East Asia and Western Pacific METEOROLOGY AND CLIMATE

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filtered from model because it can assumed as » high -
frequency noise" in comparing with the low frequency air -
sea/land interaction waves which are just what we are to
forecast in the time scale of one month or more.
According to above two basic ideas first suggested by
Chao et al., an anomalous atmosphere - ocean/land coupled
filtered model (AFM) has been developed. Recently, eight
examples of monthly forecasts during the winter months in
1976 - 1977 and 1982 - 1983 El Nino events have been
performed. Their correlation coefficients between
observations and predictions as well persistences of
monthly prediction are listed in Table 1. On the average,
the prediction of both surface temperature and height
fields are superior to the persistences. The predictions
(shown in chart (a)) of the anomalous surface temperature
and SOOhPa height fields for March 1977 are illustrated in
Fig. 1 and Fig. 2 resperctively. For the sake of making
comparison, the observations (shown in chart(b)) are also
given in the figures.
In the meanwhile, the seasonal forecasts for the
winter months 1976 - 1977 and 1982 - 1983 El Nino events
also completed. The results show in Table 2(figures
omitting) . As shown in the Table 2, it can be seen that
the seasonal forecasts in the sense of average are
promising, that means the AFM to have the potential
ability in predicting the seasonal anomalies of
large - scale circulations.
2. TELECONNECTIONS OF THE SST IN THE TROPICAL OCEAN WITH
THE 500 hPa GEOPOTENTIAL HEIGHT IN THE NORTHERN
HEMISPHERE
In recent years, many authors are interested in the
influences of the tropical SST anomalies upon the global
atmospheric circulation. Some examples have been
illustrated in this section in order to show AFM having
the capability in studying this kind of teleconnection.
The correlation between SST in the Indian Ocean (83*E
- 91 ° E, 5 ° N - 15*N) and 500 hPa GPH anomalies in the
Northern Hemisphere is. given in Fig.3. It can be seen in
Fig. 3, that there exists positive correlation in the
regions of lower and higher latitudes, while negative
correlation mainly emerges in middle latitudes* The
teleconnections also studied by using AFM based on the
fact mentioned above. Fig.4 describes the teleconnection
map of 500 hPa GPH in the Northern Hemisphere with the
heating source in the Indian Ocean (83*E - 91°E, 5 N° -15*
N) . Some interesting finding from Fig. 4 is that the
anomalous perturbations of 500 hPa GPH in the Northern
Hemisphere are spiral wave structure which is independent
with the positions of heating sources.