* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download A New Carbon-Based Algal Biomass Proxy for Photoacclimation
Southern Ocean wikipedia , lookup
Ocean acidification wikipedia , lookup
Sea in culture wikipedia , lookup
Physical oceanography wikipedia , lookup
The Marine Mammal Center wikipedia , lookup
Arctic Ocean wikipedia , lookup
Indian Ocean wikipedia , lookup
Marine pollution wikipedia , lookup
Marine habitats wikipedia , lookup
Marine biology wikipedia , lookup
Mediterranean Sea wikipedia , lookup
Geology of the North Sea wikipedia , lookup
History of navigation wikipedia , lookup
Effects of global warming on oceans wikipedia , lookup
Critical Depth wikipedia , lookup
Ancient maritime history wikipedia , lookup
Ecosystem of the North Pacific Subtropical Gyre wikipedia , lookup
A NEW CARBON-BASED ALGAL BIOMASS PROXY FOR PHOTOACCLIMATION ANALYSIS IN THE MEDITERRANEAN SEA THROUGH OCEAN COLOR DATA M. Bellacicco1,2, G. Volpe1, S. Colella1, J. Pitarch1 and R. Santoleri1 1 2 Istituto di Scienze dell’Atmosfera e del Clima (ISAC)-CNR, Via Fosso del Cavaliere 100, 00133 Rome, Italy Università degli Studi di Napoli “Parthenope”, Via Amm. F. Acton 38, 80133 Naples, Italy Photoacclimation changes the intracellular chlorophyll-a concentration (Chl), and is not currently taken into account by standard ocean color algorithms. Chl production is a process enhanced under high nutrient and low light conditions (e.g. winter and spring in the Mediterranean Sea). Historically, Chl has been used as a proxy for marine algal biomass but cannot distinguish intracellular and community variations. Here, a Mediterranean Sea specific model (Mm) is described, which makes use of SeaWiFS ocean colour imagery of 1998-2007, to analyze the effect of photoacclimation on the phytoplankton seasonal cycle. The Mm model is based on the work of Behrenfeld et al. (2005). The model produces a new carbon-based proxy, named C, derived from the particulate backscattering coefficient, bbp (λ), to describe the phytoplankton seasonal cycle, particularly for the Mediterranean Sea, where photoacclimation was shown to be of great impact on cellular processes. Results show the Chl:C ratio to temporally vary by a factor of 3 to 8, clearly highlighting the dominance of photoacclimation at seasonal and basin scales. Minimum Chl:C ratio values are observed during summer, when photo-inhibition is the dominant intracellular process, while maxima are observed in winter and spring when photoacclimation is the most important process. In the productive seasons, proxy C is high, while Chl drops quickly in response to light increase and nutrient availability. We suggest that the combined use of C and Chl is strongly needed for a better comprehension of the phytoplankton variability.