Changes in Atlantic major hurricane frequency since the late-19th century

Gabriel A Vecchi,Wei Zhang,Christopher Landsea,Thomas Knutson,Gabriele Villarini

doi:10.1038/s41467-021-24268-5

Abstract

Atlantic hurricanes are a major hazard to life and property, and a topic of intense scientific interest. Historical changes in observing practices limit the utility of century-scale records of Atlantic major hurricane frequency. To evaluate past changes in frequency, we have here developed a homogenization method for Atlantic hurricane and major hurricane frequency over 1851–2019. We find that recorded century-scale increases in Atlantic hurricane and major hurricane frequency, and associated decrease in USA hurricanes strike fraction, are consistent with changes in observing practices and not likely a true climate trend. After homogenization, increases in basin-wide hurricane and major hurricane activity since the 1970s are not part of a century-scale increase, but a recovery from a deep minimum in the 1960s–1980s. We suggest internal (e.g., Atlantic multidecadal) climate variability and aerosol-induced mid-to-late-20th century major hurricane frequency reductions have probably masked century-scale greenhouse-gas warming contributions to North Atlantic major hurricane frequency.

Highlights

Atlantic hurricanes are a major hazard to life and property, and a topic of intense scientific interest
Even though the North Atlantic (NA) basin is a minor contributor to global Tropical cyclones (TCs) frequency, Atlantic hurricanes (HUs) have been the topic of considerable research both because of the long-term records of their track and frequency that exist for this basin, and because of their impacts at landfall
There has been a substantial increase in monitoring capacity over the past 170 years, so that the probability that a HU is observed is substantially higher in the present than early in the record[10]; the recorded increase in both Atlantic TC and HU frequency in Hurricane Database version 2 (HURDAT2) since the late-19th century is consistent with the impact of known changes in observing practices[7,8,9,10,11,12]

Summary

Introduction

Atlantic hurricanes are a major hazard to life and property, and a topic of intense scientific interest. Historical changes in observing practices limit the utility of century-scale records of Atlantic major hurricane frequency. We find that recorded century-scale increases in Atlantic hurricane and major hurricane frequency, and associated decrease in USA hurricanes strike fraction, are consistent with changes in observing practices and not likely a true climate trend. There has been a substantial increase in monitoring capacity over the past 170 years, so that the probability that a HU is observed is substantially higher in the present than early in the record[10]; the recorded increase in both Atlantic TC and HU frequency in HURDAT2 since the late-19th century is consistent with the impact of known changes in observing practices[7,8,9,10,11,12]. Major hurricane frequency estimates can be impacted by changing observing systems[13]

Methods

Results

Conclusion