Biophysical model coupling ROMS and PISCES in the Canary Current Ecosystem

Abstract

Biophysical modeling is a useful tool to understand the high temporal and spatial variability observed in Eastern Boundary Currents both at large- meso- and submeso-scale levels. In the recent years, physical- biogeochemical coupled models have been successfully applied in the Humboldt and, especially, in the California Current ecosystems; however, the Canary Current Ecosystem (CCE) has been poorly studied so far. To help covering this lack, we have coupled a Regional Ocean Modeling System (ROMS) solution with the biogeochemical model PISCES (Pelagic Interaction Scheme for Carbon and Ecosystem Studies) for the first time in the CCE. The model was carried out using roms2roms, a nesting technique that employs a lesser-resolution widely validated ROMS solution to force a higher-resolution ROMS- PISCES solution in order to improve final reliability. We have used a 4 km horizontal resolution with 50 vertical levels that allows us to study the seasonal variability of the main biogeochemical processes that occur in the region. Several biology-related parameters have been tuned to enclose the particular conditions that rule the dynamic of the CCE. Physical variables coincide with real measurements both in situ and derived from remote sensing data. Due to the inherent difficulty in measuring biogeochemical variables, chlorophyll has been traditionally used to check the behavior of biogeochemical models due to their easy-access data. We have used the modeled inferred chlorophyll and observed that the temporal patterns of distribution closely agree with surface chlorophyll observations derived from remote sensing, although concentrations in the coastal area seem to be underestimated.