Poster

Abstract

The ocean surface is a highly complex and dynamic domain, where interactions with deep layers, land and atmosphere modulate Earth’s climate and the distribution and activity of marine organisms. Phytoplankton, the dominant marine primary producers, are strongly influenced by these processes which attributes them the status of highly sensitive indicators of ecosystem condition and change. The understanding of the relationship between environmental forcing and phytoplankton can be facilitated when the ocean surface complexity is reduced by partitioning it into units with unique, homogeneous properties. This thesis aimed to partition the heterogeneous surface marine domain off Southwest Iberia Peninsula (SWIP), using satellite remote sensing, and use it to assess phytoplankton variability patterns and underlying environmental drivers. Three unsupervised partition strategies, based on different input databases and temporal representations, were explored. The three approaches delineated a distinct number of partition units, but presented a consistency in what can be considered the main spatial patterns of SWIP ocean surface. In general, the spatial arrangement of the partition units showed a separation between coastal and open ocean, a latitudinal division (ca. 36.5^oN) over the open ocean and, over the coast and slope, the influence of coastal upwelling along the west Portuguese coast and Cape São Vicente, and of river discharge along the northeastern Gulf of Cadiz. The environmental drivers of phytoplankton varied across partition units. Water column stratification, riverine discharge and upwelling intensity were the most influential modulators, while large scale climate indices usually showed minor effects. Abiotic variables and phytoplankton chlorophyll-a concentration and phenology showed significant seasonal variability patterns, varying across regions. Interannual patterns were more complex, and significant trends were mostly detected within the Gulf of Cadiz. Linkages between environmental variability and phytoplankton support their use as an indicator of ecosystem status and change.

Short CV

BSc in Oceanography (Federal University of Paraná, Brazil), MSc in Remote Sensing (National Institute for Space Research, Brazil) and Post graduated in Observational Oceanography (Bermuda Institute of Ocean Sciences, Bermuda), Lilian has recently concluded her PhD in Marine, Environmental and Earth Sciences at the University of Algarve (Portugal). She has experience in satellite and model-derived data application on coastal and oceanographic studies and her main research interests are spatio-temporal analysis of ocean-atmosphere interaction, climate variability and their impacts on ocean primary productivity and marine and coastal ecosystems. As founder and executive member of the NF-POGO Alumni Network for Oceans and instructor of courses in Operational Oceanography and Ocean Data Management, Lilian is also involved in diverse capacity building and ocean literacy activities.