Increasing Tropical Cyclone Precipitation Extremes along the Southeast Atlantic Coast over the Last 350 Years
Abstract
Records of tropical cyclone precipitation (TCP) in the US typically begin in the mid-20th century and are insufficiently long to place the variability in the instrumental period into historical context. We used longleaf pine (Pinus palustris, Mill.) latewood chronologies from eight sites across coastal North and South Carolina as a proxy for TCP during 1661-2015 CE. We gathered TCP from a gridded (0.25° x 0.25°) product of TCP (TCPDat) for each grid at our eight sites. The latewood growth period of June 1st-October 15th coincides with 93% of annual TCP. Using annual latewood data during 1948-2015, we reconstructed regionally averaged TCP back to 1661 using principle component regression, explaining 40% of the variance. A notable increase in TCP extremes has occurred since the 1950s, with the three highest amounts of TCP years occurring in 1955, 1996, and 1998. Tropical cyclones are expected to be wetter in a warmer world, with increases in moisture availability and slower-moving storms. Our reconstructions suggest that TCP extremes in the observed record are unprecedented in the last 350 years. The high fidelity between longleaf pine latewood growth and TCP, coupled with the geographic distribution of the species throughout the southeastern US where tropical cyclones are common, suggest the utility of this species to help better understand the spatiotemporal variability of precipitation delivered via tropical cyclones. By increasing the record length of TCP, our findings suggest that the future could experience a continued increase in TCP extremes, resulting in catastrophic flooding. Two years after the cores were sampled (2018), Hurricane Florence produced the largest amount of TCP recorded in the region, continuing the trend of unprecedented TCP for this region.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPP42B..01M
- Keywords:
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- 4916 Corals;
- PALEOCEANOGRAPHY;
- 4920 Dendrochronology;
- PALEOCEANOGRAPHY;
- 4928 Global climate models;
- PALEOCEANOGRAPHY;
- 4932 Ice cores;
- PALEOCEANOGRAPHY