1. Some ideas for coordinated studies
Katya Popova + FAMOS biogeochemical group
National Oceanography Centre, UK 1

2. Well-defined ideas
AO productivity in observations and models (P.Matrai)
Role of the subsurface Chl-a maximum (J-E.Tremblay, P.Matrai – observations; K.Popova – global models; Nadja Steiner, Molly Palmer – 1D)
Well-defined ideas lacking critical mass (minimum 2 modelling groups)
Time series stations (biogeochemistry)
Light vs nutrient limitation
Shelf control of primary production
Vague ideas but with critical mass and a lot of enthusiasm
IPCC CMIP recommendations (model requirements, metrics, outputs)

3. 1. Subsurface Chl-a maximum
From Carmack and McLaughlin, 2011
25m
100m
Chl-a
Nutrients

4. 1. Sub-surface Chl-a maximum
(Model estimate)
Subsurface contribution to primary production
Subsurface contribution to Chl-a
About 43% of Total AO primary production is fuelled by SCM
Popova et al., 2010, Biogeosciences

5. 2. Shelf control of AO primary production?

6. 2. Shelf control of AO primary production?

7. Numerical experiment: no bottom remineralisation
(5 years run)
Control run
(Control-exper)/control
20% reduction of total AO primary production after 5 years
20% reduction of total AO primary production after 5 years

8. 3. Light vs nutrient control
Winter Summer Winter
3. Light vs nutrient control
Light –limited system
Nutrient –limited system
Half-saturation
for nutrient uptake
Nutrient-limited system