OUEVRE (Per Jonsson, revisions by F. Werner

• What have we learned? What models (or other approaches to synthesis) exist or are needed and of what type?

• How does climate influence variability of recruitment in these systems?

Model Resolution-Temporal/Spatial Issues of Model Integration

Bacteria

Birds/mammals

THE SEA

Number of Species

SPECIES IN THE MODEL

Number of State Variables

Detail of Resolution

Nested 3D physical models, linked to climate modelsu,v,w,Kz,T...

3D-coupled NPZD model(primary and secondary production)

3D-coupled ZLCM(distribution and abundance of individual zooplankton species)

3D-coupled fish larvae trophodynamic model(growth and survival of fish larvae)

Environmental conditions for recruitment

(Prey fields)

(Prey fields)

What are the critical characteristics that make these species useful for pan regional comparisons?

• Restate the question: What evidence do we have that knowledge of the life history characteristics and physiological attributes of the individual species is essential to understanding the ecosystem dynamics?

• Consensus is that detailed knowledge of the individual life histories of zooplankton is important

Egg survival

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Egg production

0

10

20

30

40

50

60

Copepod Life History Trade-offs

Pseudocalanus .

Calanus finmarchicus

The species question continued

• We have approaches and detailed knowledge to answer questions of climate forcing on recruitment of the target species

• During synthesis, we need to identify how our knowledge can be applied to the broad question of climate forcing on ecosystem and function. Do the target species responses representative of ecosystem structure and function. Will inclusion of other key species now identified be sufficient? How much simplification can we re-introduce?

Data gaps

• Identification of key species not originally targeted (e.g. pteropods)

• Microbial components for NPZ

• Nutrient and phytoplankton data for model validation

The overarching question

• Climate forcing mechanisms: local vs remote- Freshwater effects on density driven circulation and

stratification- Winds

• Model approaches: common technical issues linking the coupled models

• Different life histories- responses to forcing: compare and contrast among regions

• Similarities in geomorphology; eg. GB and Antarctica translate into similarities in forcing and ecosystem responses?

Biological challenges

1. Growth and reproduction dependency on food availability

2. Understanding the processes determining entry and exit from fall-winter dormancy

3. Mortality rates

4. Vertical distribution of life stages

Durbin et al. 2003: Gulf of Maine Runge et al. (2006): Georges Bank

Calanus finmarchicus: Relationship of egg production to

phytoplankton biomass

Biological challenges…1Description of linkage between primary production and copepod growth and reproduction

coupled ecosystem – sea-ice ocean circulation model

Le Fouest et al., submitted

Comparisons to satellite-derived fields:St. Lawrence discharge effect

model satellite

AVHRR

SeaWIFS

SeaWIFS

SST

Chl a

kCDOM

vs

Chl a

3rd – 6th of August 1998

March 95 March 99Huret M, Chen C

1997 1998 1999

Spring

Fall

Observed vs simulated chlorophyll a biomass

predicted

observed

coupled ecosystem – sea-ice ocean circulation model

Chifflet et al., in prep

1997 1998 1999

Spring

Fall

Observed vs simulated nitrate concentration

predicted

observed

coupled ecosystem – sea-ice ocean circulation model

Chifflet et al., in prep

1995

surface layer mid-layer bottom layer