A high-powered laser is now scanning the skies above Invercargill as part of a major international weather study aimed at improving forecasting and climate modelling in the Southern Hemisphere.
Launching tomorrow, the goSouth-2 project is a joint venture between German and New Zealand institutions.
Based near Invercargill Airport, Germany’s Meteorological Institute of the University of Leipzig has been brought together with the Leibniz Institute for Tropospheric Research (TROPOS), alongside New Zealand’s MetService, the University of Canterbury and The Air Quality Collective.
The project uses ground-based laser and radar systems to study how clouds form and evolve in response to tiny airborne particles known as aerosols.
TROPOS researcher Patric Seifert told 1News aerosols – such as sea salt, dust, pollen, smoke, and volcanic ash – provide a foundation around which cloud droplets and ice crystals form.
“The less aerosol particles are available, the less cloud particles can form, and vice-versa.”
The number and type of aerosols in the atmosphere can dramatically influence how clouds behave, how much sunlight they reflect, and the amount of rain produced.
Invercargill, on the northern edge of the South Ocean, provides a “unique” location to study the relationship between aerosols and clouds, Seifert said.
“The atmosphere in this region can be very clean when air masses approach from Antarctica but can also be burdened with continental-sourced aerosols when air masses approach via Australia.”
Examining the differences between the aerosol content in each air mass would help researchers better understand how clouds responded to changes in aerosol content levels.
Invercargill also makes a good location because it has the necessary facilities to house and run the equipment, Seifert said.
MetService also already runs important observations at the site, including long-term weather balloon soundings, precipitation observations, and solar and thermal radiation measurements, he added.
LIDAR systems, which use laser pulses to detect aerosols, and radar systems, which use radio waves to measure cloud structure and rain, have been deployed by the team.
Currently, most weather and climate models are based on data from the Northern Hemisphere, where the atmosphere is more polluted and better observed.
That means they often struggle to simulate cloud processes accurately in the Southern Hemisphere.
The goSouth-2 campaign also complements the HALO-South mission, an airborne study led by TROPOS and German universities.
Operating out of Christchurch, the HALO aircraft is equipped with a newly developed ice particle counter, PINE-Air, capable of measuring cloud particles in extreme cold – between minus 35 and minus 60 degrees Celsius.
“Looking into the cleaner atmosphere around Antarctica is also a glimpse into the future,” said Professor Joachim Curtius of Goethe University.
HALO-South is expected to run between September 6 and October 11, while goSouth-2 is expected to continue until March 2027.
