Abstract
AbstractSummer 2019 observations show a rapid resurgence of the Blob-like warm sea surface temperature (SST) anomalies that produced devastating marine impacts in the Northeast Pacific during winter 2013/2014. Unlike the original Blob, Blob 2.0 peaked in the summer, a season when little is known about the physical drivers of such events. We show that Blob 2.0 primarily results from a prolonged weakening of the North Pacific High-Pressure System. This reduces surface winds and decreases evaporative cooling and wind-driven upper ocean mixing. Warmer ocean conditions then reduce low-cloud fraction, reinforcing the marine heatwave through a positive low-cloud feedback. Using an atmospheric model forced with observed SSTs, we also find that remote SST forcing from the central equatorial and, surprisingly, the subtropical North Pacific Ocean contribute to the weakened North Pacific High. Our multi-faceted analysis sheds light on the physical drivers governing the intensity and longevity of summertime North Pacific marine heatwaves.
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry
Reference47 articles.
1. Siedlecki, S. et al. Impact of the Blob on the Northeast Pacific Ocean biogeochemistry and ecosystems. US CLIVAR Var. 14, 7–12 (2016).
2. Bond, N. A., Cronin, M. F., Freeland, H. & Mantua, N. Causes and impacts of the 2014 warm anomaly in the NE Pacific. Geophys. Res. Lett. 42, 3414–3420 (2015).
3. Amaya, D. J., Bond, N. E., Miller, A. J. & Deflorio, M. J. The evolution and known atmospheric forcing mechanisms behind the 2013–2015 North Pacific warm anomalies. US CLIVAR Var. 14, 1–6 (2016).
4. Di Lorenzo, E. & Mantua, N. Multi-year persistence of the 2014/15 North Pacific marine heatwave. Nat. Clim. Chang 6, 1042–1047 (2016).
5. Hu, Z. Z., Kumar, A., Huang, B., Zhu, J. & Guan, Y. Prediction skill of north pacific variability in NCEP climate forecast system version 2: impact of ENSO and beyond. J. Clim. 27, 4263–4272 (2014).
Cited by
182 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献