Characteristics and physical properties of Arctic aerosols

• Main Author: Rader, Fieke
• Format: Thesis
• Language: unknown
• Published: 2020
• Subjects: Arctic; Spitsbergen
• Online Access: https://epic.awi.de/id/eprint/53862/; https://epic.awi.de/id/eprint/53862/1/MA_Rader_final.pdf; https://hdl.handle.net/10013/epic.62fce2de-ff9a-42b5-b448-1515be50c67a

In this master thesis, Raman Lidar data from Ny-Å?lesund, Spitsbergen have beenanalysed for January to April 2019. Optical parameters (the aerosol backscatter at532 nm, the depolarisation ratio at 532 nm, the color ratio and the Lidar ratio at 355nm) and their typical values have been presented per height interval and per month,as well as the differences between those. Also, the links between the different opticalparameters have been investigated and those values were compared with values ofMarch 2018. March 2019 showed lower backscatter and higher depolarisation ratios,indicating fewer and more spherical particles as in March 2018. For January the 28thand February the 06th, hygroscopic growth has been determined. Relative humiditydata measured by radiosondes have been investigated for strong gradients andbackscatter data has been plotted against the relative humidity. The parametrizationof the scattering enhancement factor (f(RH) = (1??RH)????) has been used to plotgrowth curves through the backscatter data and optimal values for??have beenfound. For the 28th of January, the calculated??-values ranged from 0.3 to 1.4 andthe most likely value appeared to be 0.64. Growth factors (g(RH)) and??-valueshave been calculated as well based onin situ(PM10-filter) data using the Zdanovskii-Stokes-Robinson relation. The resulting??-values for January the 28th and Februarythe 6th were respectively 0.98 and 0.73. For the 19th of January, a general overviewof the aerosol situation on that day has been presented using different results fromdifferent techniques. Mostly small sized aerosol particles (14<D<300 nm) havebeen found for that day and low depolarisation values were measured, indicating thepresence of small, spherical ammonium sulfate species. Further research combiningLidar andin situdata is needed for making more precise and accurate conclusions considering Arctic aerosols.