Climatic Influences on Southern Hemisphere Oceanic Primary Production Derived From Satellite Remote Sensing Observations
Couto, AB and Maharaj, AM and Holbrook, NJ, Climatic Influences on Southern Hemisphere Oceanic Primary Production Derived From Satellite Remote Sensing Observations, Extended Abstracts of the Ninth International Conference on Southern Hemisphere Meteorology and Oceanography. , 9-13 February 2009, Melbourne, pp. xx-xx. (2009) [Conference Extract]
Oceanic phytoplankton growth is essential to
the sustainability of ocean biota (Field et al. 1998).
Ocean’s primary productivity varies in response to
environmental conditions, such as sunlight and nutrient
availability. These factors restrain the reproduction and
growth of drifting algae. In the southern hemisphere
several climate signals exist which may modulate ocean
primary productivity such as the El Niño Southern
Oscillation (ENSO), the Indian Ocean Dipole (IOD) in
the tropical Indo-Pacific region (Saji et al. 1999; Wolter;
Timlin 1998) ; and the Southern Annular Mode (SAM) in
the polar and sub-polar regions (Mo 2000a). Ocean
primary productivity is thought to response indirectly to
these climate modes of variability, by the circulation
changes that these induce (Behrenfeld et al. 2006).
Changing circulation patterns may origin an anomalous
upwelling (or downwelling), leaving anomalous nutrient
signatures in the euphotic layer, where primary
productivity will anomaly correspond (Lovenduski;
Gruber 2005). Additionally, the southern hemisphere
also includes the unique region of the Southern Ocean,
which is a critical component of the global circulation
and the biogeochemical cycles of nutrients and carbon
(Arrigo et al. 2008). Phytoplankton growth patterns
adapt to different regions depending on the intrinsic
conditions of each region.
As vast and rapidly changing as the ocean is,
satellite imagery provides an ideal tool to observe and
illustrate, at a high sampling rate, several oceanic
characteristics, including its colour (McClain et al. 2004).
Using the appropriate algorithm, one is able to retrieve
not only chlorophyll concentrations, from satellite
observations but also phytoplankton estimates (Morel;
In this study we use Empirical Orthogonal
Functions (EOF) to evaluate satellite derived chlorophyll
concentrations. The use of EOF is an ideal tool to
observe cyclical patterns within continuous observations
(Bjornsson; Venegas 1997).
This paper explores the relationship between
large-scale climate modes of variability (ENSO, IOD and
SAM) and phytoplankton distribution patterns across the
southern hemisphere oceans.