Modeling the seasonal and interannual variability (2001-2010) of chlorophyll-a in the Iberian margin

17 páginas, 4 tablas, 14 figurasA modeling study of the seasonal and interannual variability of chlorophyll-a has been carried out for the period 2001–2010 along the Iberian shelf and adjacent ocean. A high resolution regional configuration of the three-dimensional Regional Ocean Modeling System (ROMS) has been used, coupled to a N2PZD2-type biogeochemical model. Chlorophyll-a concentration ([Chl]) model outputs were compared to regional objective analysis of remotely sensed [Chl] data for the same period. The spatio-temporal variability of modeled and satellite derived [Chl] was analyzed applying an individual Empirical Orthogonal Function (EOF) analysis to monthly time series. Three main modes of sea surface [Chl] variability explained more than 90% of modeled variability and more than 85% of remotely sensed variability. The first EOF accounted for the spring phytoplankton bloom (March–April). The second EOF was related to the spring–summer coastal upwelling season (April–September). The third EOF showed a recurrent [Chl] minimum in winter coinciding with the maximum vertical mixing (February) for the northern part of the region. The influence of the hydrographic conditions on [Chl] variability was explored through a cross-correlation analysis of the three EOFs and an assortment of physical descriptors given by the model: namely the mixing/stratification cycles and the occurrence of coastal upwellingThis research has been supported by the Portuguese Fundação para a Ciencia e a Tecnologia (FCT) through a PhD grant to R.R. (SFRH/BD/33388/2008). The work has been developed within the frame of the RAIA project (Observatorio oceánico del margen Ibérico, POCTEP-FEDER, 0520_-RAIA_CO_1_E), which financed a research fellowship to N.G.F.C. The results of this work contributed partially to the objectives of the project HAB-SPOT (Harmful Algal Bloom dynamics — Shelf Processes of Transport and retention Offshore Aveiro, PTDC/MAR/100348/2008). X.A.A.S. was funded by the project CAIBEX (Shelf–ocean exchanges in the Canaries–Iberian Large Marine Ecosystem, grant no. CTM2007-66408-C02-01/MAR).Peer reviewe

Modeling the seasonal and interannual variability (2001-2010) of chlorophyll-a in the Iberian margin

A modeling study of the seasonal and interannual variability of chlorophyll-a has been carried out for the period 2001-2010 along the Iberian shelf and adjacent ocean. A high resolution regional configuration of the three-dimensional Regional Ocean Modeling System (ROMS) has been used, coupled to a N2PZD2-type biogeochemical model. Chlorophyll-a concentration ([Chl]) model outputs were compared to regional objective analysis of remotely sensed [Chl] data for the same period. The spatio-temporal variability of modeled and satellite derived [Chl] was analyzed applying an individual Empirical Orthogonal Function (EOF) analysis to monthly time series. Three main modes of sea surface [Chl] variability explained more than 90% of modeled variability and more than 85% of remotely sensed variability. The first EOF accounted for the spring phytoplankton bloom (March-April). The second EOF was related to the spring-summer coastal upwelling season (April-September). The third EOF showed a recurrent [Chl] minimum in winter coinciding with the maximum vertical mixing (February) for the northern part of the region. The influence of the hydrographic conditions on [Chl] variability was explored through a cross-correlation analysis of the three EOFs and an assortment of physical descriptors given by the model: namely the mixing/stratification cycles and the occurrence of coastal upwelling