opa – planktom5.0 - dms meike vogt * corinne le quéré erik t. buitenhuis sergio vallina *...
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OPA – PlankTOM5.0 - DMS
Meike Vogt * Corinne Le Quéré Erik T. Buitenhuis
Sergio Vallina * Laurent Bopp
PlankTOM Series
N2 fixersDMS
producers
coccolith.Nano
phytoplankton
Fe NO3Si
CaCO3
PO
4
NH4
DOM
diatoms
PlankTOM 5.0
Physics: OPA-ORCA (NEMO2) Resolution: ~2 deg, 31 depths 29 Tracers 3 Phytoplankton PFT: ‘Nanophytoplankton’,
Diatoms, Coccolithophorids 2 Zooplankton PFT: Microzooplankton,
Mesozooplankton
Food Web PlankTOM5.0
Ecosystem
High latitudes: Diatom dominated
Coccolithophorids: Don’t grow south of 40 deg yet
Nanophytoplankton: Describe ‘Rest’, include Phaeocystis
Microzooplankton: Important around Equator and high latitudes
Mesozooplankton: High latitudes
Generally: No extreme chlorophyll values
Chlorophyll - Seasonality
No extreme concentrations Seasonality rather weak Concentrations in uM Low chlorophyll in the
Southern Ocean Influence on DMS?
DMS Module
DMSPp
DMS
DMSPd
mortality
grazing/exudation
grazing/exudation
bacteriafree lyase
sea-air flux
photolysis
PO4
T
Fe
DMS Model 3 additional tracers: DMSPp, DMSPd DMS DMSPp derived from biomass and cell quota (S/C ratio)
S/C content varies with UV and nutrient stress (Sunda, 2000) S/C shows slight T dependence (cryohypothesis) (Stefels, 2007) Literature S/C values (Archer 2002)
Diatoms: S/C = 0.002
Nanophytoplankton S/C = 0.01
Coccolithophorids: S/C = 0.012
Literature values = minimal DMSPp/cell content, can vary up to 3-fold for all PFTs
ii
i
PC
SDMSPp )(
DMS Dynamics
DMS Model – SMS
DMSPd production: grazing by micro-/mesozooplankton
(~74% available)
mortality
exudation/leakage
DMSPd consumption: bacterial consumption of DMSPd
cleavage of DMSPd by free DMSP-lyase
DMS Module – SMS II
DMS production: grazing by micro-/mesozooplankton (~74% DMSPd available)
mortalityexudation/leakage cleavage of DMSPd by free DMSP-lyasebacterial consumption of DMSP (microbial yield 10%)
DMS degradation: bacterial consumption of DMSphotolysis at the sea surfacesea-air flux
Results very low compared to Kettle Equatorial regions ok. But what is happening in the high
latitudes????????? Lack of Phaeocystis may explain in
parts High latitudes diatom dominated Poor DMS producers and grazed by
large zooplankton…
Preliminary Results
DMS Kettle [nM]
DMS PlankTOM [nM]
Seasonality
Low seasonality! High latitudes a mess But I am working on it!
DJF
JJA
MAM
SON
DMS & Chlorophyll
Get decoupling for cell quota
= f(stress) Very little decouping without
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