EnsoSeasonality
ENSO_seasonality: ratio of boreal winter over spring's standard deviation of SST anomalies in the central equatorial Pacific
Computes the ratio of winter (NDJ, maximum variability in the observations) over spring (MAM, minimum variability in the observations) standard deviation of central equatorial Pacific sea surface temperature anomalies (SSTA; horizontal Niño3.4 average)
TropFlux 1979-2018 (main)
20CRv2 1871-2012, ERA-Interim 1979-2018, ERSSTv5 1854-2018, HadISST 1870-2018, NCEP2 1979-2018
Niño3.4
None
- seasonal cycle removed
- detrending (if applicable)
- spatial average
- standard deviation of Niño3.4 SSTA during NDJ over MAM
- abs((model-ref)/ref)*100
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: ratio of winter over spring's standard deviation of sea surface temperature anomalies (SSTA) in the central equatorial Pacific (Niño3.4 averaged), showing the seasonal timing of SSTA (usually weaker than observed, meaning that ENSO occurs too frequently during spring in the models; here slightly too strong seasonal timing). 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)*100.
The second level shows the mean annual structure of the ENSO amplitude: the 12 months standard deviation of the anomalies.
Figure 2: mean annual structure of the standard deviation of the sea surface temperature anomalies (SSTA) in the central equatorial Pacific (Niño3.4 averaged), showing usually a too weak variability in winter and too strong in spring (here the variability is too weak during both winter and spring). The black and blue curves show respectively the reference and the model.
The third level shows the spatio-mean annual structure of the ENSO amplitude: the Hovmöller of the standard deviation of anomalies in the equatorial Pacific.
Figure 3: spatio-mean annual structure structure of the standard deviation of sea surface temperature anomalies (SSTA) in the equatorial Pacific (5°S-5°N average), showing usually a too weak variability off South America and too strong variability in the central Pacific during string, a too weak variability in the central-eastern Pacific during winter, and a too strong variability all year long west of the dateline (here the seasonal timing of ENSO is roughly respected but the the variability is too strong in the central Pacific during autumn). The left and right maps show respectively the reference and the model.
The fourth level shows the zonal structure of the ENSO amplitude during winter and spring: the standard deviation of the anomalies along the equator in the Pacific.
Figure 4: zonal structure of the standard deviation of the sea surface temperature anomalies (SSTA) in the equatorial Pacific(5°S-5°N average) during winter (red curves) and spring (blue curves), showing usually a too weak variability in the central-eastern Pacific and too string west of the dateline during winter and too weak variability off South America and too strong everywhere else during spring (here the zonal structure of the ENSO amplitude is quite good but the variability is too weak off South America during both seasons. The dashed and solid curves show respectively the reference and the model.
The second level shows the broader picture to better understand the spatial pattern of ENSO amplitude during winter and spring: the map of the standard deviation of anomalies in the equatorial Pacific.
Figure 5: spatial structure of the standard deviation of sea surface temperature anomalies (SSTA) in the equatorial Pacific, showing usually a too weak variability off South America and too strong variability west of the dateline during both seasons, a too strong (weak) variability in the central equatorial Pacific during spring (winter) (here the variability is also too weak off South America during both seasons and the variability is too strong but not spread enough in latitude in the central Pacific during winter). The left and right maps show respectively the reference and the model. The first and second rows show respectively boreal winter and spring.