Researchers Launch Laser Study to Unravel Aerosol Impact on Climate

A new atmospheric research initiative has commenced at the MetService site near Invercargill Airport in New Zealand. The project, known as goSouth-2, aims to investigate the impact of aerosols—tiny airborne particles—on the atmosphere. This collaborative effort involves institutions from Germany and New Zealand, including the Meteorological Institute of the University of Leipzig and the Leibniz Institute for Tropospheric Research (TROPOS), along with the University of Canterbury and The Air Quality Collective from New Zealand.

The official opening of the project is set for September 3, 2023, with five staff members from TROPOS currently on site to establish the necessary equipment. According to Dr. Patric Seifert, a researcher at TROPOS, aerosols enter the atmosphere from various sources, including the sea and land. These particles, which can include salt, dust, pollen, and those from smoke or volcanic eruptions, play a crucial role in cloud formation.

Dr. Seifert explained, “The less aerosol particles are available, the less cloud particles can form, and vice-versa.” This interconnectedness makes the southern tip of New Zealand, located at the northern edge of the Southern Ocean, an ideal location for studying aerosols and clouds. The region’s atmosphere can be remarkably clean when influenced by air masses from Antarctica, contrasting with the increased aerosol levels from continental air masses arriving from Australia.

Understanding the differences in aerosol content between these air masses is vital for researchers. Improved knowledge of how clouds respond to varying aerosol levels could enhance the accuracy of atmospheric and climate models, which currently struggle to simulate cloud behavior over the Southern Ocean as effectively as they do in the northern hemisphere.

Dr. Seifert noted that the disparity in aerosol levels between the hemispheres likely contributes to the models’ varying performance. The northern hemisphere typically has more data available due to its higher levels of pollution. The choice of Invercargill for this research was also influenced by the logistical support available for running equipment and accommodating staff.

At the MetService site, researchers have access to long-term records of weather balloon soundings, precipitation observations, and measurements of solar and thermal radiation. Although all information-gathering instruments are land-based, residents in the area may notice a green laser beam in the sky, which is part of the project’s lidar (light detection and ranging) systems. These systems emit laser pulses to investigate aerosols, and airport staff have been informed about the laser’s presence.

In addition to lidar, radar systems will also be employed to detect and study clouds and precipitation. The TROPOS team will remain on site for 18 months, while approximately 15 researchers will analyze the collected data in Germany. This initiative follows the success of goSouth-1, a month-long study conducted in 2022 at Pahia, located about 50 kilometers from Invercargill, which utilized less equipment.

This comprehensive research endeavor aims to contribute valuable insights into atmospheric processes, ultimately enhancing our understanding of climate dynamics and cloud formation.