Abstract Number: 342 Working Group: Aerosols in Earth System
Abstract Hourly measurements of aerosol light absorption coefficient, measured with an AE-31 aethalometer (550 nm) at the highly elevated Zeppelin (474 m asl) and with a Particle Soot Absorption Photometer (PSAP, 530 nm) at Gruvebadet (40 m asl) stations, are studied for one and a half year period. The height of the Planetary Boundary Layer (PBL) is estimated, for the same period, with the Liu and Liang method (Liu et al, 2010), from daily radiosonde data. The radiosonde data are obtained from the Ny-Ålesund homogenized radiosonde record, available from Maturilli et al, 2016. The correlation of the time-series is examined for different seasons, with respect to the relative position of the stations inside or outside the first Surface Layer within the PBL. This methodology investigates the possibility of assessing simultaneous light absorption measurements associated with light absorbing carbon from the lower and the free troposphere. We observe that the frequency of a surface layer engulfing both measurement stations is more common in the summer than winter. In general the gradient of the absorption coefficient with height remains significant both in the case of a single layer or two decoupled layers within the first 500 meters. However, the case of distinct layers with different aerosol light absorption appearing in the free troposphere decoupled from the surface layer appears more frequently in the winter than the summer, an observation consistent with the general circulation patterns expected in the Arctic.