UKZN’s sun-photometer is part of NASA’s
worldwide AERONET network.

Data generated by UKZN’s CIMEL sun-photometer apparatus has recently been allocated a space on NASA’s online Aerosol Robotic Network (AERONET), making it publicly available to contribute to research on atmospheric aerosol conditions in KwaZulu-Natal and South Africa.

The ground-based sun-photometer, acquired by the School of Chemistry and Physics in September 2013 thanks to funding from the South African National Space Agency (SANSA), is used for monitoring to assess the quantity of pollutants in the air. It is one of 164 sun-photometers in the worldwide AERONET.

The apparatus is the first of its kind in KwaZulu-Natal and the third in the country, the other two are stationed at the University of the Witwaterstrand and the University of Pretoria.

UKZN’s sun-photometer provides important data about the tropical coastal and agricultural region and the particulates in its atmosphere.

The sun-photometer operates by measuring sun and sky radiance in order to evaluate atmospheric properties such as water vapour, ozone and optical properties of the atmosphere, for instance sun, sky, moon and soil reflectance. The sun-photometer also quantifies and characterises the physic-optical properties of aerosols.

Professor Siva Venkataraman, the Principal Investigator on the project, emphasised the importance of learning more about the tiny particles in the air which affect public health, visibility, air quality and understanding of climate change in South Africa. The ground-based sun-photometer enables researchers to collect far more specific data than previous satellite informed studies have allowed and also serves to calibrate satellite aerosol measurements and determine optical properties of the atmosphere for satellite imaging.

‘South Africa doesn’t have much information in this area so this will make an impact,’ said Venkataraman.

The instrumentation is used in combination with other state-of-the-art equipment in the School of Chemistry and Physics such as the portable LIDAR, which uses laser technology for remote sensing studies. The sun-photometer’s aerosol optical thickness data is validated by using the LIDAR.

The equipment is calibrated and maintained by AERONET and will prove useful for important, in-depth research by academics and researchers worldwide as well as providing Atmospheric Physics students at UKZN with another avenue of relevant data collection to contribute to their studies.