2023-12-13 ワシントン州立大学(WSU)
◆これは世界中の多くの地域に影響を与え、熱波が世界的に増加しているためです。春の熱波が積雪の融解を加速させる短期イベントが、長期間にわたり頻繁に発生しており、これが蓄積されると互いに増幅される可能性があります。
＜関連情報＞
- https://news.wsu.edu/press-release/2023/12/13/pacific-northwest-snowpack-endangered-by-increasing-spring-heatwaves/
- https://www.nature.com/articles/s41612-023-00521-0
2021年太平洋岸北西部のヒートドームによる高標高の積雪減少が、相次ぐ春の熱波によって増幅される High-elevation snowpack loss during the 2021 Pacific Northwest heat dome amplified by successive spring heatwaves
Luke Reyes & Marc G. Kramer
npj Climate and Atmospheric Science Published:13 December 2023
DOI:https://doi.org/10.1038/s41612-023-00521-0
Abstract
A heatwave in June 2021 exposed Pacific Northwest (PNW) snowpack to record temperatures, allowing us to probe seasonal snowpack response to short-term heat extremes. Using high-resolution contiguous snowpack and temperature datasets (daily 1 km2 SNODAS, 4 km2 PRISM), we examined daily snowmelt in cooler, higher-elevation zones during this event, contrasted with the prior 18 years (2004–2021). We found that multiple early season (spring) heatwaves, concluding with the 2021 heat dome itself, resulted in dramatic early season melt including the most persistent fraction of PNW snowpack. Using longer-term station records (1940–2021), we show that springtime +5 °C daily anomalies were historically rare but since the mid-1990s have doubled in frequency and/or intensity, now potentially affecting typically cool La Niña periods (2021). Collectively, these results indicate that successive heat extremes drive rapid snowmelt, and these extremes may increasingly threaten previously resilient fractions of seasonal snowpack.
