scholarly journals Projected impacts of climate change and ocean acidification on the global biogeography of planktonic foraminifera

2014 ◽  
Vol 11 (6) ◽  
pp. 10083-10121
Author(s):  
T. Roy ◽  
F. Lombard ◽  
L. Bopp ◽  
M. Gehlen
Keyword(s):  
Climate Change ◽  
Ocean Acidification ◽  
Food Availability ◽  
Large Scale ◽  
Planktonic Foraminifera ◽  
Global Ocean ◽  
Tropical Regions ◽  
Carbonate Concentration ◽  
Calcite Saturation ◽  
The Tropics

Abstract. Planktonic foraminifera are a major contributor to the deep carbonate-flux and the planktonic biomass of the global ocean. Their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically-based foraminifer model that incorporates three known major physiological drivers of foraminifer biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic foraminifera under anthropogenic climate change, and (ii) the alteration of the carbonate chemistry of foraminifer habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of foraminifera are simulated using temperature, plankton biomass, and light from an Earth system model forced with historical and a future (IPCC A2) high CO2 emission scenario. The broadscale patterns of present day foraminifer biogeography are well reproduced. Foraminifer abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. In the tropics, the geographical shifts are driven by temperature, while the vertical shifts are driven by both temperature and food availability. In the high-latitudes, vertical shifts are driven by food availability, while geographical shifts are driven by both food availability and temperature. Changes in the marine carbon cycle would be expected in response to (i) the large-scale rearrangements in foraminifer abundance, and (ii) the reduction of the carbonate concentration in the habitat range of planktonic foraminifers: from 10–30 μmol kg−1 in the polar/subpolar regions to 30–70 μmol kg−1 in the subtropical/tropical regions. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of their habitat drops below the calcite saturation horizon.

scholarly journals Projected impacts of climate change and ocean acidification on the global biogeography of planktonic Foraminifera

2015 ◽  
Vol 12 (10) ◽  
pp. 2873-2889 ◽  
Author(s):  
T. Roy ◽  
F. Lombard ◽  
L. Bopp ◽  
M. Gehlen
Keyword(s):  
Climate Change ◽  
Ocean Acidification ◽  
Large Scale ◽  
Planktonic Foraminifera ◽  
Marine Carbonate ◽  
Geographical Regions ◽  
Calcite Saturation ◽  
Abundance And Diversity ◽  
The Tropics ◽  
Carbonate Flux

Abstract. Planktonic Foraminifera are a major contributor to the deep carbonate flux and their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically based planktonic foraminifer model that incorporates three known major physiological drivers of their biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic Foraminifera under anthropogenic climate change and (ii) the alteration of the carbonate chemistry of foraminiferal habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of Foraminifera are simulated using temperature, plankton biomass and light from an Earth system model forced with a historical and a future (IPCC A2) high CO2 emission scenario. Foraminiferal abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. Temperature is the dominant control on the future change in the biogeography of Foraminifera. Yet food availability acts to either reinforce or counteract the temperature-driven changes. In the tropics and subtropics the largely temperature-driven shift to depth is enhanced by the increased concentration of phytoplankton at depth. In the higher latitudes the food-driven response partly offsets the temperature-driven reduction both in the subsurface and across large geographical regions. The large-scale rearrangements in foraminiferal abundance and the reduction in the carbonate ion concentrations in the habitat range of planktonic foraminifers – from 10–30 μmol kg−1 in their polar and subpolar habitats to 30–70 μmol kg−1 in their subtropical and tropical habitats – would be expected to lead to changes in the marine carbonate flux. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of the volume of their habitat drops below the calcite saturation horizon.

scholarly journals Dipole patterns in tropical precipitation were pervasive across landmasses throughout Marine Isotope Stage 5

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Katrina Nilsson-Kerr ◽  
Pallavi Anand ◽  
Philip B. Holden ◽  
Steven C. Clemens ◽  
Melanie J. Leng
Keyword(s):  
Large Scale ◽  
Marine Isotope Stage ◽  
Convergence Zone ◽  
Inter Tropical Convergence Zone ◽  
Tropical Regions ◽  
Tropical Precipitation ◽  
Rainfall Patterns ◽  
Marine Isotope Stage 5 ◽  
Climate Cooling ◽  
The Tropics

AbstractMost of Earth’s rain falls in the tropics, often in highly seasonal monsoon rains, which are thought to be coupled to the inter-hemispheric migrations of the Inter-Tropical Convergence Zone in response to the seasonal cycle of insolation. Yet characterization of tropical rainfall behaviour in the geologic past is poor. Here we combine new and existing hydroclimate records from six large-scale tropical regions with fully independent model-based rainfall reconstructions across the last interval of sustained warmth and ensuing climate cooling between 130 to 70 thousand years ago (Marine Isotope Stage 5). Our data-model approach reveals large-scale heterogeneous rainfall patterns in response to changes in climate. We note pervasive dipole-like tropical precipitation patterns, as well as different loci of precipitation throughout Marine Isotope Stage 5 than recorded in the Holocene. These rainfall patterns cannot be solely attributed to meridional shifts in the Inter-Tropical Convergence Zone.

scholarly journals Climate Change Detection and Attribution: Beyond Mean Temperature Signals

2006 ◽  
Vol 19 (20) ◽  
pp. 5058-5077 ◽  
Author(s):  
Gabriele C. Hegerl ◽  
Thomas R. Karl ◽  
Myles Allen ◽  
Nathaniel L. Bindoff ◽  
Nathan Gillett ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Climate Models ◽  
Climate Extremes ◽  
Global Ocean ◽  
Sampled Data ◽  
Free Atmosphere ◽  
Ocean Heat Uptake ◽  
Continental Scale ◽  
Detection And Attribution

Abstract A significant influence of anthropogenic forcing has been detected in global- and continental-scale surface temperature, temperature of the free atmosphere, and global ocean heat uptake. This paper reviews outstanding issues in the detection of climate change and attribution to causes. The detection of changes in variables other than temperature, on regional scales and in climate extremes, is important for evaluating model simulations of changes in societally relevant scales and variables. For example, sea level pressure changes are detectable but are significantly stronger in observations than the changes simulated in climate models, raising questions about simulated changes in climate dynamics. Application of detection and attribution methods to ocean data focusing not only on heat storage but also on the penetration of the anthropogenic signal into the ocean interior, and its effect on global water masses, helps to increase confidence in simulated large-scale changes in the ocean. To evaluate climate change signals with smaller spatial and temporal scales, improved and more densely sampled data are needed in both the atmosphere and ocean. Also, the problem of how model-simulated climate extremes can be compared to station-based observations needs to be addressed.

Large-scale redistribution of maximum fisheries catch potential in the global ocean under climate change

2010 ◽  
Vol 16 (1) ◽  
pp. 24-35 ◽  
Author(s):  
WILLIAM W. L. CHEUNG ◽  
VICKY W. Y. LAM ◽  
JORGE L. SARMIENTO ◽  
KELLY KEARNEY ◽  
REG WATSON ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Global Ocean

scholarly journals A Global Analysis of Sverdrup Balance Using Absolute Geostrophic Velocities from Argo

2014 ◽  
Vol 44 (4) ◽  
pp. 1213-1229 ◽  
Author(s):  
Alison R. Gray ◽  
Stephen C. Riser
Keyword(s):  
Large Scale ◽  
Global Analysis ◽  
Global Ocean ◽  
Reference Level ◽  
Trajectory Data ◽  
Geostrophic Velocity ◽  
Barotropic Flow ◽  
Sverdrup Balance ◽  
The Absolute ◽  
The Tropics

Abstract Using observations from the Argo array of profiling floats, the large-scale circulation of the upper 2000 decibars (db) of the global ocean is computed for the period from December 2004 to November 2010. The geostrophic velocity relative to a reference level of 900 db is estimated from temperature and salinity profiles, and the absolute geostrophic velocity at the reference level is estimated from the trajectory data provided by the floats. Combining the two gives the absolute geostrophic velocity on 29 pressure surfaces spanning the upper 2000 db of the global ocean. These velocities, together with satellite observations of wind stress, are then used to evaluate Sverdrup balance, the simple canonical theory relating meridional geostrophic transport to wind forcing. Observed transports agree well with predictions based on the wind field over large areas, primarily in the tropics and subtropics. Elsewhere, especially at higher latitudes and in boundary regions, Sverdrup balance does not accurately describe meridional geostrophic transports, possibly due to the increased importance of the barotropic flow, nonlinear dynamics, and topographic influence. Thus, while it provides an effective framework for understanding the zero-order wind-driven circulation in much of the global ocean, Sverdrup balance should not be regarded as axiomatic.

scholarly journals Large-scale phylogenetic analyses reveal the causes of high tropical amphibian diversity

2013 ◽  
Vol 280 (1770) ◽  
pp. 20131622 ◽  
Author(s):  
R. Alexander Pyron ◽  
John J. Wiens
Keyword(s):  
Species Richness ◽  
Time Scales ◽  
Large Scale ◽  
Phylogenetic Analyses ◽  
Geological Time ◽  
Tropical Regions ◽  
Extinction Rates ◽  
Tropical Diversity ◽  
Limited Dispersal ◽  
The Tropics

Many groups show higher species richness in tropical regions but the underlying causes remain unclear. Despite many competing hypotheses to explain latitudinal diversity gradients, only three processes can directly change species richness across regions: speciation, extinction and dispersal. These processes can be addressed most powerfully using large-scale phylogenetic approaches, but most previous studies have focused on small groups and recent time scales, or did not separate speciation and extinction rates. We investigate the origins of high tropical diversity in amphibians, applying new phylogenetic comparative methods to a tree of 2871 species. Our results show that high tropical diversity is explained by higher speciation in the tropics, higher extinction in temperate regions and limited dispersal out of the tropics compared with colonization of the tropics from temperate regions. These patterns are strongly associated with climate-related variables such as temperature, precipitation and ecosystem energy. Results from models of diversity dependence in speciation rate suggest that temperate clades may have lower carrying capacities and may be more saturated (closer to carrying capacity) than tropical clades. Furthermore, we estimate strikingly low tropical extinction rates over geological time scales, in stark contrast to the dramatic losses of diversity occurring in tropical regions presently.

scholarly journals Modelling ocean acidification effects with life stage-specific responses alters spatiotemporal patterns of catch and revenues of American lobster, Homarus americanus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Travis C. Tai ◽  
Piero Calosi ◽  
Helen J. Gurney-Smith ◽  
William W. L. Cheung
Keyword(s):  
Climate Change ◽  
Ocean Acidification ◽  
Large Scale ◽  
Life Stage ◽  
Homarus Americanus ◽  
Minimum Size ◽  
Future Climate Change ◽  
American Lobster ◽  
Fishing Pressure ◽  
Size Limits

AbstractOcean acidification (OA) affects marine organisms through various physiological and biological processes, yet our understanding of how these translate to large-scale population effects remains limited. Here, we integrated laboratory-based experimental results on the life history and physiological responses to OA of the American lobster, Homarus americanus, into a dynamic bioclimatic envelope model to project future climate change effects on species distribution, abundance, and fisheries catch potential. Ocean acidification effects on juvenile stages had the largest stage-specific impacts on the population, while cumulative effects across life stages significantly exerted the greatest impacts, albeit quite minimal. Reducing fishing pressure leads to overall increases in population abundance while setting minimum size limits also results in more higher-priced market-sized lobsters (> 1 lb), and could help mitigate the negative impacts of OA and concurrent stressors (warming, deoxygenation). However, the magnitude of increased effects of climate change overweighs any moderate population gains made by changes in fishing pressure and size limits, reinforcing that reducing greenhouse gas emissions is most pressing and that climate-adaptive fisheries management is necessary as a secondary role to ensure population resiliency. We suggest possible strategies to mitigate impacts by preserving important population demographics.

scholarly journals Modulation of ocean acidification by decadal climate variability in the Gulf of Alaska

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Claudine Hauri ◽  
Rémi Pagès ◽  
Andrew M. P. McDonnell ◽  
Malte F. Stuecker ◽  
Seth L. Danielson ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Ocean Circulation ◽  
Large Scale ◽  
Dissolved Inorganic Carbon ◽  
Model Simulation ◽  
Gulf Of Alaska ◽  
Sea Surface Height ◽  
Sea Surface ◽  
Global Ocean ◽  
Wind Stress Curl

AbstractUptake of anthropogenic carbon dioxide from the atmosphere by the surface ocean is leading to global ocean acidification, but regional variations in ocean circulation and mixing can dampen or accelerate apparent acidification rates. Here we use a regional ocean model simulation for the years 1980 to 2013 and observational data to investigate how ocean fluctuations impact acidification rates in surface waters of the Gulf of Alaska. We find that large-scale atmospheric forcing influenced local winds and upwelling strength, which in turn affected ocean acidification rate. Specifically, variability in local wind stress curl depressed sea surface height in the subpolar gyre over decade-long intervals, which increased upwelling of nitrate- and dissolved inorganic carbon-rich waters and enhanced apparent ocean acidification rates. We define this sea surface height variability as the Northern Gulf of Alaska Oscillation and suggest that it can cause extreme acidification events that are detrimental to ecosystem health and fisheries.

The biology of Canadian weeds. 135. Lonicera japonica Thunb.

2007 ◽  
Vol 87 (2) ◽  
pp. 423-438 ◽  
Author(s):  
Brendon M. H. Larson ◽  
Paul M. Catling ◽  
Gerald E. Waldron
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Control Method ◽  
Foliar Application ◽  
Eastern China ◽  
Lonicera Japonica ◽  
Effective Control ◽  
Tropical Regions ◽  
Change Models ◽  
Native Flora

Japanese honeysuckle (Lonicera japonica Thunb.) is a twining semi-evergreen vine native to Japan, Korea and eastern China. Over the past 150 yr it has been introduced as an ornamental and become established in temperate and tropical regions worldwide. It was first discovered in Canada in 1976 in southwestern Ontario woodlands and has since been found growing without cultivation in 15 localities. While L. japonica does not occur very frequently in southern Ontario, climate change models suggest that it may become more abundant in this region. Its predominance elsewhere derives from morphological and physiological characteristics that allow it to be particularly successful in the edge habitats of fragmented landscapes. Through extensive vegetative propagation and competitive ability it occupies space which may otherwise host a diverse native flora. The plant has many uses in Asian medicine and is a popular ornamental, but has been prohibited in some regions due to its displacement of other species. A combination of cutting and foliar application of glyphosate has proven to be an effective control method in some circumstances. Planting of L. japonica should be discouraged and horticulturalists should consider alternative attractive vines. The spread of L. japonica should be monitored in Ontario and control of newly established populations should be considered to avoid costly large scale control in the future. Key words: Invasive species, Lonicera japonica, weed biology, climate change

scholarly journals Water isotope variations in the global ocean model MPI-OM

2012 ◽  
Vol 5 (3) ◽  
pp. 809-818 ◽  
Author(s):  
X. Xu ◽  
M. Werner ◽  
M. Butzin ◽  
G. Lohmann
Keyword(s):  
Surface Waters ◽  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Deep Ocean ◽  
Ocean Surface ◽  
Ocean Model ◽  
Global Ocean ◽  
Stable Water Isotopes ◽  
Tropical Regions

Abstract. The stable water isotopes H218O and HDO are incorporated as passive tracers into the oceanic general circulation model MPI-OM, and a control simulation under present-day climate conditions is analyzed in detail. Both δ18O and δD distributions at the ocean surface and deep ocean are generally consistent with available observations on the large scale. The modelled δD-δ 18O relations in surface waters slightly deviates from the slope of the global meteoric water line in most basins, and a much steeper slope is detected in Arctic Oceans. The simulated deuterium excess of ocean surface waters shows small variations between 80° S and 55° N, and a strong decrease north of 55° N. The model is also able to capture the quasi-linear relationship between δ18O and salinity S, as well as δD and S, as seen in observational data. Both in the model results and observations, the surface δ−S relations show a steeper slope in extra-tropical regions than in tropical regions, which indicates relatively more addition of isotopically depleted water at high latitudes.

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