ó áó áAproximación a la dinámica de Aproximación a la dinámica de Ecosistemas MarinosEcosistemas MarinosEcosistemas MarinosEcosistemas Marinos

Máster Internacional en Gestión de Zonas Costeras y Estuáricasy

LIM-UPC

Nixon Nixon BahamónBahamón

bahamon@ceab.csic.esbahamon@ceab.csic.eswww marinecometrics comwww marinecometrics comwww.marinecometrics.comwww.marinecometrics.comwww.ceab.csic.es/~oceanswww.ceab.csic.es/~oceans

Centre Centre d’Estudisd’Estudis AvançatsAvançats de Blanes (CEABde Blanes (CEAB--CSIC)CSIC)

Barcelona, 15 de febrero de 2010Barcelona, 15 de febrero de 2010

Coastal Zone Ecosystem ManagementCoastal Zone Ecosystem Management

Coastal zone management requires a good understanding of marine ecosystem dynamics

Marine ecosystems are constituted by a large number of components y y g pshowing complex interactions.

Simplifying the marine ecosystem structure and its dynamics is helpful.

A way for such simplification is through conceptual models.

Modelling interactions of ecosystem components allows getting an h t t d iapproach to ecosystem dynamics.

An approach, but not a good understanding, on the ecosystem dynamics can be reached in a couple of teaching hours.

Here we go!

EcosystemEcosystem--basedbased managementmanagement

Source: http://www.ebmtools.org3

11--6: Dominio pelágico6: Dominio pelágico11. Región nerítica; . Región nerítica; 22. Región oceánica; . Región oceánica; 33. Zona . Zona EpipelágicaEpipelágica. . 44. Zona Batial (. Zona Batial (4a4a. Zona . Zona MesopelágicaMesopelágica; ; 4b4b. Zona Batipelágica); . Zona Batipelágica); 55 Zona Abisopelágica o Abisal; Zona Abisopelágica o Abisal; 66 Zona Zona HadalopelágicaHadalopelágica o o HadalHadal; ; 55. Zona Abisopelágica o Abisal; . Zona Abisopelágica o Abisal; 66. Zona . Zona HadalopelágicaHadalopelágica o o HadalHadal; ; (t: termoclina permanente)(t: termoclina permanente)

AA--D: Dominio bentónicoD: Dominio bentónico

4

AA. Plataforma continental; . Plataforma continental; BB. Talud continental (. Talud continental (B1B1. Talud continental superior; . Talud continental superior; B2B2. Talud continental inferior); . Talud continental inferior); CC. Llanura abisal; . Llanura abisal; DD. Fosa . Fosa hadalhadal..

Fuente: Fuente: WikipediaWikipedia

Clasificación de los ecosistemas marinosClasificación de los ecosistemas marinos

Según la distancia a la costa• Zona nerítica: desde la línea de la costa hasta el borde de la plataforma p

continental.• Zona oceánica: fuera del límite de la plataforma continental.

Según la profundidad• Zona fótica: zona iluminada.

– Zona epipelágica: hasta el límite de la plataforma continental (200 m de p p g p (profundidad). Tiene lugar la producción primaria (fotosíntesis).

• Zona afótica: zona oscura. – Zona mesopelágica: 200 - 1.000 m. Abundante zooplancton. Se

encuentra la termoclina permanente.– Zona batipelágica: 1.000 - 3.000 m.– Zona abisopelágica o abisal: 3.000 - 6.000 m.– Zona hadopelágica o hadal: más de 6.000 m; fosas oceánicas

5

Clasificación de los ecosistemas marinosClasificación de los ecosistemas marinos

Sistema bentónico (fondo marino)El fondo marino (rocoso, pedregoso, arenoso, fangoso) está poblado por ( , p g , , g ) p p

organismos bentónicos..• La región fótica:

– Zona supralitoral (no sumergida)– Zona mesolitoral (intermareal)– Zona sublitoral: (permanentemente sumergida en la plataforma)(p g p )

• La región afótica: – Zona circalitoral: (externa de la plataforma sin vegetación)( p g )– Zona batial: (talud continental entre 200-3.000 m.)– Zona abisal: (fondo oceánico, llanuras oceánicas, entre 3.000-6.000 m.)– Zona hadal: (Zonas de subducción o de fosasa oceánicas 6.000 - 10,000 Zona hadal: (Zonas de subducción o de fosasa oceánicas 6.000 10,000

m)

6

Adriatic SeaAdriatic Sea

Catalan SeaCatalan Sea

Gulf of LionsGulf of Lions Black SeaBlack Sea

Tyrrhenian SeaTyrrhenian Sea

AlboranAlboran SeaSeaIonian SeaIonian Sea

Aegean SeaAegean Sea

Levantine basinLevantine basin

AQUAAQUA--MODIS SeaMODIS Sea--surfacesurface chlorophyllchlorophyll, , MarchMarch 2009 2009

((SourceSource: http://oceancolor.gsfc.nasa.gov): http://oceancolor.gsfc.nasa.gov)

Adriatic SeaAdriatic SeaGulf of LionsGulf of Lions Black SeaBlack Sea

Adriatic SeaAdriatic Sea

Tyrrhenian SeaTyrrhenian SeaCatalan SeaCatalan Sea

AlboranAlboran SeaSeaIonian SeaIonian Sea

Aegean SeaAegean Sea

Ionian SeaIonian SeaLevantine basinLevantine basin

7AQUAAQUA--MODIS SeaMODIS Sea--surfacesurface chlorophyllchlorophyll, ,

SeptemberSeptember 2009 2009 ((SourceSource: http://oceancolor.gsfc.nasa.gov): http://oceancolor.gsfc.nasa.gov)

MFSPPMFSPP--VOS VOS CruisesCruises

SourceSource::A. Cruzado, A. Cruzado, ChiefChief SciSci..

OceanOcean. . LabLab., CEAB., CEAB--CSIC. CSIC.

8PrepPrep. . byby L. L. SimicSimic

25/01/01, Blanes, 25/01/01, Blanes, SpainSpain

What drives ocean circulation?What drives ocean circulation? Global surface current systemGlobal surface current system

10

Open University, Ocean Circulation, 2007Open University, Ocean Circulation, 2007

The Ocean Conveyor Belt

Ocean circulation driven by density differences. (Density is controlled by ocean temperature and saltiness.) Cold, dense water in the Arctic merges with salty water from the Gulf Stream to create the sinking North Atlantic Deep Water (NADW) in the Norwegian-Greenland Sea The NADW helps to drive global ocean circulationGreenland Sea. The NADW helps to drive global ocean circulation.

Illustration The M Factory © Smithsonian Institution. From: http://forces.si.edu/arctic/02_02_04.html

What drives ocean circulation?What drives ocean circulation?Seawater flows along the horizontal plane and in the vertical:

Typical speeds of the horizontal flow or currents: ~ 0.01-1.0 m/s Typical vertical speeds within the stratified ocean: ~ 0.001 m/syp p

1. Wind driven circulation: The wind exerting a stress on the sea surface induces movement of that water. This is called Ekman Layer transport, which extends to the surface 50 to 200 meters. The wind driven circulation is characterized by large clock-wise and counter clock-wise flowing gyres, such as the subtropical and sub polar gyres.

2 Thermohaline circulation: Buoyancy (heat and freshwater) fluxes between 2. Thermohaline circulation: Buoyancy (heat and freshwater) fluxes between the ocean and atmosphere that alter the density of the surface water.The thermohaline circulation engages the full volume of the ocean into the climate system, by allowing all of the ocean water to 'meet' and interact directly the atmosphere (on a time scale of 100-1000 years). directly the atmosphere (on a time scale of 100 1000 years).

3. Geostrophic Currents: The ocean currents are for the most part geostrophic, meaning that the Coriolis Force balances the horizontal pressure gradients pressure gradients.

4. Inertial Currents: Curve motion produced by the Coriolis force when wind ceases to blow.

http://eesc.columbia.edu/courses/ees/climate/lectures/o_circ.html

Sverdrup's Theory of the Oceanic Sverdrup's Theory of the Oceanic p yp yCirculation Circulation

• Answers to the questions can be found in a series of three• Answers to the questions can be found in a series of threeremarkable papers published from 1947 to 1951.

• In the first Harald Sverdrup (1947) showed that the• In the first, Harald Sverdrup (1947) showed that thecirculation in the upper kilometer or so of the ocean isdirectly related to the curl of the wind stress.

• Henry Stommel (1948) showed that the circulation in oceanic gyres is asymmetric because the Coriolis forcevaries with latitude.

• Finally, Walter Munk (1950) added eddy viscosity and calculated the circulation of the upper layers of the Pacific. pp yTogether the three oceanographers laid the foundations fora modern theory of ocean circulation.

http //ocean o ld tam ed / eso ces/ocng te tbook/chapte 11/chapte 11 01 htmhttp://oceanworld.tamu.edu/resources/ocng_textbook/chapter11/chapter11_01.htm

Ecuaciones de MomentoEcuaciones de Momento

En dinámica de fluidos, las ecuaciones de momento describen el movimiento de un fluido compresible no viscosomovimiento de un fluido compresible no viscoso.

Ecuaciones de momento = Navier-Stokes eq. ≈ Euler eq.- sin Fr) q q )Fuerza de Coriolis(~7.3 x105 radianes s-1Gradiente de presión

fricciónlatitud

Harald Sverdrup (1947). The Oceans: Their Physics, Chemistry and General Biology

Circulación termohalina y transporte de partículaspartículas

Open University, Mar.Biog.Cycles, 2005Open University, Mar.Biog.Cycles, 2005

Molar Molar redfieldredfield ratios ratios

Δ Δ P:P: Δ Δ N:N: Δ Δ Si:Si: Δ Δ C = 1:16:15:106 C = 1:16:15:106 ((BrzezinskiBrzezinski, 1985)., 1985).

16

Utilización aparente de oxígeno (AOU) Utilización aparente de oxígeno (AOU)

17

Parámetro conservativo POParámetro conservativo PO(Fosfato preformado)(Fosfato preformado)(Fosfato preformado)(Fosfato preformado)

18

Niveles troficos del ecosistema marinoNiveles troficos del ecosistema marino

c le

vel

c le

vel

hro

ph

ich

rop

hic

Th

Th

Coll et al., 2008

FishingFishing groundsgrounds in a in a benthicbenthic environmentenvironmentIn the Blanes canyon In the Blanes canyon A. antennatusA. antennatus

dwells from 600 to 900 m depth, dwells from 600 to 900 m depth, coinciding with the lower boundary coinciding with the lower boundary

Iberian Iberian

BarcelonaBarcelona The Blanes CanyonThe Blanes Canyon

coinciding with the lower boundary coinciding with the lower boundary of Levantine Intermediate Water of Levantine Intermediate Water (LIW) and the upper boundary of (LIW) and the upper boundary of

Western Mediterranean Deep Water Western Mediterranean Deep Water Iberian Iberian peninsulapeninsula

Western Mediterranean Western Mediterranean SeaSea

Western Mediterranean Deep Water Western Mediterranean Deep Water (WMDW).(WMDW).

The Blanes canyonThe Blanes canyonyy

Fuente: Sarda et al. 2009.Prog. Oceanog. 82: 227-238

Ecosistema pelágicoEcosistema pelágico

200 m

Seasonal changes in upper water layersg pp y

EUPHOTIC ZONE EUPHOTIC ZONEEUPHOTIC ZONE

MIXED-LAYER

EUPHOTIC ZONE

MIXED-LAYER

Phy -N Phy N Ph N

NO -N NO -N

Phy -N

NO -N

Phy -N

NO -N

Phy -N

NH4-N

NZoo -N

NO -NNH4-N

NZoo -N

NO -NNH4-N

NZoo -N

NO -NNH4-N

NZoo -N

NO -N

NONO33-N-N NONO33-N-N NONO33-NNONO33 -N

winter spring autumnsummer

Summer phytoplankton chlorophyll in the 24.5°North Atlantic WOCE section

01 02 03 05 1 2 3 5 1 2

North Atlantic WOCE section

01 .02 .03 .05 .1 .2 .3 .5 1 2

SeaWiFS Station 101 12035506783 122742597590SeaWiFS

-100

-50

Station 101 12035506783 122742597590

-300

-250

-200

-150

Dep

th (m

)

-450

-400

-350

D

Chlorophyll a (mg / m3)

-75° -70° -65° -60° -55° -50° -45° -40° -35° -30° -25° -20°

Longitude

Bahamon et al., 2003

Surface chlorophyll Surface chlorophyll aa and trophic levels of the oceansand trophic levels of the oceans

EutrophicEutrophicMesotrophicMesotrophic

Chl a(mg m-3)

OligotrophicOligotrophic

(mg m )

Depth-integrated PP<0.5 g C m-2 d-1

0 5 1 5 C 2 d 1

Surface Clorophyll aOligotrophic 0.05 mg Chl a m-3

M t hi 0 5 Chl 3

A.Morel(1996)S Nixon 0.5 -1.5 g C m-2 d-1

1.5 - 2.5 g C m-2 d-1Mesotrophic 0.5 mg Chl a m-3

Eutrophic >1 mg Chl a m-3

S. Nixon(1995)

Observation, Analysis and Modeling of Marine SystemsObservation, Analysis and Modeling of Marine SystemsBiBi directional communicationdirectional communication Antenna

Daily data reception &Daily data reception &Publication on the webPublication on the web

BiBi--directional communicationdirectional communicationTemperature

Humidity

Pressure

Irradiance

Antenna

Wind speed& direction

GPSData Data

processingprocessingChlorophyll

TemperaturePressure GPS

Data Data processing & processing &

assimilation in assimilation in i li l

Phone cardPhone cardData loggerData logger

BatteriesBatteries

Solar panels

Lab Lab numerical numerical

modelsmodels

Field sampling Field sampling on board R/V & on board R/V &

1 DVCoupled

CEAB-CSIC

Current-meter T, S

analysisanalysis

VOSVOSPhysicalBiogeochemical Model

Mooring Site Mooring Site

TemperatureSalinityPARDissolved Oxygen

IM125 m

3 DCoupled Physical

Biogeochemical M d l

Blanes StationBlanes Station OxygenTurbidityChlorophyll

IM250 m

Model

Operational Oceanography, CEAB-CSIC

Vertical resolution of models

•Mixed layer models (Evans - Parslow, 1985; Fasham et al., 1990)

V i ll l d d l•Vertically resolved models:

z-dependent: z-level systems (~1 to 5 m layer thickness) ith t b l t diff i t i ti (V l t l with turbulent diffusion parameterisations (Varela et al.,

1994; Oguz et al., 1996; Levy et al., 1998; Bahamon and Cruzado, 2003, etc…)

sigma-dependent: vertical coordinates are layers following terrain; of common use in ocean circulation models (e. g. Mellor and Yamada 1974; Zavatarelli et al 2000 Ahumada Mellor and Yamada, 1974; Zavatarelli et al., 2000, Ahumada & Cruzado, 2007, etc...)

Isopycnal-dependent: vertical coordinates are isopycnalsIsopycnal dependent: vertical coordinates are isopycnals

Grids used in 3D modelsGrids used in 3D modelsGrids used in 3D modelsGrids used in 3D models

27Some model references: Y. Tony Song & Yi Chao. 1999; Blumberg & Mellor. 1987;

Schopf, PS. 1995, etc.Figures from Open University, Ocean Circulation, 2007Open University, Ocean Circulation, 2007

z vs. sigma coordinate models

z vs. sigma coordinate models Simulation of the vertical temperatureSimulation of the vertical temperatureSimulation of the vertical temperatureSimulation of the vertical temperature

in an area of the Algerian Seain an area of the Algerian Sea

-100

-50

)

-150

Dep

th (m

-250

-200D

Model results

Time (days)

Model results300 330 360 30 9060 120

( y )

Bahamon, 2002

Modelos biogeoquímicosModelos biogeoquímicosg qg q

Los modelos biogeoquímicos representan un conjunto de interacciones entre procesos biológicos, geológicos y químicos

El acoplamiento de los procesos biogeoquímicos y ecológicos a los procesos hidrodinámicos (medioambientales) dan como resultado

un modelo acoplado

Un modelo acoplado representa la interacción de elementos bióticos y abióticos con diferentes aproximaciones

(relaciones funcionales)(relaciones funcionales)

Modelo físico + bio-geo-químico o biológico o ecológico o =bio geo químico o biológico o ecológico o

Modelo acoplado

The nitrogen cycling in a pelagic ecosystem The nitrogen cycling in a pelagic ecosystem

Heat, wind stress, H2O, N2 , O2 , CO2ATMOSPHEREAtmosphereHeat, wind stress, H20, N2 , O2 , CO2

Small phytoplankton Small zooplankton

OCEAN Ocean

Large phytoplankton

p y p

Large zooplankton

pGrazing PredationGrazing

DA

RIE

Sda

ry

ryUptake

Mortality+ Fecalpellets

Excretion

Mortality

RA

L BO

UN

Dra

l bou

nd

l bou

ndar

y

NO2DIN

Uptake

Exudation

P O ND O N pellets

LATE

RLa

ter

Late

ral

MortalitySinking

NO3

NH4

Nitrification

Mortality

MineralisationBacteria

Uptake ExcretionExcretion

DEEPER WATERS

Fasham et al., 1990

Mineralisation

Comparison between surface ChlComparison between surface Chl--a from a 3D model and a from a 3D model and satellite observations in NW Mediterranean Sea satellite observations in NW Mediterranean Sea satellite observations in NW Mediterranean Sea satellite observations in NW Mediterranean Sea

Bernardello et al. 2007

Cambio instantáneo de una población: Cambio instantáneo de una población: Modelo biológicoModelo biológicoModelo biológicoModelo biológico

Nt+1 = Nt - (d+e) + (b+i)

La población de una especie en un momento determinado (Nt+1)La población de una especie en un momento determinado (Nt+1)(i.e. una microalga seleccionada como posible indicadora ambiental) está determinada por:

el número actual de individuos (Nt)menos el número de individuos que mueren (d) o emigran (e), más los individuos que nacen (b) e inmigran (i)

Cambio instantáneo de una población:Cambio instantáneo de una población:Modelo biológico y físico (acoplado)Modelo biológico y físico (acoplado)Modelo biológico y físico (acoplado)Modelo biológico y físico (acoplado)

( ) PHYswwPHY

zKt

PHY+

∂∂

+−⎥⎦⎤

⎢⎣⎡

∂∂

∂∂

=∂

∂ ( )zszzzt ∂⎥⎦⎢⎣ ∂∂∂

( ) G PHYNH4UNO2UNO3UPHYEXU

−−+++

La variación temporal de un grupo funcional (PHY, fitoplancton) dependerá de componente difusivo ( K ) componente difusivo (…Kz…)

menos las pérdidas por advección vertical y hundimiento de las células (…w+ws…)más factores biológicos:

consumo de nitrógenogmenos pérdidas de nitrógeno y consumo por parte del zooplancton

Fases para la implementación de un modelo Fases para la implementación de un modelo ecológicoecológicoecológicoecológico

• Calibración¿E d d l t i ió d l d l ?– ¿Es adecuada la parametrización del modelo?

– ¿El modelo reacciona como se espera?

V ifi ió• Verificación– ¿El modelo es estable a largo plazo? – ¿ Conserva la masa?

• Validación– ¿Los datos observados se corresponden con los estimados?

A áli i lit ti tit ti d l i l ió l ió – Análisis cualitativo y cuantitativo de la simulación en relación con las observaciones.

• Sensibilidad• Sensibilidad– Sensibilidad a las formulaciones, parámetros, constantes,

submodelos, variables de estado.– Análisis estadístico de las simulaciones en relación a la Análisis estadístico de las simulaciones en relación a la

sensibilidad de parámetros, etc.

Example: 1DV model of the Example: 1DV model of the oligotrophic pelagic environmentoligotrophic pelagic environment

A physical/ecological model is proposed to assess the timedependent vertical variability of plankton and nutrients inoligotrophic pelagic ecosystems: western Mediterraneanand subtropical NE Atlantic

Model description

Irradiance,lenght of daylight

• Blanes is 1DV , z-dependent

Mixed layer

Surface = 0 m

Euphotic

lenght of daylight

• Simulates vertical fluxes in the upper 300 m of the water Euphotic

layer

N-stock

column

V ti l l ti 3δ z = 3

TurbulentMi i

• Vertical resolution = 3m

• Variable non-uniformMixing(Kz ,Wz )

Variable non uniform vertical turbulent diffusion (Osborn, 1980)

Bottom = 300 m

N-Input N-Output• Depth-uniform (0.05 m/d)

upward vertical velocityupward vertical velocity

A ti l t b l t diff i d l

Physical componentsA vertical turbulent diffusion model

K (m2 s-1)1 -3

Typical summerstratification

N (s-1)10 3 10-2

σθ(kg m-3)10

110-3 stratification10-3 10 2

Mixedlayer

0 m28.0 29.0

(Z)2 ρgN ∂

•−=100 m Pycnocline

Zw(Z)

ρN

∂•=

(Z)2

(z)(z) N

0.25K

ε =Water

Stability(Brunt-

200 m

Density

(Z)N

Turbulentε10-8 10-7

(Brunt-Vaisala)

300 m

Osborn, 1980

Densityanomaly

Turbulentdiffusion

ε(m 2 s -3)

TKE

Physical componentsp

Application of the pp c o o evertical turbulent diffusion model to

a subtropical North Atlantic

section (above 500section (above 500 m depth)

Bahamón et al., 2003

Physical components :Time evolution of irradiance

Th B k (1981) ti ll th l th f d li ht (L1)

Time evolution of irradiance

• The Brock (1981) equations allow the length of daylight (L1) to be computed according to latitude

• Time variation of PAR in surface:

⎟⎠⎞

⎜⎝⎛+=

365N 2 sinP1P0PAR(0) π

⎟⎟⎠

⎞⎜⎜⎝

⎛⎥⎦

⎤⎢⎣

⎡

⎭⎬⎫

⎩⎨⎧ −+

π+=L1

L1tcosPAR(0)t)PAR(0, 1221⎠⎝ ⎦⎣ ⎭⎩

Time evolution of daylight and PAR

D li h (h ) 2Daylight (hours) PAR (Watts m-2)

50018

300

400

Wat

ts m

-2)

12

15

t (H

ours

)

200

300

PAR

(W

9

12

Day

light

1000 2000 4000 6000 8000

Time (Hours)

60 2000 4000 6000 8000

Subtropical NE Atlantic

Time (Hours)Time (Hours)

Catalan Sea

Light extinction in sea waterBlanes Canyon head - NW Mediterranean, 2002 The depth variation of PAR

⎟⎟⎠

⎞⎜⎜⎝

⎛⎥⎦⎤

⎢⎣⎡ ∗∗+ zD PHY(i) ckwk -

)()(⎟⎠

⎜⎝ ⎥⎦⎢⎣= zexp t)1,-PAR(it)PAR(i,

100 %

1.0 %Water extinction+

Phytoplankton self-th

0.1%

Phytoplankton self-shadingD

ept

The biological model fuelling

The upward diffusive flux of nitrogen (μmol m-2 s-1) results

g g

from the diffusivity (Kz) multiplied by the nitrate gradient:

⎥⎦⎤

⎢⎣⎡∂∂

=zNK flux N z ⎥⎦⎢⎣ ∂z

The new production deduced from the Redfield ratio:

16 mol of nitrate = 106 mol of carbon

-50

VOS 2 3 5 6 8 9 104 7

-150

-100

Dep

th

Validation-250

-200

Field data

Validation of temperature

(°C) simulations306 333 73343 13 30 10341 119

( C) simulations in the

Algerian Sea

-150

-100

-50

h (m

)

Algerian Sea

-250

-200

-150

Dep

t

Time (days)

Model results300 330 360 30 9060 120

VOS 2 3 5 6 8 9 104 7

-50

VOS 2 3 5 6 8 9 104 7

-200

-150

-100

Dep

th (m

)

-250

-200

Field data306 333 73343 13 30 10341 119

Validation of

-50

306 333 73343 13 30 10341 119temperature (°C)

simulations in the C l S

-150

-100

epth

(m)

Catalan Sea

-250

-200

D

Model results

Time (days)300 330 360 30 9060 120

Biological components and interactions

A simplified nitrogen cycling conceptual model

NH4+ - N

ExcretionZooplankton - N4

UptakeF l ll t

p

Grazing

Phytoplankton - N

Uptake

Fecal pellets,deaths

NO2- - N

p

Exudation

Sinking

NO3- - N

Exudation

Upward transport

Best fitting parameters and coefficients

¿Which parameters are best?

Symbol Value Definition Units

p

KNO3KNO2KNH4

0.90.80.7

Half saturation constant for nitrate uptakeHalf saturation constant for nitrite uptakeHalf saturation constant for ammonium uptake

mmol N m-3

mmol N m-3

mmol N m-3

KNO3KNO2KNH4

0.90.80.7

Half saturation constant for nitrate uptakeHalf saturation constant for nitrite uptakeHalf saturation constant for ammonium uptake

mmol N m-3

mmol N m-3

mmol N m-3

ψγVPHY

1.50.0253.00 1

pAmmonium inhibition parameter for nitrate and nitrite uptakePhytoplankton exudation fraction of nitritePhytoplankton maximum growth rateZooplankton mortalit rate

mmol N m-3

%d-1

d-1

ψγVPHY

1.50.0253.00 1

pAmmonium inhibition parameter for nitrate and nitrite uptakePhytoplankton exudation fraction of nitritePhytoplankton maximum growth rateZooplankton mortalit rate

mmol N m-3

%d-1

d-1μ∈Ωλ

0.1802030

Zooplankton mortality rateAmmonium fraction of zooplankton excretionFaecal pellets fraction of zooplankton excretion (detrital)Zooplankton assimilation efficiency

d 1

%%%

μ∈Ωλ

0.1802030

Zooplankton mortality rateAmmonium fraction of zooplankton excretionFaecal pellets fraction of zooplankton excretion (detrital)Zooplankton assimilation efficiency

d 1

%%%λ

KgImax

301.681.2

oop a to ass at o e c e cyZooplankton half saturation for ingestionZooplankton maximum ingestion rate

%mmol N m-3

d-1

λKgImax

301.681.2

oop a to ass at o e c e cyZooplankton half saturation for ingestionZooplankton maximum ingestion rate

%mmol N m-3

d-1

Sensitivity analysis would give an insight on the effect of changing parameters on model simulations

The evolution equation of N-phytoplankton (PHY) q p y p ( )

( ) PHYPHYPHY ∂⎤⎡ ∂∂∂ ( )z

PHYsww

zPHY

zKzt

PHY+

∂∂

+−⎥⎦⎤

⎢⎣⎡

∂∂

∂∂

=∂

∂

( ) G PHYNH4UNO2UNO3UPHYEXU

−−+++

NH + NExcretion

Zooplankton NNH + NExcretion

NH + NExcretion

Zooplankton NZooplankton N

Phytoplankton - N

NH4 - N

Uptake

NO2- - N

Uptake

Exudation

Sinking

Fecal pellets,deaths

NO3- - N

Zooplankton - N

Grazing

Phytoplankton - NPhytoplankton - N

NH4 - N

Uptake

NH4 - N

Uptake

NO2- - N

Uptake

ExudationNO2

- - N

Uptake

Exudation

SinkingSinking

Fecal pellets,deathsFecal pellets,deaths

NO3- - NNO3- - N

Zooplankton - N

Grazing

Zooplankton - N

Grazing

Upward transportUpward transportUpward transport

Some model interactions

The phytoplankton uptake of nutrients (UNO3) is as follows:

(NH4)NO3VU Ψ

Uptake of nitrate:

(NH4)

NO3PHYNO3 e

NO3KNO3VU Ψ

+=

(NH4)NO2VU Ψ

Uptake of nitrite(NH4)

NO2PHYNO2 e

NO2KVU Ψ

+=

NH4VU PHYNH4 =

Uptake of ammonia

NH4KVU

NO4PHYNH4 +

BLANES (model) run-time display

Simulations of N-phytoplankton (mmol m-3)p y p ( )

-100

0(m

)

0.70.80.91.0

-200Dep

th (

0 20.30.40.50.6

Catalan Sea0 60 120 180 240 300

-3000.10.2

0

Catalan Sea

-100

h (m

)

0.3

0.4

0.5

-200Dep

t

0.2

0.3

Subtropical North Atlantic 0 60 120 180 240 300

-300 0.1

Seasonal validation of N-phytoplankton (mmol m-3)in the Catalan Seain the Catalan Sea

0

m) -100

-50

Dep

th (m

-200

-150

winter350

-300

-250

spring summer autumn

0.0 0.5 1.0-350

0.0 0.5 1.0 0.0 0.5 1.0 0.0 0.5 1.0

Lines indicate model results Points indicate field observationsLines indicate model results. Points indicate field observations

55

The evolution equations of nutrients:iii

Phytoplankton - N

NH4+ - N

Excretion

Uptake

NO2- - N

UptakeSinking

Fecal pellets,deaths

NO3- - N

Zooplankton - N

Grazing

Phytoplankton - NPhytoplankton - N

NH4+ - N

Excretion

Uptake

NH4+ - N

Excretion

Uptake

NO2- - N

Uptake

NO2- - N

UptakeSinkingSinking

Fecal pellets,deathsFecal pellets,deaths

NO3- - NNO3- - N

Zooplankton - N

Grazing

Zooplankton - N

Grazing

N - Nitrate:

PHYUNO3NO3KNO3 ∂⎤⎡ ∂∂∂

2 Exudation 3

Upward transport

2 Exudation2 Exudation 3

Upward transport

3

Upward transport

PHYUz

wz

Kzt NO3z ∗−

∂−⎥⎦

⎤⎢⎣⎡

∂∂=

∂

N - Nitrite:

PHYUPHYNO2NO2KNO2 ∂⎤⎡ ∂∂∂ PHYUPHYz

wz

Kzt NO2EXUz ∗−+

∂−⎥⎦

⎤⎢⎣⎡

∂∂=

∂

N - Ammonia:

PHYUNH4wNH4KNH4∗∈+

∂⎥⎤

⎢⎡ ∂∂

=∂ PHYU

zw

zK

zt NH4z ∗−∈+∂

−⎥⎦⎢⎣ ∂∂=

∂

Simulations of N-nitrate (mmol m-3)( )

0

6

7

8

-200

-100

Dep

th (m

)

2

3

4

5

6

0 60 120 180 240 300-300

1

2

0 4.0

Catalan Sea

-100

0

h (m

)

2 0

2.5

3.0

3.5

.0

300

-200Dep

th

0.5

1.0

1.5

2.0

Subtropical North Atlantic 0 60 120 180 240 300

-300

Seasonal validation of N-nitrate (mmol m-3) in the Catalan SeaCatalan Sea

0

(m) -100

-50

Dep

th

-250

-200

-150

winter-350

-300

250

spring summer autumn

0 2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6 8

Lines indicate model results and points indicate field observations

Simulations of N-nitrite (mmol m-3)( )

-100

0

m)

0.5

0.6

0.7

-200Dep

th (m

0 1

0.2

0.3

0.4

C t l S

00 40

0.45

0 60 120 180 240 300-300

0.1Catalan Sea

-100

epth

(m)

0.20

0.25

0.30

0.35

0.40

0 60 120 180 240 300-300

-200De

0.00

0.05

0.10

0.15

Subtropical North Atlantic 0 60 120 180 240 300

Seasonal validation of N-nitrite (mmol m-3) in the Catalan SeaCatalan Sea

0

m) -100

-50

Dep

th (m

-200

-150

winter-300

-250

spring summer autumn

0.0 0.1 0.2 0.3 0.4-350

p g

0.0 0.1 0.2 0.3 0.4 0.0 0.1 0.2 0.3 0.4 0.0 0.1 0.2 0.3 0.4

Lines indicate model results and points indicate field observationsLines indicate model results and points indicate field observations

Model productsp

Estimates of vertical nitrogen fluxes upwardthe euphotic zone

Depth Advective fluxes Diffusive fluxes Total fluxes2 1 2 1 2 1 2 1

g p p

m µmol m-2 d-1 µmol m-2 d-1 µmol m-2 d-1 mol m-2 y-1

Catalan Sea120 - 130 144 1632 1776 0.64120 130 144 1632 1776 0.64190 - 200 298 140 438 0.16290 -300 380 5 385 0.14

Subtropical NE Atlantic150 - 160 24 582 606 0.22190 200 120 197 317 0 11190 - 200 120 197 317 0.11290 - 300 187 5 192 0.07

Algunas ventajas de la modelación numéricaAlgunas ventajas de la modelación numérica

• Validar hipótesis sobre elementos que forzan el (eco) sistema( )

• Simular flujos realistas de cuencas oceánicas y topografía del fondo. Se pueden simular ( d i ) f t i i l l l (predecir) futuros escenarios a nivel local, regional, global.

• Interpolar información dispersa de barcos boyas • Interpolar información dispersa de barcos, boyas, satélites

Algunas desventajas de la simulación numérica Algunas desventajas de la simulación numérica

ó• La simulación no es fiel reflejo de la realidad. • Muchas posibles fuentes de error: condiciones

i i i l ódi f t (b ) ál l d l iniciales, códigos fuente (bugs), cálculo de la difusión turbulenta, supuestos…etc.

– Las ecuaciones algebraicas, esenciales en los códigos de los programas, son ecuaciones discretas o aproximaciones l b i d l i dif i l ( id )algebraicas de las ecuaciones diferenciales (grid approx.).

– Los modelos prácticos deben ser más simples que el sistema p p qreal

Referencias onReferencias on--linelineReferencias onReferencias on--lineline

• Numerical Modelling Theoryg y

http://www.physics.uq.edu.au/xmds/documentation/html/node65.html

• Introduction to physical oceanography. Robert Steward. Free web-based text book (and pdf) in physical oceanography and a chapter in numericalmodelling

http://www-ocean.tamu.edu/education/oceanworld-old/resources/ocng_textbook/contents.html

• Reference hidrodynamic model: Princeton Ocean Model (POM)Reference hidrodynamic model: Princeton Ocean Model (POM)

http://www.aos.princeton.edu/WWWPUBLIC/htdocs.pom/

• List of coastal models• List of coastal models

http://www.scisoftware.com/environmental_software/referral.phphttp://woodshole.er.usgs.gov/operations/modeling/ecomsi.htmlhttp://www.ebmtools.org/

• ….

¿Dónde publicar o conseguir ¿Dónde publicar o conseguir informacióninformaciónsobre dinámica y modelado marino?sobre dinámica y modelado marino?sobre dinámica y modelado marino?sobre dinámica y modelado marino?

• Ecological modelling• Ecological modelling• Continental Shelf Research• Deep Sea Research• Dynamics of Atmospheres & Oceans• Encyclopedia of Ocean Sciences• Geophysical Research Letters• Journal of Atmospheric & Oceanic Technology• Journal of Geophysical Research• Journal of Geophysical Research• Journal of Marine Research• Journal of Marine Systems• Journal of Physical Oceanography• Ocean Dynamics • Ocean Modeling• Oceanography• Physics Today• Physics Today• Progress in Oceanography• Nature, Science, Tellus• PLoS (Public Library of Science)• …