Laser Research Begins in New Zealand to Study Aerosol Impact

A new atmospheric research initiative has launched at the MetService site near Invercargill Airport, where scientists will investigate the effects of aerosols on the atmosphere. The project, known as goSouth-2, is a collaboration involving institutions from Germany and New Zealand, including the Meteorological Institute of the University of Leipzig and the Leibniz Institute for Tropospheric Research (TROPOS). The project officially opens on September 3, 2023.

The research aims to gather insights into how tiny airborne particles, known as aerosols, influence cloud formation. According to Patric Seifert, a researcher at TROPOS, aerosols originate from various sources, including salt from the sea, dust, pollen, and emissions from human activity, such as smoke and volcanic eruptions. These particles play a crucial role in cloud nucleation, meaning they provide a surface for water droplets to form. Dr. Seifert noted, “The less aerosol particles are available, the less cloud particles can form, and vice-versa.”

Unique Research Location

The southern tip of New Zealand, particularly the area near the Southern Ocean, presents a unique opportunity for this research. The atmosphere can be remarkably clean when influenced by air masses from Antarctica, contrasting sharply with the more polluted air from continental sources like Australia. Dr. Seifert explained that understanding the differences in aerosol content between these air masses is vital for improving knowledge about cloud responses to changing aerosol levels.

Current atmospheric and climate models struggle to accurately predict cloud behavior over the Southern Ocean compared to regions in the northern hemisphere. Researchers believe that the disparity in aerosol levels between hemispheres may be a reason for this difference in model performance. The northern hemisphere, being more polluted, has more extensive data available, which contributes to the higher accuracy of its climate models.

Invercargill was chosen as the research site due to its logistical advantages, including established support for equipment operation and accommodation for staff. The MetService has been conducting significant observations at this site, maintaining long-term records of weather balloon soundings, precipitation data, and measurements of solar and thermal radiation.

Advanced Technology in Use

Residents in the area may notice a green laser beam in the sky near Invercargill Airport. This beam is part of the lidar (light detection and ranging) systems employed by researchers to analyze aerosol distribution. The laser pulses emitted by these systems assist in determining the presence and characteristics of aerosols in the atmosphere. Airport officials have been informed about the fixed beam to ensure safety and awareness.

In addition to lidar systems, the team will utilize radar technology to monitor and study cloud formations and precipitation patterns. The TROPOS team will remain on site for an estimated 18 months, while a group of approximately 15 researchers in Germany will focus on data analysis.

This project follows the goSouth-1 study conducted in 2022, which lasted one month and involved fewer resources. That initial study took place in Pahia, about 50 kilometers from Invercargill, paving the way for the more extensive investigations planned in goSouth-2.

The findings from this research are expected to enhance scientific understanding of atmospheric dynamics, provide valuable data for climate models, and ultimately contribute to better predictions of weather and climate patterns in the Southern Hemisphere.