Spatial and temporal variability in chlorophyll, primary production and export production in the Southern Ocean
B.
Greg
Mitchell, Scripps Institution of Oceanography, gmitchell@ucsd.edu
(Presenting)
Mati
Kahru, Institution of Oceanography, mkahru@ucsd.edu
(Presenting)
Haili
Wang, Institution of Oceanography, hlwang@ucsd.edu
Ralph
Keeling, Institution of Oceanography, rkeeling@ucsd.edu
Matt
Charette, Woods Hole Oceanographic Institution, mcharette@whoi.edu
Cynthia
Nevison, University of Colorado, nevison@ucar.edu
(Presenting)
Satellite ocean color and temperature data are used from various satellite sensors (OCTS, SeaWiFS, MODIS, AVHRR) to generate improved time-series of ocean phytoplankton photosynthetic pigments, primary production, and export production in the Southern Ocean. For the Southern Ocean there is a large range in values for chlorophyll and primary production estimated by different satellite sensors and algorithms. This unconstrained uncertainty propagates into models of export production. We present radiometry and chlorophyll algorithm data from several hundred Southern Ocean stations occupied by our group during the past 10 years as participants in diverse projects (JGOFS, AMLR, SOFEX).
This integrated data set from diverse Southern Ocean ecosystems is being used to develop and validate methods for satellite retrieval of chl-a, primary production and export production. Export flux estimates are constrained by independent data including thorium results from JGOFS and SOFEX, JGOFS sediment traps, and results of inverse models. We are exploring different models and algorithms in an effort to implement the best performing methods with the multi-sensor ocean color time-series to study the spatio-temporal variability in plankton communities and export flux of organic carbon. Time-series reveal large interannual and seasonal variability that we are exploring through correlations with environmental forcing (ENSO, winds, sea ice) in an attempt to elucidate mechanisms that govern Southern Ocean primary and export production, and to better understand the implications of climate change on these processes.
NASA Carbon Cycle & Ecosystems Active Awards Represented by this Poster: