Extreme events in the multi-proxy South Pacific drought atlas

Abstract

Droughts are a natural occurrence in many small Pacific Islands and can have severe impacts on local populations and environments. The El Niño-Southern Oscillation (ENSO) is a well-known driver of drought in the South Pacific, but our understanding of extreme ENSO events and their influence on island hydroclimate is limited by the short instrumental record and the infrequency of ENSO extremes. To address this gap, we developed the South Pacific Drought Atlas (SPaDA), a multi-proxy, spatially resolved reconstruction of the November–April Standardised Precipitation Evapotranspiration Index for the southwest Pacific islands. The reconstruction covers the period from 1640 to 1998 CE and is based on nested principal components regression. It replicates historical droughts linked to ENSO events with global influence, compares well to previously published ENSO reconstructions, and is independently verified against fossil coral records from the Pacific. To identify anomalous hydroclimatic states in the SPaDA that may indicate the occurrence of an extreme event, we used an Isolation Forest, an unsupervised machine learning algorithm. Extreme El Niño events characterised by very strong southwest Pacific drought anomalies and a zonal SPCZ orientation are shown to have occurred throughout the reconstruction interval, providing a valuable baseline to compare to climate model projections. By identifying the spatial patterns of drought resulting from extreme events, we can better understand the impacts these events may have on individual Pacific Islands in the future.

Principles to guide research and policy on psychological well-being in remote island developing states in the South Pacific

“…The climate of the South Pacific region diverges from average global patterns. While droughts and cyclones have been recorded in the past ( 27 ), the South Pacific’s equatorial location and surrounding large body of warm water has sheltered this region from the types of extreme temperature fluctuations and anomalous weather patterns detected elsewhere on the planet ( 28 ). At the same time, the future is more uncertain: sea level rise, beach erosion and increased temperature fluctuations could mean having to face a level of environmental stress that this region has not seen in the last 100 ky.…”

Leading Pattern of Spring Drought Variability over East Asia and Associated Drivers

“…Drought events, characterized by prolonged periods of abnormally low precipitation (Chen et al [1] ; Li et al [2] ), can exert significant impacts on the hydrological cycles, ecosystems, and human society (Huang et al [3] ; Chen et al [4] ; Kostopoulou and Giannakopoulos [5] ). The occurrence of severe droughts not only affects crop growth and agricultural production in the spring (Han et al [6] ; Santini et al [7] ; Higgins et al [8] ), but also leads to an increased frequency of natural disasters such as heatwaves and wildfires in summer due to dry surface conditions (Purich et al [9] ; Wang et al [10] ; Heino et al [11] ). In recent decades, drought events have become more frequent across the world, resulting in substantial socioeconomic impacts (Suska and Piotr [12] ; Li et al [13] ; Dong et al [14] ).…”