Torill Hamre

Satellite earth observation in operational oceanography

The role and contribution of satellite data in operational oceanography is reviewed, with emphasis on northern European seas. The possibility to observe various ocean parameters and processes by existing satellite sensors, such as optical instruments, infrared radiometers, passive microwave radiometers, and active microwave systems (altimeter, scatterometer, SAR) is discussed. The basic parameters are: sea-surface temperature observed by infrared radiometers, ocean colour by spectrometers, sea-surface elevation by altimeters, and surface roughness by active and passive microwave systems, which can be used to derive surface wind and waves. A number of ocean processes can be derived from synoptic mapping of the basic parameters of larger sea areas, such as current patterns, fronts, eddies, water mass distribution, and various water quality parameters (chlorophyll, surface slicks, suspended sediments). The suitability of existing satellite data to fulfil the operational requirements for temporal and spatial coverage, data delivery in near-real-time, and long-term access to data is discussed in light of the fact that optical/infrared data in northern Europe are severely hampered by frequent cloud cover, while microwave techniques can provide useful data independent of weather and light conditions. Finally, the use of data assimilation in oceanographic models is briefly summarised, indicating that this technique is under development and will soon be adopted in operational oceanography.

Design and Implementation of a Distributed GIS Portal for Oil Spill and Harmful Algal Bloom Monitoring in the Marine Environment

A web-based distributed system for monitoring and forecasting of the marine environment has been developed in line with INfrastructure for SPatial InfoRmation in Europe (INSPIRE) and Global Monitoring for Environment and Security (GMES) recommendations for a European Spatial Data Infrastructure (SDI). This system, called DISPRO, enables integration and distribution of multi-source data from satellites, aircraft, and in situ instruments, as well as results from numerical models. Geographic data and metadata are stored on a set of distributed computer nodes and retrieved and integrated by a web GIS client by means of Open Geospatial Consortium (OGC) Web Map Server (WMS) technologies. A profile of ISO 19115 was developed for metadata handling, using eXtensible Markup Language (XML) as a platform independent encoding mechanism. DISPRO has been demonstrated in six European coastal zone and ocean regions in the spring and summer of 2005. The overall positive experiences of both service providers and end users indicate that the system should be further developed into an operational GMES service.

Marine SAR Analysis and Interpretation System - MARSAIS

In a marine coastal ocean monitoring and prediction system, multisensor in-situ and remote sensing observations (of coastal currents, fronts, eddies, upwelling patterns, internal waves, phytoplankton distribution, algae patchiness, oil pollution and high-resolution wind fields) need integration and combination with fine resolution numerical ocean models. Only via such integrated systems will realistic representation of the initial state be derived and properly utilized to provide reliable and accurate forecasts of, for instance, location of eddies, upwelling patterns, and high-concentration of toxic algae. The role of sar in such systems is addressed and characterized in terms of current status and further need for research and development. Use of synergetic remote sensing observations, in particular from optical remote sensing, is also considered in this context.

A 4D marine data model: Design and application in ice monitoring

Large amounts of heterogeneous datasets are collected for monitoring and forecasting of environmental phenomena and processes. These data vary in both spatial and temporal resolution, but there is still a demand for integrating them to improve the results of analyses and simulations. We propose a conceptual data model for representation of measured and simulated data at different spatial and temporal scales. An object‐oriented technique has been used to develop this data model, leading to a model that is close to the users view of the data, and flexible with respect to incorporation of new types of data. It is shown how the developed data model can be applied in an ice monitoring system.

Satellite-Based Wind Maps as Guidance for Siting Offshore Wind Farms

Offshore wind farms have started to contribute important supplies of renewable energy. The energy production of a wind farm depends upon the local wind climate and so may be predicted in advance. Usually, the prediction is based on at least one year of accurate wind measurements. Satellite Synthetic Aperture Radar (SAR) wind mapping can be a useful tool in selecting optimal sites and may therefore increase the cost-effectiveness of planning wind farms, e.g., in feasibility studies. In the WEMSAR project1 wind fields from SAR, in situ measurements and model output from three test-sites have been analysed [1]. Subsequently, a WEMSAR tool for effectively retrieving wind data from SAR images and utilising them in the WAsP micrositing model, has been developed. Testing of the WEMSAR tool at Horns Rev offshore wind farm in Denmark is ongoing.

Developing a Marine Information System by Integrating Existing Ocean Models Using Object-Oriented Technology

Information systems developed for different applications within the environmental domain have common characteristics, which can potentially be abstracted for sharing and reuse of design and software modules. This article presents an approach to designing for reuse by abstracting commonalities in the design of a Marine Information System (MIS), facilitating data management in a prototype operational monitoring, forecasting, and management system for the North Atlantic and the Nordic Seas. A detailed study of the requirements and data analysis was carried out, and Object-Oriented Technology (OOT) is employed to encapsulate abstractions and to promote reuse of code and design. This article identifies the Object-Oriented Frameworks (OOFW) required to build the MIS. It also provides guidelines to environmental scientists for restructuring legacy software and employing modern programming techniques.

ICEWATCH-real-time sea ice monitoring of the Northern Sea Route using satellite radar technology

ICEWATCH is the first joint project in Earth observation between Russian Space Agency (RKA) and European Space Agency (ESA). The overall objective of the project is to implement satellite monitoring by combined use of ESA ERS SAR, RKA Okean SLR and other remote sensing data to support ice navigation in the Northern Sea Route (NSR), offshore industry and environmental studies. ERS-1 SAR images have been used in ice monitoring of the NSR in several demonstration campaigns since 1991. The experience from use of SAR data onboard Russian icebreakers to assist in ice navigation is very positive although ERS-1 can only provide data in selected parts of the NSR with a limited swath width of 100 km. In the ICEWATCH project a concept for integrating ERS SAR data in the Russian ice monitoring service is demonstrated where Okean SLR data are included. The system is currently tested in pilot demonstration phase before it is planned to become operational. In addition to data acquisition and interpretation techniques for data integration, ice classification and data transmission techniques have been tested. Also user requirements have been investigated, suggesting that there are many new and potential users of SAR ice information in the NSR. In future other radar satellites will also be used such as ESA ENVISAT which will be launched in 1999. The first results of ICEWATCH were presented at the Second ERS Applications Workshop in London in December 1995.

A review of the possible applications of satellite earth observation data within EuroGOOS

This paper summarise the current and near future marine applications of satellite earth observation (EO) within the five defined modules of EuroGOOS. The conclusions indicate that several applications of EO data are beneficial or even exclusive for efficient information retrieval. The ultimate use of EO data will be most beneficial through an integrated use with field observations, numerical prediction models, using advanced data assimilation techniques. The operationalization of EO data in the EuroGOOS context has perspectives in current applications, near future operational implementation and longer term development, both with respect to development of methods and new sensor technologies.

Offshore wind maps from ERS-2 SAR and wind resource modelling

ERS-2 SAR satellite scenes in PRI format are calibrated and processed into offshore wind maps for a site in the North Sea. The wind direction is retrieved by the two-dimensional Fast Fourier transform method, and the wind direction is used as input to the CMOD-IFR and CMOD-4 scatterometer algorithms for the calculation of wind speed maps. The wind speed maps are regridded to 400 m by 400 m in order to reduce noise. Each of the wind maps are compared to high-quality meteorological in-situ observations collected from a 62 m tall mast located 14 km offshore. The development of offshore wind farms is in rapid growth. In the planning phase of such wind farms, it is important to asses the wind resources. A new wind resource mapping method based on satellite SAR images may prove useful. A pc-software has been developed for applied use and is presented here.

ACOUSTIC MONITORING OF OCEAN CLIMATE IN THE ARCTIC (AMOC).

Abstract The unique combination of the underwater acoustic remote sensing with satellite remote sensing of the ice cover including modelling and data assimilation, in the predicted sensitive climate region of the Arctic Ocean, is perhaps the key solution to monitor global climate changes and early detection of global warming.