1. Ecosystem dynamics in Arctic models: role of physical processes
K.Popova, A.Yool, Y.Aksenov
F. Dupont (EC, Canada), M.Jin (Univ Alaska Fairbanks), E.Hunke (LANL)
J. Zhang, M. Steele (Univ of Washington)

2. AO Primary production Horizontal advection
Annual AO primary production is
limited by nutrients not light!
[except for N.Chukchi sea and NA inflow]
Deep winter mixing

3. Total primary production gC/m2/yr
Model intercomparison experiment
General agreement between models and models and satellite-derived data.
Spatial variability of ice concentration and winter mixing are crucial for good agreement with data on Primary productivity
Models disagree what factor (nutrients or light) controls primary production
Year 1998

4. What factors control primary production outside of Pacific and Atlantic
inflows? ?

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

6. 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

7. Shelf control of AO primary production?
Aagaard et al. (1981)

8. 35 30 25 20 3 2 1
Near bottom salinity
Near bottom DIN

9. Shelf control of AO primary production?
Aagaard et al. (1981)

10. Shelf control of AO primary production?
Aagaard et al. (1981)

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

12. Questions
Does water column become homogenised during the brine release?
Do physical model reproduce advective formation of upper halocline?

13. years