Caribbean coral tracks Atlantic Multidecadal Oscillation and past hurricane activity
Abstract
It is highly debated whether global warming contributed to thestrong hurricane activity observed during the last decade. Thecrux of the recent debate is the limited length of the reliableinstrumental record that exacerbates the detection of possiblelong-term changes in hurricane activity, which naturally exhibitsstrong multidecadal variations that are associated with theAtlantic Multidecadal Oscillation (AMO). The AMO, itself a majormode of climate variability, remains also poorly understoodbecause of limited data. Here, we present the first coral-basedproxy record (<IMG SRC="/math/delta.gif" ALT="{delta}" BORDER="0">18O) that clearly captures multidecadal variationsin the AMO and the hurricane activity. Our record, obtainedfrom a brain coral situated in the Atlantic hurricane domain,is equally sensitive to variations in sea surface temperature(SST) and seawater <IMG SRC="/math/delta.gif" ALT="{delta}" BORDER="0">18O, with the latter being strongly linkedto precipitation, by this means amplifying large-scale climatesignals in coral <IMG SRC="/math/delta.gif" ALT="{delta}" BORDER="0">18O. The SST and precipitation signals in thecoral provide the longest, thus far, continuous proxy-basedrecord of hurricane activity that interestingly exhibits a long-termincrease over the last century. As multidecadal SST variationsin this region are closely related to the AMO, this study raisesnew possibilities to extend the limited observations and togain new insights into the mechanisms underlying the AMO andlong-term hurricane variations.
- Publication:
-
Geology
- Pub Date:
- January 2008
- DOI:
- 10.1130/G24321A.1
- Bibcode:
- 2008Geo....36...11H