Laser Research Project Launches to Study Aerosols in New Zealand

A new atmospheric research project, known as goSouth-2, is set to launch on September 3, 2023, at the MetService site near Invercargill Airport. This initiative aims to gather crucial data on how aerosols—tiny airborne particles—affect the atmosphere. The project is a collaborative effort between institutions from Germany and New Zealand, including the Meteorological Institute of the University of Leipzig, the Leibniz Institute for Tropospheric Research (TROPOS), and local partners such as the University of Canterbury and The Air Quality Collective.

As part of the setup, five staff members from TROPOS are currently establishing equipment at the research site. This project follows the earlier goSouth-1 study, which took place in 2022 and lasted for one month near Pahia, approximately 50 kilometers from Invercargill.

Aerosols and Their Importance in Cloud Formation

According to Dr. Patric Seifert, a researcher from TROPOS, aerosols enter the atmosphere from multiple sources, both terrestrial and marine. These airborne particles include salt, dust, pollen, as well as particles originating from smoke and volcanic activity. They play a critical role in cloud formation by serving as nuclei for cloud particles to attach to.

“The less aerosol particles are available, the less cloud particles can form, and vice-versa,” Dr. Seifert explained. The southern tip of New Zealand, situated at the northern edge of the Southern Ocean, presents a unique environment for studying the interplay between aerosols and clouds. The region can experience very clean atmospheric conditions when air masses arrive from the Antarctic, contrasting sharply with the more polluted air masses coming from Australia.

Researching these differences will provide insights into how clouds respond to varying aerosol levels, which is important as atmospheric models have historically been less accurate in simulating clouds over the Southern Ocean compared to the northern hemisphere. Dr. Seifert noted that discrepancies in aerosol levels between the hemispheres might account for these variations in model performance.

Research Infrastructure and Community Impact

Invercargill serves as an ideal location for this research due to the logistical support available for operating equipment and accommodating staff. The MetService site already conducts vital observations, including long-term weather balloon soundings, precipitation measurements, and assessments of solar and thermal radiation.

While all data collection instruments will be land-based, residents near Invercargill Airport may notice a green laser beam in the sky. “Our lidar [light detection and ranging] systems emit laser pulses to investigate the aerosols,” Dr. Seifert stated. The laser beam will be fixed, and airport authorities have been informed about its presence. Additionally, radar systems will be employed to detect and analyze clouds and precipitation.

The TROPOS team will be on site for a duration of 18 months, while a team of approximately 15 researchers in Germany will focus on data analysis. With the launch of goSouth-2, expectations are high for new discoveries that could enhance understanding of atmospheric dynamics, particularly regarding aerosol-cloud interactions in this unique region of the world.