Saturday, August 24, 2013

New paper finds Pacific cyclones are at the lowest levels of the past 5,000 years

A paper published today in Quaternary Science Reviews reconstructs cyclones of the central Pacific and finds cyclone activity of the 21st century is at the lowest levels of the past 5,000 years. The paper also shows typhoons in Japan at the lowest levels of the past 3,500 years and that North Atlantic hurricanes were more frequent/severe than modern times during various intervals over the past 3,000 years. The authors attribute the changes in Pacific cyclones to the El Nino Southern Oscillation [ENSO], which is also shown to be at the lowest levels of the past 5,000 years. In addition, the paper shows sea levels of the central Pacific were ~.5 meters [~1.6 feet] higher than modern times from ~1,700 to ~2,500 years ago. Contrary to the claims of climate alarmists, the paper demonstrates cyclone activity and the frequency of El Ninos are currently at very low levels relative to the past 5,000 years.

Cyclone activity is shown in the graph at the right and shows a decline of cyclone activity over the past 250 years.

Top 2 graphs show sea levels were ~0.5 meters higher from ~1,700 to ~2,500 years ago. Bottom 2 graphs show modern cyclone activity is at the lowest levels of the past 5,000 years.

Top 2 graphs show cyclone activity in the South Pacific, 3rd graph shows typhoon activity in Japan, 4th graph N. Atlantic hurricane activity. Horizontal axis is thousands of years before the present. Bottom graph shows ENSO/El Ninos are at the lowest levels of the past 5,000 years.

Reconstructing mid-late Holocene cyclone variability in the Central Pacific using sedimentary records from Tahaa, French Polynesia

  • a Department of Geology & Geophysics, Woods Hole Oceanographic Institution, MS #22, 360 Woods Hole Rd., Woods Hole, MA 02543, USA
  • b Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
  • c Department of Geosciences, University of Massachusetts, Amherst, MA 01003, USA


Recent coarse deposits in lagoon sediments match closely with observed storms.
Increased tropical cyclone strikes to French Polynesia from 5 to 3.8 and 2.9 to 0.5 ka BP [from 5,000 to 3,800 years ago and from 2,900 to 500 years ago].
ENSO and precession are potentially the drivers of these changes in storm activity.
Historic record is inadequate for assessing risk of French Polynesia to future storms.


We lack an understanding of the geographic and temporal controls on South Pacific cyclone activity. Overwash records from backbarrier salt marshes and coastal ponds have been used to reconstruct tropical cyclone strikes in the North Atlantic basin. However, these specific backbarrier environments are scarce in the South Pacific, with cyclone records limited primarily to the period of modern observation. This instrumental record suggests a correlation with the El NiƱo–Southern Oscillation (ENSO), but longer records are necessary to test this relationship over geologic timescales and explore other potential climate drivers of tropical cyclone variability. Deep lagoons behind coral reefs are widespread in the Pacific and provide an alternative setting for developing long-term sedimentary reconstructions of tropical cyclone occurrence. Coarse-grained event deposits within the sediments of a back-reef lagoon surrounding Tahaa reveal a 5000-year record of cyclone occurrences. Timing of recent high-energy deposits matches well with observed tropical cyclone strikes and indicates coarse deposits are storm derived. Longer records show tropical cyclone activity was higher from 5000 to 3800 and 2900 to 500 yrs BP. Comparison to records from the North Pacific (out-of-phase) and North Atlantic (in phase) suggests a coordinated pattern of storm activity across tropical cyclone basins over the mid-late Holocene. The changes in tropical cyclone activity we observe in the South Pacific and across other basins may be related to ENSO as well as precession driven changes in ocean-atmosphere thermal gradients.

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