Author: Andrew RothwellPublisher:
ISBN:
Category :
Languages : en
Pages : 272
Book Description
Coral-based Climate Reconstructions in the Central Subtropical North Pacific During the Marine Isotope Stage 11 to 10 Transition
Author: Andrew RothwellCoral Records of Central Tropical Pacific Sea-surface Temperature and Salinity Variability Over the 20th Century
Author: Intan Suci NurhatiPublisher:
ISBN:
Category : Climatic changes
Languages : en
Pages :
Book Description
Accurate forecasts of future regional temperature and rainfall patterns in many regions largely depend on characterizing anthropogenic trends in tropical Pacific climate. However, strong interannual to decadal-scale tropical Pacific climate variability, combined with sparse spatial and temporal coverage of instrumental climate datasets in this region, have obscured potential anthropogenic climate signals in the tropical Pacific. In this dissertation, I present sea-surface temperature (SST) and salinity proxy records that span over the 20th century using living corals from several islands in the central tropical Pacific. I reconstruct the SST proxy records via coral Sr/Ca, that are combined with coral oxygen isotopic (d18O) records to quantify changes in seawater d18O (hereafter d18Osw) as a proxy for salinity. Chapter 2 investigates the spatial and temporal character of SST and d18Osw-based salinity trends in the central tropical Pacific from 1972-1998, as revealed by corals from Palmyra (6°N, 162°W), Fanning (4°N, 159°W) and Christmas (2°N, 157°W) Islands. The late 20th century SST proxy records exhibit warming trends that are larger towards the equator, in line with a weakening of equatorial Pacific upwelling over this period. Freshening trends revealed by the salinity proxy records are larger at those sites most affected by the Inter-Tropical Convergence Zone (ITCZ), suggesting a strengthening and/or an equatorward shift of the ITCZ. Taken together, the late 20th century SST and salinity proxy records document warming and freshening trends that are consistent with a trend towards a weakened tropical Pacific zonal SST gradient under continued anthropogenic forcing. Chapter 3 characterizes the signatures of natural and anthropogenic variability in central tropical Pacific SST and d18Osw-based salinity over the course of 20th century using century-long coral proxy records from Palmyra. On interannual timescales, the SST proxy record from Palmyra tracks El Niño-Southern Oscillation (ENSO) variability. The salinity proxy record tracks eastern Pacific-centered ENSO events but is poorly correlated to central Pacific-centered ENSO events - the result of profound differences in precipitation and ocean advection that occur during the two types of ENSO. On decadal timescales, the coral SST proxy record is significantly correlated to the North Pacific Gyre Oscillation (NPGO), suggesting that strong dynamical links exist between the central tropical Pacific and the North Pacific. The salinity proxy record is significantly correlated to the Pacific Decadal Oscillation (PDO), but poorly correlated to the NPGO, suggesting that, as was the case with ENSO, these two modes of Pacific decadal climate variability have unique impacts on equatorial precipitation and ocean advection. However, the most striking feature of the salinity proxy record is a prominent late 20th century freshening trend that is likely related to anthropogenic climate change. Taken together, the coral data provide key constraints on tropical Pacific climate trends, and when used in combination with model simulations of 21st century climate, can be used to improve projections of regional climate in areas affected by tropical Pacific climate variability.
Coral Reefs and Climate Change
Author: Jonathan Turnbull PhinneyPublisher: American Geophysical Union
ISBN: 0875903592
Category : Science
Languages : en
Pages : 251
Book Description
Published by the American Geophysical Union as part of the Coastal and Estuarine Studies, Volume 61. The effects of increased atmospheric carbon dioxide and related climate change on shallow coral reefs are gaining considerable attention for scientific and economic reasons worldwide. Although increased scientific research has improved our understanding of the response of coral reefs to climate change, we still lack key information that can help guide reef management. Research and monitoring of coral reef ecosystems over the past few decades have documented two major threats related to increasing concentrations of atmospheric CO2: (1) increased sea surface temperatures and (2) increased seawater acidity (lower pH). Higher atmospheric CO2 levels have resulted in rising sea surface temperatures and proven to be an acute threat to corals and other reef-dwelling organisms. Short periods (days) of elevated sea surface temperatures by as little as 1–2°C above the normal maximum temperature has led to more frequent and more widespread episodes of coral bleaching-the expulsion of symbiotic algae. A more chronic consequence of increasing atmospheric CO2 is the lowering of pH of surface waters, which affects the rate at which corals and other reef organisms secrete and build their calcium carbonate skeletons. Average pH of the surface ocean has already decreased by an estimated 0.1 unit since preindustrial times, and will continue to decline in concert with rising atmospheric CO2. These climate-related Stressors combined with other direct anthropogenic assaults, such as overfishing and pollution, weaken reef organisms and increase their susceptibility to disease.
Global Climate Change and Coral Reefs
Author: Clive R. WilkinsonPublisher: IUCN
ISBN: 2831702046
Category : Climatic changes
Languages : en
Pages : 140
Book Description
A global overview of the potential impacts of climate change and sea level rise on coral reefs, and of the implications of such impacts for ecological sustainable use of coral reefs. Includes information on the status and trends of reef conservation and use around the world, and suggestions for management of reefs in a changing world.
Climate and ocean variability reconstructed from stable isotop records of modern subtropical corals (northern red sea)
Author: T. FelisCoral Reefs in the Anthropocene
Author: Michael SweetPublisher: Frontiers Media SA
ISBN: 2889634183
Category :
Languages : en
Pages : 261
Book Description
Every year, 10 outstanding Research Topics are selected as finalists of the Frontiers Spotlight Award. These shortlisted article collections each address a globally important field of research with the potential to drastically impact our future. They bring together the latest, cutting-edge research to advance their fields, present new solutions and foster essential, large-scale collaborations across multiple disciplines and research groups worldwide. This international research prize recognizes the most innovative and impactful topics and the winning team of editors receives $100,000 to organize an international scientific conference on the theme of their successful collection.
Coral Records of Radiocarbon Variability in the Central Tropical Pacific During the Last Millennium
Author: Laura Katharine ZaunbrecherPublisher:
ISBN:
Category : Carbon
Languages : en
Pages :
Book Description
Coral Reconstructions of Decadal-to-centennial Climate Variability in the Great Barrier Reef Since 1565 AD
Author: Erica Jane HendyPublisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 317
Book Description
Pacific in Peril
Author: Assessing the Reproducibility of Coral Oxygen and Carbon Isotope Time Series from Fiji and Tonga and Their Application to the Reconstruction of South Pacific Convergence Zone Movements Since the Mid-1800s
Author: Emilie Pauline DassiéPublisher:
ISBN:
Category : Analytical geochemistry
Languages : en
Pages : 211
Book Description