Metocean Models for the Shipping Industry, Explained

Meteorological and oceanographic models (metocean models) help experts forecast the conditions in the atmosphere and ocean over the coming hours, days, and weeks.

 

Metocean models use a coordinate system to map the earth onto a geospatial grid of latitude and longitude coordinates. This mapping includes properties like elevation, land-use, and the depth of water in oceans, seas, or lakes. Different models have different use-cases. For example, a spectral wave model­ uses wind, ice and current, and bathymetric data to predict waves on each cell of the grid.

"MeteoGroup provides tailored metocean forecast and historical datasets at any desired resolution and area on the globe. For that purpose, we make use of a new cloud infrastructure that enables us to respond to customer requests quickly. We owe ourselves to provide the best quality datasets, assessed against both our own station observation network (including public observations) and customer observation data."

- Dr Hugo Hartman
Senior Meteo Scientist

 

 By using the coordinate system to map the earth onto a grid, metocean models can be used by the experts to provide:

 

● Analyzed metocean conditions: these are the actual environmental state and latest observations for a specific point in time.

 

● Forecasted metocean conditions: these follow the analyzed conditions and are usually provided in the coming hours or days (though, in individual cases, it can be weeks or months ahead).

 

External Metocean models: What You Need to Know

 

External metocean models offer a range of different datasets. Weather companies will buy specific datasets, depending on their requirements. External metocean model data is a key component of your weather forecast. Data from the models contributes to long-term forecasts. In shipping, for example, this information is used by companies during planning to determine the intended route for a voyage, within the constraints of the likely conditions.

External metocean models also support near real-time monitoring of the weather. This insight is essential for companies to keep voyages on schedule, prevent damage to assets, and keep the crew safe.

But the data from the external models alone is not enough. A specialist weather company will advise you on how to use the model data. Plus, you can understand how to avoid bad decisions made when using misinterpreted model output data. A specialist weather company will offer several key benefits, including:

● (Statistical) multi-models approaches, enhancing data from external providers;

● Ensemble forecasts that aggregate 50 scenarios for probabilistic forecasting and estimate risk and confidence to the forecasts; and

● Two- or three-year archives of model forecasts.

 

In-House Metocean Modelling: What You Need to Know

 

External datasets, which are readily available in the market, are a valuable part of the forecaster's toolkit. However, they are just part of the puzzle. For example, wave spectra from ECWMF (an external model provider) are available every 3 to 6 hours.

But this might not be the required temporal resolution for your specific use case. In-house models can provide a higher resolution with insights for every hour - or even intra-hourly. Or  provide spatial resolution down to hundreds of meters.

"Modeling is both an art and a science. Where science delivers the empirical formula that forms the basis of the models themselves, it is up to the metocean modeler to simplify the complex world into an optimal configuration that ensures maximum quality while using as little resources as possible."

-Sander Hulst
Senior Oceanographic Researcher

 

What is the difference between external and in-house metocean models?

 

External models are purchased datasets. In-house models are custom configurations, which allow experts to select source terms (physical equations) and grid resolutions for particular use cases. To translate global data to your specific area of interest, the experts nest one or more feature-resolving grids in regional grids and then the regional grids in the global grids. This is called physical downscaling, an alternative to statistical downscaling.

 

How do the experts create a numerical metocean model?

 

Reliable forecasts are essential but complicated to produce. Taking the example of a specific oceanographic / wave model, we can see how the experts both produce the model and apply it to real-life situations.

To provide an accurate forecast in challenging locations, it often requires the development of in-house models using an innovative approach. Off the coast of Belgium, sandbanks can cause high or long waves to break early or induce waves to bend. These sea conditions make it harder to predict wave height, which is a real challenge. In the past, forecasts at the Belgian coast have been up to half a meter off because global wave models do not account for the sandbanks

By coupling atmospheric forcing with in-house wave models, the in-house model not only looks at the conditions at sea but also incorporates the atmospheric winds that drive the waves.

Furthermore, it includes detailed tidal information, a prerequisite when working in shallow water. The model was calibrated both with local observations (in-situ) and remote sensing data.  The model runs on a cloud-based High-Performance Cluster. This approach ensures there's always enough computing power for it to run and new models can be set up for any desired site around the world.

 

What is the added value of in-house metocean models for shipping companies?

 

Different models have different strengths. Where a coarse model is set up to perform well in the deep ocean, a more detailed model is required closer to shore.

The advantage of in-house modeling means different models can be coupled: the output from one becoming the input for another. For instance, a regional WAVEWATCHIII model can be fed surface wind data computed by a regional WRF domain, of which both receive boundary conditions from a global grid.

Shipping companies, that need to plan operations in marginal weather conditions, benefit from specific in-house models and combinations. In the case of near shore locations, a SWAN model, run on a high-resolution grid, can take spectral wave data from the regional WAVEWATCHIII, surface winds from WRF, tidal data from harmonic components, and ocean circulation data from Mercator, to accurately capture the wave-current interactions over complex seafloor features. The resulting dataset provides unique insights into current and future conditions.   


What to learn more about shipping related topics? Visit our Shipping Knowledge Base now.

Visit Shipping Knowledge Base

MeteoGroup provides tailored metocean forecast and historical datasets at any desired resolution and area on the globe. For that purpose, we make use of a new cloud infrastructure that enables us to respond to customer requests quickly. We owe ourselves to provide the best quality datasets, assessed against both our own station observation network (including public observations) and customer observation data.

- Dr Hugo Hartman
Senior Meteo Scientist