Prevention, not clean up, should be New Zealand's strategy for major weather events

A team of New Zealand scientists from Te Whai Ao —Dodd-Walls Centre for Photonic and Quantum Technologies is working to improve weather forecasting and reduce the impact of atmospheric river events. It says rather than spending millions regularly mopping up after floods, governments could be funding better predictive systems and mitigating the effects of storms.

Dr Mallika Suresh and the team are working on developing a photonic sensor to detect atmospheric gases like ozone, which affect our wind and weather systems. The new Agnes Blackie Fellow at the Centre, Dr Suresh explains that all objects at a temperature above absolute zero glow, including ozone molecules.

“Hundreds of kilometres up, satellites can detect the glow from these wiggling molecules. Our new device, the principle of which has proven successful in the laboratory environment, could measure this glow by mixing the weak signal from ozone with a strong laser signal, boosting the energy needed to determine atmospheric change,” Dr Suresh says.

The device converts light in the low frequency microwave range, to light at the high frequency infrared end of the spectrum. It’s called a resonator and it’s tiny – about 4 mm across – sitting inside a radiometer which is the remote sensor. This is where much of its potential lies. Because it is so small, this sensitive measurement tool can be sent into space at considerably lower cost than today’s weather satellites.

Working with the University of New South Wales Australian National Concurrent Design Facility in Canberra, the team has designed a space mission and confirmed the feasibility of sending the sensor inside a 6-litre cubesat. There are considerable engineering challenges, but it can be done.

Team leader, University of Otago Associate Professor Harald Schwefel, says the availability and cost of cubesats, box-shaped satellites which start as small as a 1-litre Rubic’s cube, means trialling the instrument in space is now a fiscal as well as a scientific reality. And he argues, this is why funding predictive science makes sense when compared to the cost of not doing so.

“Rather than repair the damage afterwards, like the ambulance at the bottom of the cliff, our sensor will be able to identify bad weather well ahead of time. Low-cost cubesats reduce the risk associated with space missions,” Schwefel, says.

Cubesats can be sent up on a rocket and Schwefel points out that launch opportunities frequently arise at short notice.

“We could get a call saying ‘A rocket is leaving in six months if you want a free ride.’ So we need to have something prepared and sitting on the shelf ready to go.”

The team is working hard to create one. The next step is to launch the radiometer on a balloon with the partners in the research venture, Kea Aerospace and NIWA. Together the teams plan to launch the radiometer from NIWA’s base in Lauder, south Otago and then from Antarctica, before eventually putting it on Kea Aerospace’s Kea Atmos – a remotely piloted (unmanned) solar-powered aircraft that can fly for months at a time.

Meanwhile, climate scientists working on the project say time is running out to get the instrument into space before the NASA satellite which currently measures the ozone layer in 3D, becomes defunct.

Otago University Atmosphere and Climate Associate Professor Annika Seppälä says it’s driving a sense of urgency among scientists around the world.

“Contrary to popular belief the Antarctic ozone hole will not recover for many more decades and it affects our weather patterns, not just climate. NASA has confirmed their satellite will come down in 2026. Basically there will be no useable data from it after next year.”

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Image Description: Femtosecond laser being used to cut a disk shaped resonator, used to create optical components for Dr Suresh's sensor.