Hydrodynamik und Datenassimilation


Ein wichtiger Teil unserer Arbeit ist die Kooperation mit anderen Forschungsinstituten, öffentlichen Institutionen und Unternehmen. Wir waren und sind an vielen nationalen und internationalen Projekten beteiligt. Einige unserer laufenden Projekte sind hier beschrieben.

Coastal unstructured resolution for aquatic environments

Project timeline: APR 2018 – MAR 2020

The main objective of CURAE is to prepare a new set of downscaling and coupling tools, which, based on present Copernicus - Marine environment monitoring service (CMEMS) products, will open a wide range of coastal applications and contribute to enhance the coastal dimensions. The core of the project is the incorporation of the coastal fringe as an active boundary layer, interacting bi-directionally with the shelf sea and including the continental discharge in terms of water, sediment and nutrient fluxes. To prove the feasibility of this approach two coastal pilots have been selected that feature river and irrigation discharges, dredging and their interactions. The selected sites also represent two contrasting environments (micro and macro tidal, low to high wave energy, mild though point wise torrential and medium to high precipitation rates) and two different numerical approaches for downscaling so that the derived conclusions and tools should be generic enough and of direct value for a CMEMS extension towards the coast.
Such a general aim and structure will be done trough: (i) introducing asymmetric interpolation and error assessment techniques as required by anisotropic coastal domains; (ii) assessing the different relative weights of processes and coupling in coastal areas, with respect to deep water oceanography, providing criteria and recommendations for the further evolution of the marine services; (iii) proving the feasibility of including some selected coastal interventions into the forecasting tools, to illustrate another coastal extension with high added value for specific applications and general land/water planning; (iv) promoting the use of unstructured grids , benefiting from the higher flexibility for distributing mesh nodes.

Das vom Bundesministerium für Wirtschaft und Energie (BMWi) geförderte Forschungsprojekt untersucht die Windenergienutzung in der Deutschen Bucht. Hierzu haben sich mehrere Forschungsinstitutionen zu einem Projektkonsortium zusammengeschlossen. Forschungsgegenstand des Projekts X-Wakes ist die „Interaktion der Nachläufe großer Offshore-Windparks und Windparkcluster mit der marinen atmosphärischen Grenzschicht“. Dabei geht es um die Fragestellung, wie sich die Windbedingungen bei einem großflächigen Ausbau von Offshore Windparks in der Deutschen Bucht ändern. Hierzu werden die Daten umfangreicher Messkampagnen und hochauflösender Modelle für die Weiterentwicklung von in der Industrie eingesetzten Modellen zur anschließenden Berechnung der Auswirkungen des Offshore-Windenergieausbaus genutzt. Das Institut für Küstenforschung am Helmholtz-Zentrum Geesthacht entwickelt dazu Methoden zur Abschätzung von Nachlaufeffekten der Windparks, basierend auf Satellitendaten und empirischen Modellen.

Das vom BMBF geförderte Projekt findet in enger Kooperation mit den Universitäten von Haifa und Tel Aviv sowie dem DLR statt. Das Ziel des Projektes besteht darin, durch Einsatz einer innovativen Technologie die Vorhersage von dreidimensionale Strömungsfeldern insbesondere in Küstenregionen zu verbessern. Um dieses Ziel zu erreichen müssen sowohl technologische als auch methodische Entwicklungen betrieben werden. Auf technologischer Seite geht es um die Entwicklung von Ansätzen, eine Gruppe von Unterwasserdriftern mit akustischer Kommunikation so zu betreiben, dass möglichst akkurate Strömungsinformation daraus abgeleitet werden können. Aus methodischer Sicht liegt der Schwerpunkt auf der Entwicklung von Verfahren, die aus den innovativen Messungen Vorhersagen berechnen sollen. Dazu werden sowohl statistisch-empirische Verfahren als auch Methoden der Datenassimilation herangezogen.

Consistent wave-mean flow modelling in coupled atmosphere-wave-ocean models

Project timeline: APR 2018 - MAR 2020

WaveFlow addresses the impact that unresolved wave-mean flow effects have on the circulation in the upper ocean. Specifically, the project aims to introduce recent improvements to the physical parameterizations of wave physics in a state-of-the-art wave model used for operational wave forecasting. The wave fields and fluxes will be implemented in an openly available wave model code and new processes tested with fields and fluxes from a decades-long wave hindcast of the soon to be completed ERA5 reanalysis studied. The tests will be carried out on scales, ranging from vertical column one-dimensional setups to regional, high-resolution models and all the way to global ocean-only and fully coupled atmosphere-wave-ocean forecast systems. The project aims to explore the beneficial impact on the predictability of forecast systems and the potential improvement to the circulation of the upper ocean. The project brings together a consortium with complementary competence on wave and ocean modelling and will lay novel foundations for how wave and ocean models should interact.

Black Sea CONNECT - Coordination of marine and maritime research and innovation in the Black Sea

OKT 19 – SEP 22

Restoring and maintaining the resilience of the Black Sea ecosystem, while enabling a sustainable exploitation of its natural resources is vital. A better coordination and alignment of research and innovation efforts alongside developing improved knowledge base and joint infrastructures could substantially support this timely challenge. Towards this end the Burgas Vision Paper was produced, by an initiative supported by the European Commission, as the key framework document for a shared vision for a productive, healthy, resilient, sustainable and better-valued Black Sea by 2030. It addresses the four key pillars on which a new Strategic Research and Innovation Agenda (SRIA) and its Implementation Plan can be built on: (1) Addressing fundamental Black Sea research challenges, (2) Developing products, solutions and clusters underpinning Black Sea Blue Growth, (3) Building of critical support systems and innovative Infrastructures, (4) Education and capacity building.
Building on this recently emerging policy framework, the core contribution of the Black Sea CONNECT CSA will be to scientifically, technically and logistically support the Black Sea Blue
Growth Initiative towards the implementation of the Burgas Vision Paper, with a view on boosting the blue economy in the region. The overall objective is to coordinate the development of the SRIA and its implementation plan both at national and regional levels. The SRIA and its implementation plan will guide stakeholders from academia, funding agencies, industry, policy and society to address together the fundamental Black Sea challenges, to promote blue growth and economic prosperity of the Black Sea region, to build critical support systems and innovative research infrastructure and to improve education and capacity building. The project will support the design of synergistic activities such as developing an operational network of funders, new transnational joint activities and achieving the knowledge transfer.

Provision of ocean analysis and forecast products for the Black Sea

Project timeline: JAN 2018 – MAR 2021

Black Sea – Monitoring Forecasting Centre (BS MFC) contributes to the development of the COPERNICUS Marine Environment Monitoring Service (CMEMS). It provides regular and systematic information about the physical state of the ocean and marine ecosystems for the Black Sea. The system is based on a numerical ocean model assimilating in-situ and satellite data. BS MFC gathers expertise in the field of ocean analysis and forecast in the Black Sea, brings together knowledge of the regional Black Sea dynamics, and enhances technical links with other CMEMS components and strong connection with the other CMEMS MFCs. Moreover, BS MFC’s objectives include the planning and efficient implementation of systems upgrades. BS MFC provides marine data about the Black Sea such as analysis and 10 days forecasts and reanalysis, describing waves, currents, temperature, salinity, sea level and biogeochemistry. HZG is responsible for the Waves Physics Production Unit, including synergy between model and observational data as well assimilation of newly available data. HZG is also involved in coupling of waves and circulation models and system evolution.

WAVE2NEMO contributes to the development of the COPERNICUS Marine Environment Monitoring Service (CMEMS). It specifically aims at improving the coupling of the ocean model system to wave models. The target areas are the North Sea, the Baltic Sea and the Mediterranean Sea. The main objectives of the project are:
• Further development of the NEMO ocean model and the forcing which will explicitly include the effect of waves from wave models on the upper ocean dynamics;
• Providing software for additional parameters which have to be exchanged between waves and hydrodynamic models,
• Improved validation methods by retrieved wave information from satellite data and in situ platforms (buoys, moorings, HF radars, etc.);
• Demonstrating the interaction of waves and currents at small scales both in the ocean interior as well as near the shoreline.
Most of the CMEMS target fields - marine safety, marine resources, marine environment and forecasting – will directly benefit from the proposed R&D work proposed here. Thus, it could be expected that the project will make connections to CMEMS in order to support the future production of more consistent ocean-marine weather information including on surface waves, which is often requested by users.

About the ESM project

The ESM project started on 1 April 2017 partly funded by the Helmholtz Association over a period of three years. The project comprises eight Helmholtz Research Centers and aims to improve the representation of the components of the Earth system and their coupling, as well as to perform a series of selected numerical experiments to address Grand Challenges (Frontier Simulations). A long-term strategy for the development of an Earth System Modelling capacity is also an objective of the project.

Human societies are facing grand challenges, which are expected to become even more prominent during the next decades – with climate change, availability of food, clean water and geoenergy resources being just some examples. In order to address these grand challenges, the scientific community needs to develop tools that provide decision makers with the information required to effectively manage these issues.

Earth system modelling is such a tool, as it enables investigating problems in an integrated manner considering interactions between different Earth system compartments and across scales – from local to global scales, and from weather time scales to millennia and beyond.

The ultimate goal of the project is to develop, evaluate and apply a world-leading Earth system modelling infrastructure —leading into an Earth System Simulator— to provide solutions to grand challenges faced by the Earth and environmental sciences.
Scientific and technical activities—the Scientific-technical Core—lie at the heart of the project. These include Earth System Model Development (WP1), the establishment of Earth System Data Assimilation (WP2) capacity as well as the development of an Earth System Diagnosis (WP3) framework. It is this Scientific-technical core, which will be developed into the first version of the “Earth System Simulator” in PoF-IV. In order to push existing boundaries in numerical experimentation, Frontier Simulations will be carried out in WP4. These “community” simulations will contribute to solving some of the grand challenges faced by the Earth and environmental sciences. At the same time, these simulations serve as demonstrations of the capability of the Earth system model infrastructure. The scientifically focussed work will be flanked by a Strategic Development component (WP5) that will lead into a long-term Earth system modelling strategy as well as a concrete implementation plan for PoF-IV.

DWD Vertrag

Within the framework of further improvements of the community wave model WAM and the atmospheric model ICON, a detailed comparison between the roughness lengths obtained by WAM and ICON provides profound insight whether the use of the more realistic WAM roughness lengths over sea would be able to improve the operational weather forecast system of the German Met Service (DWD: Deutscher Wetterdienst). That presents a first step into the development of a future coupled system between ICON and WAM. Furthermore several new integrated wave parameters will be included in the official output list of the wave model WAM which are up to three different swell systems instead of a total swell only and the energy and momentum fluxes into the ocean that are required for coupling purposes with hydrodynamic models.
The contract is funded by the DWD.

DEC 18 – NOV 22

IMMERSE – Improving Models for Marine EnviRonment SErvices

The overarching goal of the IMMERSE project is to ensure that the Copernicus Marine Environment Monitoring Service (CMEMS) will have continuing access to world-class marine modelling tools for its next generation systems while leveraging advances in space and information technologies, therefore allowing it to address the ever-increasing and evolving demands for marine monitoring and prediction in the 2020s and beyond. In response to the future priorities for CMEMS, IMMERSE will develop new capabilities to: - enable the production of ocean forecasts and analyses that exploit upcoming high resolution satellite datasets, - deliver ocean analyses and forecasts with the higher spatial resolution and additional process complexity demanded by users, - exploit the opportunities of new high performance computing (HPC) technology – allow easy interfacing of CMEMS products with detailed local coastal models. These developments will be delivered in the NEMO ocean model, an established, world-class ocean modelling system that already forms the basis of the majority of CMEMS analysis and forecast products. Hence the pathway from the research in IMMERSE to implementation in CMEMS will be simple and seamless, as the model code developed will be directly applicable in CMEMS models. NEMO has a long track record of producing and maintaining a stable, robustly engineered code base of the type that is needed for operational applications, including CMEMS. The IMMERSE consortium combines world-class expertise in ocean modelling, applied mathematics and HPC, established software engineering processes and infrastructure, and in-depth knowledge of the CMEMS systems and downstream CMEMS systems. Thus IMMERSE is exceptionally well placed to deliver the operationalquality model code required to meet the emerging needs of CMEMS, and maintain it into the future. HZG contributes to IMMERSE by demonstrating the impact of NEMO and CMEMS evolution on downstream case studies related to coastal processes in the German Bight.