Shape of the oceans
WOCE CFC-11 Inventories for N. Atlantic Water Masses
Labrador Sea Water
is the Atm. 14/12 Ratio by Definition
The 14 C half-life is 5700 years, so a 10‰
drop is ~80 years and the 0.87 value for
the deep ocean is ~1100 years.
THE GREAT BIOGEOCHEMICAL LOOP
TWO BOX MODEL OF OCEAN
Dissolved CO 2
Dissolved CO 2
But not all 1° production
falls out of surface layer.
In fact there is a large
amount of “recycling”.
=1.53 mol/m 2 /yr
PP=22.2 g/m 2 /yr
Martin et al. (1987)
How to Make a Phytoplankton:
+ 16HNO 3
+ PO 4
+ 122H 2
O CH 2
) + 138O 2
In the North Atlantic this reaction consumes all available nutrients,
not so in the Southern Ocean. There is a larger value of “Preformed”
Phosphate in AABW than in NADW.
Also, this reaction only draws down about 10% of the Dissolved
Inorganic Carbon (DIC) in surface waters
One of the oldest questions in Oceanography is what limits primary
production, Nitrate or Phosphate (or light, or Fe or Zn).
On the other hand, the remineralization of organic matter in the
deep ocean will release a large amount of N and P back to the
Gruber and Sarmiento, 1997
Advection of Negative N* Around the Ocean
High Nutrient-Low Chlorophyll (HNLC) Regions of the
Dust from the Galapagos Islands is fertilizing new phytoplankton growth down
wind of the land mass...
Martin and Fitzwater, 1988
Boyd et al., 2000
So, what are a few of the outstanding questions in the field:
-Why is deep DOC so old?
-How do you get “new” Nitrate into the euphotic zone?
-How much fossil fuel CO 2
can the ocean adsorb?