2026-04-06 バージニア工科大学（Virginia Tech）
＜関連情報＞
- https://news.vt.edu/articles/2026/04/cnre-research-flash-drought.html
- https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2026GL121772
プエルトリコで突発的な鉛直速度体制の変化が急激な干ばつを引き起こす Sudden Vertical Velocity Regime Shifts Initiate Flash Drought in Puerto Rico
Tyler Gingrich, Craig A. Ramseyer
Geophysical Research Letters Published: 17 March 2026
DOI:https://doi.org/10.1029/2026GL121772
Abstract
This study focuses on flash drought events in Puerto Rico and the Caribbean. Because the rapid onset and intensity of flash drought can potentially cause more devastation without established prediction methods, this research seeks to understand the synoptic scale atmospheric drivers of flash drought events. The primary goal of this study is to understand how the vertical velocity environments over and upwind of the eastern Caribbean can potentially initiate flash drought. We use a flash drought definition that implements Evaporative Demand Drought Index (EDDI) on a pentad temporal scale to adequately resolve the rapidity of drought onset possible in tropical regimes. Results indicate that flash droughts typically initiate during rapid changes in the vertical velocity environment, initiating at the transition from upward vertical velocity regimes to highly subsident regimes. This suggests some longer-term predictability may be possible and could have linkages to subseasonal atmospheric oscillations.
Plain Language Summary
Drought is a well-known occurrence typically caused by high temperatures and low precipitation rates and can have catastrophic impacts including crop losses, impacts to tourism, water availability, and even fatalities. In recent years, it has been discovered that drought has a high-impact counterpart known as flash drought. Flash drought is very similar to flash flooding due to the rapid onset and intensification. Flash drought has been studied for the United States in some cases, but there is very little known about flash drought in Puerto Rico and other tropical environments. This study seeks to understand how flash drought initiates and intensifies in Puerto Rico. Results of this study suggest that flash drought can initiate immediately after large-scale change in Earth’s atmosphere related to the vertical movement of air. These results can help long-term forecasting of these high-impact droughts.
