Marine Ecosystems Research Department - jamstec japan agency ...
Marine Ecosystems Research Department - jamstec japan agency ...
Marine Ecosystems Research Department - jamstec japan agency ...
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Japan <strong>Marine</strong> Science and Technology Center<br />
Frontier <strong>Research</strong> System for Global Change<br />
provide realistic initial conditions for adequate prediction<br />
and also useful re-analysis datasets for accurate<br />
estimation of ocean circulation processes.<br />
a. Coupled Model Development<br />
a-. Future Climate Change Projection Using a High-<br />
Resolution Coupled Ocean-Atmosphere Climate<br />
Model<br />
The aim of this project is to conduct a series of future<br />
climate change projection experiments using a high-resolution<br />
coupled ocean-atmosphere climate model on the<br />
Earth Simulator. The project team consists of members<br />
of Center for Climate System <strong>Research</strong> of the<br />
University of Tokyo (CCSR), National Institute for<br />
Environmental Studies (NIES), and Frontier <strong>Research</strong><br />
System for Global Change (FRSGC).<br />
For the high-resolution future climate change projection,<br />
we have targeted the following spatial resolution<br />
of the model:<br />
<br />
T spectral truncation (approximately .˚) in horizontal<br />
and levels in vertical for the atmospheric part<br />
<br />
.˚ .˚ in horizontal and levels in vertical<br />
for the oceanic and sea-ice part<br />
With this atmospheric resolution, regional-scale climatic<br />
features such as Baiu front and tropical cyclones<br />
can be represented. The oceanic resolution should be<br />
higher so that the model can reproduce realistic temporal<br />
variation of sea-surface height and the complex ocean<br />
current system in the northern North Atlantic and the<br />
Arctic Oceans, which is critically important to reproduce<br />
the North Atlantic Deep Water (NADW) realistically.<br />
Further details are referred to the report of the project<br />
in this volume.<br />
a-. Improvement of Physical Processes in Climate<br />
Models<br />
(i) Development of new radiation scheme<br />
So far there has been no unique method applicable<br />
to treat any overlapping of bands on radiative transfer<br />
calculation when we require both high accuracy and<br />
computational efficiency. After examining several possible<br />
schemes, it is found that only one scheme is not<br />
sufficient to treat all overlapping bands with the same<br />
accuracy. Therefore we develop an optimized scheme<br />
to obtain k-distribution parameters for overlapping<br />
bands by combining completely uncorrelated, perfectly<br />
correlated and partly correlated schemes.<br />
By use of this newly developed scheme, calculations<br />
of radiative flux and atmospheric heating/cooling rate<br />
were performed and the results were compared with<br />
corresponding results of the LBL calculations for six<br />
model atmospheres (Tropical, Midlatitude summer and<br />
winter, Subarctic summer and winter and the US<br />
Standard Atmosphere). The results are shown in Fig.<br />
P (mb)<br />
0.1<br />
1<br />
10<br />
1E+2<br />
a<br />
TRO<br />
CKD<br />
LBL<br />
Error<br />
1E+3<br />
-12.0 -8.0 -4.0 0.0 4.0<br />
Heating Rate (K/d)<br />
P (mb)<br />
0.1<br />
1<br />
10<br />
1E+2<br />
c<br />
CKD<br />
LBL<br />
Error<br />
CKD<br />
LBL<br />
Error<br />
-0.2 0.2<br />
-0.4 0.0 0.4<br />
Error (K/d)<br />
1E+3<br />
-12.0 -8.0 -4.0 0.0<br />
Heating Rate (K/d)<br />
P (mb)<br />
0.1<br />
1<br />
10<br />
1E+2<br />
e<br />
MLW<br />
SAW<br />
1E+3<br />
-12.0 -8.0 -4.0 0.0<br />
Heating Rate (K/d)<br />
P (mb)<br />
0.1<br />
1<br />
10<br />
1E+2<br />
1E+3<br />
b<br />
P (mb)<br />
0.1<br />
1<br />
10<br />
1E+2<br />
d<br />
MLS<br />
CKD<br />
LBL<br />
Error<br />
-12.0 -8.0 -4.0 0.0<br />
Heating Rate (K/d)<br />
CKD<br />
LBL<br />
Error<br />
CKD<br />
LBL<br />
Error<br />
-0.2 0.2<br />
-0.4 0.0 0.4<br />
Error (K/d)<br />
1E+3<br />
-12.0 -8.0 -4.0 0.0<br />
Heating Rate (K/d)<br />
-0.2 0.2<br />
-0.4 0.0 0.4 -0.2 0.2<br />
-0.4 0.0 0.4<br />
Error (K/d)<br />
Error (K/d)<br />
-0.2 0.2<br />
-0.4 0.0 0.4<br />
Error (K/d)<br />
P (mb)<br />
0.1<br />
1<br />
10<br />
1E+2<br />
1E+3<br />
f<br />
SAS<br />
USS<br />
-12.0 -8.0 -4.0 0.0<br />
Heating Rate (K/d)<br />
-0.2 0.2<br />
-0.4 0.0 0.4<br />
Error (K/d)<br />
Fig.18 The comparison of heating rates for four transmission<br />
schemes to those of LBL model. Black solid line represents<br />
LBL results; the dashed lines with different colors<br />
represent errors of the four schemes to LBL results. (a)<br />
H 2 O, CO 2 and O 3 (630-700cm -1 ); (b) H 2 O, N 2 O and CH 4<br />
(1200-1350cm -1 ); (c) H 2 O, CO 2 and O 3 (940-1200cm -1 ); (d)<br />
H 2 O and CH 4 (3900-4540cm -1 ).<br />
135