East Asia and Western Pacific METEOROLOGY AND CLIMATE

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specifically at the modeling and predicting of climate
phenomena on time scales of months to years. It is a large
scale air-sea interaction climate program. Underlying the TOGA
program is the premise that the dynamic time scale of the
tropical oceans are far more rapid than that at higher
latitudes. Thus, disturbances emanating from the Western
Pacific Ocean may propagate to the eastern basin on the time
scale of weeks compared to years for corresponding propagation
at higher latitudes. The significance of the higher frequency
dynamic time scales in the tropical ocean is that they are
similar to those of highly energetic atmospheric modes. This
similarity allows the formation of coupled modes between the
ocean and the atmosphere in the tropics.
The specific goals and scientific objectives of the TOGA
program are (WCRP, 1985):
( i) To gain a description of the tropical oceans and the
global atmosphere as a time dependent system in order
to determine the extent to which the system is
predictable on time scales of months to years and to
understand the mechanisms and processes underlying its
predictability;
(ii) To study the feasibility of modeling the coupled
ocean-atmosphere system for the purpose of
predicting its variations on time scales of months to
years; and,
(iii)To provide the scientific background for
designing an observing and data transmission
systems or operational prediction, if this
capability is demonstrated by coupled oceanatmosphere
models.
The TOGA program began on January 1, 1985 and is planned
to last for at least ten years. From the TOGA large scale
monitoring and process studies, there has been significant
progress in identifying many of the important physical
processes driving the coupled ocean atmosphere system. Areas
where there appear to be substantial progress and
understanding include:
o
On ENSO time scales, the Pacific Ocean is
predominant. Oceanic disturbances appear to extend
from the western Pacific warm pool along the
equator to the east. The disturbed sea surface
temperature of the Pacific Ocean so alters the
large scale heating of the tropical atmosphere that
the basic circulation of the tropical atmosphere on
the largest scale is perturbed.