Chapter 23
FORECASTING THE DRIFT
OF OBJECTS AND SUBSTANCES IN THE
OCEAN
Bruce Hackett, Øyvind Breivik, and Cecilie Wettre
Norwegian Meteorological Institute, Oslo, Norway
Abstract
Forecasting the drift of floating objects, ships and oil spills is an important ocean application. Most nations support services for ship safety,
oil spill combatment and search-and-rescue, all of which may benefit
from drift forecasts. Examples from Norwegian services are discussed.
The models for drifting things themselves are founded on hydrodynamic
principles (ship drift), empirical parameterizations (floating objects)
and oil-water chemistry. An overview of these models is given. All
the drift models share a crucial reliance on geophysical forcing data. In
operational services, these data are obtained from weather, wave and
ocean forecast models. Currently, ocean forecasts are the component
with greatest scope for improvement. Effective interfacing of drift forecasting services to the users - the emergency response services - is vital
for obtaining optimal benefit from the forecasts.
Keywords: Oil spill, search and rescue, ship drift, ocean forecasting.
1.
Introduction
Ocean forecasting is founded on the operational prediction of the
prognostic variables in hydrodynamic models: water level, temperature,
salinity and currents. While these variables are essential for describing
the state of the ocean, they are in themselves of limited interest outside
of the scientific community. Most people are not concerned with, for
example, tomorrow’s forecast for surface current 2 km out to sea - even
those who reside on the coast. Of more interest to public is how these
physical variables affect other things in the ocean. In the case of currents, there is considerable interest in how various things in the ocean
507
E.P. Chassignet, Jacques Verron (eds.), Ocean Weather Forecasting, 507-523.
© 200 Springer. Printed in the Netherlands.
6
FORECASTING THE DRIFT
OF OBJECTS AND SUBSTANCES IN THE
OCEAN
Bruce Hackett, Øyvind Breivik, and Cecilie Wettre
Norwegian Meteorological Institute, Oslo, Norway
Abstract
Forecasting the drift of floating objects, ships and oil spills is an important ocean application. Most nations support services for ship safety,
oil spill combatment and search-and-rescue, all of which may benefit
from drift forecasts. Examples from Norwegian services are discussed.
The models for drifting things themselves are founded on hydrodynamic
principles (ship drift), empirical parameterizations (floating objects)
and oil-water chemistry. An overview of these models is given. All
the drift models share a crucial reliance on geophysical forcing data. In
operational services, these data are obtained from weather, wave and
ocean forecast models. Currently, ocean forecasts are the component
with greatest scope for improvement. Effective interfacing of drift forecasting services to the users - the emergency response services - is vital
for obtaining optimal benefit from the forecasts.
Keywords: Oil spill, search and rescue, ship drift, ocean forecasting.
1.
Introduction
Ocean forecasting is founded on the operational prediction of the
prognostic variables in hydrodynamic models: water level, temperature,
salinity and currents. While these variables are essential for describing
the state of the ocean, they are in themselves of limited interest outside
of the scientific community. Most people are not concerned with, for
example, tomorrow’s forecast for surface current 2 km out to sea - even
those who reside on the coast. Of more interest to public is how these
physical variables affect other things in the ocean. In the case of currents, there is considerable interest in how various things in the ocean
507
E.P. Chassignet, Jacques Verron (eds.), Ocean Weather Forecasting, 507-523.
© 200 Springer. Printed in the Netherlands.
6