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Abstract The El Niño Southern Oscillation and Pacific Decadal Oscillation (PDO) are key drivers of cool‐season precipitation variability in the western United States (US), including the Rocky Mountains. Together, they help modulate the north‐south “precipitation dipole,” a regional climate pattern operating on multi‐decadal timescales leading to dry conditions north of 40°N latitude when the south is wet, and vice versa. We investigate the natural evolution of this climate pattern using two precisely‐dated (5900 years ago to present), multi‐proxy, coeval stalagmite records of hydroclimate from Titan Cave, Wyoming, located just north of the modern‐day dipole transition zone. Consistent trace element and stable isotope records from the two stalagmites reflect the amount and seasonality of regional precipitation, documenting decreased winter snowfall and dry conditions over multi‐decadal intervals characterized by the warm phase of the PDO and more frequent and stronger El Niño events.
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Last glacial hydroclimate variability in the Yucatán Peninsula not just driven by ITCZ shifts
Abstract We reconstructed hydroclimate variability in the Yucatán Peninsula (YP) based on stalagmite oxygen and carbon isotope records from a well-studied cave system located in the northeastern YP, a region strongly influenced by Caribbean climate dynamics. The new stalagmite isotopic records span the time interval between 43 and 26.6 ka BP, extending a previously published record from the same cave system covering the interval between 26.5 and 23.2 ka BP. Stalagmite stable isotope records show dominant decadal and multidecadal variability, and weaker variability on millennial timescales. These records suggest significant precipitation declines in the broader Caribbean region during Heinrich events 4 and 3 of ice-rafted discharge into the North Atlantic, in agreement with the antiphase pattern of precipitation variability across the equator suggested by previous studies. On millennial timescales, the stalagmite isotope records do not show the distinctive saw-tooth pattern of climate variability observed in Greenland during Dansgaard–Oeschger (DO) events, but a pattern similar to North Atlantic sea surface temperature (SST) variability. We propose that shifts in the mean position of the Intertropical Convergence Zone (ITCZ), per se, are not the dominant driver of last glacial hydroclimate variability in the YP on millennial timescales but instead that North Atlantic SSTs played a dominant role. Our results support a negative climate feedback mechanism whereby large low latitude precipitation deficits resulting from AMOC slowdown would lead to elevated salinity in the Caribbean and ultimately help reactivate AMOC and Caribbean precipitation. However, because of the unique drivers of future climate in the region, predicted twenty-first century YP precipitation reductions are unlikely to be modulated by this negative feedback mechanism.
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- Award ID(s):
- 2102983
- PAR ID:
- 10508130
- Publisher / Repository:
- Scientific Reports
- Date Published:
- Journal Name:
- Scientific Reports
- Volume:
- 13
- Issue:
- 1
- ISSN:
- 2045-2322
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1038/s41598-023-40108-6
