 ± 0.0027), followed by dust ( τ900cm-1 = 0.0039 ± 0.0029) and black carbon ( τ900cm-1 = 0.0017 ± 0.0007). Sea salt ( τ900cm-1 = 0.0012 ± 0.0002), which has the weakest emission ability in the infrared wave band, shows the lowest AOD value. Such ...