Climate forcing of C. finmarchicus populations of the North Atlantic
The three-gyre hypothesis
Climatological
C. finmarchicus distributions
GLOBEC study sites in the North Atlantic
Genetic basis for the three-gyre hypothesis
Life cycle of Calanus finmarchicus
C. finmarchicus climatology:
Globec Broadscale surveys 1995-1999
C. finmarchicus model
C. finmarchicus solution: January- June
Inferred
Mortality
Are the inverse solutions ecologically realistic?
January-June average mortality rate
Term-by-term analysis
A numerical experiment: turn off the upstream sources of C. finmarchicus to GB
Spatially averaged mortality rate
Biological control of the vernal population increase of C. finmarchicus on Georges Bank
Climatological
C. finmarchicus distributions
Overall Objectives
Inversions of the Òmean stateÓ
Climatological mean seasonal forcing
Diapause entry hypotheses: food, photoperiod
Diapause exit hypotheses: development, photoperiod
Control parameter: mortality (spatially variable, stage dependent
Skill assessment: cross-validation
Use the genetic data to estimate the rate of population exchange between gyres, and compare with model predictions of same
 Investigate interannual to decadal variability
High-NAO state vs. low-NAO state
Hindcast 1950s-present

Interannual to interdecadal variability
Initial Objectives – Year 1
(1) Configure climatological model (Julia)
(2) Assemble CPR observations (Dennis/Peter/Gregory)
(3) Use the genetic data to estimate exchange between gyres (Ann)
(4) Synthesize Globec data: (Peter/Nancy)
- stage resolution
- vertical distribution
(5) Initial inversion (Dennis/Keston/Dale/Julia)
Climatological mean seasonal forcing
CPR C6 surface data only
No population dynamics
Control parameter: spatially variable source (molting flux) / sink (mortality)

C. finmarchicus abundance, 1958-2007
Compiled by Gregory Beaugrand
END