Geoscience Reference
In-Depth Information
(1% level),
0.41 (5% level) with
AIR and PIR. Succeeding November, December, and DJF TCI (C-N) show
negative CCs of
−
0.42 (2% level),
−
0.38 (5% level), and
−
0.39 (5% level).
As far as antecedent relationships are concerned, TCI (C-N) of February
shows strong and significant negative CCs of
0.48 (1% level),
0.37 (5% level), and
−
−
−
0.50 (1% level) with AIR,
−
−
0.38 (5% level) with PIR, while April
TCI (C-N) shows significant negative CCs of
0.42 (2% level) with NWR, and
−
0.38 both at
5% level with AIR and PIR. Thus, February TCI (C-N) appears to be a
potential predictor for AIR, NWR, and PIR.
For TCI (I-N), it is found that concurrent JJA shows significant
negative CCs of
−
0.39 and
−
0.37 (5% level) with PIR.
In addition, significant negative CCs are also obtained between concurrent
July TCI (I-N) and AIR (CC =
−
0.43 at 2% level) and PIR (CC =
−
0.39
at 5% level) and September TCI (I-N) with PIR (CC =
0.39 at 5% level with AIR and
−
−
0.36 at 5% level).
Succeeding DJF TCI (I-N) shows significant negative CCs of
−
0.61 (0.1%
−
level) with AIR and NWR and
0.57 (0.1% level) with PIR. For antecedent
relationship, Table 1 shows significant negative CCs of
−
0.39 (5% level)
with January TCI (I-N) and NWR. The antecedent May TCI (I-N) shows
significant CCs of 0.46 at 1% level and 0.39 at 5% level with AIR and PIR.
From the above analysis, it appears that May TCI (I-N) has some
potential as a predictor for long-range forecasting of Indian summer
monsoon rainfall over AIR and PIR. The strong and significant inverse CCs
between TCI (I-N) of succeeding DJF suggest that a strong (weak) summer
monsoon rainfall activity is followed by unusually high (low) pressure over
northwest India and unusually low (high) pressure over Mascarene High
during the following winter months.
Considering TCI (I-M), Table 1 shows significant negative CC of
−
0.36
(5% level) between concurrent TCI (I-M) JJA and AIR. TCI (I-M) of
August shows significant negative CCs of
−
−
0.51 (1% level) with AIR,
−
0.49
(1% level) with NWR, and
0.41 (5% level) with PIR. Succeeding DJF
−
shows negative CCs of
0.57
(0.1% level) with AIR, NWR, and PIR, respectively. Significant relationship
(CC =
0.61 (0.1% level),
0.64 (0.1% level), and
−
−
−
0.40 at 5% level) is also found between antecedent TCI (I-M) DJF
and NWR. In addition, significant negative CCs are also obtained between
antecedent TCI (I-M) of January and AIR (CC =
−
0.37 at 5% level) and
−
NWR (CC =
0.50 at 1% level).
To examine the consistency of significant TCI relationships, the CCs
of different months for the sliding 25-year periods have been recomputed
during the period 1953-1982. Stability analysis has been done only for
−
