Marine Ecosystems Research Department - jamstec japan agency ...

JAMSTEC 2002 Annual Report
Frontier Research System for Global Change
our understanding of the effects of solar radiation on
the terrestrial carbon cycle, and provides a critical foundation
for satellite-based monitoring of PAR and modeling
of the global carbon cycle.
d. Marine Biological Process Model Group
We have evaluated the effects of global climatic and
environmental changes on biological process such as
productivity in the ocean. We also have examined that
possible feedback to the global environments through
changes in the ocean carbon cycles resulted from the
ecosystem changes. Especially, we aim at discovering
the functional relationship of the lower trophic level
ecosystem change in the North Pacific to the recent
global climate variation.
During FY , we observed signals of alteration of
physical, chemical, and biological environments of the
water column in one of the world's most productive
regions, the Oyashio Water in the western subarctic
North Pacific from s to s. We found increased
a) conventional view
wind stress
solar radiation
month Jan. Feb. Mar. Apr. May. Jun. Jul.
fresh water inflow
Phytoplankton bloom
50m
100m
150m
b) novel view
wind stress
solar radiation
month Jan. Feb. Mar. Apr. May. Jun. Jul.
fresh water inflow
50m
100m
150m
Critical Depth
Mixed Layer Depth
Critical Depth
Mixed Layer Depth
Nutrient concentration
Fig.17 Physical/chemical/biological processes from winter to
spring in the Oyashio Water: comparison of the conventional
view a) and novel view b).
density gradient between surface and subsurface waters
that curbed the vertical mixing of seawater during this
period. Consequently, not enough nutrients from the
deeper ocean were supplied to diatoms. The biomass of
spring zooplankton, as an indicator of the secondary production,
was also decreased (Figure ). On the other
hand, looking only at wintertime, production of diatoms
was enhanced due to a stable, shallow mixed layer with
sufficient nutrients, which may be the result of an
increased wintertime food availability to Neocalanu spp
and that caused earlier maturity of these species.
6. Integrated Modeling Research Program
The mission of the Program is to develop "new" climate
models, global environmental models and ocean
data assimilation systems to be run on the world's fastest
"Earth Simulator" which was completed in March .
The following are the current targets of development :
(i) Spectral atmosphere model with a horizontal resolution
T and layers in the vertical, world ocean
model with . horizontal resolution and layers in
the vertical, and a coupled A-O GCM consisting of
the two. An objective is to carry out long-term global
warming experiments for oceans that contain eddies.
(ii) Atmosphere model with a horizontal mesh size of
km or less by which tropical cloud clusters and
other meso-scale atmospheric systems can be represented
explicitly. Similarly, eddy resolving world
ocean models are being developed as the coordinate
system to cover the globe cubic-grid and incosahedral-grid
(quasi-uniform grids) are adopted.
(iii) Development of models to include new elements
such as aerosols' effects on clouds, or the global carbon
cycle, on the basis of currently existing climate
models cooperating with other research programs.
(iv) In addition to the above described model development,
ocean data assimilation systems are also being
developed in this program. Four-dimensional variational
data assimilation systems, which incorporate
satellite and in-situ observational data into numerical
models, are the target of development. These can
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