Caribbean cyclone activity: an annually-resolved Common Era record

Area of Science:

• Paleoclimatology
• Climate Science
• Oceanography

Background:

• Tropical cyclones (TCs) pose significant risks to Caribbean populations, with climate change potentially increasing their intensity.
• Current climate models lack the resolution to accurately predict long-term TC patterns beyond the instrumental era.
• Understanding past TC activity is vital for predicting future changes in magnitude and frequency.

Purpose of the Study:

• To reconstruct a high-resolution, long-term tropical cyclone record for the Caribbean.
• To investigate the relationship between past TC patterns and Common Era climate variations.
• To identify the climate mechanisms driving long-term TC activity.

Main Methods:

• Analysis of an annually-resolved sedimentary archive from the Great Blue Hole, Belize, spanning 1885 years.
• Correlation of the TC record with climate phenomena such as El-Niño-Southern Oscillation, North Atlantic Oscillation, and Atlantic Multidecadal Oscillation.
• Interpretation of climate shifts, including the Medieval Warm Period and Intertropical Convergence Zone migration.

Main Results:

• The 1885-year TC record provides unprecedented resolution and duration for the region.
• Long-term TC patterns show a connection to Common Era climate variations and major climate modes.
• A shift in TC activity in the southwestern Caribbean occurred around 1100 CE, from a stable, less active period to a more active and variable state.

Conclusions:

• Basin-scaled climate modes modulate TC formation by influencing sea-surface temperature and wind shear.
• The Medieval Warm Period may have coincided with a southward shift of the Intertropical Convergence Zone, altering the tropical Atlantic TC regime.
• Past TC activity in the Caribbean was influenced by millennial and multi-decadal climate variability, offering insights into future climate scenarios.