Detection of compound and seesaw hydrometeorological extremes in New Zealand: A copula-based approach

Bennet, Morgan J.; Kingston, Daniel G.; Cullen, Nicolas J.

doi:10.5194/hess-30-4437-2026

Articles | Volume 30, issue 14

https://doi.org/10.5194/hess-30-4437-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/hess-30-4437-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 30, issue 14

Research article

|

17 Jul 2026

Research article |

| 17 Jul 2026

Detection of compound and seesaw hydrometeorological extremes in New Zealand: A copula-based approach

Morgan J. Bennet, Daniel G. Kingston, and Nicolas J. Cullen

Supplement

https://doi.org/10.5194/hess-30-4437-2026-supplement

Data sets

ERA5 Land hourly time-series data on single levels from 1950 to present Copernicus Climate Change Service, Climate Data Store https://cds.climate.copernicus.eu/datasets/reanalysis-era5-land-timeseries

Short summary

Compound hot-dry and the dry-wet seesaw transition are extreme meteorological events driven by the interaction between rainfall, temperature and soil moisture. Using data covering New Zealand for the 1950-2021 period we model these interactions using both copulas and single variables. The copula approach detects more frequent and intense events, particularly across eastern regions of the country, while also better representing the event drivers and improving our understanding of their risk.