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Kicking Off My Dust-DN Journey: Reflections from the UAV Spring Campaign 2025

Blog post from Kenneth M. Tschorn

My first experiences as a Dust-DN Doctoral Candidate

I joined Dust-DN in April 2025. Before relocating to Cyprus, I worked as a research associate in a long-term air quality monitoring program in Western Norway. This transition has given me a firsthand experience of the stark contrast between one of Europe’s northernmost, colder regions and Cyprus, which has one of the warmest climates in the Mediterranean part of the EU. I was particularly drawn to Dust-DN for its strong networking opportunities—with fellow students, their supervisors, and leading experts in the field of atmospheric dust. I see this as a unique chance to expand my scientific network and gain valuable cultural experiences. My doctoral project (DC2) is embedded within Work Package 2 (WP2) of the DUST-DN, which focuses on the fundamental properties of dust. Specifically, DC2 aims to explore and validate new measurement techniques that can enhance our understanding of dust particle morphology and orientation.

This includes collecting dust particles during major outbreaks over Cyprus using devices called impactors. These are small tools with sticky surfaces that catch dust particles as they pass by, allowing scientists to examine individual particles in detail. For our work, we used specially modified Giant Particle Collectors (GPAC) mounted on an unmanned aerial vehicle (UAV) called Skywalker. These GPACs included Transmission Electron Microscopy (TEM) grids, which are fine mesh structures that let us study the particles in three dimensions using an electron microscope.

One additional aspect of my project is to investigate whether dust particles in the atmosphere align in a certain direction – a phenomenon that has been reported in some studies. To test this hypothesis, we used a second Skywalker UAV equipped with two differently pointing Compact Optical Backscatter AerosoL Detectors (COBALD). One of these instruments was mounted vertically and the other horizontally. These instruments emit light in two different wavelengths, and a detector measures the amount of light being scattered back to the instruments. Mounting them at different angles helps us to look for signs of particle orientation/alignment. This unique, novel approach may shed new light on how atmospheric dust particles behave in the air and how they affect the Earth’s climate system.

Starting my PhD project right as the UAV Spring Campaign 2025 kicked off was both exciting and demanding. I had to rapidly become familiar with new instruments and techniques—such as the principles of the COBALD system and aerosol sampling—while actively participating in campaign operations. In this post, I share my first hands-on experiences and how they relate to the objectives of my doctoral project.

Campaign Objectives

The UAV Spring Campaign 2025 took place at the Cyprus Institute (CYI) from April 3rd to May 31st, a period selected due to favorable atmospheric conditions for dust transport from North Africa to Cyprus. Throughout this period, the remote sensing group produced daily observational and model-based dust forecasts to assess whether atmospheric conditions were suitable for UAV flights from CYI’s airfield at Orounda.

In collaboration with the Unmanned Systems Research Laboratory (USRL) of CYI, the team successfully conducted UAV operations on eight different days, catching various different dust events. The primary goal was to evaluate the performance of newly developed instruments designed to characterize the microphysical properties of dust particles during significant dust events. These novel tools added new capabilities to CYI’s well-established instrumentations that measure dust particle size, like the POPS and UCASS instruments (more on those below).

Each day began with a crucial question: Are we going to fly today?

UAV Platforms and Scientific Instrumentation

Quadrocopter / POPS

A quadrocopter platform was equipped with the Printed Optical Particle Spectrometer (POPS), which measures aerosol particle sizes in the range of 0.115 to 3.37 µm (optical equivalent diameter). Accordingly, POPS is an instrument designed to detect rather small particles. On most flight days, the POPS was deployed first to obtain vertical profiles of dust concentration. These data helped identify optimal target altitudes for particle sampling by subsequent Skywalker flights.

Figure 1: POPS mounted on quadrocopter (note: drying inlet is not attached here)
Figure 2: POPS in detail (note: drying-inlet is not attached here)

Skywalker / UCASS and Impactors

The Skywalker fixed-wing UAV carried two key instruments for studying larger dust particles. Under each wing, we mounted the Universal Cloud and Aerosol Sounding System (UCASS), measuring particles ranging from 0.45 to 56.06 µm (optical equivalent diameter) using optical detection.

Figure 3: Skywalker UAV carrying both UCASS and an adjustable mount for the collection of giant dust particles.

Alongside the UCASS, we also attached two custom-built particle impactors, so called Giant Particle Collectors (GPAC). These were also placed beneath each wing and used for collecting dust particles at target altitudes. For this campaign, the GPACs were specially modified to include TEM grids allowing for advanced, three-dimensional morphological analysis in the lab.

Figure 4: UCASS (left) and adjustable mount for giant dust particle collection with our modified TEM-grid impactors (see arrow).
Figure 5: Example of a TEM-grid being used during this campaign.

COBALD

A third UAV carried two Compact Optical Backscatter Aerosol Detectors (COBALD), oriented differently to investigate the potential for detecting particle alignment. One COBALD instrument was mounted vertically and the other horizontally (see picture below). Each operates at two wavelengths: blue (λ = 455 nm) and near-infrared (λ = 940 nm). Due to the sensitivity of the sensors, meaningful data could only be collected during nighttime conditions to avoid oversaturation from sunlight.

Figure 6: COBALD backscatter sonde with horizontal and vertical field of view mounted on a third UAV.
Figure 7: COBALD backscatter sondes during ground calibration (high-dynamic-range picture). The beam of the blue wavelength can be identified, but the red channel remains unseen, as it is not within the visible light spectrum. Picture: Fotis Manelidis.
Figure 8: View from the control monitor during one of our UAV flights.
Figure 9: Lidar signal indicating very strong dust presence on 17th May 2025. The volume depolarization ratio (bottom plot) clearly indicates the arrival of non-spherical dust particles starting to descent gradually from around noon until it has reached the surface air level in the evening.

Relevance to my Doctoral Project DC2

This campaign was a perfect starting point for my doctoral project. The use of TEM grid-equipped GPACs matches with my research goal of investigating advanced dust particle morphology. Furthermore, the COBALD deployment supports the evaluation of dust particle orientation—a key hypothesis in DC2. These innovative measurement strategies may lead to valuable insights into dust microphysics and contribute to broader atmospheric science objectives.

Participating in this campaign was an invaluable experience that provided hands-on exposure to field operations, instrumentation, and scientific coordination. It also set a solid foundation for the research tasks ahead in my doctoral journey.

Planning is already underway for future campaigns. And when the time comes, I expect we’ll find ourselves once again asking that same familiar question:

Are we going to fly today?