Spatial distribution and variability of boundary layer aerosol particles observed in Ny-Ålesund during late spring in 2018

• Published in: Aerosol Research
• Main Authors: Harm-Altstädter, Barbara, Bärfuss, Konrad, Bretschneider, Lutz, Schön, Martin, Bange, Jens, Käthner, Ralf, Krejci, Radovan, Mazzola, Mauro, Park, Kihong, Pätzold, Falk, Peuker, Alexander, Traversi, Rita, Wehner, Birgit, Lampert, Astrid
• Format: Text
• Language: English
• Published: 2023
• Subjects: Arctic; Mount Zeppelin; Ny-Ålesund; Svalbard; Ny Ålesund
• Online Access: https://doi.org/10.5194/ar-1-39-2023; https://ar.copernicus.org/articles/1/39/2023/

This article aims to improve the understanding of the small-scale aerosol distribution affected by different atmospheric boundary layer (ABL) properties. In particular, transport and mixing of ultrafine aerosol particles (UFPs) are investigated as an indicator for possible sources triggering the appearance of new particle formation (NPF) at an Arctic coastal site. For this purpose, flexible measurements of uncrewed aerial systems (UASs) are combined with continuous ground-based observations at different altitudes, the Gruvebadet observatory close to the fjord at an altitude of 67 m above sea level (a.s.l.) and the observatory at Mount Zeppelin at an altitude of 472 m a.s.l. The two uncrewed research aircraft called ALADINA and MASC-3 were used for field activities at the polar research site Ny-Ålesund, Svalbard, between 24 April and 25 May 2018. The period was at the end of Arctic haze during the snowmelt season. A high frequency of occurrence of UFPs was observed, namely on 55 % of the airborne measurement days. With ALADINA , 230 vertical profiles were performed between the surface and the main typical maximum height of 850 m a.s.l., and the profiles were connected to surface measurements in order to obtain a 4-D picture of the aerosol particle distribution. Analyses of potential temperature, water vapor mixing ratio and aerosol particle number concentration of UFPs in the size range of 3–12 nm ( N 3−12 ) indicate a clear impact of the ABL's stability on the vertical mixing of the measured UFPs, which results in systematical differences of particle number concentrations at the two observatories. In general, higher concentrations of UFPs occurred near the surface, suggesting the open sea as the main source for NPF. Three different case studies show that the UFPs were rapidly mixed in the vertical and horizontal scale depending on atmospheric properties. In case of temperature inversions, the aerosol population remained confined to specific altitude ranges and was not always detected at the observatories. ...