HelmHoltz-zentrum GeestHacHt

COSYNACoastal Observation System for Northern and Arctic Seas

COSYNA Mission

COSYNA Partners

COSYNA is financed and coordinated by the Helmholtz-Zentrum Geesthacht Centre for Materials and Coastal Research GmbH. The scientific work is carried out together with partners from Helmholtz-Gemeinschaft Deutscher Forschungszentren, universities and monitoring authorities.

COASTLAB Room: Presentation of and working with real-time observation data and

numerical model results

Development and test of analysis

systems, consisting of observation and

numerical modelling, for the operatio-

nal synoptic description of the environ-

mental status of the North Sea and of

Artic coastal waters. COSYNA aims to

provide knowledge tools that can help

authorities and other stakeholders to

manage routine tasks, emergency

situations and to evaluate trends.

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Zentrum für Marine und Atmosphärische Wissenschaften

The North Sea

Arctic Coasts

cosYna

The North Sea is surrounded by densely populated, highly-industri-alised regions and therefore is extensively used for fisheries, waste disposal, oil drilling, wind energy generation, transportation, recreati-on, etc.. The interests of users differ and often conflict. The North Sea is one of the best investigated shelf sea areas, but we are only slowly beginning to understand the forces that govern energy budgets, material fluxes, balances, and the factors that control and direct ecosystem dynamics. Complex processes influence the North Sea at the local, regional and global level: Hydrological as well as biological fluctuations and variabilities, exchange processes with the Atlantic, and the inputs of rivers, atmosphere and sediment defy exact measurement and prediction. Many processes – especially in the con-text of expected changes due to global warming and other anthropoge-nic influences - are still not fully understood and knowledge is still too scarce for sound prognoses. In addition, there is the highly dynamic and sensitive Wadden Sea that, due to its unique biodiversity, is on the UNESCO World Heritage List since June 2009.

For a comprehensive, synoptic picture of the North Sea, an automated observation network and numerical models that describe realistically the physical and biogeochemical state are needed and are now estab-lished within COSYNA.

Climate change will have major consequences in the Arctic regions: Due to the temperature rise, large areas will be ice free in summer. Larger waves from the open waters could lead to higher erosion rates of the permafrost cliffs along the coast (photo right). Higher concentrations of nutrients as well as dissolved and particulate matter will change the productivity of phytoplankton in coastal waters. In addition methane emissions from the thawing permafrost could have far-reaching effects in terms of global warming.

COSYNA will apply methods that have been proved and tested in the North Sea to coastal waters in the Lena Delta, Siberia. The Lena Delta covers 32.000 km2 and discharges freshwater from a catchment area of 2.400.000 km2 into the Arctic Ocean. COSYNA activities will comprise remote sensing techniques for the quantification of suspen-ded matter and chlorophyll as well as in situ measurements using a FerryBox system for the measurement of turbidity, oxygen, coloured dissolved organic matter, and methane, in addition to standard para-meters such as temperature, salinity, and pH.

According to the COSYNA approach all measurement data will be processed in mathematical models for interpolation, assimilation, and forecasting scenarios to describe e.g., wave activities, coastal erosion, and transport of dissolved and particulate matter.

© Karsten Reise, AWI

Source: change-of-climate.com

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Why COSYNA

Like many shelf and coastal seas, the North Sea hosts unique ecosys-tems and they mediate important biogeochemical fluxes. The ecosys-tems transform anthropogenic riverine compounds, and act as impor-tant interfaces for global carbon and nitrogen cycles. The processes of the North Sea are in numerous ways connected to the well-being of human societies. Recurrent issues are safety of transportation (e.g., frequency of extreme waves, or hazardous spills), coastal defence against storm surges and slowly rising sea levels, or morphology changes due to sediment transport. Current observations revealed drastic changes in biogeochemistry and food webs accompanied by the occurrence of new and the disappearance of established species. Neither the causes nor consequences of these shifts are known.A high priority research question is to obtain a synoptic description of

the key state variables of the North Sea and their physical, chemical and ecological drivers and responses. The principal quest is how the numerous interactions between physics, biogeochemistry and ecology of coastal seas can be best described at present, and how they will evolve in future. This challenging task first requires an improved ca-pability to produce a coherent state description, by melding data and numerical models. The knowledge about the state of the German Bight can support natio-nal monitoring authorities to comply with the requirements of the Euro-pean Water Framework Directive and the Marine Strategy Framework Directive. The coastal observatory involves national and international co-operation, and makes a German contribution to international pro-grammes, such as COASTAL GOOS, GEOSS, GEOHAB and GMES.

General Objectives COSYNA addresses fundamental research questions of operatio-nal oceanography: Which instrumentation and monitoring strategy provides relevant, cost effective and high quality information? How are observational gaps filled and model uncertainties reduced by new schemes of merging dynamic models and statistical methods (data assimilation)?COSYNA seeks to significantly advance technological development for, e.g., automated, quality controlled routine measurements or for error and data analysis. A major challenge is system integration, i.e. to build a coherent platform for sharing or retrieving data, products, and infrastructure. The COSYNA products, in particular model hind-, now- or forecasts, support information services and decision making. The generation, e.g., of maps of water elevation, harmful algal blooms, or contaminants and of scenarios can support coastal management in the context of human impact and climate change.

Scientific Questions

What are the long-term changes of the hydro-physical environ-ment, e.g. currents, waves, water elevation, temperatures, salini-ties, irradiance and sediments?

How does the hydro-physical environment respond to short-term events or slowly changing forces and interactions?

How is the biogeochemical state of the Wadden Sea and the North Sea responding to anthropogenic change?

How large is the exchange of suspended matter, nutrients and organic matter between the Wadden Sea and the North Sea?

To what extent can we reconstruct anomalies in ocean waves or in near-coast currents?

What are the driving factors for algal blooms and under which conditions are they formed?

How are environmental conditions for growth/existence of different trophic levels developing?

What are the effects of planned off-shore wind farms on the physical dynamics, sediment transport, and biological processes?

Realisation of COSYNA

From a capital investment for construction/development the Helm-holtz-Zentrum Geesthacht received about nine million euros from the German Federal Ministry of Education and Research to build COSYNA with focus on the German Bight in the years 2010–2013. COSYNA

will be carried out together with partner institutions in order to utilize their expertise in specialist fields. All additional money for personal, operational and maintenance purposes is taken from the basic funds of Helmholtz-Zentrum Geesthacht and its partners.

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cosYna

Integrated Approach - from Data to Information

COSYNA is a unique system that offers a new level of marine monito-ring methods. COSYNA will be a pre-operational system - in contrast to an experimental system - comprised of observations and models, which will reliably deliver quality-assured data as well as model prog-noses over a period of several decades to be used for the solution of scientific problems as well as for the preparation of political decisions.

The main characteristic of the COSYNA system is the integrated approach that combines observations and numerical modelling.

The observations comprise of different in situ techniques as well as remote sensing from shore by radar and from space by satellite. The basis of the in situ observational part is a common package of sensors at fixed and mobile platforms. Key physical, sedimentary, geochemical and biological parameters are observed at high temporal resolution in the water column and at the upper and lower boundary layers.

A nested modelling system with different levels of spatial resolution is used for the estimation of various parameters, e.g., salinity, waves, and currents, for suspended matter and for biogeochemical processes (ecosystem). By using sophisticated data assimilation procedures, i.e. continuous corrections of the models by observations, the reliability of now-casts and short-term forecasts is much improved.

One important motivation in COSYNA is the continuous provision of near real-time and post-processing products from pre-operational service, bridging the gap between operational oceanography and the various users of forecasts of the marine state. The systematic coupling of observation and forecast systems will form the foundation of scien-tific applications and enable strategic development of applicability to analyses, prognoses and scenarios.

By providing infrastructure as well as various information products, COSYNA will have immediate benefits for coastal management and for marine science in Germany and Europe.

The observatory will be accessible by research institutes in Germany and Europe, which already take significant responsibilities in setting-up, maintaining and working with individual components. By bringing together the expertise of the ‘marine excellence pool’ COSYNA also plays an outstanding role in the integration of marine sciences in Germany.

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Quality-assured, science-based, near real-time environmental informa-tion derived from an optimized synthesis of observations and model data can support decision makers and answer essential questions relevant to society. One of the main characteristics of COSYNA is the pre-operational, i.e., routine provision of ‘products’ that are beyond the present routinely applied techniques in observation and modelling. These products range from routine time series at different locations, to regular maps of system relevant parameters, e.g., currents, waves, salinity, temperature, chlorophyll, oxygen, etc. to routinely short-term forecasts (days) for these parameters in the North Sea.

One of the first COSYNA products is the pre-operational prognosis of current fields in the German Bight from HF-radar fields.

Below the principal processing steps in the assimilation of HF-radar surface current measurements into a numerical circulation model for the German Bight are illustrated. Measurements are collected over a certain period and combined with the corresponding numerical model results. This blending procedure is based on estimates for both the model and the observation accuracies. The resulting analyzed surface current field is then used as part of the initial model state required to launch the next forecast. Due to the regular corrections of the model the quality of the forecast is improved and the area is expanded over the observations area.

The continuous forecasts are disseminated over the internet for further use by different end-users.

COSYNA Products

cosYna-Products

Principle of a pre-operational

forecast scheme for

current fields in the German

Bight as an example for a

COSYNA product.

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cosYna

Stationary in situ observations - Poles

The continuously operating reference network of COSYNA is built from fixed platforms producing high-resolution time series of meteorologi-cal, oceanographic, and water quality parameters. They yield insights into the system’s variability on time scales ranging from seconds to years. In the German Bight, existing and planned off-shore platforms, e.g., FINO3 (photo right) and wind energy installations, will provide power and broadband capacities to operate FerryBoxes and wave radars. Smaller, self-contained poles in the Wadden Sea (figure below) and the mouth of the Elbe record data through which to study the exchange of energy and matter between the shallow, intertidal near-coast basins and the German Bight.

Parameters meteorology: Wind, air temperature and pres-sure, precipitation, irradiance, humidity

oceanography: Current velocity, wave height, temperature, salinity, suspended matter, chlorophyll, pH, oxygen saturation

The figure depicts a typical high-resolution 10 min time

series, measured in the Hörnum Deep, south of Sylt Island.

From top to bottom, data on water level, wind speed, turbidi-

ty and oxygen saturation are shown for two months.

One can see that high wind speeds, e.g., during 4 October,

2009 and 19 November, 2009, influenced not only the water

level (inflow of North Sea water into the Hörnum Deep),

but also led to higher erosion rates that are mirrored by an

increase in turbidity.

observations: in situ

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observations: in situ

Transectional in situ observations - FerryBox

FerryBox is an automated measuring system used in the determina-tion of physical and biogeochemical parameters in surface waters. It is mounted on ‘ships of opportunity’, such as ferries or container ships, on their regular routes across the North Sea (picture right) or on shore-based installations (Helgoland Island, Cuxhaven, and FINO3). Water is pumped from a subsurface inlet into the measuring circuit of multiple sensors. An important feature is the regular automated cleaning and antifouling procedure of the box. All processes can be controlled remotely via the telemetry line from land. Data are trans-mitted and made available after each transect via the Internet. Due to the automated biogeochemical instrumentation of the FerryBoxes the regular transects give detailed insights into the processes and are a main source for data assimilation into models.

Parameters Temperature, salinity, turbidity, chlorophyll, pH, oxygen, algal groups, nutrients, automatic water samples for further lab analysis Future pCO2, alkalinity, flow-cytometer, gene-probes

Measurement of Chlorophyll: Comparison between FerryBox and MERIS

satellite data (relative units, 18 May, 2010, time difference between the

measurements is up to half a day). Differences are mainly due to different

methods: MERIS: Light absorption; FerryBox: Chlorophyll-fluorescence.

Salinity on transects between Immingham (UK) and Cuxhaven (D)

in 2008. Differences in salinity are governed by river discharge,

precipitation, and evaporation. In May low salinity represents inflow

of Rhine water.

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cosYna

observations: in situ

Surveys with Research Vessels

Cruises by research ships across the German Bight complement the regular in situ stationary and ship of opportunity observations. They provide a quasi-synoptic overview of the German Bight from time to time. The chosen criss-cross ship-track of RV ‘Heincke’ (see figure of results below) contacts the fixed COSYNA and state monitoring BSH-MARNET stations and catches the East-West and South-North cross-shore gradients in the German Bight. Additional near-transects are carried out using the smaller RV ‘Ludwig Prandtl’. The research vessels are equipped with a FerryBox, profiling water samplers and an undulating towed instrument carrier (‘Scanfish’™, figure right).

These surveys thus fulfil several purposes at once: Interpolating spatially observed variables between the fixed sta-

tions Adding vertical depth information to the surface FerryBox and

remote sensing data Calibrating instruments by well-controlled in situ water samples Testing of new sensor packages to be included later in the pre-

operational observation mode Enabling additional process studies with the support of voluminous

information from the standard COSYNA equipment running on board.

Scanning the water columns with Scanfish™

Scanfish™ is a towed undulating vehicle system. Flaps control the up and down movement of the ‘fish’. Scanfish™ is designed to carry several oceanographic sensors. Over the German Bight cruise, the steady up and down movement generates a curtain-like data stream of millions of data points along the ship track thus allowing a detailed and quasi-synoptic view of the ocean (see figures below).

Parameters Temperature, salinity, suspended matter, chlorophyll, oxygen, local water depth, volume scattering function

Quasi-synoptic view of water temperatures (left) and chlorophyll a-fluore-

scence (right) from Scanfish™ data during a 10-day German Bight cruise,

28 July to 5 August, 2009. Note the high fluorescence values in the cool

deeper water layer in the north-west corner of the surveyed area, indi-

cating large phytoplankton concentrations in the lower and darker water

column. (Note: Map not adjusted to north.)

NN

°C μg/l

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observations: remote sensinG

Radar Remote Sensing

Ground-based radars are used to obtain synoptic maps of hydrogra-phic parameters, particularly waves, currents and the local water depth (bathymetry). Two radar systems operating in the high frequency (HF-band) and the microwaves (X-band) regime are used to probe the sea surface in COSYNA.

As the microwave signal only covers the line of sight area, the X-band combines local spatial coverage with high resolution (7 m). Under certain conditions the bathymetry of shallow water areas can be calculated from X-band radar signals (figure below). Sea surface waves are imaged by microwave radar and from the phase speed of the

waves tidal current and bathymetric maps can be obtained. The data support coastal protection, monitoring of morphodynamics and safety of traffic.

The HF signal propagates along the air-sea interface far behind the optical horizon (up to 150 km) and provides broad coverage at the expense of the spatial resolution (typically 2 km). In COSYNA the antennae for the HF-band system - used to monitor ocean surface currents, waves and wind direction - are located on Sylt, near Büsum and at Wangerooge.

Synoptic current map derived from the

continuous measurements of the HF-radar

system (9 September, 2010, 14UTC,

snapshot from COSYNA data portal). From

the Doppler shift of the backscattered

signal the radial current components are

retrieved. Combining the measurement

from the stations, located on Sylt, near

Büsum and at Wangerooge, 2D surface

current vectors are retrieved (current

direction depicted by line, current velocity

colour coded). The synoptic current data

from the German Bight are used for data

assimilation into numerical models.

Change of bathymetry during a

single storm, observed with a radar

installation at the island of Sylt

(February 2002). The bathymetric

maps show the seafloor relief, cal-

culated from X-band radar signals,

before and after a severe storm

passed. Within 5 days a volume of

50.000 m3 sand (error about 25%)

was transported into the observa-

tion area.

m/s

1211109876543210

Depth (m)

1.5

1.0

0.50

0.0

Radar Radar

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cosYna

observations: remote sensinG

Ocean Colour from Satellite Remote Sensing

Chlorophyll concentration over the North Sea, 17 May, 2010 at

10.30UTC derived from MERIS with the 'Case-2-Regional' Proces-

sor. Note that only natural clouds (no contrails) are visible due to

airspace closure over Europe.

Maximum monthly chlorophyll concentrations in 2003

(from REVAMP Project).

March

May

July

September

April

June

August

Oktober

Satellite remote sensing is a unique technique used to observe large areas of ocean and land surface simultaneously. It is possible to measure concentrations of chlorophyll, suspended matter and yellow substance (also referred to as CDOM) in the visible light spectrum. The algorithms for the open, blue ocean are well established, whereas for coastal regions with highly variable waters they are still the subject of research. Recently, the ESA decided to use an algorithm developed at Helmholtz-Zentrum Geesthacht to reprocess all coastal data from MERIS. This currently optimal algorithm is also used in COSYNA on a daily basis, as shown in the figure (below right) of a snapshot of chlorophyll concentrations in the North Sea on 17 May, 2010.

To obtain a better overview over chlorophyll dynamics and to reduce the effect of cloud coverage on data, monthly means and monthly maxima are derived. The pictures (below left) show the monthly maximum concentrations of chlorophyll in 2003. They were created by combining many daily scenes for each month. Optical remote sensing is an ideal instrument through which to obtain spatial information for large areas almost every day. The lack of information in deeper water levels and under clouds requires additio-nal information from other in situ measurements in combination with numerical models to interpolate missing data.In addition, further in situ measurements from campaigns and from regular stations are necessary to validate and improve satellite-derived data.

Parameters Concentrations of suspended matter, chlorophyll and CDOM

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observations: sediment-water, new tecHnoloGies

In the coastal areas of shelf seas the exchange processes between sediment and water are especially important for the whole system. Transport processes near the bottom induce topographical changes, re-suspension at the sediment surface, and suspension of particles in the water column. This depends on the material properties of sediment and suspended matter. Despite many investigations, a holistic picture of these complex processes, especially the small-scale interactions between turbulence, micro-topography and biogeochemical exchange processes, is still needed.Within COSYNA, two systems will be built to take continuous near-bot-tom measurements; one system will focus more on physical processes (SedOBS) and the other will concentrate on biogeochemical exchange (NusOBS). Autonomous ‘lander systems’ (figure right) will be used as instrument carriers, which later will be coupled to underwater nodes.The instruments will be operated by partners AWI, MARUM and ZMAW.

Sediment-Water Measurements (SedOBS & NusOBS)

Parameters & instruments for sedobsHigh-resolution current profile (ADCP), turbulence, CTD, eddy correlation, particle size (LISST), floc-cam, high-resolution sonar, noise-recording

Parameters & instruments for nusobsParticle sampler, benthic flow-chamber, current CTD, in situ water sampler, in situ porewater sampler, in situ autoanalyser

© Olaf Pfannkuche, IfM Geomar

New technologies - Zooplankton Recorder (MOKI)

Rapid mapping of plankton abundance in combination with taxono-mic and size composition will be undertaken using the zooplankton recorder (MOKI, figure right: a pre-decessor type). The zooplankton recorder can provide high-resolution images of minute objects below 100μm. The modular configuration enables the device to be towed by research vessels, to be a component of the FerryBox or to be a com-ponent on unmanned platforms, e.g., poles or underwater nodes. Images of dominant plankton groups can be classified in the MOKI-Browser and objects can be assigned to their respective environmental parameters: Depth, temperature, salinity and oxygen concentration.The instrument has been developed and will be modified and operated by partner AWI. Parameters

Zooplankton species and size

© Hirche, AWI

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cosYna

observations: underwater node, new tecHnoloGies

Observation Centres - Underwater Nodes

Within the last few years, ‘underwater nodes’ have gained importance as interfaces for underwater observation networks, for example, NEPTUNE Canada Network. They provide the necessary infrastructure, i.e., power and data communication, to operate various sensors and complex devices at the sea bottom. Within COSYNA, a stable tech-nology will be developed for shallow-water (<100m) applications. The objective is to establish autonomous systems that can be deployed in different North Sea areas and later in the Arctic and that can enable a flexible and modular coupling of different near-bottom measurement systems. Thus, a network of long-term underwater observatories can be established to investigate processes at the sediment-water

interface at a sufficient spatial and temporal resolution and operated independently of ship cruises.The main challenge in developing an underwater node is to provide po-wer and broadband data communication to many instruments of diffe-rent users in a reliable manner: Even if an instrument is short circuited by penetrating water, the other instruments should not be influenced. All data will be transferred to the users’ desks in a transparent way at 100 Mbit/s and each user can control his/her individual instrument via the Internet. The unterwater node will be developed and operated jointly by Helmholtz-Zentrum Geesthacht and AWI.’

New technologies – Nucleic Acid Biosensor

The surveillance of marine phytoplankton will be greatly facilitated by nucleic acid biosensors. The core of the biosensor is a multiprobe chip that can be used for the simultaneous detection of a variety of algae (sandwich hybridization, figure right). A molecular probe as a detection component specifically binds to the target of interest. In turn, an antibody-enzyme-complex coupled to the signal moiety transforms this detection event into a redox-reaction that can be measured as an electrochemical signal. This technique allows rapid detection and counting of microalgae in complex samples. The main steps are automatically carried out in a portable device. The detection principle has already been verified; however, the main challenge for COSYNA is to construct a device that (1) reliably filters sea water in order to concentrate algae cells, (2) ‘cracks’ the cells (lysis) and (3) transports the resulting fluid to the detector.The instrument will be operated jointly by Helmholtz-Zentrum Geest-hacht and partner AWI.

Parameters Algae taxa and algal groups

Algal DNA

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modellinG

Hydrodynamic Modelling

Numerical models are required to estimate ocean state variables at times and locations for which observations are not available. Of particular importance for the COSYNA project is the ability to provide forecasts of different parameters concerning ocean waves, circulation, and suspended matter. The combination of models covering different processes and spatial scales provides a comprehensive picture of the physical ocean state in the German Bight.

Circulation model

The nested-grid pre-operational circulation model consists of three model configurations: (1) Coarse-resolution outer model for the North Sea-Baltic Sea (grid size about 5 km), (2) fine-resolution inner model (grid size about 0.8 km) covering the German Bight, (3) very fine-resolution model for the Wadden Sea region (grid size about 200 m) resolving the barrier islands and the tidal flats. Although the simulation of features such as vertical stratification is very complex, the model is in good agreement with observations (figure below).

Wave model

The grid-nested COSYNA wave model system provides 24-hour wave forecasts twice a day on a regional scale for the North Sea and on a local scale for the German Bight. Wind fields and boundary information provided by the German Weather Service (DWD) force the forecast runs delivering a number of wave parameters such as wave height, period and direction. On 21 April, 2010 at midnight (below), the wave heights in the German Bight show a typical distribution with low values at the coast and higher values off shore.

Simulated wave heights in the German Bight (21 April, 2010)

Three-dimensional distribution of water temperatures computed with

a numerical model. The data are co-located with Scanfish measure-

ments taken between 28 Juli and 5 August, 2009 (see page 9).

°C

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cosYna

modellinG

Hydrodynamic Modelling

SPM model

The distribution of suspended particulate matter (SPM) is of primary importance for the ecological status of the sea because it impedes the daylight penetration into deeper water layers and because of its role in the accumulation of pollutants. In addition to advection, the model takes into account vertical exchange processes due to currents and waves, sedimentation, re-suspension, and erosion at the bottom, as well as processes of bioturbation in the sediment.

Data Assimilation

State estimates provided by numerical models contain errors that increase with prediction time. Errors are due to imperfect model dynamics as well as to uncertainties in the initial state and the forcing fields. Data assimilation is a technique to reduce estimation errors by dynamically consistent combination of numerical models and observations. COSYNA applies different statistical and variational assimilation techniques to correct the now- and forecasted model state estimates.

The two figures below contrast model results of the "free" run, i.e.,without use of observations, with the respective data assimilation run using HF radar measurements as additional information. The grey shading in the figure (bottom left) represents the observational area of the HF radar. The data assimilation obviously affects areas beyond the observational coverage. This is nicely demonstrated in the validation at FINO1 (bottom right). Both model results are plotted for a full tidal cycle at the position of the FINO1 platform located outside the HF ra-dar range. Data assimilation forces the tidal phase about an hour back in time making it more consistent with the observations taken with an ADCP mounted at the platform. Note that these observations are not included in the assimilation.

Typical distribution of modelled SPM concentrations

(improved by assimilated satellite data) in mg/l at the sea

surface (22 March, 2003, 10:20).

Free RunAnalysisObs

FINO1

The assimilation of surface

current fields derived from

HF radar observations

(5 December, 2009, 4:00 UTC).

"Free" run and assimilation

run (left) and validation with

FINO-1 ADCP data (right).

Hrs since Dec 5, 2009, 00:00 UTC

55.5

55

54.5

54

53.5

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modellinG

Biogeochemical Modelling

Biogeochemical cycling of matter is characterized by the interaction of physical, chemical and biological processes. Its complexity is enhan-ced in shallow coastal waters due to a tight coupling of processes in sediments and the water column. Biogeochemical interactions, with all kinds of feedback loops, entail highly dynamic carbon, nitrogen, and phosphorus mass fluxes that can be estimated with biogeochemical models.

The Model for Adaptive Ecosystems in Coastal Seas (MAECS) resolves the dynamics of nutrients, phytoplankton, zooplankton, dissolved organic matter, and detritus. Its novelty is the focus on adaptation in the biota, including aspects such as size-selective grazing by zoo-plankton or photo-acclimation of algae, expressed by variations in the chlorophyll-to-carbon (Chla:C) ratio. MAECS is coupled to the physical General Estuarine Transport Model GETM (see right figure). In the present version, observations are used to calibrate model pa-rameterisations and to validate the model under a range of boundary conditions. In this way, COSYNA observations provide important constraints for flux estimation and magnitudes of spatial and temporal variability. On a longer-term, the assimilation of data into MAECS will improve state estimation, delivering reliable forecasts of ecosystem key-state variables.

Two examples of model results are presented in the figures below. First, the models ability to resolve physiological variations of the phytoplankton’s cellular Chla:C ratio is relevant when relating actual nitrogen biomass to observed chlorophyll concentrations. Patterns exhibit regions with enhanced chlorophyll synthesis, compensating for reduced light availability, e.g., due to deeper mixing or increased light attenuation. Second, growth of phytoplankton (“primary production”) and the exudation of polysaccharides control the coagulation and sett-ling behaviour of suspended matter. Patterns can reflect regions with enhanced aggregation and sinking of algae, exporting organic matter to the sediments.

Chla/C ratio: Surface distribution of Chla:C (gChla/gC) from the shallow

Wadden Sea towards the central German Bight.

Particulate organic detritus: Bottom concentration of organic detritus

(carbon, nitrogen and phosphorus converted to total mass (mg/l), that

represents an organic fraction of SPM).

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cosYna

data manaGement

Data Management

COSYNA data management organizes the data streams bet-ween observational and storage systems at Helmholtz-Zentrum Geesthacht and partner sites, the data documentation and the user interfaces for data retrieval and presentation. Monitoring the actual status of the systems and subsequent pre-operational state reconstructions and forecasts require fast transmission, automatic quality checks and data assimilation. The metadata are based on the German NOKIS standard and are used for data retrieval and display. The compliance with national and international standards or guidelines for data management and quality assurance ensures interoperability with other marine/coastal data centres regarding information sources, exchange of data, and metadata including data quality. In this way COSYNA is prepared to contribute to an European-wide network of coastal observatories. Together, meta, observational and model data will grow into a long-term searcha-ble archive that can be used to detect patterns in the North Sea systemsʼ development over a broad range of temporal and spatial scales.COSYNA follows an open data policy for users from the scienti-fic community, coastal managers or interested lay persons. The COSYNA data portal presents all COSYNA data and metadata in a comprehensive way. The user can select parameter, data sources, time range and presentation type (overlay raster map or time series diagram). The actual data retrieval is controlled exclusively by the metadata. The user can download the selected data.

In the COSYNA data portal all routine data that are measured in

COSYNA can be selected and displayed in combination with remote

sensing and radar data. The example above depicts a combination

of FerryBox data and MERIS data for chlorophyll.

COSYNA data portal: www.coastlab.org

InternetCOSYNA data portal

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Contact

Website: www.cosyna.deCOSYNA data portal: www.coastlab.org E-mail: friedhelm.schroeder@hzg.de rolf.riethmueller@hzg.de

Helmholtz-Zentrum GeesthachtCentre for Materials and Coastal Research GmbH Max-Planck-Straße 1 l 21502 Geesthacht

Telefon: (04152) 87-0Telefax: (04152) 87-1403www.hzg.de

November 2010