2007 Annual Report - jamstec japan agency for marine-earth ...

~ 40 km ~ 20 km ~ 10 km
Fig.5
The sea surface height variability in centimeters. The solid line shows streamline through Drake Passage.
large scale ocean circulation. In this region, mesoscale eddies
may play important role in the formation of the intermediate
water. Three horizontal resolutions of 10, 20, and 40 km are
used for this investigation. Figure5 shows the SSH variability
evaluated as the root-mean-square of SSH. This variability represents
the strength of eddy activities. For the 40 km case, the
SSH variability is relatively weak. Since the deformation
than the 40 km case and 34.5 salinity water spreads along the 0
=27.1 surface up to about 500 m depth. For the 10 km case, the
34.5 salinity water, which is subducted along the 0 =27.1 surface,
reaches more than 1400 m depth. Although the spreading
of the salinity is still somewhat weak even for the 10 km case
compared with the climatology salinity distribution, it is much
better than the low resolution cases.
radius is about 20 km at a latitude 54S, it seems that mesoscale
eddies are not resolved well. For the 20 km case, the variability
increases significantly from the 40 km case. The variability is
high in the equatorward flank of the ACC, especially on the
northern boundary of the ACC. The variability is large in the
Argentine Basin and the Agulhas Retroflection region. For the
10 km case, the intensity of the variability reaches about 50 cm
in the Brazil-Malvinas Current confluence and the Agulhas
Retroflection region. Figure6 shows the vertical section of
salinity at 30 W. For the 40 km case, low salinity water is not
transported downward along the 0 =27.1 surface. The 34.5
salinity water reaches only about 400 m depth. For the 20 km
case, the low salinity water is transported downward deeper
2Development of an Integrated Earth System Model for
Predication of Global Environmental Changes
a. Long-term climate change projection with an integrated earth
system model
Using the integrated earth system model, we have calculated
future CO 2 emission pathways allowable to achieve CO 2 stabilization
at 550 ppm and 1000 ppm around year 2300 i.e.,
SP550 and SP1000. It has been confirmed that, when one
takes into consideration the possible feedback between climate
and carbon cycle, necessary reduction of CO 2 emission is severer
than it is when one does not Fig.7. It turned out that the
terrestrial carbon cycle saturates rather quickly and cannot act
~ 40 km
~ 20 km ~ 10km
Fig.6
Vertical section of salinity at 30 W. The vertical axis indicates depth in kilometers. The red line denotes 0 =27.1 isopycnal.