The Experts below are selected from a list of 84060 Experts worldwide ranked by ideXlab platform
Tim Li - One of the best experts on this subject based on the ideXlab platform.
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interactions between the Seasonal Cycle and el nino southern oscillation in an intermediate coupled ocean atmosphere model
Journal of the Atmospheric Sciences, 1995Co-Authors: Ping Chang, Bin Wang, Link Ji, Tim LiAbstract:Abstract The nonlinear interactions between the Seasonal Cycle and El Nino-Southern Oscillation (ENSO) in the coupled ocean-atmosphere system are examined using a newly developed intermediate coupled ocean-atmosphere model. The model permits coupling between total sea surface temperature (SST) and total surface winds and thus is able to produce its own Seasonal Cycle. This coupling approach allows for the examination of full dynamic interactions between the Seasonal Cycle and interannual oscillations. Numerical simulations with realistic surface heat fluxes indicate that this model is capable of capturing the essential variability of the coupled ocean-atmosphere system on Seasonal-to-interannual timescale in the tropical Pacific. Model sensitivity experiments were carried out by independently varying the external forcing strength and coupling strength. These experiments reveal a very different behavior of the coupled system with and without the Seasonal Cycle. In the presence of the Seasonal Cycle, the co...
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interactions between the Seasonal Cycle and the southern oscillation frequency entrainment and chaos in a coupled ocean atmosphere model
Geophysical Research Letters, 1994Co-Authors: Ping Chang, Bin Wang, Tim Li, Link JiAbstract:Nonlinear interactions between the Seasonal Cycle and interannual variations in the coupled ocean-atmosphere system have recently been proposed as the cause of irregularity of El Nino-Southern Oscillation (ENSO). We investigated such a hypothesis using a coupled ocean-atmosphere model which allows coupling between total sea surface temperature (SST) and total surface winds. Numerical simulations indicate that the model is capable of capturing the essential SST variability on Seasonal-to-interannual time scale. Furthermore, it is shown that, as the Seasonal forcing amplitude is gradually increased from zero, the coupled model undergoes several transitions between periodic (frequency-locking) and chaotic states before it finally ‘gives up’ its intrinsic ENSO mode of oscillation entirely and acquires the frequency of the Seasonal forcing. Chaotic response is found as the forcing amplitude approaches the observed value and the route to ENSO chaos is identified to be the period-doubling cascade. The study suggests that the response of a coupled system, coupled General Circulation Models of the ocean and atmosphere for example, can be very sensitive not only to changes in the internal model parameters but also to changes in the external forcing conditions.
Link Ji - One of the best experts on this subject based on the ideXlab platform.
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interactions between the Seasonal Cycle and el nino southern oscillation in an intermediate coupled ocean atmosphere model
Journal of the Atmospheric Sciences, 1995Co-Authors: Ping Chang, Bin Wang, Link Ji, Tim LiAbstract:Abstract The nonlinear interactions between the Seasonal Cycle and El Nino-Southern Oscillation (ENSO) in the coupled ocean-atmosphere system are examined using a newly developed intermediate coupled ocean-atmosphere model. The model permits coupling between total sea surface temperature (SST) and total surface winds and thus is able to produce its own Seasonal Cycle. This coupling approach allows for the examination of full dynamic interactions between the Seasonal Cycle and interannual oscillations. Numerical simulations with realistic surface heat fluxes indicate that this model is capable of capturing the essential variability of the coupled ocean-atmosphere system on Seasonal-to-interannual timescale in the tropical Pacific. Model sensitivity experiments were carried out by independently varying the external forcing strength and coupling strength. These experiments reveal a very different behavior of the coupled system with and without the Seasonal Cycle. In the presence of the Seasonal Cycle, the co...
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interactions between the Seasonal Cycle and the southern oscillation frequency entrainment and chaos in a coupled ocean atmosphere model
Geophysical Research Letters, 1994Co-Authors: Ping Chang, Bin Wang, Tim Li, Link JiAbstract:Nonlinear interactions between the Seasonal Cycle and interannual variations in the coupled ocean-atmosphere system have recently been proposed as the cause of irregularity of El Nino-Southern Oscillation (ENSO). We investigated such a hypothesis using a coupled ocean-atmosphere model which allows coupling between total sea surface temperature (SST) and total surface winds. Numerical simulations indicate that the model is capable of capturing the essential SST variability on Seasonal-to-interannual time scale. Furthermore, it is shown that, as the Seasonal forcing amplitude is gradually increased from zero, the coupled model undergoes several transitions between periodic (frequency-locking) and chaotic states before it finally ‘gives up’ its intrinsic ENSO mode of oscillation entirely and acquires the frequency of the Seasonal forcing. Chaotic response is found as the forcing amplitude approaches the observed value and the route to ENSO chaos is identified to be the period-doubling cascade. The study suggests that the response of a coupled system, coupled General Circulation Models of the ocean and atmosphere for example, can be very sensitive not only to changes in the internal model parameters but also to changes in the external forcing conditions.
Ping Chang - One of the best experts on this subject based on the ideXlab platform.
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interactions between the Seasonal Cycle and el nino southern oscillation in an intermediate coupled ocean atmosphere model
Journal of the Atmospheric Sciences, 1995Co-Authors: Ping Chang, Bin Wang, Link Ji, Tim LiAbstract:Abstract The nonlinear interactions between the Seasonal Cycle and El Nino-Southern Oscillation (ENSO) in the coupled ocean-atmosphere system are examined using a newly developed intermediate coupled ocean-atmosphere model. The model permits coupling between total sea surface temperature (SST) and total surface winds and thus is able to produce its own Seasonal Cycle. This coupling approach allows for the examination of full dynamic interactions between the Seasonal Cycle and interannual oscillations. Numerical simulations with realistic surface heat fluxes indicate that this model is capable of capturing the essential variability of the coupled ocean-atmosphere system on Seasonal-to-interannual timescale in the tropical Pacific. Model sensitivity experiments were carried out by independently varying the external forcing strength and coupling strength. These experiments reveal a very different behavior of the coupled system with and without the Seasonal Cycle. In the presence of the Seasonal Cycle, the co...
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interactions between the Seasonal Cycle and the southern oscillation frequency entrainment and chaos in a coupled ocean atmosphere model
Geophysical Research Letters, 1994Co-Authors: Ping Chang, Bin Wang, Tim Li, Link JiAbstract:Nonlinear interactions between the Seasonal Cycle and interannual variations in the coupled ocean-atmosphere system have recently been proposed as the cause of irregularity of El Nino-Southern Oscillation (ENSO). We investigated such a hypothesis using a coupled ocean-atmosphere model which allows coupling between total sea surface temperature (SST) and total surface winds. Numerical simulations indicate that the model is capable of capturing the essential SST variability on Seasonal-to-interannual time scale. Furthermore, it is shown that, as the Seasonal forcing amplitude is gradually increased from zero, the coupled model undergoes several transitions between periodic (frequency-locking) and chaotic states before it finally ‘gives up’ its intrinsic ENSO mode of oscillation entirely and acquires the frequency of the Seasonal forcing. Chaotic response is found as the forcing amplitude approaches the observed value and the route to ENSO chaos is identified to be the period-doubling cascade. The study suggests that the response of a coupled system, coupled General Circulation Models of the ocean and atmosphere for example, can be very sensitive not only to changes in the internal model parameters but also to changes in the external forcing conditions.
Le H Treut - One of the best experts on this subject based on the ideXlab platform.
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the Seasonal Cycle over the tropical pacific in coupled ocean atmosphere general circulation models
Monthly Weather Review, 1995Co-Authors: Carlos R Mechoso, N Barth, M K Davey, P Delecluse, S Ineson, Benjamin Kirtman, Andrew W Robertson, Peter R Gent, Mojib Latif, Le H TreutAbstract:Abstract The Seasonal Cycle over the tropical Pacific simulated by 11 coupled ocean–atmosphere general circulation models (GCMs) is examined. Each model consists of a high-resolution ocean GCM of either the tropical Pacific or near-global means coupled to a moderate- or high-resolution atmospheric GCM, without the use of flux correction. The Seasonal behavior of sea surface temperature (SST) and eastern Pacific rainfall is presented for each model. The results show that current state-of-the-art coupled GCMs share important successes and troublesome systematic errors. All 11 models are able to simulate the mean zonal gradient in SST at the equator over the central Pacific. The simulated equatorial cold tongue generally tends to be too strong, too narrow, and extend too far west. SSTs are generally too warm in a broad region west of Peru and in a band near 10°S. This is accompanied in some models by a double intertropical convergence zone (ITCZ) straddling the equator over the eastern Pacific, and in others...
Pedro M S Monteiro - One of the best experts on this subject based on the ideXlab platform.
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the Seasonal Cycle of mixed layer dynamics and phytoplankton biomass in the sub antarctic zone a high resolution glider experiment
Journal of Marine Systems, 2015Co-Authors: Sandy J Thomalla, Sebastiaan Swart, Pedro M S MonteiroAbstract:Abstract In the Southern Ocean there is increasing evidence that Seasonal to subSeasonal temporal scales, meso- and submesoscales play an important role in understanding the sensitivity of ocean primary productivity to climate change. In this study, high-resolution glider data (3 hourly, 2 km horizontal resolution), from ~ 6 months of sampling (spring through summer) in the Sub-Antarctic Zone, is used to assess 1) the different forcing mechanisms driving variability in upper ocean physics and 2) how these may characterize the Seasonal Cycle of phytoplankton production. Results highlight the important role meso- to submesoscale features have in driving vertical stratification and early phytoplankton bloom initiations in spring by increasing light exposure. In summer, the combined role of solar heat flux, mesoscale features and subSeasonal storms on the extent of the mixed layer is proposed to regulate both light and iron to the upper ocean at appropriate time scales for phytoplankton growth, thereby sustaining the bloom for an extended period through to late summer. This study highlights the need for climate models to resolve both meso- to submesoscale and subSeasonal processes in order to accurately reflect the phenology of the phytoplankton community and understand the sensitivity of ocean primary productivity to climate change.
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regional scale characteristics of the Seasonal Cycle of chlorophyll in the southern ocean
Biogeosciences, 2011Co-Authors: Sandy J Thomalla, Nicolas Fauchereau, Sebastiaan Swart, Pedro M S MonteiroAbstract:Abstract. In the Ocean, the Seasonal Cycle is the mode that couples climate forcing to ecosystem response in production, diversity and carbon export. A better characterisation of the ecosystem's Seasonal Cycle therefore addresses an important gap in our ability to estimate the sensitivity of the biological pump to climate change. In this study, the regional characteristics of the Seasonal Cycle of phytoplankton biomass in the Southern Ocean are examined in terms of the timing of the bloom initiation, its amplitude, regional scale variability and the importance of the climatological Seasonal Cycle in explaining the overall variance. The Seasonal Cycle was consequently defined into four broad zonal regions; the subtropical zone (STZ), the transition zone (TZ), the Antarctic circumpolar zone (ACZ) and the marginal ice zone (MIZ). Defining the Southern Ocean according to the characteristics of its Seasonal Cycle provides a more dynamic understanding of ocean productivity based on underlying physical drivers rather than climatological biomass. The response of the biology to the underlying physics of the different Seasonal zones resulted in an additional classification of four regions based on the extent of inter-annual Seasonal phase locking and the magnitude of the integrated Seasonal biomass. This regionalisation contributes towards an improved understanding of the regional differences in the sensitivity of the Southern Oceans ecosystem to climate forcing, potentially allowing more robust predictions of the effects of long term climate trends.
