New Zealand Launches Laser Research on Aerosols and Clouds

A new atmospheric research project, known as the goSouth-2, is set to commence at the MetService site near Invercargill Airport on September 3, 2023. This initiative aims to study the impact of aerosols—tiny airborne particles—on cloud formation and atmospheric conditions. The project represents a collaboration between several institutions from Germany and New Zealand, including the University of Leipzig and the Leibniz Institute for Tropospheric Research (TROPOS), along with the University of Canterbury and The Air Quality Collective.

Research Focus and Methodology

Five researchers from TROPOS are currently setting up essential equipment at the research site. According to Patric Seifert, a researcher at TROPOS, aerosols enter the atmosphere from various sources, including sea salt, dust, pollen, and particles resulting from smoke or volcanic activity. These aerosols play a crucial role in cloud formation, serving as nuclei for cloud particles to attach to. Dr. Seifert emphasized, “The less aerosol particles are available, the less cloud particles can form, and vice-versa.”

The southern tip of New Zealand, positioned at the northern edge of the Southern Ocean, provides a unique environment for this research. The region’s atmosphere can be exceptionally clean when air masses come from the Antarctic, contrasting sharply with the more polluted conditions that arise from continental air masses coming from Australia. By examining the differences in aerosol content across these air masses, researchers hope to gain insights into how clouds respond to varying aerosol levels.

Significance of the Research

Dr. Seifert noted that current atmospheric and climate models struggle to accurately simulate cloud behavior over the Southern Ocean compared to the northern hemisphere. This discrepancy is thought to be influenced by the differing levels of aerosol pollution between the hemispheres, with the northern hemisphere generally being more polluted and better documented. The research conducted in Invercargill is not only timely but necessary for improving the accuracy of these models.

The logistical advantages of conducting research in Invercargill, including support for equipment and accommodation, further enhance the feasibility of the project. The MetService has already established a solid foundation for atmospheric observations, including long-term records of weather balloon soundings, precipitation measurements, and solar and thermal radiation data.

While most of the research equipment is land-based, residents near Invercargill Airport may notice a green laser beam in the sky. This beam is part of the lidar (light detection and ranging) systems used to investigate aerosol concentrations. The fixed beam has been communicated to airport staff, ensuring awareness of its presence during the research period.

Researchers will also utilize radar systems to detect and analyze clouds and precipitation, providing further depth to their studies. The TROPOS team will be on site for an estimated 18 months, while an additional group of around 15 researchers will analyze data back in Germany. This follows the success of the goSouth-1 project in 2022, which was conducted at Pahia, approximately 50 kilometers from Invercargill.

The goSouth-2 project is anticipated to contribute significantly to the understanding of aerosol-cloud interactions, with potential implications for climate modeling and atmospheric science on a global scale.