Background
The Proudman Oceanographic Laboratory, part of the
Natural
EnvironmentResearch Council , conducts world-class research
in:
- estuary, coastal and shelf sea circulation & ecosystem
dynamics
- wind-wave dynamics and sediment transport
- global sea level and geodetic oceanography
- marine technology and operational oceanography
The Problem
Simulation of the marine environment is becoming increasingly
important to a wide range of human activity including coastal
engineering, offshore industry, fishery management, pollution
monitoring, climate forecasting and leisure. Sustainable management
of coastal environments requires an ability to predict a system
which is mobile in three dimensions on a wide range of space and
time scales.
The Challenge
The development and execution of a coupled model required
efficient linking of the hydrodynamic model to the ecosystem model
and the re-casting of all parts of the code into a parallel format
such that the resulting coupled model would run at 1km resolution
on a large enough area in a reasonable time.
While models have existed for hydrodynamic and for
biogeochemical simulation, no coupled model had previously been
available. Marine plant variation is becoming potentially hazardous
and harmful algal blooms ('red tides') are well known and
widespread. In this study a coupled hydrodynamic-ecosystem model is
developed and applied to the simulation of seasonal variation in
algal blooms around the UK coast.
The Solution
Working with the Proudman Oceanographic Laboratory, the
Daresbury experts were able to construct parallel algorithms which
enabled their existing hydrodynamic code (POLCOMS) to link
efficiently to the European Seas Ecosytem Model (ERSEM) and to
perform successful simulations at 1km resolution using Daresbury's
high performance computer HPCx. The coupled code overcame the
difficulties in linking disparate phenomena by using a 3D
hydrodynamic model to provide realistic physical forcing to
interact with, and transport, environmental parameters. By
integrating from ocean to coast the simulations were able to
determine biological production and the fate of contaminants. Area
plots of the time evolution of surface chlorophyll levels were
carried out successfully for 12 day periods in the months of April
and July.
The Benefits
- The customer was able to simulate important marine ecosystem
phenomena on a major scale and at high resolution for the first
time
- Computational capability was delivered to the customer in terms
of code conversion to parallel operation, model coupling and
hardware architecture, saving compute time and costs
- A validated model for coastal modelling is now available which
can be routinely applied to predict potentially harmful
phytoplankton levels. This is of great importance in maintaining
marine water quality for a wide variety of commercial activities
from food chain security to leisure safety assurance