http://press.princeton.edu/titles/8223.html

http://www.up.ethz.ch/people/ngruber/publications

DefinitionDefinition: discipline studying the chemical reactions and

processes within the ocean and those between the ocean and its borders

Chemical oceanographyChemical oceanography mainly mainly studies the cycles of the elements studies the cycles of the elements forming seawater, these are the forming seawater, these are the biogeochemical cyclesbiogeochemical cycles. .

=> Movement of the elements and => Movement of the elements and compounds within the organisms compounds within the organisms and the environmentand the environment

Gruber 2004

ESQUEMA CICLO DEL C, N, O2, P EN EL OCÉANO

Physical oceanography

Biological oceanography

Geological oceanography

Global carbon cycle

+65 -125

1.7 Land use change

+18

21.9 20

1.9 Land sink

1.6

+100

5.4

-220

+161

& the anthropogenic perturbation

PgC/yr = 10 15 gC = 1 000 000 000 tons = 1 billón de kilos

1 tonelada = 1 000 000 gC = 1000 kilos

RelevanceRelevance:

• inmense carbon reservoir, 50 times the carbon in the atmosphere, specially inorganic carbon

• air-sea exchange of CO2 is relatively quick

• the oceans absorb between 26 and 44% of the anthropogenic CO2 driven into the atmosphere

• the CO2 uptaken by the ocean: => it does not affect the earth radiactive balance => mitigates the greenhouse effect

=> sequestered on long time scales, much longer than in the terrestial biosphere

Carbon accumulation on real scalesCarbon accumulation on real scales

Antia, NATO Summer School, Ankara, 2006

On a time scale of millenia: On a time scale of millenia:

the oceans determine the CO2 concentration in the atmospherethe oceans determine the CO2 concentration in the atmosphere

Fluxes in PgC/yr & stocks in PgC

DIC: dissolved inorganic carbon; DOC: dissolved organic carbon

POC: particulate organic carbon; PIC: particulate inorganic carbon = CaCO3

NPP: net primary production

Chisholm, Nature 2000

Biological pumpBiological pump Physical or Physical or solubility pumpsolubility pump

Primary Prod.Primary Prod.100100

Export > 100mExport > 100m1010

SedimentsSediments0.10.1

Temporal Temporal Scale Scale 1 year1 year

100-1000 years100-1000 years

> 10> 1066 years years

weeks weeks

Photic layer, Photic layer, epi-pelagicepi-pelagic

Who plays Who plays here?here?

Aphotic layer: meso Aphotic layer: meso & bati-pelagic& bati-pelagic

Biological processesBiological processes::

+ soft-tissue pump: photosynthesis/ remineralization of OM + soft-tissue pump: photosynthesis/ remineralization of OM

+ carbonate pump: formation/dissolution of CaCO+ carbonate pump: formation/dissolution of CaCO33

1 mol CaCO3=> 0.6 mol CO2

Organic matter synthesis – stoichiometry - Redfield ratiosOrganic matter synthesis – stoichiometry - Redfield ratios::

Redfield ratiosRedfield ratios::

+ C:N:P:O+ C:N:P:O22

+ 106:16:1:-138+ 106:16:1:-138

+ mean phyto composition (lipids + + mean phyto composition (lipids + proteins + sugars + nucleid acids) in the proteins + sugars + nucleid acids) in the ocean … BUT … it varies … ocean … BUT … it varies …

+ what else??+ what else??

Organic matter synthesisOrganic matter synthesis- limiting factors - nutrients- limiting factors - nutrients

Where do they come from?Where do they come from?

+ atmosphere+ atmosphere

+ lateral transport+ lateral transport

+ vertical transport: upwelling, + vertical transport: upwelling,

winter mixing, vertical mixingwinter mixing, vertical mixing

Chisholm, Nature 2000

Organic matter synthesisOrganic matter synthesis- limiting factors - nutrients- limiting factors - nutrients

¿ De dónde vienen?¿ De dónde vienen?

+ atmósfera+ atmósfera

+ transporte lateral+ transporte lateral

+ transporte vertical: upwelling, winter mixing, vertical + transporte vertical: upwelling, winter mixing, vertical mixingmixing

Organic matter synthesisOrganic matter synthesis- limiting factors - nutrients- limiting factors - nutrients

Organic matter synthesis Organic matter synthesis – limiting factors – nutrients – limiting factors – nutrients

- light + ????- light + ????

Euphotic zone:Euphotic zone: area well iluminated, where area well iluminated, where photosynthesis takes place, but it depends on photosynthesis takes place, but it depends on turbidity, hours of light, balance between turbidity, hours of light, balance between photosynthesis and respirationphotosynthesis and respiration

Definitions

P= phytoplancton

Z= zooplancton

B= bacteria

DON: dissolved organic nitrogen

PON: particulate organic nitrogen

More concepts: More concepts: new, regenerated and export productionA

tmosp

heri

c in

put

Vert

ical input

Exp

ort

as

part

icu

late

Exp

ort

or

import

as

dis

solv

ed

Production & recycling

Mainly production

N fixation

f ratio = f ratio = New Prod / Primary productionNew Prod / Primary production

e ratio = e ratio = export prod / PPexport prod / PP

over long time and space scales f ratio = e ratioover long time and space scales f ratio = e ratio

Biological efficiency: Biological efficiency: capacity to consume the nutrients available in the photic zone

ICE: ICE: the marginal sea iceSPSP: subpolarST-SS/PSST-SS/PS: Subtropical Seasonally / Permanently Stratified EQ-D/EQ-UEQ-D/EQ-U: Equatorial downwelling/upwellingLL-U:LL-U: low-latitude upwelling biome

OCEAN BIOMASOCEAN BIOMAS

The efficiency of the biological pump is The efficiency of the biological pump is inversely correlated to the efficiency in inversely correlated to the efficiency in the export of organic matter out of the the export of organic matter out of the photic zonephotic zone

The input of nutrients, light, physical conditions, etc.. Affect the efficiency of The input of nutrients, light, physical conditions, etc.. Affect the efficiency of the biological pump, but the export mainly depends on the community the biological pump, but the export mainly depends on the community structure, which organisms are in the photic zone. structure, which organisms are in the photic zone.

Export depends on temperature + nutrients input + FeExport depends on temperature + nutrients input + Fe

1 mol CaCO3=> 0.6 mol CO2

Rain Ratio = POC / PIC exportRain Ratio = POC / PIC export

La eficiencia del secuestro depende del transporte de carbono por La eficiencia del secuestro depende del transporte de carbono por debajo de la capa de mezcla invernal (WML)debajo de la capa de mezcla invernal (WML)

Secuestro de C = Flujo POC · [(Rain Ratio-0.6)/ Rain Ratio]Secuestro de C = Flujo POC · [(Rain Ratio-0.6)/ Rain Ratio]

Producción primariaProducción primaria

Secuestro de C bajo WMLSecuestro de C bajo WML

Moderada PP- Bajo secuestro – WML profundo

Alta PP- Alto secuestro – WML somero

Antia et al. (GBC, 2001)

PgC/yr = 10 15 gC = 1 000 000 000 toneladas = 1 billón de kilos

1 tonelada = 1 000 000 gC = 1000 kilos

pH

TIC

Complex systemComplex system:

• Equilibrium system controlled by T, S & pressure

• thanks to it, seawater is a weak alcaline buffer, pH varies within a 7.5 and 8.5

• 4 variables: TIC, pH, TA, fCO2

fCO2 = x(CO2) patm = [CO2]/0(S,T)

AT=[HCO3-]+2·[CO3

2-]+[B(OH)4-]+[OH-]-[H3O+]

CT=[CO2] + [HCO3-] + [CO3

2-]

Mass balanceMass balance

Charge balanceCharge balance

pH= -log [H3O+]

fCO2 = x(CO2) patm = [CO2]/0(S,T)

General rule:

more dissolved CO2 in cold waters

CT=[CO2] + [HCO3-] + [CO3

2-]

Mass balanceMass balance

(CT a.k.a. CO2 or DIC or TIC)

Independent of T & Pr

pH

TIC

1%

85%

14%

Explicit approach: Explicit approach:

5 species (unknowns) 5 species (unknowns) H H22COCO

33* , HCO* , HCO33

–– , CO , CO33

–2 –2 , H , H++ , OH , OH––

3 equilibrium equations3 equilibrium equations K K11, K, K

22, Kw , Kw

1 concentration condition1 concentration condition C CTT

1 proton condition1 proton condition Alk Alk

Any Any twotwo carbonate system parameters fix the values of all the rest: carbonate system parameters fix the values of all the rest:  CCTT , , AlkAlk , H , H

22COCO33* (or * (or pCOpCO

22), HCO), HCO33

–– , CO , CO33

–2 –2 , , pHpH

+ Table 2 Millero et al. (1993) showing estimates of the analytical precision (reproducibility) and accuracy of measurements of pH, TA, TIC and fCO2:

Analysis Precision Accuracy Reference pH (spectrofot.) ±0.0004 ±0.002 Clayton & Byrne (1993)TA (potentiom.) ±2 umol/kg ±4 umol/kg Millero et al. (1993)TIC (coulometric) ±1 umol/kg ±2 umol/kg Johnson et al. (1993)fCO2 (infrared) ±0.5 uatm ±2 uatm Wannikhof & Thoning (1993)

+ Table 3 Millero et al. (1993) with the estimated errors in the calculated parameters of the CO2 system using various input measurements

Input pH TA TIC fCO2

Accuracy ±0.002 ±2 umol/kg ±2 umol/kg ±2 uatm.

pH-TA ±3.8 ±2.1 pH-TIC ±2.7 ±1.8 pH-fCO2 ±21 ±18 fCO2-TIC ±0.0025 ±3.4 fCO2-TA ±0.0026 ±3.2 TA-TIC ±0.0062 ±5.7

Total error: squared root of the errors due to each input parameter

pH

in

cre

as

e

pH increase

Zeebe and Wolf-Galdrow (2001)

Three pumps:Three pumps:

- gas-exchange: T + bio

- Soft tissue

- Carbonate

Chisholm, Nature 2000

Factores físicosFactores físicos::

+ intercambio aire-agua+ intercambio aire-agua

+ disolución en el agua+ disolución en el agua

Physical factorsPhysical factors::

+ air-sea exchange+ air-sea exchange

Piston velocity, units of velocity

¿CO2 equilibration time in the mixed layer?¿CO2 equilibration time in the mixed layer?

Takahashi et a. (DSRII, 2002)

Questions:

+ why are there sinks and sources of CO2 ?

+ what factors control pCO2?

Physical factorsPhysical factors::

+ temperature+ temperature

+ salinity+ salinity

122

2·0423.0

ln·

1 CT

pCO

T

pCO

pCO

1ln

ln· 22

2

S

pCO

S

pCO

pCO

S

pCO2 = 300 uatm, T= 20, S=35pCO2 = 300 uatm, T= 20, S=35

- 1ºC increase in T => +13 uatm1ºC increase in T => +13 uatm

- 1 unit increase in S => + 9 uatm1 unit increase in S => + 9 uatm

biotemp pCOpCOpCO 222

Quantification of the biological and physical factors:Quantification of the biological and physical factors:

MinTobsMaxTobstemp pCOpCOpCO 222

)(*0423.0exp(*22 meanobsTmeanTobs TTpCOpCO

Seasonal variations in Temp Seasonal variations in Temp are high in subtropical areas, are high in subtropical areas, tropical and polar areas have tropical and polar areas have limited variability in T and limited variability in T and so on pCOso on pCO22

temptemp

tempbio pCOpCOpCO 222

pCO2 decreases due to pCO2 decreases due to biological activity biological activity (photosynthesis) north of (photosynthesis) north of 40ºN, subpolar areas, 40ºN, subpolar areas, upwelling areas.upwelling areas.

Quantification of the biological and physical factors:Quantification of the biological and physical factors:

BiologyBiology: green-blue, : green-blue, high north latitudes, high north latitudes, Eq. Pacific, SOEq. Pacific, SO

TempTemp: temperate & : temperate & subtropical areassubtropical areas

!!!!: areas of water : areas of water mass formation, mass formation, biology biology predominates.predominates.

Quantification of the biological and physical factors:Quantification of the biological and physical factors:

The Royal Society (2005)

-60 -40 -20 0 20 40 60

Latitude (º)

-6000

-5000

-4000

-3000

-2000

Dep

th (

m)

7.50

7.55

7.60

7.65

7.70

7.75

7.80

7.85

7.90

7.95

8.00

8.050

-1000

-500

-1500

Caldeira & Wickett (2003)

Oceanography (Vol 17, 2004)

Oceanography (Vol 17, 2004)

-60 -40 -20 0 20 40 60

Latitude (º)

-6000

-5000

-4000

-3000

-2000

Dep

th (

m)

33.8

34

34.3

34.5

34.8

35

35.2

35.5

35.7

36

36.2

36.4

36.7

36.90

-1000

-500

-1500

Salin ity

-60 -40 -20 0 20 40 60

Latitude (º)

-6000

-5000

-4000

-3000

-2000

Dep

th (

m)

-2 ºC

0 ºC

2 ºC

4 ºC

6 ºC

8 ºC

10 ºC

12 ºC

14 ºC

16 ºC

18 ºC0

-1000

-500

-1500

T heta

-60 -40 -20 0 20 40 60

Latitude (º)

-6000

-5000

-4000

-3000

-2000

Dep

th (

m)

2060

2080

2100

2120

2140

2160

2180

2200

2220

2240

22600

-1000

-500

-1500

T otal Inorgan ic C arb on

Global mean profiles of the three main carbon pumps.

Sarmiento & Gruber (2006)Sarmiento & Gruber (2006)

-60 -40 -20 0 20 40 60

Latitude (º)

-6000

-5000

-4000

-3000

-2000

Dep

th (

m)

33.8

34

34.3

34.5

34.8

35

35.2

35.5

35.7

36

36.2

36.4

36.7

36.90

-1000

-500

-1500

Salin ity

-60 -40 -20 0 20 40 60

Latitude (º)

-6000

-5000

-4000

-3000

-2000

Dep

th (

m)

2280

2295

2310

2325

2340

2355

2370

2385

2400

24150

-1000

-500

-1500

T otal A lk alin ity

-60 -40 -20 0 20 40 60

Latitude (º)

-6000

-5000

-4000

-3000

-2000

Dep

th (

m)

2290

2305

2320

2335

2350

2365

2380

23950

-1000

-500

-1500

NTA = TA*35 / SalNTA = TA*35 / Sal

Relevance of the coastRelevance of the coast

LOICZ, 2006

Relevancia costas:Relevancia costas:

ocupan ocupan ±± 20% de la superficie del océano 20% de la superficie del océano

contienen más de un 40% de la población mundialcontienen más de un 40% de la población mundial

proveen de 75% de las capturas de pescaproveen de 75% de las capturas de pesca

representan un 25% de la PP representan un 25% de la PP

directamente afectadas por la actividad humana directamente afectadas por la actividad humana (contaminación, eutrofización): ríos, aerosoles en atmósfera, (contaminación, eutrofización): ríos, aerosoles en atmósfera,

interacción tierra-océano-atmósfera-sedimentos en escalas de interacción tierra-océano-atmósfera-sedimentos en escalas de años.años.

muy heterogéneas y dinámicas, vehículo conductor de carbono muy heterogéneas y dinámicas, vehículo conductor de carbono hacia el interior del océano.hacia el interior del océano.

proyectos: LOICZ (1992-2005-2012), CARBOOCEAN (2005-proyectos: LOICZ (1992-2005-2012), CARBOOCEAN (2005-2009)2009)

0.24 PIC0.32 POC

33.6 DIC, 1.44 DOC,0.012 PIC, 0.26 POC

33.92 DIC, 0.84 DOC0.048 POC

CARBON budget (PgC yCARBON budget (PgC y-1-1) in the continental margins) in the continental margins

0.18 PIC0.18 POC

River, drainage & ice

Primary Prod: 0.48 PIC, 6.19 POCNew Prod.:0.28 DOC, 0.23 PIC, 0.50 POC

Coast & open platforms0.38 DIC, 0.32 DOC,0.18 PIC, 0.22 POC

0.0012 CH4 from sediments0.0017 DMS from biolog. Act.

Sediments & fishery

Open ocean

Mixed layer

Deep layer

Sediments

0.0036 CPrecipitation & dust

Atmosphere

Chen (2004)Chen (2004)Chen & Borges (2009)Chen & Borges (2009)

0.31 IC (DIC)0.31 IC (DIC)0.81 OC (74% DOC)0.81 OC (74% DOC)

Net sink ofNet sink of COCO22

CONTINENTAL SHELF PUMPCONTINENTAL SHELF PUMP

??????????

??????????

??????????

??????????

Wollast (1998)Wollast (1998)

0.36 CO0.36 CO22

New Prod 0.25 PIC

0.0008 DMS

Net air-sea CONet air-sea CO22 flux on european coasts flux on european coasts

Borges et al., ECSS, 2006Frankingnoulle & Borges GBC 2001

Borges et al., ECSS, 2006

Golfo de Vizcaya-0.8 molC m-2 yr-1

Net air-sea CONet air-sea CO22 flux on european coasts flux on european coasts