PP12A:
Subsurface and Subseasonal Productivity: Mechanisms, Magnitudes, Variability, and Key Species II


Session ID#: 11537

Session Description:
Our understanding of oceanic primary production and producers has been dominated by sampling of the surface ocean (typically < 20m). Similarly, our knowledge of global patterns of primary production has been led by ocean colour measurements from satellite sensors that again, have surface bias. During the 20th Century there were few systematic attempts to target the subsurface resulting in a gap dating back to Schimper’s pioneering use of closing nets on the 1898 Valdivia cruise. Over the past two decades, however, a burgeoning suite of observations has highlighted the significance of subsurface production. A range of mechanisms have been identified including the ability to grow in low light in subsurface chlorophyll maxima, exploitation of mixing events at the pycnocline/ nutricline, buoyancy regulation allowing the mining of deep nutrients. Significantly, new research is also demonstrating that this subsurface production may be of major significance for carbon export. With climate change driving increased ocean stratification, these styles of subsurface production may become more significant so it is timely to focus on them. This session will aim to bring together observation, theory and modelling of the subsurface to synergistically improve understanding and to identify new targets and priorities for research.
Primary Chair:  Alan E S Kemp, University of Southampton, Southampton, SO14, United Kingdom
Chairs:  Bror F Jonsson1, Tracy A Villareal2 and Joseph Salisbury II1, (1)University of New Hampshire, Durham, NH, United States(2)The University of Texas at Austin, Port Aransas, TX, United States
Moderators:  Alan E S Kemp, University of Southampton, Southampton, SO14, United Kingdom and Bror F Jonsson, University of New Hampshire, Durham, NH, United States
Student Paper Review Liaison:  Bror F Jonsson, University of New Hampshire, Durham, NH, United States
Index Terms:

4805 Biogeochemical cycles, processes, and modeling [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4845 Nutrients and nutrient cycling [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4855 Phytoplankton [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
4858 Population dynamics and ecology [OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL]
Co-Sponsor(s):
  • B - Biogeochemistry and Nutrients
  • ME - Marine Ecosystems
  • MM - Microbiology and Molecular Biology
  • PC - Past, Present and Future Climate

Abstracts Submitted to this Session:

Are Methods for Estimating Primary Production and the Growth Rates of Phytoplankton Approaching Agreement? (88866)
John J Cullen, Dalhousie University, Halifax, NS, Canada
How Winter Vertical Mixing Affects the Seasonal Surface Chlorophyll-a Signal in Oligotrophic Regions? (89525)
Heloise Lavigne1, Giuseppe Civitarese2, Miroslav Gacic1, Marina Levy3 and Fabrizio D'Ortenzio4, (1)Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Oceanografia, Trieste, Italy, (2)OGS, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Oceanography, Trieste, Italy, (3)LOCEAN, Paris Cedex 05, France, (4)Observatoire Océanologique de Villefranche, Villefranche Sur Mer, France
Seasonal variability of phytoplankton community structure in the subtropical western North Pacific (88126)
Tetsuichi Fujiki1, Kosei Sasaoka1, Kazuhiko Matsumoto1, Masahide Wakita2 and Yoshihisa Mino3, (1)JAMSTEC, Yokosuka, Japan, (2)JAMSTEC/MIO, Mutsu, Japan, (3)Nagoya University, Japan
Problems with Predicting Size-Fractionated Productivity from Chlorophyll Biomass in Marine Ecosystem Models (91991)
Tammi L Richardson, University of South Carolina, Department of Biological Sciences, Columbia, SC, United States
Modeling the Impact of Fine Temporal and Spatial Scale Processes on Large-scale Ecosystem Dynamics and Carbon Cycling. (90346)
Naomi Marcil Levine, University of Southern California, Los Angeles, CA, United States and Xiao Liu, University of Southern California, Department of Earth Sciences, Los Angeles, CA, United States
Phytoplankton traits over an annual cycle in the NW Mediterranean (91180)
Nicolas Mayot1, Fabrizio D'Ortenzio1, Julia Uitz1 and Herve Claustre2, (1)Sorbonne Universités, UPMC Univ Paris 06, INSU-CNRS, Laboratoire d’Océanographie de Villefranche-sur-Mer (LOV), Villefranche-sur-mer, France, (2)Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, France
Primary productivity (PP) in the North Pacific Subtropical Gyre: Understanding drivers of variability via 14C-tracer incubations and PP diagnosed via the diurnal cycle of particulate carbon. (93606)
Angelicque E White, Oregon State University, Corvallis, OR, United States and Ricardo M Letelier, Oregon State Univ, Corvallis, OR, United States