Correlation coefficient between current anomalies and optimal structure
The current (for JJA ) projection of the tropical IndoPacific SSTA pattern onto the optimal structure is -0.027 .
Penland and Sardeshmukh (1995) have shown how this optimal initial structure, obtained from Linear Inverse Modeling applied to COADS SST anomaly data
a)
precedes a mature El Niño or La Niña event by about 7 to 9 months.
b)
(a) The optimal initial structure for sea surface temperature anomaly growth. Pattern is normalized to unity; contour interval = 0.035. Areas with loadings greater than 0.035 are red; dashed lines indicate negative contours. (b) Predicted pattern when (a) is used as an initial condition.
That this sequence of patterns does indeed occur in nature is verified by comparing the time series of SSTA anomaly in Niño 3.4 (6N-6S, 170W-120W) (blue line) with that of the pattern correlation between the optimal structure and the corresponding SST anomaly pattern eight months earlier (red line). Vertical line shows the beginning of independent forecast for Real-time Surface Marine data. For each time series plot, the corresponding scatter plot is also given, along with ONE standard deviation of scatter from best fit line. Red asterisk denotes the current Niño 3.4 SST anomaly value and the pattern correlation of the optimal structure with the SST anomaly pattern eight months before. Arrow denotes value of current projection onto the optimal structure.
COADS data + Real-time Surface Marine:
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