Quinn T.M.

Paleoclimate proxy perspective on Caribbean climate since the year 1751: Evidence of cooler temperatures and multidecadal variability

Kilbourne, K. H., T. M. Quinn, R. Webb, T. Guilderson, J. Nyberg, and A. Winter. 2008. Paleoclimate proxy perspective on caribbean climate since the year 1751: Evidence of cooler temperatures and multidecadal variability RID A-5755-2008. Paleoceanography 23 (3) (SEP 19): PA3220.

Abstract: 
Annually resolved coral d18O and Sr/Ca records from southwestern Puerto Rico are used to investigate Caribbean climate variability between 1751 and 2004 C.E. Mean surface ocean temperatures in this region have increased steadily by about 2C since the year 1751, with Sr/Ca data indicating 2.1 ± 0.8C and d18O data indicating 2.7 ± 0.5C. Coral geochemical records from across the tropics demonstrate that regional variability is important for understanding climate variations at centennial time scales. A strong multidecadal salinity signal in the oxygen isotope data correlates with observed multidecadal temperature variations in the Northern Hemisphere. Instrumental wind and precipitation data indicate that the most recent coral isotopic variations are caused by expansion and contraction of the steep regional salinity gradient, forced by trade wind anomalies through meridional Ekman transport. The timing of the fluctuations suggests that the multidecadal-scale wind and surface circulation anomalies might play a role in Atlantic temperature variability and meridional overturning circulation, but further work is needed to confirm this suggestion.

Paleoclimate proxy perspective on Caribbean climate since the year 1751: Evidence of cooler temperatures and multidecadal variability

Kilbourne, K. H., T. M. Quinn, R. Webb, T. Guilderson, J. Nyberg, and A. Winter (2008), Paleoclimate proxy perspective
on Caribbean climate since the year 1751: Evidence of cooler temperatures and multidecadal variability, Paleoceanography, 23,
PA3220, doi:10.1029/2008PA001598.

Abstract: 
Annually resolved coral delta O-18 and Sr/Ca records from southwestern Puerto Rico are used to investigate Caribbean climate variability between 1751 and 2004 C. E. Mean surface ocean temperatures in this region have increased steadily by about 2 degrees C since the year 1751, with Sr/Ca data indicating 2.1 +/- 0.8 degrees C and delta O-18 data indicating 2.7 +/- 0.5 degrees C. Coral geochemical records from across the tropics demonstrate that regional variability is important for understanding climate variations at centennial time scales. A strong multidecadal salinity signal in the oxygen isotope data correlates with observed multidecadal temperature variations in the Northern Hemisphere. Instrumental wind and precipitation data indicate that the most recent coral isotopic variations are caused by expansion and contraction of the steep regional salinity gradient, forced by trade wind anomalies through meridional Ekman transport. The timing of the fluctuations suggests that the multidecadal-scale wind and surface circulation anomalies might play a role in Atlantic temperature variability and meridional overturning circulation, but further work is needed to confirm this suggestion.

Low Atlantic hurricane activity in the 1970s and 1980s compared to the past 270 years

Nyberg, J., B. A. Malmgren, A. Winter, M. R.
Jury, K. H. Kilbourne, and T. M. Quinn
(2007), Low Atlantic hurricane activity in the
1970s and 1980s compared to the past 270
years, Nature, 447, 698–701.

Abstract: 
Hurricane activity in the North Atlantic Ocean has increased significantly since 1995 (refs 1, 2). This trend has been attributed to both anthropogenically induced climate change3 and natural variability1, but the primary cause remains uncertain. Changes in the frequency and intensity of hurricanes in the past can provide insights into the factors that influence hurricane activity, but reliable observations of hurricane activity in the North Atlantic only cover the past few decades2. Here we construct a record of the frequency of major Atlantic hurricanes over the past 270 years using proxy records of vertical wind shear and sea surface temperature (the main controls on the formation of major hurricanes in this region1,3–5) from corals and a marine sediment core. The record indicates that the average frequency of major hurricanes decreased gradually from the 1760s until the early 1990s, reaching anomalously low values during the 1970s and 1980s. Furthermore, the phase of enhanced hurricane activity since 1995 is not unusual compared to other periods of high hurricane activity in the record and thus appears to represent a recovery to normal hurricane activity, rather than a direct response to increasing sea surface temperature. Comparison of the record with a reconstruction of vertical wind shear indicates that variability in this parameter primarily controlled the frequency of major hurricanes in the Atlantic over the past 270 years, suggesting that changes in the magnitude of vertical wind shear will have a significant influence on future hurricane activity.
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