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Droughts over Hawaii and the U.S.-Affiliated Pacific Islands: A Framework to Understand Processes and Feedbacks, Assess Predictability, and Reduce Uncertainties

NIDIS Supported Research
NIDIS-Supported Research
Main Summary

El Niño-Southern Oscillation (ENSO) characteristics exert measurable imprints on droughts over Hawaii and the U.S. affiliated Pacific Islands. However, local air-sea interactions, remotely forced teleconnections, and phase and intensity of other natural modes of variability are also expected to contribute to observed drought characteristics. Indirect evidence shows that since the U.S. Drought Monitor started in 2000, the longest duration of drought (D1-D4 categories) in Hawaii lasted 388 weeks (April 22, 2008 to September 22, 2015); such an unprecedented persistence beyond ENSO timescales clearly indicates that factors other than ENSO are involved, and until now, no studies have attempted to explain the processes and feedbacks that led to this drought persistence.

There is a need in the Insular Pacific to identify precursors to monitor and predict the severity and persistence of droughts. Thus, the project team, in consultation with local stakeholders, will devise a framework with a focus on understanding processes and feedbacks, assessing causality, and reliably quantifying uncertainties in their prediction. The overarching goal of this project is to improve drought early warning in the Pacific and contribute to the NIDIS/MAPP Drought Task Force IV

To accomplish this goal, the project has the following objectives:

  1. Based on specific stakeholder-relevant thresholds, study characteristics of severe and prolonged droughts from a multitude of observations and reanalysis products.
  2. Assess the predictability of drought life cycle, and develop a robust system for drought monitoring.
  3. Work closely with various regional stakeholders and NIDIS, and link the research results to improve drought prediction.

This project is part of the NIDIS/MAPP Drought Task Force IV.

For more information, please contact Britt Parker (

Research Snapshot

Research Timeline
September 2020 – August 2023
Principal Investigator(s)
H. Annamalal, University of Hawai’i International Pacific Research Center
Project Funding
Modeling, Analysis, Predictions, and Projections (MAPP) FY 2020

What to expect from this research

  • A set of benchmark metrics to monitor the onset, intensity, and persistence of droughts.
  • Regional maps of “drought characteristics” and various predictability measures (metrics) to help identify precursors to drought in the Pacific Islands. 
  • Manuscripts on drought characteristics and life cycle in the Pacific Islands, skill measures and physical understanding of the processes in NMME-2 models, and Drought Early Warning Systems.

By performing these tasks, this project will improve the dissemination of drought information for an underserved region. The team will also contribute to the Drought Task Force IV by sharing the developed approaches and metrics.

Key Regions

Research Scope