CASIX Centre for observation of Air-Sea Interactions and fluXes Jim Aiken, Plymouth Marine Laboratory Director of CASIX

. Vertical structure, salinity CASIX purpose: to exploit EO data to derive air-sea interactions, CO 2 fluxes NOAA-AVHRR Terra & Aqua MODIS AIRS Seastar SeaWiFS TOPEX-Poseidon, JASON, Altimeters ERS-1 & 2 SAR Quickscat-SeaWinds Envisat MERIS, AATSR ASAR, RA-2 SCIAMACHY ADEOS II NSCAT, SeaWinds OCTS, Polder Complexity and the diverse data sources, needs integration by modelling 1-D & 3-D Ocean and Shelf circulation models + coupled biology, C-cycle and the assimilation of EO data into models Atmospheric aerosols and gases, CO 2 Air-sea exchange Surface roughness/ Surface height Ocean colour Plankton Marine Biogeochemistry Temperature

Air-sea exchange Surface roughness/ Surface height Ocean colour Plankton Marine Biogeochemistry Vertical structure, salinity NOAA-AVHRR Terra & Aqua MODIS AIRS Seastar SeaWiFS TOPEX-Poseidon, JASON, Altimeters ERS-1 & 2 SAR Quickscat-SeaWinds CASIX purpose: to exploit EO data to derive air-sea interactions, CO 2 fluxes Envisat MERIS, AATSR ASAR, RA-2 SCIAMACHY ADEOS II NSCAT, SeaWinds OCTS, Polder 1-D & 3-D Ocean and Shelf circulation models + coupled biology, C-cycle Atmospheric aerosols and gases, CO 2 Temperature

The CASIX goal is: To quantify accurately the global air-sea fluxes of CO 2. 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 CO 2, we can constrain both the terrestrial component and the global CO 2 budget. CASIX partners have world-renowned expertise in this study

Quantifying the global air-sea fluxes of CO 2 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-ecosystem models, 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. inc UV and respiration Partial analysis of RS variables linked to air-sea exchange of CO 2 Problems are: 1. COMPLEXITY2. ACCURACY The imperative is to develop novel, theoretically-based EO algorithms for improved accuracy of prediction. CASIX

The 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 CO 2 Flux data and climatologies Improved numerical models Better understanding of processes New EO algorithms

SST AATSR, NPOES MSG, AMSR, TMI Wave height JASON, ALT-2 Surface topography TOPEX, JASON, ALT-2 Exploiting the wide array of data sources Surface roughness Sea-Winds, N-SCAT ASAR, Radarsat, AMSR, Windsat TOPEX, JASON, ALT-2 Wind stress Surface films Air-sea flux parameterisations Air-sea gas flux (CO 2 ) climatology Atmospheric CO 2 Atmos. Sensors Sciamachy, AIRS Ocean colour SeaWiFS, MERIS, MODIS, GLI Chlorophyll Primary production processes controlling upper ocean pCO 2 Ocean circulation models with bio-geo- chemistry and air-sea interface processes

4: Integration (climatology and analysis) Wider application The science elements and their interaction 1 : Physical controls on surface exchange 2: Biogeochemistry and bio-optics 3a: 3-D N. Atlantic ocean model for CO 2 3b: 3-D N.W. European shelf model for CO 2 3c: Interface modelling Experiment with parameterisations and process models Define flux parameterisation using EO input Optimise input from EO colour CO 2 flux climatology In situ flux data Satellite data 10 year hind-cast of CO 2 fluxes

Utilising all the UK’s available skills

Management 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 PlymouthSOCUEAMetOfficeBangorpolELR CASIX Management Group Director, co-director CASIX Advisory Committee

Staffing the Science elements Person years

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 1Year 2 Year 3Year 4Year 5

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? 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 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 CO 2 (“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 aSea 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 Aim To accurately predict air-sea fluxes of CO 2 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