Toward Implementing BLING

(Biogeochemistry with Light, Iron, Nutrients and Gases)

in the MITgcm

Brendan Carter,Ariane Verdy, Matt Mazloff, Bob Key, and Jorge

Sarmiento

brendan.carter@gmail.com

WHY?

DIC package

TOPAZ

Darwin NEMURO

Full Ecosystem

WHY?

DIC package

WHY?

DIC package

WHY?

BLING?DIC TOPAZ/Darwin

WHY?

BLING?DIC TOPAZ/Darwin

LIFE

34PO

DIC

DOM

Fe

0.66

0.33

34PO Fe

DOM

2O

2O

LIFE

34PO

DIC BLING

DOM

Fe 34PO

DOM

Fe

LIFE0.66

0.33

0.66

0.33

2O2O

LIFE

34PO

DIC BLING

DOM

Fe

0.66

0.33

34PO

DOM

Fe

LIFE0.1

?

2O2O

LIFE

34PO

DIC BLING

DOM

Fe The

rest

0.66

0.33

34PO

DOM

Fe

LIFE0.1

?

Implicit microbial loop.

2O2O

LIFE

34PO

DIC BLING

DOM

Fe The

rest

0.66

0.33

34PO

DOM

Fe

0.1Small

PhytoplanktonLarge Phytoplankton

1 0.18

2O2O

Implicit size structure.

Small v. Large Biomass

BLING assumes that:

1. Growth and mortality are in steady state.

2. Large phytoplankton has less density dependence to mortality (^4/3) than small (^2).

Biomass

Gro

wth

Horray!

Why hast thou forsaken us?

Small v. Large Biomass

BLING assumes that:

1. Growth and mortality are in steady state.

2. Large phytoplankton has less density dependence to mortality (^4/3) than small (^2).

Biomass

Gro

wth

/mor

tali

ty

Horray!

Why hast thou forsaken us?

Small

Large

Small v. Large Biomass

BLING assumes that:

1. Growth and mortality are in steady state.

2. Large phytoplankton has less density dependence to mortality (^4/3) than small (^2).

Biomass

Gro

wth

/mor

tali

ty

Horray!

Why hast thou forsaken us?

Small

Large

Small v. Large Biomass

BLING assumes that:

1. Growth and mortality are in steady state.

2. Large phytoplankton has less density dependence to mortality (^4/3) than small (^2).

Biomass

Gro

wth

/mor

tali

ty

Small

LargeHorray!

Why hast thou forsaken us?

Small v. Large Biomass

BLING assumes that:

1. Growth and mortality are in steady state.

2. Large phytoplankton has less density dependence to mortality (^4/3) than small (^2).

Biomass

Gro

wth

/mor

tali

ty

Small

LargeSmall phytoplankton do better when it is warm and when times are hard.

…they also export less.

Iron and light interaction

Experimental evidence suggests:

When iron is abundant, more chloroplasts are made, and chloroplasts are more efficient.

FeFe

FeFe

FeFe

FeFe

Fe

FeFe

Iron and light interaction

Experimental evidence suggests:

When iron is scarce, organisms can’t use light as effectively.

Fe

FeFe

Iron and light interaction

34

34

C C0 Fe CPO

0 Fe memPO

21 ^

2kT

kT

IP P e L L e

P e L L I

min max min FeL

min max min FeL

Shows up twice in the light limitation…

In the chlorophyll to carbon ratio

and a term representing photosynthetic efficiency

Both effectively decrease light limitation with iron.

As promised…With and B we can estimate [Chl]…

Excellent food for

a budding adjoint

state estimate.

With and B we can estimate [Chl]…

Excellent food for

a budding adjoint

state estimate.

But what if

was really ?

As promised…

DOM

DOM

LIFE

34PO

DIC BLING

DOM

Fe The

rest

0.66

0.33

34PO

DOM

Fe

0.1Small

PhytoplanktonLarge Phytoplankton

1 0.18

LIFE

34PO

DIC BLING

DOM

Fe The

rest

0.66

0.33

34PO Fe

0.1Small

PhytoplanktonLarge Phytoplankton

1 0.18

DOFe

DOP

Other changes

• Oxygen is required to remineralize POFe and POP

• Remineralization curve is not quite a Martin curve even with oxygen.

• Minor light-adaptation… the amount of light a plankton needs decreases slightly as the mixed layer consistently grows darker

Next steps

• Resolve: co-limitation vs. Leibig’s Law of the minimum.

• Resolve: mixed layer averaging for irradiance memory term.

• Compile/debug, test, optimize, and check-in.

Temp

and

prod.

Is BLING right for your application?

[Chl]

Large and

Small

Fe-Light

Light Weight

DIC BLING