What the study found
The study found that observed trends in atmospheric river (AR) frequency are mostly still limited to the ocean, while landfalling AR trends are not yet robust in synoptic-scale features. However, moisture transport measures show stronger increases over parts of southern New Zealand and Tasmania.
Why the authors say this matters
The authors say these findings matter because the South Pacific is projected to be a hotspot for some of the largest AR changes. The study suggests that more widespread and detectable trends in landfalling ARs, along with a possible doubling of extreme events before mid-century, could have significant societal impacts.
What the researchers tested
The researchers reviewed historical trends and high-resolution downscaled climate projections for landfalling atmospheric rivers over the South Pacific. They compared reanalysis data with projections from six models and examined both synoptic-scale features and percentile-based moisture transports.
What worked and what didn't
Significant AR frequency trends from reanalysis were mostly confined to the ocean, roughly 45–60°S. For landfalling ARs, synoptic-scale trends were not yet considered robust, but percentile-based moisture transports increased over parts of southern New Zealand and Tasmania. High-resolution projections indicated that landfalling AR trends should become more widespread and robustly detectable in 5 of 6 models within the next 10–20 years, first appearing across southern New Zealand in spring and winter.
What to keep in mind
The abstract does not describe detailed limitations beyond noting where trends are or are not yet robust. It also reports projections from a moderate emissions scenario and the near-term window in which modeled trends become detectable.
Key points
- Observed AR frequency trends are mostly still confined to the ocean rather than landfalling areas.
- Landfalling synoptic-scale AR trends are not yet considered robust in the available observations.
- Percentile-based moisture transports show stronger increases over parts of southern New Zealand and Tasmania.
- High-resolution projections suggest landfalling AR trends will become more widespread in the next 10–20 years.
- The frequency of extreme landfalling ARs could double before mid-century under a moderate emissions scenario.
Disclosure
- Research title:
- Landfalling atmospheric river trends are becoming more widespread
- Authors:
- Peter B. Gibson, Neelesh Rampal, Felix Goddard, Bin Guan, Michael J. DeFlorio, Hamish D. Prince
- Institutions:
- Education New Zealand, Education New Zealand, Jet Propulsion Laboratory, Joint Replacement Institute, Scripps Institution of Oceanography, Statistics New Zealand, Statistics New Zealand, University of Canterbury, University of Wisconsin–Madison
- Publication date:
- 2026-01-28
- OpenAlex record:
- View
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