Ozone, UV and Aerosol studies

Since 2010, RMI operates several instruments for atmospheric aerosol in-situ measurements at the Belgian Antarctic research station Princess Elisabeth. The station is situated in Dronning Maud Land, East Antarctica (71.95° S, 23.35° E, 1390 m asl). The station is inhabited from November to February. During March to October, the station and instruments are controlled remotely.

The aerosol in-situ instruments are installed in the southern scientific shelter of the Princess Elisabeth station, built on the Utsteinen ridge, 60 m south of the main station. The shelter is equipped with power from the main station, heating and internet connection. The instruments are connected to a server in the main station, from which they can be remotely controlled. In addition, an IP power switch enables to switch each instrument on and off individually via remote access. An installed webcam allows visual inspection.

The data is available on demand. Available periods per instrument are listed further below. The data has been used e.g. within the AEROCLOUD project. On the webpage of that project, quickplots per available day for the project duration can be viewed.

The multi-wavelength aethalometer (Magee Sci. AE31) measures the aerosol absorption coefficient (m-1) at seven wavelengths (370, 450, 520, 590, 660, 880, 950 nm) and the mass concentration (nanogram/m3) of light-absorbing aerosol (at the 7 wavelengths). The aethalometer technique uses light-transmission through a quartz fibre filter to derive the attenuation caused by the aerosol particles. From the difference of the attenuation between two measurement intervals, the absorption coefficient and the mass concentration can be derived. 

Installation: The aethalometer is installed inside the southern scientific shelter of PE station. The inlet is a 2 m long, vertical, flexible conductive tubing, with the outside air intake on top of the shelter. There is no specific size-cut-off and the inlet is not heated.

With a Tapered Element Oscillating Microbalance with Filter Dynamic Measurement System (TEOM-FDMS; Thermo Electron Corp), the total aerosol mass concentration is measured. It employs a filter on a microbalance, oscillating with an instrument-specific frequency. Any mass change on the filter causes a change of the oscillating frequency which can be converted to a mass concentration.

Installation: The TEOM-FDMS is installed inside the southern scientific shelter of PE station. The inlet is a vertical stainless steel tubing, with the outside air intake on top of the shelter. There is no specific size cut-off, thus bulk sampling. The inner part of the inlet where the measurements are taken, is kept at 30 °C.

The nephelometer (Ecotech, Aurora 3000) measures the intensity of light scattered by aerosol particles at 450, 525 and 635 nm. The instrument uses light emitting diodes as light sources. The measured variables are the total scattering coefficient (m-1) and the backscatter coefficient (m-1). Calibrations with a pure reference gas (CO₂) are done during summer season. During winter zero adjust checks are done weekly (for security reasons, no open gas bottles can be left unattended).

Installation: The nephelometer is installed inside the southern scientific shelter of PE station. The inlet is a 2 m long, vertical aluminium tubing and the outside air intake is on top of the shelter. There is no specific size-cut-off and the inlet is not heated. The instrument is configured to have at least 15 °C in the optical detection chamber.

The Laser Aerosol Spectrometer (LAS, TSI Inc, model 3340) measures the intensity of light scattered by aerosol particles. The light source is a HeNe gas laser at 633 nm. The instrument can measure the number of particles in 100 user-selectable size bins within the diameter range 90 to 7000 nm. It is configured to measure aerosol number in 99 log-channels between 90 and 7000 nm.

Installation: The LAS is installed inside the southern scientific shelter of PE station. The 2 m inlet is in the beginning flexible conductive tubing and then stainless steel to the outside, with the outside air intake on top of the shelter. There is no specific size-cut-off and the inlet is not heated. 

The Ultrafine condensation particle counter (U-CPC, TSI Inc., model 3776) measures the total aerosol number concentration (#/cm-3) in the size range from 3 to 3000 nm. The instrument uses n-butanol as working liquid. The particles come first into a warm chamber, saturated with butanol vapour, and subsequently into a cooled chamber, where supersaturation conditions are thus created, leading to particle growth with the butanol vapour. The particles can then be optically detected and counted.

Installation: The U-CPC is installed inside the southern scientific shelter of PE station. The inlet is 2 m long and in the beginning flexible conductive tubing and then stainless steel to the outside, with the outside air intake on top of the shelter. There is no specific size-cut-off and the inlet is not heated. The U-CPC has been equipped with a 5 L butanol reservoir bottle for the operation during uninhabited winter months.