Investigating the Small-Scale Vertical and Horizontal Variability of the Atmospheric Boundary Layer Aerosol using Unmanned Aerial Vehicles
Final Report Abstract
To investigate the vertical and horizontal structure of the wind field and the formation of aerosol particles in the polar atmospheric boundary layer (ABL), the three project partners from the Technical University of Braunschweig, the Leibniz Institute for Tropospheric Research in Leipzig, and the Eberhard Karls University Tübingen conducted an extensive measurement campaign with UAS (small, automatically operating research aircraft). The campaign took place at the airfield of Ny-Alesund, Spitsbergen, Svalbard near the Global Atmosphere Watch Observatory in April and May 2018. The campaign started in April when the snow cover was closed and covered the period of snowmelt in May. Two different types of UAS were deployed: UAS ALADINA of the Technische Universität Braunschweig focused on meteorological conditions and the measurement of aerosol particle concentrations in different size classes. ALADINA was revised for the campaign in Svalbard, including insulation and active heating, and brakes for landing for the low temperatures. ALADINA was deployed to study the small-scale vertical and horizontal variability of aerosol, and as linking element between the two observatories Gruvebadet (at the Kongsfjord) and at the Zeppelin Mountain (470 m altitude), which frequently measure different aerosol properties. By combination with the meteorological data it was possible to understand the distribution, e.g. the enhanced aerosol concentration below a temperature inversion. Further, the relationship wiht surface properties and the complex orographic situation was analysed. The transition between land and open water also showed changes in aerosol properties. In particular there was sometimes an enhanced concentration of ultrafine particles above water, which indicates local processes involved in new particle formation. The UAS of type MASC-3 of the University of Tübingen focused on the measurement of the complex wind field around Ny-Alesund. The results of the MASC-3 measurements show the strong horizontal and vertical variability in the local wind field, which is influenced by the surrounding complex terrain and glaciers. This analysis of wind conditions contributes to the understanding of the general microclimate around Ny-Alesund and is an important prerequisite to understand the transport processes of aerosol particles. In preparation for the measurement campaign, the MASC type UAS was further developed to version 3 and adapted to the operational conditions in the Arctic. In addition, the development of the VTOL version (vertical take-off and landing) MASC-V was triggered. Also, new sensor systems for measuring particles and electrical charges on board MASC-3 were initiated and implemented as part of the project.
