CASIXCASIXCentre for observation of Air-Sea Interactions

and fluXes

Jim Aiken, Plymouth Marine LaboratoryDirector of CASIX

.

Vertical structure, salinity

CASIX purpose: to exploit EO data to derive air-sea interactions, CO2 fluxes

NOAA-AVHRR Terra & AquaMODIS AIRS

SeastarSeaWiFS

TOPEX-Poseidon,JASON, Altimeters

ERS-1 & 2 SARQuickscat-SeaWinds

EnvisatMERIS, AATSR

ASAR, RA-2SCIAMACHY

ADEOS IINSCAT, SeaWinds

OCTS, Polder

Complexity and the diverse data sources, needs integration by modelling1-D & 3-D Ocean and Shelf circulation models + coupled biology, C-cycle

and the assimilation of EO data into models

Atmospheric aerosols and gases, CO2

Air-seaexchange

Surface roughness/ Surface height

Ocean colour Plankton Marine

Biogeochemistry

Temperature

Air-seaexchange

Surface roughness/ Surface height

Ocean colour Plankton

Marine Biogeochemistry

Vertical structure, salinity

NOAA-AVHRR Terra & AquaMODIS AIRS

SeastarSeaWiFS

TOPEX-Poseidon,JASON, Altimeters

ERS-1 & 2 SARQuickscat-SeaWinds

CASIX purpose: to exploit EO data to derive air-sea interactions, CO2 fluxesEnvisat

MERIS, AATSRASAR, RA-2SCIAMACHY

ADEOS IINSCAT, SeaWinds

OCTS, Polder

1-D & 3-D Ocean and Shelf circulation models + coupled biology, C-cycle

Atmospheric aerosols and gases, CO2

Temperature

The CASIX goal is: To quantify accurately the global air-sea fluxes of CO2.

This is a priority Earth System Science activity, directly related to Oceanic Biogeochemical Cycles and Climate Change – a piece of QUEST.

For the Marine Environment, the coupled surface ocean and boundary-layer atmosphere, the questions are:

•How do marine ecosystems vary with time?•How are marine ecosystems regulated by ocean processes?•How do marine ecosystems interact with the global carbon cycle?

CASIX

The big Earth System Science question, (of both global and regional relevance) is:

How is the Earth changing and what are the consequences for life on Earth?

By quantifying the oceanic fluxes of CO2, we can constrain both the terrestrial component and the global CO2 budget.CASIX partners have world-renowned expertise in this study

Quantifying the global air-sea fluxes of CO2

The needs are: global data from Earth Observation sensors.EO missions provide high temporal and high spatial resolution data and

long-term data sets for many ocean and atmospheric variables.

The imperative is to exploit high-res, 3-D circulation-ecosystemmodels, improve air-sea interaction parms, add EO data assimilation.

Can EO data provide the variables (and parameters) for

biogeochemical models?Yes –

but insufficient accuracy.

The same for air-sea exchange of biogases?

Yes – but insufficient accuracy.

Wind Sea Surface Height Temperature Solar Radiation Ocean Colour

Currents Mixed Depth Layer

Chlorophyll Light Attenuation inc inc UV

Nutrient Fluxes

Export Production

Primary Productivity

CaCO3 Export TCO2

pCO2

Air Sea CO2 Flux

Alkalinity

inc UV

and respiration

Partial analysis of RS variables linkedto air-sea exchangeof CO2

Problems are: 1. COMPLEXITY 2. ACCURACY

The imperative is to develop novel, theoretically-based EO algorithms for

improved accuracy of prediction.

CASIX

The purpose of CASIX: Major deliverablesThe purpose of CASIX: Major deliverables– New algorithms for wave breaking and film damping from EO data– Parameterisation of air-sea exchange coefficients by EO – New techniques to estimate primary production directly from EO data

– Improved process models of biogeochemical fluxes and exchanges– Tools to assess sensitivity of C flux errors to model parameterisations and data assimilation

procedures

– Algorithms for ocean atmosphere material exchange within FOAM– HadOCC integrated into FOAM – Operational ocean carbon model, assimilating EO ocean colour– Improved coupled physical-biological shelf seas model

– 10 year hind-cast of air sea fluxes for FOAM and POLCOMS domains– 10 year climatologies of air-sea fluxes of CO2– Analysis of the CO2 climatologies– Relationships between CO2 fluxes and other climate indicators

CO2 Flux data and climatologies

Improved

numerical

models

Better understanding of processes

New EOalgorithms

SSTAATSR, NPOES

MSG, AMSR, TMI

Wave heightJASON, ALT-2

Surface topographyTOPEX, JASON, ALT-2

Exploiting the wide array of data sourcesExploiting the wide array of data sources

Surface roughnessSea-Winds, N-SCAT

ASAR, Radarsat, AMSR, Windsat TOPEX, JASON, ALT-2

Wind stressSurface films

Air-sea fluxparameterisations

Air-sea gas flux (CO2)climatologyAtmospheric CO2

Atmos. SensorsSciamachy, AIRS

Ocean colour SeaWiFS, MERIS,

MODIS, GLI

ChlorophyllPrimary production

processes controlling upper ocean pCO2

Ocean circulation models with bio-geo-chemistry and air-sea interface processes

4: Integration (climatology and analysis) Wider

application

The science elements and their interactionThe science elements and their interaction

1: Physical controls on surface exchange 2: Biogeochemistry

and bio-optics

3a: 3-D N. Atlantic ocean model for CO2

3b: 3-D N.W. European shelf model

for CO2

3c: Interface modelling

Experiment with parameterisations and process models

Define flux parameterisationusing EO input Optimise input from EO colour

CO2 flux climatologyIn situ flux data

Satellite data

10 year hind-cast of CO2 fluxes

Utilising all the UK’s available skills

Management StrategyManagement Strategy• An accountable overall management structure

• Create teams for each science Element• Composed of PIs responsible for tasks within an Element, and their staff

• Shared responsibility for deliverables within the Element

• The basic working unit within CASIX

• Team leader will promote integration if there is geographic dispersion

• Weekly electronic forum of team members and meetings at least bi-monthly

• Regular meeting and reporting• Management group meets bi-monthly (monthly in first 6 months)

• Principle Investigators meet 3-4 times per year

• Annual 2-day CASIX meetings for all team members including 1 publicised open day for external presentations of progress

Partner entities representing PIs Plymouth SOC UEA MetOffice Bangorpol ELR

CASIX Management Group

Director, co-directorCASIX AdvisoryCommittee

Staffing the Science elementsStaffing the Science elements

10

11.5

14

10.5

Personyears

Scientific Milestones Scientific Milestones

E1

E2

E3

E4

Detection

Variability

Validation

Z structure

process models

W, SST

New flux approach

Climatology

Database

C-Fluxes

FOAM

POLCOMS Devpt.

Interface model

a

b

c

CO2 Hindcast

Operational oc. carbon model

Multi-yr CO2

Public release of new flux climatologies

Climate analysis

K parameterisation

Films

Algorithms

parameterisation

Year 1 Year 2 Year 3 Year 4 Year 5

The timeliness of the proposal The timeliness of the proposal

• CASIX deliverables are urgently needed for the global climate debate

• The data required for global air-sea gas flux measurements are just coming on stream from new sensors

• The existing skills in UK need to be co-ordinated into a national programme if they are not to be diluted by dispersion

• Embryo operational oceanography systems presage a strong

demand for EO-based flux measurements in the near future

CASIX as a NERC Collaborative Centre?CASIX as a NERC Collaborative Centre?

• Addresses fundamental research questions in NERC’s Strategy

– Earth’s life-support systems: Water, biogeochemical cycles and biodiversity

– How can we integrate biogeochemical cycles into physical and geological models, with particular attention to processes at critical interfaces?

– What are the sources, sinks and transportation processes of carbon within the Earth system?

– Climate change - Predicting and mitigating the impacts

– What will be the future atmospheric concentrations and distributions of greenhouse-gases and aerosols?

• Complementarity with other EO Centres -

– Data Assimilation Research Centre

– Centre for Terrestrial Carbon Dynamics.

– Reducing uncertainties in the terrestrial carbon budget

A leading international role for UK scienceA leading international role for UK science

• The UK already has the required expertise• Air-sea gas fluxes; EO methods for ocean colour, SST, altimetry, surface

roughness; nested ocean circulation models with added biogeochemistry; analysis of climate datasets

• World-class personnel in all the fields needed for CASIX tasks, e.g.

• Ensure that UK delivers world-class output • A co-ordinating structure like CASIX is essential to focus collaborative

work on air-sea gas fluxes

• CASIX PIs already have the contacts to ensure CASIX products will be quickly utilised by international programmes.

• Global climate science needs CASIX products– At present we believe CASIX is at the forefront internationally

– If the CASIX concept is not established in the UK, it will be reinvented somewhere else

Project 1: “Study of Physical Controls on Air-Sea Gas Flux”

• Task: Improve estimates of Transfer Velocity of CO2 (“K” in Air-Sea Flux = -K C)

• Rationale:

• 1) Transfer velocity doesn’t depend simply on “wind speed” but is related primarily to the slope of short surface waves and to breaking waves

• 2) We can use EO (especially Altimetry, SAR and Scatterometry) to make estimates of these critical properties of the wave field

Project 1: Observing Surface Processes from Space

Estimating the Slope of Short Waves by Dual-Frequency Altimetry

Development of Wave Field from Altimetry

Backscatter is related to mean square slope of waves longer than a critical wavelength (related to radar frequency).

By measuring backscatter at two frequencies and subtracting the two estimates of slope we can isolate the slope of the waves primarily driving gas exchange

E2: Biogeochemistry of the Upper Ocean

Aim: to develop new algorithms and error quantified data sets of biogeochemical properties and processes from EO data.

Includes:

• Project 4: Biogeochemistry of the Open Oceans

• Project 5: Biogeochemistry of the Shelf Seas

Colour Composite

Chlorophyll a Sea Surface Temperature (SST)

CASIX will create biogeochemical products from the ocean colour time series of SeaWiFS, MODIS and MERIS.

The conventional ocean colour product is chlorophyll-a, but CASIX will take the next step and predict parameters such as Carbon based biomass and growth rate with quantified error bars. These can then be combined with other EO parameters (e.g. SST) and assimilated into models.

Envisat (MERIS)

Projects 4 & 5: Biogeochemistry

Open-Ocean Modelling of Air-sea Carbon Dioxide Fluxes

• AimTo accurately predict air-sea fluxes of CO2 in the North Atlantic and over the rest of the globe using a high resolution GCM.

• Modelling Approach– The Hadley Centre Ocean Carbon Cycle model (HadOCC) will be

embedded in the Met Office Forecasting Ocean Assimilation Model (FOAM).

– Assimilation methods for Ocean Colour will be developed and applied in the FOAM-HadOCC system.

– New air-sea flux parameterisations will be implemented in FOAM-HadOCC.

The Models

• HadOCC– Four-compartment ecosystem

model plus carbon cycling

• FOAM– Operational ocean models that use

data assimilation to forecast 5 days ahead

– Driven by 6-hourly forcing from the Met Office Numerical Weather Prediction (NWP) system

An Example of FOAM/HadOCC

• The model captures the spring bloom signature in the SeaWiFS chlorophyll data in early March 2000

• The model can extrapolate under cloud and to other quantities not remotely observable