WORLD METEOROLOGICAL ORGANIZATION ________________________ INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION (OF UNESCO) ________________________ JOINT WMO/IOC TECHNICAL COMMISSION FOR OCEANOGRAPHY AND MARINE METEOROLOGY (JCOMM) EXPERT TEAM ON MARINE ACCIDENT EMERGENCY SUPPORT ETMAES-I/Doc. 3.3(2) (17.I.2007) __________ ITEM 3.3 FIRST SESSION ANGRA DOS REIS, BRAZIL, 29 TO 31 JANUARY 2007 Original: ENGLISH Support for Accidental Marine Pollution and Search and Rescue at the Norwegian Meteorological Institute (met.no) (Submitted by Mr Bruce Hackett and Mr Øyvind Breivik from the Norwegian Meteorological Institute (met.no)) Summary and Purpose of Document This document contains a report from the Norwegian Meteorological Institute (met.no) that aims to describe its support for Accidental Marine Pollution and Search and Rescue (SAR) operations. ACTION PROPOSED The Expert Team on Marine Accident Emergency Support (ETMAES) is invited to note and comment on the information provided, as appropriate, and generally to take it into account when discussing relevant agenda items. ______________________ ETMAES-I/Doc. 3.3(2), p. 2 DISCUSSION 1. Introduction 1.1 The Norwegian Meteorological Institute (met.no) has a national responsibility for weather and ocean forecasting in Norwegian waters. The responsibilities extend to the support of Marine Pollution Response (including oil spill fate and algal bloom forecasting), and to Search and Rescue (SAR) operations. Norway has taken on the role of MSI Coordinator for NAVAREA XIX, and has offered to take the responsibility as Coordinating Issuing Service for the corresponding METAREA XIX; met.no will carry out the responsibilities for the latter. METAREA XIX corresponds to the Arctic waters north of 71° N on MPI Area I. 1.2 Responsibility for forecast support to oil spill fate and search and rescue activities are carried out by met.no's Forecasting Division for Western Norway (VV), located in Bergen. Development of models and the forecasting systems is supported by the met.no Research and Development Department, located in Oslo. 2. Geophysical forcing data 2.1 Forecasting the drift of oil and objects, as well as algal blooms, is founded on forcing data from operational models for the atmosphere, ocean circulation and waves. The goal is to apply the best available forcing data for a given area and time span. Given the complicated terrain and rugged coastline, much effort is expended on developing fine-scale models that can resolve the topographic features. For atmospheric forecasting, the HIRLAM and Unified Model (UM) codes are run at met.no at various resolutions from 20 km (for Europe and the Arctic), down to 1-4 km (for Norway proper). Lateral boundary conditions are obtained from the ECMWF. The met.no-produced data are supplemented by ECMWF data for forecasting beyond 60 hours ahead. For ocean circulation, met.no runs the MIPOM code operationally on a range of nested domains. A coupled ocean-ice model is run for the North Atlantic and Arctic Oceans at 20 km resolution. The main source of ocean data is the Nordic4 domain, a 4 km grid covering the North and Nordic Seas (see Figure 1). This model is nearly eddy-resolving, and will be coupled with an ice model for operational forecasting in 2007. Higher resolution domains covering selected regions of the Norwegian coast are nested in Nordic4. For lateral boundary conditions, data are obtained from global and basin-scale systems, such the UK FOAM, the French Mercator and the Norwegian TOPAZ. For waves, the WAM code is applied on two domains: a large scale model for the North Atlantic and Nordic Seas at 45 km resolution, and a Nordic Seas mode at 10 km resolution. Lateral boundary forcing is obtained from the ECMWF global WAM. Figure 1: Nordic4 model domain. Met.no runs the MIPOM 3D hydrodynamic code on this domain with 4 km grid ETMAES-I/Doc. 3.3(2), p. 3 intervals. Model runs are performed daily to produce forecasts of sea level and 3D currents, temperature and salinity to +60 hours. Color shading shows bathymetry. 3. Drift forecast services 3.1 Met.no maintains three drift models to support marine emergency response: 1.) an oil spill fate model, 2.) a model for surface drifting objects, and 3.) a model for ship drift. Technically speaking, there are strong similarities between the models as well as the services for which they are used. Therefore, the models are implemented in such a way that they share a common user interface and dependence on a common processor for geophysical forcing data. Furthermore, all three models are based on a “particle” representation of the object or substance, so that the main difference lies in the particular characteristics of the particles. Met.no has cooperated with leading centers of expertise on oil weathering and drift characteristics for floating objects, in an effort to attain state-of-the-art models. Oil spill fate model (OD3D) 3.2 Met.no's oil spill model system OD3D calculates the drift and chemical evolution of surface and sub-surface oil in the guise of a cloud of "superparticles", each of which represents a certain amount of oil or its by-products. The model is three-dimensional and features a novel deep source module for handling, for example, bottom blowouts. It has been developed in cooperation with SINTEF Chemistry (Trondheim, Norway). At present, over 60 different oil types are implemented in the weathering module. The model is started by a user request and returns a prognosis in the form of a time series of characteristics for each superparticle. The OD3D is driven by ocean data (3D currents, temperature and salinity), atmospheric data (surface winds) and wave data (Stokes drift), which are obtained from a variety of real-time or archive sources, steered by the forcing processor. Drifting objects model (LEEWAY) 3.3 The LEEWAY model simulates the drift of floating objects, and is aimed particularly at supporting search and rescue operations. The model has been developed in cooperation with the U.S. Coast Guard, who have provided leeway (“windage”) characteristics for an extensive taxonomy of object types. In order to give the operational user an estimate of the uncertainty of the predictions, the drifting object is represented by a cloud of particles, where the initial distribution of the cloud is determined by the uncertainty in the last known position (location and time) of the lost object. Furthermore, each particle is subjected to random fluctuations in drift. The cloud representation is very similar to the representation of oil in OD3D, and the geophysical forcing data are applied in the same manner. For LEEWAY, only surface currents and winds are required. Ship drift model 3.4 The model for ship drift is closely-related to the LEEWAY model, the main difference being the size of the object with respect to the length of the dominant surface waves. For large floating objects - “ships” - wave effects become important for the drift velocity. In analogy with the leeway characteristics of small objects, the hull characteristics of a ship are required to model the ship drift. Met.no has cooperated with Det norske Veritas (Høvik, Norway), who provide hull characteristics and wave effect algorithms for the ship drift model. At present, the ship drift model calculates a single drift trajectory, but the implementation of Monte Carlo ensemble methods is under development. Geophysical forcing data are surface currents, surface winds and wave spectra, which again are obtained through the forcing processor. Forcing processor 3.5 Over the past few years, met.no has recognized the similarities between the three drift ETMAES-I/Doc. 3.3(2), p. 4 models described above, all of which were developed over the years as autonomous computer programs. An effort is underway to isolate the application-specific algorithms (oil weathering, leeway and ship drift) and to let them share the same methods for accessing geophysical forcing data. Development of a forcing processor has been an ongoing activity, supported by the Mersea Integrated Project (EU DG Enterprise). 3.6 The aim of the forcing processor is to provide a variety of available forcing data sets from met.no and external operational models. Weather and wave forecast data for regional and global scales are taken from met.no and the ECMWF. Ocean forecast data are obtained from several sources, including met.no (for national services) and Mersea providers (see Figure 2). A default list of prioritized sources is maintained and checked for availability when a simulation is requested. An additional facility will allow the user to select specific forcing data sets (e.g., in order to assess the sensitivity to forcing). Climatological ocean data from Mersea will be a component of the ocean forcing data, to be used as a fall-back in cases when operational sources fail and for making rough forecasts beyond 10 days ahead. Figure 2: Schematic of data sources for the ocean forcing data processor for emergency drift models at met.no. Accessed data include 3D currents, temperature and salinity. 3.7 Mersea operational ocean data: Currently, two types of access are being tested: daily delivery by ftp from MetOffice FOAM and NERSC TOPAZ, and on-demand access to the Mersea forecast TEPs’ (Thematic Portal) OpenDAP servers (cf. Figure 2). The daily delivery method has the advantage of being quickly accessible and allowing nested operational models at met.no. The disadvantages are storage and fixed geographical coverage. The Mersea TEPs offer a range of data from shelf to global scales with a fairly consistent method of access. The TEPs can be queried to determine what data are available at any time, and the data fetch can be limited to just what is needed. The main disadvantage of the TEP OpenDAP service is that the data products placed there are not optimal for many oil spill applications (e.g., only daily means). User interface 3.8 The user enters information in web order forms which are accessed from a common webpage (see example for oil spill in Figure 3). The order is submitted to a met.no server where it is checked for consistency and given a unique identification. A simulation is then set up and run, usually completing within a few minutes. The user can monitor the progress of the simulation and view setup and log files. The models output their results in standard forms that may be filtered to user-specified formats. Results may be delivered to the user as email attachments or as downloads from the webpage. In addition, results are stored in an internal ETMAES-I/Doc. 3.3(2), p. 5 format for viewing with met.no's graphical display tool DIANA (see http://met.no/diana/). This allows the duty meteorologists to immediately view results in combination with other environmental information, in order to provide expert advice to the user. It also facilitates display of the results in a web mapping service client operating on the same web site as the order form, thus enabling users with a web browser alone (see Figure 4). Figure 3: Screen shot of web page at met.no showing an order form for oil spill fate forecasts at right (grey panels). Menu at upper left shows common portal for three drift models (oil, leeway, ship drift) along with access to simple visualization via a web mapping service (WMS) client. Access to the web page is restricted to registered users. Figure 4: Screen shot of web page at met.no showing simple presentation of oil spill fate simulation using a WMS client. _____________