A 1,000-year, Annually-Resolved Record of Hurricane Activity From Boston, Massachusetts by Besonen et al.

Climate Science: Roger Pielke Sr. Research Group News: A 1,000-year, Annually-Resolved Record of Hurricane Activity From Boston, Massachusetts by Besonen et al.

There is a new paper which uses paelo-data to extend the record of hurricane activity back before the histroical record. The paper is

Besonen, M. R., R. S. Bradley, M. Mudelsee, M. B. Abbott, and P. Francus (2008), A 1,000-year, annually-resolved record of hurricane activity from Boston, Massachusetts,Geophys. Res. Lett., 35, L14705, doi:10.1029/2008GL033950.

with the abstract

“The annually-laminated (i.e., varved) sediment record from the Lower Mystic Lake (near Boston, MA), contains a series of anomalous graded beds deposited by strong flooding events that have affected the basin over the last millennium. From the historic portion of the record, 10 out of 11 of the most prominent graded beds correspond with years in which category 2-3 hurricanes are known to have struck the Boston area. Thus, we conclude that the graded beds represent deposition related to intense hurricane precipitation combined with wind-driven vegetation disturbance that exposes fresh, loose sediment. The hurricane signal shows strong, centennial-scale variations in frequency with a period of increased activity between the 12th-16th centuries, and decreased activity during the 11th and 17th-19th centuries. These frequency changes are consistent with other paleoclimate indicators from the tropical North Atlantic, in particular, sea surface temperature variations.”

The conclusion reads,

“The LML sedimentary record provides a well-controlled and annually-resolved record of category 2–3 hurricane activity in the Boston area over the last millennium. The hurricane signal shows centennial-scale variations in frequency with a period of increased activity between the 12th–16th centuries, and decreased activity during the 11th and 17th–19th centuries. We recognize that the LML record is a single point source record representative for the greater Boston area, and hurricanes that passed a few hundred km to the east or west may not have produced the very heavy rainfall amounts and vegetation disturbance in the lake watershed necessary to produce a strong signal within the LML sediments. Nevertheless, we also note that clear evidence of a secular change in hurricane frequency identified in the LML record is consistent with other lines of evidence that conditions for the development of hurricanes have changed on centennial timescales. Hence, it appears that hurricane activity was more frequent in the first half of the last millennium when tropical Atlantic SSTs were warmer and eastern equatorial Pacific SSTs were cooler than in subsequent centuries.”

This study adds to the clear documentation in the paleo-record that climate is not stationary, and never has been! …