Atlantic hurricane activity during the last millennium

Area of Science:

• Paleoclimatology
• Tropical Cyclone Climatology
• Geochemistry

Background:

• Atlantic hurricanes pose significant socio-economic risks, particularly in the Main Development Region (MDR).
• Attributing hurricane variability to specific climate forcings is challenging due to limited historical observational data.
• Previous studies relied on climate models and shorter proxy records for understanding hurricane activity.

Purpose of the Study:

• To develop the first empirical reconstruction of Atlantic tropical cyclone activity spanning the last millennium.
• To establish a long-term, high-resolution index for assessing hurricane variability.
• To compare contemporary hurricane activity with natural climate variability over the past 1000 years.

Main Methods:

• Utilized a high-resolution geochemical record from Jamaican lake sediments to create the Extended Hurricane Activity (EHA) index.
• Correlated the EHA index with instrumental records of tropical Atlantic sea surface temperatures (SSTs) and Accumulated Cyclone Energy (ACE).
• Validated the EHA index against annually-resolved coral-based SST reconstructions from the MDR.

Main Results:

• The Extended Hurricane Activity (EHA) index shows significant correlations with tropical Atlantic SSTs (r=0.68) and ACE (r=0.90).
• The reconstruction confirms an increasing trend in hurricane activity during the Industrial Era.
• Current hurricane activity levels have not surpassed the natural variability observed over the last millennium.

Conclusions:

• The EHA index provides a robust, millennium-long perspective on Atlantic hurricane activity.
• While hurricane activity has increased, it remains within the bounds of natural climate variability.
• This long-term perspective is crucial for understanding future hurricane risk and climate change impacts.