Hannah Kessenich busts ozone hole myths
For World Ozone Day, the University of Otago asked Hannah what people misunderstand about the ozone hole. The short answer: almost everything.
Building critical capability for space-based climate monitoring with next generation photonics.
An MBIE Endeavour Programme, 2025–2030, led by the University of Otago.
The 25-year record of atmospheric composition from NASA’s EOS-Aura satellite is coming to an end. Aura’s Microwave Limb Sounder is the only instrument that can measure ozone and related gases through the Antarctic polar winter, when the ozone hole forms, and it is about to run out of fuel. No replacement mission has been funded, because conventional instruments of this kind are prohibitively expensive.
Tuwhiri is developing a photonic radiometer small enough and cheap enough to fly on a CubeSat. It converts faint microwave and terahertz signals from the atmosphere into optical light, which can then be measured with ordinary photonics. Along the way we are establishing the atmospheric science, photonics and space engineering capability that Aotearoa New Zealand needs to keep that record going.
Three research areas
Atmospheric Science
What the data is for — how ozone drives extreme weather, what accuracy end users need, and what we can retrieve from the instrument.
Photonics
The sensor itself — electro-optic up-conversion in whispering-gallery-mode resonators, from bench demonstration to flight-ready device.
Space Systems Engineering
Everything around the sensor — the payload, beam-steering antenna, thermal and vibration control, and the flight campaigns.
Outreach and engagement
Building the instrument is only part of the work. Tuwhiri also builds the people, partnerships and public understanding that a long-term climate monitoring capability depends on.
Working with community groups and organisations, we bring atmospheric science and photonics to life for the wider public, as well as inspire school students, with a particular focus on pathways into science for Māori and Pacific learners. Alongside this, we work with New Zealand industry on the manufacturing, commercialisation and deployment of the instrument, so that what we develop here can be built and sold here.
Latest news
Minister Penny Simmonds visits the photonics laboratory
The Minister of Science, Innovation and Technology toured the laboratory on 11 August, eight months after her predecessor made the same visit.
JPL meetings and an invited talk in Long Beach
Harald Schwefel met collaborators at NASA’s Jet Propulsion Laboratory and gave an invited talk at Nonlinear Photonics, part of the Optica Advanced Photonics Congress.
Recent publications
(2026).
A novel diagnostic metric for quantifying Antarctic ozone hole dynamics.
European Geosciences Union (EGU) Assembly.
(2026).
Millimeter-Wave Atmospheric Radiometry via Nonlinear Optical Upconversion.
European Geosciences Union (EGU) Assembly.
(2025).
Quantifying the contribution of transport to Antarctic springtime ozone column variability.
Atmospheric Chemistry and Physics, 25(23), 17527-17552.
(2025).
Visualization and selective manipulation of sub-terahertz whispering gallery modes.
Applied Physics Letters, 127(21), 211102.
(2025).
Multichannel upconversion of terahertz radiation in an optical disk resonator.
Optics Express, 33(5), 10302-10311.
Industry partners
Manufacture and deployment
Industry partner
Contact
Enquiries about Tuwhiri are welcome. Dr Carla Meledandri, our Programme Manager, is the first point of contact and will route anything technical to the right person.
Where we are
Tuwhiri Programme
Department of Physics
University of Otago
PO Box 56
Dunedin 9054
New Zealand
For media and outreach
Students and prospective researchers
Tuwhiri supports doctoral and masters students across atmospheric science, photonics and space systems engineering. Get in touch if you would like to work on this.
Meet the team