NinoSstdiversity
Computes the interquartile range (IQR) of the distribution of zonal location of the maximum sea surface temperature anomalies (SSTA) in the equatorial Pacific (meridional 5°S-5°N average) during boreal winter (December value smoothed with a 5-month triangular-weighted moving average)
TropFlux 1979-2018 (main)
ERA-Interim 1979-2018, HadISST 1870-2018
Niño3.4, equatorial Pacific
model and observations regridded toward a generic 1°x1° grid (using cdms esmf linear method)
- seasonal cycle removed
- detrending (if applicable)
- smoothed with time running average
- spatial average
- seasonal cycle removed
- detrending (if applicable)
- smoothed with time running average
- regridding (if applicable)
- meridional average
- smoothed with zonal running average
- detect December Niño3.4 SSTA > 0.75std
- detect the zonal location of the maximum SSTA during all El Niño peak (December)
- compute interquartile range (IQR) of the distribution of location
- abs((model-ref)/ref)
monthly
% of error
sea surface temperature (SST)
The first level shows the diagnostic used to compute the metric and highlight the difference between the model and the reference.
Figure 1: width of zonal location of the maximum SSTA during all El Niño, showing the "diversity" of El Niño events (usually smaller than the reference). The black and blue markers show respectively the reference and the model. The metric derived is the absolute value of the relative difference: abs((model-ref)/ref).
The second level shows the distribution of zonal location of the maximum SSTA during El Niño peak: the ENSO diversity.
Figure 2: distributions of zonal location of the maximum SSTA during La Niña (left) and El Niño (right), showing usually a too wide distribution for La Niña and too narrow for El Niño and for both type of events the distributions are shifted eastward. The black and blue boxplots show respectively the reference and the model, the left and right panels show respectively La Niña distributions and the El Niño distributions. Boxplots: whiskers extend to the 10th and 90th percentiles; boxes encompass the 25th and 75th percentiles; and a diamond marks the mean. La Niña (El Niño) events are defined when December Niño3.4 SSTA (December value smoothed with a 5-month triangular-weighted moving average) is below -0.75 (above 0.75) standard deviation.