Written by ANDREW KACIMAIWAI
Images supplied
A German research aircraft has been sampling the airspace up to 15 km above the Pacific Ocean, off Queensland, to improve climate forecasting.
The aircraft is part of a CAFE-Pacific Mission investigating how the tropical atmosphere deals with air pollution; how clouds form over oceans; how to refine weather and climate forecast models, and expand understanding of the chemistry of climate.
The mission is co-ordinated by the Max Planck Institute for Chemistry and Goethe University Frankfurt, of Germany.
Flying out of Cairns in Far North Queensland, the Chemistry of the Atmosphere: Field Experiment (CAFE) team are tracking weather events and taking atmospheric measurements. They are using a highly-modified Gulfstream G550 ultra-long range jet to explore the troposphere from the ground up to about 15km above sea level.
The German Aerospace Centre owns and operates the HALO (High Altitude and Long Range) aircraft.
Described by some as the atmosphere’s washing machine, weather events in the tropics play a crucial role in clearing gases and particulates emitted from both natural and human-induced sources.
“In past missions, we have collected data under pristine conditions above the Amazon and in regions in Africa where biomass is burned, and where dust and pollutants are released into the atmosphere. We will compare these results with the data we now measure over the Pacific Ocean,” explains Professor Jos Lelieveld, Director of the Atmospheric Chemistry Department at the Max Planck Institute for Chemistry, and Principal Investigator for the CAFE-Pacific research project.
The area offshore from Queensland is of particular interest to the team as the high temperature of the ocean there causes the strongest high-reaching convection in the world. These columns of upward-rising warm air act as highways for heat, moisture, particulates, and gasses to be transported from the surface of the planet high into the atmosphere.
“The combination of intense solar radiation, mixing due to convection, large regional differences in lightning activity, and contrasting tropical waters and the Australian continent means there’s everything you need for a lot of interesting atmospheric chemistry to occur,” says Dr Clara Nussbaumer, a post-doctoral researcher working on the mission from the Max Planck Institute for Chemistry.
“It’s an exciting place to explore as an atmospheric scientist.”
Each flight on the HALO aircraft can last up to nine hours; four researchers onboard the aircraft monitor and control 15 scientific instruments, maintain contact with the ground and advise the pilots of sudden course corrections.
“When we have a prediction that a weather event will happen, we can design a flight path to go check if what we expected actually occurs,” says Professor Joachim Curtius, Professor at the Institute for Atmosphere and Environment, Goethe University Frankfurt.
Prof. Curtius is also the mission’s co-principal investigator.
“Of course, it’s great when we find things where we expect them – it means our models are reliable – but it’s probably more exciting to find things that we don’t quite expect as it gives us the chance to further improve the forecasts and predictions under our changing climate.”
The research aircraft is equipped with highly sensitive instruments normally found in chemistry labs. Many of these instruments were modified or custom built to achieve the sensitivity, accuracy and reliability required to use in an aircraft.
“We are often measuring trace gases in the atmosphere at levels as low as 1 part per trillion. Imagine this as around 1 drop in 20 Olympic-sized swimming pools,” adds Dr Nussbaumer.
“We have to do this extremely fast because we’re flying in an aircraft at around 250 metres per second. It is normal for the instrument I take care of to measure 10 data points in a single second.”
By the end of February, the science team will have completed around 150 flight hours. Preparations for the flights began in October 2023 and ends in early March.
“All the CAFE measurements will help us improve the computer models of the chemical processes in the atmosphere. This will help us even more accurately predict future climate developments,” says Prof. Curtius.
THIRD PARTY INTEREST
The research caught the attention of Rebecca Lee, Managing Director of Merck Life Science, Country Speaker Merck Group ANZ, and chairwoman of the Advisory Council of the German-Australian Chamber of Industry and Commerce.
Merck ANZ helped with the mission by providing the chemicals to calibrate the aircraft’s instruments.
“This fundamental research being carried out by the Max Planck Institute for Chemistry with several scientific partners from Germany is essential to our understanding of atmospheric science,” Ms Lee says.
“It is crucial for open international collaboration to continue for the good of our collective knowledge, environment, and humanity at large. Australia has much to share with the rest of the world, and there is also so much we can learn from our colleagues overseas.”
Tasman Aircraft 