90 likes | 416 Views
SW – 5 Primary production in the ocean. Francisco Chavez, Miquel Rosell , Anna Rumyantseva, Joanna Paczkowska , Cristina Garcia – Munoz, SM Sharifuzaman. Rationale. Factors affecting phytoplankton growth: Physical controls (turbulent mixing and light exposure)
E N D
SW – 5 Primary production in the ocean Francisco Chavez, MiquelRosell, Anna Rumyantseva, Joanna Paczkowska, Cristina Garcia – Munoz, SM Sharifuzaman
Rationale Factors affecting phytoplankton growth: • Physical controls (turbulent mixing and light exposure) • Biological controls (grazing and respiration) • Chemical controls (availability of nutrients) (from http://modis.gsfc.nasa.gov) Our goal: Develop a growth index based on temperature, nutrients and light to describe patterns of global primary production distribution.
Methods GROWTH INDEX Temperature index: Light index Nutrient index: • Input Data: • 1º monthly climatology • Chl a (SeaWIFs) • PAR (SeaWIFs) • Surface Nitrate concentration (WOA) Annual average • MLD (model output) • SST (blended satellite products) • Nutricline (WOA)
Methods • Temperature Index: • Nutrient Index: • Irradiance Index: PAR/MLD GI = T0.8 x N x I All the index were normalized by the maximum values to obtain a value between 0 and 1 If [Nitrate] = 0 then 0.1 If [Nitrate] >= 2 then 1 Otherwise [Nitrate]/nutricline (from Behrenfeld & Falkowski, 1997)
Growth Index performance Temperature Index PAR Index Nutrient Index
Conclusions • The growth index seems to correlate between with chlorophyll in low/mid latitudes • Lack of data in high latitudes could lead to some biases in our analysis for this region FUTURE WORK: - Improve performance in the Growth Index - Introduce limiting factors, mainly IRON -> Dust - Compare coastal and ocean areas