ENSO Drove 2500-Year Collapse of Eastern Pacific Coral Reefs

Science ◽  
2012 ◽  
Vol 337 (6090) ◽  
pp. 81-84 ◽  
Author(s):  
Lauren T. Toth ◽  
Richard B. Aronson ◽  
Steven V. Vollmer ◽  
Jennifer W. Hobbs ◽  
Dunia H. Urrego ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Global Climate Change ◽  
Southern Oscillation ◽  
Global Climate ◽  
Intertropical Convergence Zone ◽  
Eastern Pacific ◽  
Convergence Zone ◽  
Reef Growth ◽  
Tropical Eastern Pacific

Cores of coral reef frameworks along an upwelling gradient in Panamá show that reef ecosystems in the tropical eastern Pacific collapsed for 2500 years, representing as much as 40% of their history, beginning about 4000 years ago. The principal cause of this millennial-scale hiatus in reef growth was increased variability of the El Niño–Southern Oscillation (ENSO) and its coupling with the Intertropical Convergence Zone. The hiatus was a Pacific-wide phenomenon with an underlying climatology similar to probable scenarios for the next century. Global climate change is probably driving eastern Pacific reefs toward another regional collapse.

Disturbances with hiatuses in high-latitude coral reef growth during the Holocene: Correlation with millennial-scale global climate change

2012 ◽  
Vol 80-81 ◽  
pp. 21-35 ◽  
Author(s):  
Nozomu Hamanaka ◽  
Hironobu Kan ◽  
Yusuke Yokoyama ◽  
Takehiro Okamoto ◽  
Yosuke Nakashima ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Global Climate Change ◽  
High Latitude ◽  
Global Climate ◽  
Reef Growth ◽  
The Holocene ◽  
Millennial Scale

scholarly journals Increased Terrestrial Perturbations Modify Skeletal Properties and Mechanical Strength of Hard Corals

2016 ◽  
Vol 6 (4) ◽  
pp. 153 ◽  
Author(s):  
Shaaban A. Mwachireya ◽  
Tim R. McClanahan ◽  
Isabelle M. Cote ◽  
Brian E. Hartwick
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Global Climate Change ◽  
Global Climate ◽  
High Porosity ◽  
Growth Forms ◽  
Management Options ◽  
Skeletal Density ◽  
Change Events ◽  
Hydrodynamic Energy

Skeleton properties determine coral survival by influencing the range of hydraulic conditions colonies can withstand, selection of suitable habitat, ability to compete for space and light, repair damage and the overall fitness and ecological success of scleractinian corals. Skeletal properties of 16 coral species comprising 3 growth forms collected from Kenyan coral reef lagoons were investigated and found to vary considerably not only between species but between reefs as well, with corals exposed to both sediment and nutrients showing consistent lower skeleton density and strength but high porosity compared to those from sediment-unaffected reefs. Further, high skeletal density and strength but low porosity values were measured in branching relative to other growth forms. The present findings also suggest that the negative effects of nutrients on skeleton properties may be counteracted by high hydrodynamic energy, resulting in stronger skeletons in high hydrodynamic energy-nutrient-polluted reef habitats relative to pristine reefs. These findings have important ecological and management implications with regard to the existence, persistence, productivity and protective value of reefs, damage risks, maintenance and conservation of biological diversity with respect to future global climate change events. Consequently, appropriate watershed, reef and fisheries management options the impacts of local anthropogenic stresses (sediments, nutrients, overexploitation) would be expected to alleviate the effects of these disturbances and have the potential to minimize future large-scale coral reef damage resulting from increased and frequent global climate change events, such as increased ocean acidification (due to elevated atmospheric CO2) and sea surface temperature.

scholarly journals Objective Identification of the Intertropical Convergence Zone: Climatology and Trends from the ERA-Interim

2014 ◽  
Vol 27 (5) ◽  
pp. 1894-1909 ◽  
Author(s):  
Gareth Berry ◽  
Michael J. Reeder
Keyword(s):  
Climate Model ◽  
Southern Oscillation ◽  
Weather Prediction ◽  
Lower Troposphere ◽  
Intertropical Convergence Zone ◽  
Eastern Pacific ◽  
Tropical Cyclogenesis ◽  
Convergence Zone ◽  
Operational Forecasts ◽  
The Mean

Abstract An objective method for the identification of the intertropical convergence zone (ITCZ) in gridded numerical weather prediction datasets is presented. This technique uses layer- and time-averaged winds in the lower troposphere to automatically detect the location of the ITCZ and is designed for use with datasets including operational forecasts and climate model output. The method is used to create a climatology of ITCZ properties from the Interim ECMWF Re-Analysis (ERA-Interim) dataset for the period 1979–2009 to serve as an indicator of the technique's ability and a benchmark for future comparisons. The automatically generated objective climatology closely matches the results from subjective studies, showing a seasonal cycle in which the oceanic ITCZ migrates meridionally and the land-based ITCZ features are predominantly summertime phenomena. Composites based on the phase of the El Niño–Southern Oscillation index show a major shift in the mean position and changes in intensity of the ITCZ in all ocean basins as the index varies. Under La Niña conditions, the ITCZ intensifies over the Maritime Continent and eastern Pacific, where the ITCZ weakens over the central and equatorial eastern Pacific. An analysis of changes in the ITCZ and its divergence during the period 1979–2009 indicates that the mean position of the ITCZ shifts southward in the western Pacific and a broad global intensification of the convergence into ITCZ regions. The relationship between tropical cyclogenesis and the ITCZ is also examined, finding that more than 50% of all tropical cyclones form within 600 km of the ITCZ.

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