Use of GMES / Copernicus data for Monitoring Phytoplankton Blooms off Portugal
B.Oliveira, Paulo1; Mateus, Marcos2; Silva, Alexandra1; Moita, Teresa1
1IPMA, PORTUGAL; 2IST / MARETEC, PORTUGAL
An assessment of the applicability of data provided by the GMES / Copernicus Marine Monitoring Service to track and predict the evolution of phytoplankton blooms off the Portuguese coast is presented.
Time sequences of merged L4 daily Chlorophyll (CHL) concentration maps are used identify high CHL concentration (bloom) areas and characterize their spatial and temporal variability.
The evolution of the areas occupied by the blooms is estimated using lagrangian tracers released in the bloom areas and advected with the velocity fields from operational IBI (Iberian Biscay Irish) Ocean Analysis and Forecasting system and a regional hydrodynamical model.
The prediction skill is assessed through the comparison of bloom areas from the satellite images and the areas occupied by lagrangian tracers.
Despite the simplification of neglecting the non-conservative phytoplankton dynamics, the results show that the predictability of the evolution of the area occupied by the blooms is strongly dependent on the model's ability to reproduce the shelf circulation details which, in turn, are mainly linked to the accuracy of the wind forcing field.
The simulations performed recommend the use of historical data to characterize the model prediction skill for a large number of bloom events under different atmospheric forcing conditions. This will allow the identification of the modelling system components that should be perfected and give insight on the forecasting uncertainty.