Catalyst: Seeding award to build a partnership with NASA JPL
A Catalyst: Seeding project, Bridging CMOS and Photonic Spectroscopy for Stratospheric Water Vapour Measurements, establishes a formal research collaboration between the University of Otago and NASA’s Jet Propulsion Laboratory.
Harald Schwefel is principal investigator, with Dr Subash Khanal of NASA JPL as co-applicant. Annika Seppälä leads the atmospheric science, Mallika Suresh the photonic science, and Randy Pollock the systems engineering. On the JPL side the project also draws on Dr Adrian Tang, who directs JPL’s Space System-on-Chip programme, and Dr Nathaniel Livesey, who led the Aura Microwave Limb Sounder for nearly two decades and sits on Tuwhiri’s advisory board.
Catalyst:Seeding is administered by the Royal Society Te Apārangi on behalf of MBIE. It funds the building of international research relationships rather than the research those relationships go on to produce, which is exactly what is needed here.
Why water vapour
Tuwhiri’s instrument was conceived for ozone. Water vapour is a natural second target: the most abundant greenhouse gas in the atmosphere, closely tied to atmospheric circulation, extreme weather and ozone recovery — and poorly observed in the stratosphere, particularly in the Southern Hemisphere.
The Hunga Tonga–Hunga Haʻapai eruption made the gap plain. It injected an unprecedented quantity of water vapour into the stratosphere, and the observing system was not well placed to track what followed.
Ozone and water vapour sensing share their physical principles but differ in frequency and in what calibration demands. Extending the photonic approach from one to the other is a real piece of work, not a relabelling.
Benchmarking against a proven instrument
Laboratory validation only takes a millimetre-wave spectrometer so far. At some point it has to be measured against an instrument whose behaviour is already understood.
JPL has a compact, flight-proven CMOS spectrometer operating at the 183 GHz water line. The project’s aim over two years is technical alignment — workshops, research exchanges and joint engineering studies — working towards flying the two sensors side by side on a Kea Aerospace Kea Atmos stratospheric aircraft. Measuring the same air at the same moment with a new instrument and an established one is the most credible way to find out what the new one can actually do.
That is a rare opportunity. It also reduces the risk carried by everything Tuwhiri builds afterwards.
Harald Schwefel is a Professor in the Physics Department of the University of Otago and Science Lead of Tuwhiri. He is also the Deputy Director Science in Te Whai Ao – Dodd-Walls Centre for Photonic and Quantum Technologies and Principal Investigator in Quantum Technologies Aotearoa (QTA).
His research interests are in the use of optical resonators. Such high-quality resonators are great to generate very high field intensities. With high fields the interaction of light with matter can show significant nonlinearities and light can interact with itself and new colours can be created. A side effect of these high-quality resonators is that they are extremely sensitive to changes in the environment making them an ideal candidate to measure such changes.
