Catalyst: Strategic - Supporting HALO-South: New Zealand-German Climate Science Collaboration

Contract details

Contracting organisation: University of Canterbury

Start date: 1 March 2025

End date: 30 June 2026

Public statement

Accurate climate projections are critical for supporting effective climate change adaptation policies in Aotearoa New Zealand (ANZ). The largest uncertainties in these models are due to longstanding issues in the simulation of cloud-aerosol interactions, as a scarcity of measurement data from the region means that models are calibrated using data from the Northern Hemisphere. These uncertainties lead to biases near ANZ in sea surface temperatures and the storm track position. We will build on a strong international partnership to conduct a targeted data collection campaign, addressing key gaps identified by the global climate modelling community.

Our collaborative measurement campaign will be spearheaded by detailed measurements of cloud and aerosol properties made by the German HALO instrumented aircraft deployed from Christchurch. New Zealand researchers will support flight planning activities to maximise the value of the aircraft measurements and make complementary reference measurements at two field sites, Invercargill and Tāwhaki National Aerospace Centre, to allow the first full characterisation of cloud and aerosol properties over ANZ. Subsequent analysis of the data collected will produce a step change in our understanding of the physical and chemical processes controlling cloud formation in the Southern hemisphere and provide critical data needed by model developers.