Geoscience Reference
In-Depth Information
4. Impacts of the Pacific-Indian Ocean Temperature
Anomaly Mode on Asian Climate Systems
Figure 7 shows the composite of 100 hPa geopotential height for positive and
negative phases (1954, 1955, 1964, 1970, 1988, and 1996 with the composite
index less than or equal to 2.5) of PIM. The South Asian high is weaker
and stretches eastward and southward for the positive phase. In contrast,
the South Asian high is stronger and stretches westward and northward for
the negative case.
Figures 8(a) and 8(b), respectively, show the composites for positive
and negative phases of PIM at 500 hPa. In the case of positive phase, the
contour of 5860 gpm of the western Pacific subtropical high is shifted to
the coast areas of Fujian Province. The contour of 5880 gpm is found over
the western Pacific to the east of Taiwan. During the year of negative
phase, the contour of 5860 gpm retreats to the east of Taiwan Island. We
cannot find the contour of 5880 gpm. So the PIM can influence the intensity
and the longitudinal position of the western end of the western Pacific
subtropical high.
(a) (b)
Fig. 7. The composite of 100 hPa geopotential height for positive (a) and negative
(b) phases.
(a) (b)
Fig. 8. The composite of 500 hPa geopotential height for positive (a) and negative
(b) phases.
