SIBER SPIS sept 2011.pdf - IMBER

SIBER
Science Plan and Implementation Strategy
Ap p e n d i x III.
Is s u e s to b e c o n s i d e r e d in SIBER
m o d e l d e v e l o p m e n t
This appendix is based upon recommendations put forward in Appendix III of the ICED Science
Plan and Implementation Strategy (Murphy et al., 2008). SIBER will therefore adopt a strategy
for model development that is consistent with ICED.
One of the first challenges to address is to define the theoretical and technical process required
to model whole ocean biogeochemical cycles and ecosystem dynamics. It is imperative to
identify the main areas and building blocks that will provide the underlying understanding
required to inform and evaluate these models. Some key science areas and associated model
requirements are listed below.
Objective 1: To understand the structure and dynamics of biogeochemical cycles and
ecosystem dynamics in the Indian Ocean and how they might be affected by climate
change and anthropogenic impacts
The development of models of IO biogeochemical cycles and ecosystem dynamics is still at an
early stage and much of the work undertaken to date has been of restricted geographical or
trophic scope. There are major questions regarding the criteria that should be used to develop
realistic models of IO ecosystems. Model development should involve consideration of the
following issues:
1. The development of integrated biogeochemical and ecosystem models must be
done in conjunction with experimental and field studies to provide the basis for model
parameterizations.
2. A range of approaches to food web representation is required, involving models with
different spatial, temporal and trophic complexity. Specific issues include the effects of
horizontal advection of chemical and biological materials (see below) and the effects of
behavioral processes, such as vertical migration of plankton or predator-prey interactions.
The importance of energy transfer from phytoplankton to upper trophic levels in structuring
food webs, and the spatial and temporal resolution required for coupling lower trophic
level models with those developed for top predators are important issues, as are regional
differences and the links between benthic and pelagic systems, particularly in coastal
regions.
3. The development of coupled physical-biological models will require close collaboration
with physical modeling groups. As a basis for SIBER modeling efforts physical models
that provide outputs relevant to the scales of operation of the biological processes under
consideration are required, for example such models may include: basinwide atmosphereocean
models (e.g. OFAM/BLUElink), coupled models for key regions of the IO, such as the
AS, the BoB, the equatorial zone, and the Leeuwin and Agulhas Current systems, and high
resolution mesoscale (10s-100s km) models of shelf and cross-shelf, island and frontal
regions and processes.
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