<p&amp... more <p>Upwelling systems are very productive regions of the ocean that strongly contribute to the local economies holding very different fisheries. These dynamic systems are characterized by a high degree of spatial and temporal variability of biogeochemical properties, including carbon, which is generally poorly represented in coarse-resolution global models. The importance of the marine carbon system characterizing these systems has been demonstrated in different regions from multiple perspectives. For the first time, we evaluate the drivers of the spatiotemporal variability of the seawater partial pressure of CO<sub>2</sub> (pCO<sub>2</sub>) in the Canary-Iberian Upwelling System (25.5-45ºN, 5.5-20.5ºW) to better understand the inorganic carbon cycle in this highly-productive upwelling region. To do so, we first coupled a regional high-resolution ocean circulation model CROCO with the ocean biogeochemical model PISCES and run a climatological simulation. A first-order Taylor expansion was applied over this simulation to compute the contribution of four variables to the pCO<sub>2</sub> spatiotemporal variability: salinity-normalized dissolved inorganic carbon (sC<sub>T</sub>), salinity-normalized total alkalinity (sA<sub>T</sub>), temperature (T) and freshwater fluxes (FW). Modeled pCO<sub>2</sub> is in agreement with that of recent data-based monthly climatologies (open ocean RMSE: 5.2-10.8 µatm; coastal ocean RMSE: 7.9-18.7 µatm), measured data from the Surface Ocean CO₂ Atlas (SOCAT) (RMSE: 6.6-13.9 µatm) and computed pCO<sub>2</sub> from measured A<sub>T</sub> and pH at the European Station for Time series in the Ocean Canary islands (ESTOC) (RMSE: 5.1 µatm). The spatial distribution of the pCO<sub>2</sub> anomalies relative to the domain mean shows two different areas with opposite anomalies: positive anomalies around the coast in the entire domain and in open ocean south of 33ºN and negative anomalies in open ocean north of 33ºN. This pattern is mainly driven by the contribution of the T component and a minor influence of sA<sub>T</sub> and FW, with the…
Egu General Assembly Conference Abstracts, May 1, 2010
The study of the connectivity between populations is one of the 'hot&... more The study of the connectivity between populations is one of the 'hot' applications of numerical models of the ocean circulation. An IBM (Individual Based model) was developed, using Carcinus manenas larvae crab as a model. A set of particles was used as a representation of larvae, in order to study their larval life cycle, including the larval growth, larval mortality
This work aims at a better understanding of the variability of the Iberian Upwelling Ecosystem, n... more This work aims at a better understanding of the variability of the Iberian Upwelling Ecosystem, not only in the present regime, but also in a future climate change scenario. The purpose of the present study is to assess whether downscaling is an appropriate methodology for the region and its physical processes. Numerical simulations with the Regional Ocean Modelling System (ROMS)
ABSTRACT The Western Iberian Margin is the northern limit of the Canary Upwelling System, a regio... more ABSTRACT The Western Iberian Margin is the northern limit of the Canary Upwelling System, a region of strong mesoscale activity, seasonal variability and thus very likely to be sensitive to climate change. Using a regional ocean model and data from several coupled global climate models (CGCM), climatological simulations were set up for present and for a future scenario. Forcing is obtained from averaging the outputs of an ensemble of CGCM provided by the Intergovernmental Panel for Climate Change (IPCC) A2 emission scenario. Results are focused on the continental shelf (similar to 200 m). In general, the sea surface temperature (SST) seasonal evolution shows, for the future, an increase of about 1 degrees C during the upwelling season (April to September) and 2 degrees C in the rest of the year, while sea surface salinity (SSS) shows a freshening of about -0.2. These results agree with a general increase in air temperature and in fresh water input resulting from ice melting in the North Pole, which characterize this future scenario. However, differences depend on latitude and distance from the coast (higher differences to the south and more offshore, respectively). Also, SSS undergoes a shift of its minimum from July to May or September. Cross-shore sections show that SST and SSS differences are mainly observed in the upper 200 m. In winter, the typical upper slope poleward flow undergoes a slight weakening and shallowing. In summer, while the upwelling jet intensifies at the surface, it is also more restricted in both width and depth.
ABSTRACT This work evaluates the performance of several global climate models (GCMs) as forcing o... more ABSTRACT This work evaluates the performance of several global climate models (GCMs) as forcing of a regional ocean model configuration centered in the Iberian Basin. The study is divided in two parts. First, the output of nine GCMs is analyzed based on the fields needed to force the ocean model (Regional Ocean Modelling System—ROMS). GCMs differ greatly between them and their performance depends on the field. In the second part, the two GCMs with the worst performances in both extremes of the ensemble are used as forcing for two ROMS simulations, with the purpose of assessing the range of uncertainty comprised in this set of GCMs. Two other ROMS runs are setup: one climatologically forced control run, and one forced with the average of all the nine GCMs—the ensemble mean. Results show that the tendency of overestimation/underestimation of the forcings is reflected in the modeled hydrography, both at the surface and deeper layers down to 500 m. Nevertheless, in terms of circulation, all four runs reproduce the Azores Current, as well as the coastal transition zone seasonality (winter poleward flow and summer upwelling-associated equatorward flow). The CGCMs output performance as forcing depends on the forcing variable: one performs well for one or more variables, but badly for others, and which field is well or badly reproduced varies for each CGCM. Therefore, there is not a single CGCM having the best forcing for all variables. Hence, our results indicate that the most adequate approach consists of using the ensemble mean as forcing rather than using an individual model. This is supported by the general low overall (i.e. for all forcing variables) errors of the ensemble mean regarding the control climatological dataset, and the good comparison of the ensemble-forced ROMS run with the control run.
<p&amp... more <p>Upwelling systems are very productive regions of the ocean that strongly contribute to the local economies holding very different fisheries. These dynamic systems are characterized by a high degree of spatial and temporal variability of biogeochemical properties, including carbon, which is generally poorly represented in coarse-resolution global models. The importance of the marine carbon system characterizing these systems has been demonstrated in different regions from multiple perspectives. For the first time, we evaluate the drivers of the spatiotemporal variability of the seawater partial pressure of CO<sub>2</sub> (pCO<sub>2</sub>) in the Canary-Iberian Upwelling System (25.5-45ºN, 5.5-20.5ºW) to better understand the inorganic carbon cycle in this highly-productive upwelling region. To do so, we first coupled a regional high-resolution ocean circulation model CROCO with the ocean biogeochemical model PISCES and run a climatological simulation. A first-order Taylor expansion was applied over this simulation to compute the contribution of four variables to the pCO<sub>2</sub> spatiotemporal variability: salinity-normalized dissolved inorganic carbon (sC<sub>T</sub>), salinity-normalized total alkalinity (sA<sub>T</sub>), temperature (T) and freshwater fluxes (FW). Modeled pCO<sub>2</sub> is in agreement with that of recent data-based monthly climatologies (open ocean RMSE: 5.2-10.8 µatm; coastal ocean RMSE: 7.9-18.7 µatm), measured data from the Surface Ocean CO₂ Atlas (SOCAT) (RMSE: 6.6-13.9 µatm) and computed pCO<sub>2</sub> from measured A<sub>T</sub> and pH at the European Station for Time series in the Ocean Canary islands (ESTOC) (RMSE: 5.1 µatm). The spatial distribution of the pCO<sub>2</sub> anomalies relative to the domain mean shows two different areas with opposite anomalies: positive anomalies around the coast in the entire domain and in open ocean south of 33ºN and negative anomalies in open ocean north of 33ºN. This pattern is mainly driven by the contribution of the T component and a minor influence of sA<sub>T</sub> and FW, with the…
Egu General Assembly Conference Abstracts, May 1, 2010
The study of the connectivity between populations is one of the 'hot&... more The study of the connectivity between populations is one of the 'hot' applications of numerical models of the ocean circulation. An IBM (Individual Based model) was developed, using Carcinus manenas larvae crab as a model. A set of particles was used as a representation of larvae, in order to study their larval life cycle, including the larval growth, larval mortality
This work aims at a better understanding of the variability of the Iberian Upwelling Ecosystem, n... more This work aims at a better understanding of the variability of the Iberian Upwelling Ecosystem, not only in the present regime, but also in a future climate change scenario. The purpose of the present study is to assess whether downscaling is an appropriate methodology for the region and its physical processes. Numerical simulations with the Regional Ocean Modelling System (ROMS)
ABSTRACT The Western Iberian Margin is the northern limit of the Canary Upwelling System, a regio... more ABSTRACT The Western Iberian Margin is the northern limit of the Canary Upwelling System, a region of strong mesoscale activity, seasonal variability and thus very likely to be sensitive to climate change. Using a regional ocean model and data from several coupled global climate models (CGCM), climatological simulations were set up for present and for a future scenario. Forcing is obtained from averaging the outputs of an ensemble of CGCM provided by the Intergovernmental Panel for Climate Change (IPCC) A2 emission scenario. Results are focused on the continental shelf (similar to 200 m). In general, the sea surface temperature (SST) seasonal evolution shows, for the future, an increase of about 1 degrees C during the upwelling season (April to September) and 2 degrees C in the rest of the year, while sea surface salinity (SSS) shows a freshening of about -0.2. These results agree with a general increase in air temperature and in fresh water input resulting from ice melting in the North Pole, which characterize this future scenario. However, differences depend on latitude and distance from the coast (higher differences to the south and more offshore, respectively). Also, SSS undergoes a shift of its minimum from July to May or September. Cross-shore sections show that SST and SSS differences are mainly observed in the upper 200 m. In winter, the typical upper slope poleward flow undergoes a slight weakening and shallowing. In summer, while the upwelling jet intensifies at the surface, it is also more restricted in both width and depth.
ABSTRACT This work evaluates the performance of several global climate models (GCMs) as forcing o... more ABSTRACT This work evaluates the performance of several global climate models (GCMs) as forcing of a regional ocean model configuration centered in the Iberian Basin. The study is divided in two parts. First, the output of nine GCMs is analyzed based on the fields needed to force the ocean model (Regional Ocean Modelling System—ROMS). GCMs differ greatly between them and their performance depends on the field. In the second part, the two GCMs with the worst performances in both extremes of the ensemble are used as forcing for two ROMS simulations, with the purpose of assessing the range of uncertainty comprised in this set of GCMs. Two other ROMS runs are setup: one climatologically forced control run, and one forced with the average of all the nine GCMs—the ensemble mean. Results show that the tendency of overestimation/underestimation of the forcings is reflected in the modeled hydrography, both at the surface and deeper layers down to 500 m. Nevertheless, in terms of circulation, all four runs reproduce the Azores Current, as well as the coastal transition zone seasonality (winter poleward flow and summer upwelling-associated equatorward flow). The CGCMs output performance as forcing depends on the forcing variable: one performs well for one or more variables, but badly for others, and which field is well or badly reproduced varies for each CGCM. Therefore, there is not a single CGCM having the best forcing for all variables. Hence, our results indicate that the most adequate approach consists of using the ensemble mean as forcing rather than using an individual model. This is supported by the general low overall (i.e. for all forcing variables) errors of the ensemble mean regarding the control climatological dataset, and the good comparison of the ensemble-forced ROMS run with the control run.
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