The Experts below are selected from a list of 117012 Experts worldwide ranked by ideXlab platform
Mark A Cane - One of the best experts on this subject based on the ideXlab platform.
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Orbital controls on the El Nifio/Southern Oscillation and the Tropical Climate
2016Co-Authors: Amy C Clement, Richard Seager, Mark A CaneAbstract:Abstract. The global synchroneity of glacial-interglacial events is one of the major problems in understanding the link between Milankovitch forcing and the Climate of the late Quaternary. In this study we isolate a part of the Climate system, the Tropical Pacific, and test its sensitivity to changes in solar forcing associated with changes in the Earth's orbital parameters. We use a simplified coupled ocean-atmosphere model that is run for the past 150,000 years and forced with Milankovitch changes in the solar insolation. This system responds primarily to the precessional cycle in solar forcing and is capable of generating a mean response to the changes in the seasonal distribution of solar radiation even while the annual mean insolation is roughly constant. The mean response to the precessional forcing is due to an interaction between an altered seasonal cycle and the El Nifio/Southern Oscillation (ENSO). Changes in the ENSO behavior result in a mean Tropical Climate change. The hypothesis is advanced that such a change in the Tropical Climate can generate a globally synchronous Climate response to Milankovitch forcing. 1
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orbital controls on the el nino southern oscillation and the Tropical Climate
Paleoceanography, 1999Co-Authors: Amy C Clement, Richard Seager, Mark A CaneAbstract:The global synchroneity of glacial-interglacial events is one of the major problems in understanding the link between Milankovitch forcing and the Climate of the late Quaternary. In this study we isolate a part of the Climate system, the Tropical Pacific, and test its sensitivity to changes in solar forcing associated with changes in the Earth's orbital parameters. We use a simplified coupled ocean-atmosphere model that is run for the past 150,000 years and forced with Milankovitch changes in the solar insolation. This system responds primarily to the precessional cycle in solar forcing and is capable of generating a mean response to the changes in the seasonal distribution of solar radiation even while the annual mean insolation is roughly constant. The mean response to the precessional forcing is due to an interaction between an altered seasonal cycle and the El Nifio/Southern Oscillation (ENSO). Changes in the ENSO behavior result in a mean Tropical Climate change. The hypothesis is advanced that such a change in the Tropical Climate can generate a globally synchronous Climate response to Milankovitch forcing.
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Orbital controls on the El Niño/Southern Oscillation and the Tropical Climate
Paleoceanography, 1999Co-Authors: Amy C Clement, Richard Seager, Mark A CaneAbstract:The global synchroneity of glacial-interglacial events is one of the major problems in understanding the link between Milankovitch forcing and the Climate of the late Quaternary. In this study we isolate a part of the Climate system, the Tropical Pacific, and test its sensitivity to changes in solar forcing associated with changes in the Earth's orbital parameters. We use a simplified coupled ocean-atmosphere model that is run for the past 150,000 years and forced with Milankovitch changes in the solar insolation. This system responds primarily to the precessional cycle in solar forcing and is capable of generating a mean response to the changes in the seasonal distribution of solar radiation even while the annual mean insolation is roughly constant. The mean response to the precessional forcing is due to an interaction between an altered seasonal cycle and the El Nifio/Southern Oscillation (ENSO). Changes in the ENSO behavior result in a mean Tropical Climate change. The hypothesis is advanced that such a change in the Tropical Climate can generate a globally synchronous Climate response to Milankovitch forcing.
Amy C Clement - One of the best experts on this subject based on the ideXlab platform.
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Orbital controls on the El Nifio/Southern Oscillation and the Tropical Climate
2016Co-Authors: Amy C Clement, Richard Seager, Mark A CaneAbstract:Abstract. The global synchroneity of glacial-interglacial events is one of the major problems in understanding the link between Milankovitch forcing and the Climate of the late Quaternary. In this study we isolate a part of the Climate system, the Tropical Pacific, and test its sensitivity to changes in solar forcing associated with changes in the Earth's orbital parameters. We use a simplified coupled ocean-atmosphere model that is run for the past 150,000 years and forced with Milankovitch changes in the solar insolation. This system responds primarily to the precessional cycle in solar forcing and is capable of generating a mean response to the changes in the seasonal distribution of solar radiation even while the annual mean insolation is roughly constant. The mean response to the precessional forcing is due to an interaction between an altered seasonal cycle and the El Nifio/Southern Oscillation (ENSO). Changes in the ENSO behavior result in a mean Tropical Climate change. The hypothesis is advanced that such a change in the Tropical Climate can generate a globally synchronous Climate response to Milankovitch forcing. 1
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orbital controls on the el nino southern oscillation and the Tropical Climate
Paleoceanography, 1999Co-Authors: Amy C Clement, Richard Seager, Mark A CaneAbstract:The global synchroneity of glacial-interglacial events is one of the major problems in understanding the link between Milankovitch forcing and the Climate of the late Quaternary. In this study we isolate a part of the Climate system, the Tropical Pacific, and test its sensitivity to changes in solar forcing associated with changes in the Earth's orbital parameters. We use a simplified coupled ocean-atmosphere model that is run for the past 150,000 years and forced with Milankovitch changes in the solar insolation. This system responds primarily to the precessional cycle in solar forcing and is capable of generating a mean response to the changes in the seasonal distribution of solar radiation even while the annual mean insolation is roughly constant. The mean response to the precessional forcing is due to an interaction between an altered seasonal cycle and the El Nifio/Southern Oscillation (ENSO). Changes in the ENSO behavior result in a mean Tropical Climate change. The hypothesis is advanced that such a change in the Tropical Climate can generate a globally synchronous Climate response to Milankovitch forcing.
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Orbital controls on the El Niño/Southern Oscillation and the Tropical Climate
Paleoceanography, 1999Co-Authors: Amy C Clement, Richard Seager, Mark A CaneAbstract:The global synchroneity of glacial-interglacial events is one of the major problems in understanding the link between Milankovitch forcing and the Climate of the late Quaternary. In this study we isolate a part of the Climate system, the Tropical Pacific, and test its sensitivity to changes in solar forcing associated with changes in the Earth's orbital parameters. We use a simplified coupled ocean-atmosphere model that is run for the past 150,000 years and forced with Milankovitch changes in the solar insolation. This system responds primarily to the precessional cycle in solar forcing and is capable of generating a mean response to the changes in the seasonal distribution of solar radiation even while the annual mean insolation is roughly constant. The mean response to the precessional forcing is due to an interaction between an altered seasonal cycle and the El Nifio/Southern Oscillation (ENSO). Changes in the ENSO behavior result in a mean Tropical Climate change. The hypothesis is advanced that such a change in the Tropical Climate can generate a globally synchronous Climate response to Milankovitch forcing.
Gilles Bellon - One of the best experts on this subject based on the ideXlab platform.
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Analysis of the Tropical Climate variability in a two-column framework
Climate Dynamics, 2011Co-Authors: Gilles Bellon, Guillaume Gastineau, Aurélien Ribes, Hervé Le TreutAbstract:This work examines the relevance of a classical two-column modeling framework of the Tropical Climate in terms of observed natural variability. A method is developed to analyze the observed Tropical Climate in a simple framework that features a moist, ascending column and a dry, subsiding one. This method is used to analyze the natural variability of the Tropical Climate in the ERA40 reanalysis and in ISCCP satellite data. It appears that the seasonal cycle of the tropic-wide sea surface temperature (SST) is almost linearly linked to the seasonal cycle of the relative area of the moist regions, as predicted by the sensitivity of the two-column models. A more detailed analysis shows that this link is the product of a complex interaction and adjustments between the moist and dry regions. The seasonal cycle of low-cloud cover in the dry regions also appears to interact with the SST seasonal cycle: the low-cloud cover influences the tropic-wide SST via its direct radiative forcing on the local SST and it appears to be controlled by the SST difference between moist and dry regions. By contrast, the SST interannual variability appears to be driven by the El Niño Southern Oscillation (ENSO), with no significant impact from the changes in the relative area of the moist regions or in the low-cloud cover in the dry regions independently of the ENSO. ENSO-related changes in the area of moist regions and low-cloud cover constitute negative feedbacks on the ENSO-related SST variability.
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Analysis of the Tropical Climate variability in a two-column framework
Climate Dynamics, 2010Co-Authors: Gilles Bellon, Guillaume Gastineau, Aurélien Ribes, Hervé Le TreutAbstract:International audienceThis work examines the relevance of a classical two-column modeling framework of the Tropical Climate in terms of observed natural variability. A method is developed to analyze the observed Tropical Climate in a simple framework that features a moist, ascending column and a dry, subsiding one. This method is used to analyze the natural variability of the Tropical Climate in the ERA40 reanalysis and in ISCCP satellite data. It appears that the seasonal cycle of the tropic-wide sea surface temperature (SST) is almost linearly linked to the seasonal cycle of the relative area of the moist regions, as predicted by the sensitivity of the two-column models. A more detailed analysis shows that this link is the product of a complex interaction and adjustments between the moist and dry regions. The seasonal cycle of low-cloud cover in the dry regions also appears to interact with the SST seasonal cycle: the low-cloud cover influences the tropic-wide SST via its direct radiative forcing on the local SST and it appears to be controlled by the SST difference between moist and dry regions. By contrast, the SST interannual variability appears to be driven by the El Niño Southern Oscillation (ENSO), with no significant impact from the changes in the relative area of the moist regions or in the low-cloud cover in the dry regions independently of the ENSO. ENSO-related changes in the area of moist regions and low-cloud cover constitute negative feedbacks on the ENSO-related SST variability
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Minimal models of the Tropical Climate: theoretical aspects and implication for the future Climate change
2004Co-Authors: Gilles BellonAbstract:Why does the surface temperature in thee Tropics exhibit a maximum around 30°C, what are the mechanisms that control the stability of the Tropical Climate, and what are the specificities of Climate change in that region of the Earth? A simple two-column model is used to confirm the high sensitivity of the Tropical Climate to a change of relative surfaces covered by moist and dry zones, particularly in the context of a warming related to the increase of greenhouse gas concentration. The influence of surface winds is shown to be significant. Two-column moist/dry systems exhibit a bimodal size distribution in the observations, with a synoptic mode and a large-scale one. This bimodality can be reproduced with a simple model, in which the surface dynamics select the spatial scales. Finally, the limits of idealized modelling of the trade-wind boundary layer are analyzed.
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Large-scale and evaporation-wind feedbacks in a box model of the Tropical Climate
Geophysical Research Letters, 2003Co-Authors: Gilles Bellon, H. Le Treut, Michael GhilAbstract:[1] A four-box model of the Tropical Climate is used to assess its sensitivity to changes in the relative area of the moist and dry regions and to radiative perturbations. The feedbacks modulating this sensitivity are analyzed, particularly the dynamical feedbacks associated with the surface fluxes. The link between the large-scale circulation and these fluxes is found to play a crucial role in the tropics' sensitivity to radiative perturbations.
Olivier Hue - One of the best experts on this subject based on the ideXlab platform.
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The influences of Tropical Climate on imagined walking time
Journal of Cognitive Psychology, 2017Co-Authors: Nicolas Robin, Guillaume Coudevylle, Olivier Hue, Lucette ToussaintAbstract:This study investigated the effects of a Tropical Climate (TC) on actual and imagined walking times. Participants had to execute and imagine walking 3 distances with or without a 10-kg weight in ei...
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The influences of Tropical Climate on imagined walking time
Journal of Cognitive Psychology, 2017Co-Authors: Nicolas Robin, Guillaume Coudevylle, Olivier Hue, Lucette ToussaintAbstract:This study investigated the effects of a Tropical Climate (TC) on actual and imagined walking times. Participants had to execute and imagine walking 3 distances with or without a 10-kg weight in either a TC or an Air Conditioning (AC) condition. The motor imagery quality was evaluated by computing the isochrony index. The results revealed that movement times were shorter for imagined walking than for actual walking and increased with the distance of the paths in both cases. By contrast, the effect of the load increased actual walking times for the 10- and 15-meter distances without affecting imagined walking times. Importantly, the isochrony index was negatively affected by the increase in load and distance and the effects of distance were amplified in a TC. These findings showed that the environmental Climate in which motor imagery arises can modulate the subject’s ability to build up the temporal characteristics of simulated actions.
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Physical and Perceptual Cooling with Beverages to Increase Cycle Performance in a Tropical Climate
PLoS ONE, 2014Co-Authors: Florence Riera, Stéphane Sinnapah, Than Tran Trong, Olivier HueAbstract:Purpose: This study compares the effects of neutral temperature, cold and ice-slush beverages, with and without 0.5% menthol on cycling performance, core temperature (T co) and stress responses in a Tropical Climate (hot and humid conditions). Methods: Twelve trained male cyclists/triathletes completed six 20-km exercise trials against the clock in 30.7uC60.8uC and 78%60.03% relative humidity. Before and after warm-up, and before exercise and every 5 km during exercise, athletes drank 190 mL of either aromatized (i.e., with 0.5 mL of menthol (5 gr/L)) or a non-aromatized beverage (neutral temperature: 23uC60.1uC, cold: 3uC60.1uC, or ice-slush: 21uC60.7uC). During the trials, heart rate (HR) was continuously monitored, whereas core temperature (T co), thermal comfort (TC), thermal sensation (TS) and rate of perceived exertion (RPE) were measured before and after warm-up, every 5 km of exercise, and at the end of exercise and after recovery. Results: Both the beverage aroma (P,0.02) and beverage temperature (P,0.02) had significant and positive effects on performance, which was considerably better with ice-slush than with a neutral temperature beverage, whatever the aroma (P,0.002), and with menthol vs non-menthol (P,0.02). The best performances were obtained with ice-slush/menthol and cold/menthol, as opposed to neutral/menthol. No differences were noted in HR and T co between trials. Conclusion: Cold water or ice-slush with menthol aroma seems to be the most effective beverage for endurance exercise in a Tropical Climate. Further studies are needed to explore its effects in field competition.
Tan S Ang - One of the best experts on this subject based on the ideXlab platform.
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EFFECTS OF MOISTURE ON PROPERTIES OF ASPHALT MIXES IN A WET Tropical Climate: A LABORATORY STUDY
Transportation Research Record, 1993Co-Authors: Tien Fang Fwa, Tan S AngAbstract:A moisture treatment designed to simulate the condition that pavements are exposed to in the wet Tropical Climate of Singapore is described. A weathering chamber was specially fabricated to introduce simultaneous wetting-drying and thermal cycles. The experimental program subjected four different asphalt mixtures--an open-graded, a gap-graded, and two dense-graded mixes--to the moisture treatment. Results indicate that the treatment was able to induce bleeding, stripping, and softening (loss of strength) in test specimens. The extent and severity of the resultant moisture damage varied with the mixture type and with the length of the treatment cycle period and the number of treatment cycles. On the basis of the test results, a procedure consisting of 150 4-hr cycles of simultaneous wetting-drying and thermal cycles was recommended. The treatment procedure shows significant potential as a research and development tool for studying the moisture damage resistance of new asphalt mixtures and the effect of modified binders in a wet Tropical Climate.
