IHCantabria publishes unprecedented global dataset to assess tropical cyclone risk considering ENSO phenomenon

Their results help identify how cyclone intensity and frequency varies in key areas ─the Caribbean, Pacific or Indian─ between El Niño or La Niña phases, contributing to improved tropical cyclone risk planning and prevention

The Environmental Hydraulics Institute of the Universidad de Cantabria (IHCantabria) has developed a synthetic dataset of tropical cyclone tracks that considers the behavior of tropical cyclones when ENSO phases occur, which modify tropical cyclone activity on some oceanic accounts.

The new dataset incorporates the interannual variability in the generation of synthetic cyclones, necessary for tropical cyclone risk assessment. The study from which these data are derived is led by Marie Curie postdoctoral researcher Itxaso Odériz, under the supervision of IHCantabria’s Research Director, Íñigo J. Losada.

As a result of this research, IHCantabria has generated a database that simulates 12,000 years of tropical cyclone trajectories, differentiating between the phases of El Niño, La Niña and the neutral state of ENSO, for the period between 1980 and 2021. This information is fundamental for improving risk assessment models, as it reflects year by year the changes that these extreme events can cause in different regions of the planet.

Their results, recently published in the journal Scientific Data, provide a unique tool for assessing how cyclone risk varies with the natural cycle of the El Niño-Southern Oscillation (ENSO) phenomenon, which is responsible for much of the interannual climate variability.

Influence of El Niño or of El Niño or La Niña on the behavior of cyclones

According to the National Oceanic and Atmospheric Administration (NOAA), the Atlantic basin ─which includes the Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico─ recorded 18 named tropical storms. in 2024 (winds of 62.8 km/h or more). Eleven of these were hurricanes (winds of 119 km/h or more) and five intensified to major hurricanes (winds of 178 km/h or more).

Tropical cyclones behave differently, depending on the ENSO phases. Because El Niño and La Niña phenomena alter global atmospheric and oceanic conditions, which significantly affect the formation, intensity, frequency and trajectory of cyclones. For example, the study developed by IHCantabria’s research staff confirms that El Niño increases the frequency of intense cyclones in the eastern Pacific (as in Acapulco); while La Niña intensifies activity in the North Atlantic (as in the islands of Barbados or Dominica). In the Indian Ocean and South Pacific regions, relevant variations are also detected, depending on the ENSO phase, with direct impacts on tropical cyclone risk assessment in coastal megacities and Small Island Developing States (SIDS).

To obtain the data set, the STORM model, which establishes statistical relationships between environmental conditions (sea temperature and atmospheric pressure) and historical cyclone tracks, has been adapted to generate plausible synthetic tracks that represent each ENSO phase as an independent climatic period.

Useful results for disaster planning and weather insurance design

The results allow quantifying how cyclone risk exposure changes between years ─providing key information for risk reduction─, improving early warning protocols, and establishing such variations in the insurance industry, with more realistic price variations. In addition, this dataset represents a benchmark standard for the international scientific community by facilitating model comparisons and new research.

As a result of this research, IHCantabria has obtained a tool that has great potential for application. Although the model may have some limitations -as it does not include certain atmospheric factors that also affect the intensity of cyclones-, the statistical approach used allows an accurate representation of ENSO-induced variability. It is therefore a database that opens up new opportunities for the study of future trends and risk scenarios, especially in vulnerable regions such as the Caribbean, Southeast Asia and the Indian Ocean.