The ROMA project monitors the composition of the Antarctic atmosphere through continuous optical observations at Princess Elisabeth Antarctica. Using ground-based remote sensing instruments, the project measures atmospheric aerosols and ozone, providing long-term observations from one of the cleanest atmospheric environments on Earth.

A key instrument in the project is the CIMEL sunphotometer, a passive radiometer that measures direct sunlight and diffuse sky radiation at multiple wavelengths. These observations are used to determine the Aerosol Optical Depth (AOD), integrated precipitable water vapour and other aerosol properties, including particle size distribution and light-scattering characteristics.

The project also supports the transition to a new generation of atmospheric monitoring instruments. Alongside the CIMEL, reference instruments such as the Pandora system are being introduced to measure total atmospheric ozone columns, ensuring the continuity of long-term atmospheric observations as existing instruments are phased out.

Together, these measurements contribute to a better understanding of atmospheric composition, aerosol properties and ozone over Antarctica, providing valuable data for atmospheric and climate research.