surface, at 500m depth (that corresponds to the 6th layer in the model) and at 1000m depth (that corresponds to 9th or 10the layer). At the depth of 500m and 1000m in the model and in the obseration, it is seen that the warm water in the western Pacific Ocean at 20N and in the southern Ocean south of 40S migrate toward the equatorward and southern hemispheric Indian and Pacific Oceans become warmer, while Atlantic warm water in the southern ocean moves northward from spring through autumn to winter. The annual cycle of the model temperature anomaly shows strong barotropic nature from the depths of 5500m to 1000m.
Warn temperature anomaly in the Atlantic southern hemisphere propagates northward along western boundary and warm temperature anomaly in the western Pacific propagate toward the equatorward through the Indonesian sea into the Indian Ocean.
3b Seasonal variation of the Indo-Pacific Throughflow
In this study, the volume transport of the Indonesian throughflow is defined as the vertically integrated volume transport across the zonal sectin of 10S, bounded by the Greater Sunda Islands (Indonesia) to Australia. Since horizontal resolution in the Indonesian Sea is too coase to resolve Lombok strait and Makassar strait, The maximum depth of the connecting channel is about 2000m and its width is more than 500km at the depth of in this model(Fig. 7). As shown in the vertcal section of meridional velocity in January and in July, the southward flow in January is strongly barotropic and is concentrated along the Greater Sunda Islands (Figure 7). In July northward current between 900m and 2100m with maximum velocity of 2.5 cm/sec near the sea bottom is found at 10 5, and it flows northward to gain barotropic nature at 2 5 in the eastern half of Banda strait (Figure 7, and Figure 9).
Figure 8 shows the meridional component of the layer velocity along 10S between 123E and 132E. The meridional components of the mixed layer and the second layer are consistent with the existing simulation and observation results: the throughflow shows maxium values of layer averaged velocities of about 9-10 cm/sec. The volume transport of the mixed layer shows maxium value of 15 SV in August and minimum value of about 1 Sv in February. Since the bottom of the second layer is situated at about 200m from the surface, it is speculated that these flow may exhibit the surface pressurelevel gradient as demonstrated by Wyrtki [1987].
The vertically integrated volume transport from the mixed layer to the 7 the layer situated at about 450m shows maximum value of about 205V in August and minimum value of 135v in February. This is consistent with the existing simulation with differnt models [Masumoto,1995; Miyama et al., 1996]. The velocities from the 3rd layer to 10th layer show no coherent feature to those of the mixed layer and of the second layer, indicating that these layer may be controled by differnt mecahnism than the mixed layer and the second layer. Moreover, the flow in the
