EnsoSstMapJja
Computes the spatial root mean square error (RMSE) of global (60°S-60°N) surface temperature anomalies (TSA) during boreal summer (JJA averaged) between model and observations
ERA-Interim 1979-2018 (main)
TS: 20CRv2 1871-2012, NCEP2 1979-2018
Niño3.4, global60
model and observations regridded toward a generic 1°x1° grid (using cdms esmf linear method)
- seasonal cycle removed
- detrending (if applicable)
- spatial average
- seasonal cycle removed
- detrending (if applicable)
- regridding (if applicable)
- JJA Niño3.4 SSTA regressed onto JJA TSA global (60°S-60°N)
- RMSE computation
monthly
°C/°C
surface temperature (TS)
The first level shows the diagnostic used to compute the metric and highlight the main differences between the model and the reference.
Figure 1: structure of surface temperature anomalies (TSA) on Earth (between 60°S-60°N), showing the location of TSA associated with ENSO. Usually the teleconnection pattern is ok (rmse ~ 0.25°C/°C). The left and right maps show respectively the reference and the model. The main metric derived is the spatial RMSE between the model map and the reference map.
The second level shows the same diagnostic with La Niña (norm. December Niño3.4 SSTA < -0.75) and El Niño (norm. December Niño3.4 SSTA > 0.75) events composites.
Figure 2: structure of surface temperature anomalies (TSA) on Earth (between 60°S-60°N), showing the location of TSA associated with La Niña (top) and El Niño (bottom). It shows that teleconnections are not totally symmetric (e.g. northeastern Pacific ocean & USA). It also shows that some model biases are more related to one phase of ENSO than the other: here the teleconnection biases over eastern Europe and the USA are more related to too weak teleconnections during La Niña.
The Third level focusses on teleconnections over key land regions: southern half of Africa, North America, South America, South East Asia, Australia.
Figure 3: surface temperature anomalies (TSA) over the southern half of Africa. The reference shows a positive teleconnection almost everywhere (reaching 1°C/°C over Somalia) but over southwestern South Africa. Here, the model simulates a positive teleconnection everywhere and it is generally too strong south of the equator. The left and right maps show respectively the reference and the model.
Figure 4: same as Figure 3 with La Niña (norm. December Niño3.4 SSTA < -0.75) and El Niño (norm. December Niño3.4 SSTA > 0.75) events composites.
Figure 5: surface temperature anomalies (TSA) over North America. The reference shows a negative teleconnection (up to -0.8°C/°C) over most of the USA and Canada, and positive teleconnections over British Colombia (up to 0.5°C/°C) and Mexico (up to 1°C/°C). Here, the model simulates negative teleconnection that does not extend enought west and the its amplitude is everywhere divided by a factor of two. The left and right maps show respectively the reference and the model.
Figure 6: same as Figure 5 with La Niña (norm. December Niño3.4 SSTA < -0.75) and El Niño (norm. December Niño3.4 SSTA > 0.75) events composites.
Figure 7: surface temperature anomalies (TSA) over South America. The reference shows a strong positive teleconnection over southern South America (Argentina, southern Brazil, Paraguay, Uruguay) reaching 1°C/°C. Here, the model simulates a too weak positive teleconnection over southern South America. The left and right maps show respectively the reference and the model.
Figure 8: same as Figure 7 with La Niña (norm. December Niño3.4 SSTA < -0.75) and El Niño (norm. December Niño3.4 SSTA > 0.75) events composites.
Figure 9: surface temperature anomalies (TSA) over South East Asia. The reference shows a positive teleconnection over India (up to 0.6°C/°C), and a negative teleconnection over eastern China (up to -0.4°C/°C). Here, the model reproduces poorly the observed pattern, with negative teleconnections over southern India, the Indochinese peninsula and Borneo island and no teleconnection over eastern China. The left and right maps show respectively the reference and the model.
Figure 10: same as Figure 9 with La Niña (norm. December Niño3.4 SSTA < -0.75) and El Niño (norm. December Niño3.4 SSTA > 0.75) events composites.
Figure 11: surface temperature anomalies (TSA) over Australia. The reference shows three poles of teleconnections: positive (both up to 0.3°C/°C) over western and eastern (up to 0.5°C/°C) Australia and negative over northwestern Australia (both up to -0.5°C/°C). Here, the model rather simulates a dipole with negative teleconnection over the northern half of Australia and positive teleconnection over central and southeastern Australia. The left and right maps show respectively the reference and the model.
Figure 12: same as Figure 11 with La Niña (norm. December Niño3.4 SSTA < -0.75) and El Niño (norm. December Niño3.4 SSTA > 0.75) events composites.