High-tech Flights Tackle Climate Modelling Dilemma

HALO-South mission seeks to improve climate modeling by studying aerosols, clouds and precipitation over the Southern Ocean

Published on Feb. 26, 2026

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The High Altitude and Long-Range Observatory (HALO)-South mission, led by researchers from Germany and the US, has conducted extensive flights over the Southern Ocean to gather data on aerosols, clouds and precipitation in order to improve climate modeling. The project, which is supported by over €9 million in international funding, is based in Christchurch, New Zealand, taking advantage of the city's location near the Southern Ocean and its experience as an Antarctic gateway.

Why it matters

Accurate climate modeling is critical for developing effective climate change adaptation plans, but current models are compromised by challenges in factoring in aerosol and cloud behavior. The HALO-South mission aims to address this gap by collecting comprehensive in-situ measurements in the pristine Southern Ocean environment, which will help tune high-resolution regional climate models for New Zealand and the broader Southern Hemisphere.

The details

The HALO-South mission brings together researchers from seven German research institutes, Carnegie Mellon University, the University of Canterbury, and the New Zealand MetService. The sophisticated HALO aircraft carried out 21 research flights from Christchurch in 2025, gathering data on clouds and aerosols in the Southern Ocean air as well as polluted air masses traveling towards New Zealand from Australia. Extensive ground-based measurements were also conducted at sites in Christchurch and Invercargill, with over 50 weather balloons launched on flight days.

  • The HALO-South mission flights took place in September and October 2025.
  • The HALO-South project runs from 2025 to 2027 as part of the broader goSouth-2 campaign.
  • The University of Canterbury will support additional ground-based observations through the ACADIA project in 2026 and the ACAROA Southern Ocean research voyage in 2027-2028.

The players

Professor Mira Poehlker

Researcher at the Leibniz Institute of Tropospheric Research and the lead of the HALO-South mission.

Professor Adrian McDonald

Associate Head of the School of Physical and Chemical Sciences at the University of Canterbury and the New Zealand lead researcher for the HALO-South project.

University of Canterbury

A partner institution in the HALO-South mission, providing local expertise and supporting ground-based research.

New Zealand MetService

A partner in the HALO-South mission, using the data collected to support weather forecasting.

Carnegie Mellon University

A partner institution in the HALO-South mission, contributing researchers from the United States.

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What they’re saying

“the Southern Ocean sits at the crossroads of weather systems that affect New Zealand and much of the Southern Hemisphere, but until now we haven't had the measurements needed to properly understand what's happening there.”

— Professor Adrian McDonald, Associate Head of School of Physical and Chemical Sciences, University of Canterbury (Mirage News)

“By measuring clouds in one of the cleanest atmospheric environments on Earth, we can better understand how these systems behave without human influence. That's increasingly important as the world moves toward lower-emissions futures.”

— Professor Adrian McDonald, Associate Head of School of Physical and Chemical Sciences, University of Canterbury (Mirage News)

“HALO-South has successfully collected the most comprehensive set of in-situ aerosol and cloud measurements currently available over New Zealand and the Southern Ocean, filling a long-standing gap identified by the global climate modelling community.”

— Professor Adrian McDonald, Associate Head of School of Physical and Chemical Sciences, University of Canterbury (Mirage News)

What’s next

The data collected during the HALO-South flights will now be used by the University of Canterbury-led team in a Smart Ideas project to tune a high-resolution regional climate model for New Zealand conditions. Additionally, the University of Canterbury will support further ground-based observations through the ACADIA project in 2026 and the ACAROA Southern Ocean research voyage in 2027-2028.

The takeaway

The HALO-South mission demonstrates the value of international collaboration and the use of advanced technology to address critical gaps in climate modeling, particularly in the understudied Southern Ocean region. The data collected will help improve climate projections and support the development of effective climate change adaptation plans for New Zealand and the broader Southern Hemisphere.