EnsoSstMapDjf
Computes the spatial root mean square error (RMSE) of global (60°S-60°N) surface temperature anomalies (TSA) during boreal winter (DJF 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)
- DJF Niño3.4 SSTA regressed onto DJF 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 ~ 0.23°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. East Africa, southeastern South America, USA). It also shows that some model biases are more related to one phase of ENSO than the other: here the teleconnection bias over the Indian Ocean and USA are more related to too strong 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 (more than 1°C/°C) over southern Africa (South of 15°S) and a small negative teleconnection (up to -0.5°C/°C) over eastern Africa (Kenya). Here, the spatial teleconnection pattern is quite well simulated but the positive teleconnection over southern Africa is too weak (around 0.5°C/°C). 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 positive teleconnection (up to 1°C/°C) over Canada and a negative teleconnection (up to -0.5°C/°C) over Mexico and the south of the USA. Here, the model simulates a pattern close to the observed one but the negative teleconnection is too strong and extends too far north and east, and the over positive teleconnection is too weak and too far north over Canada. 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 around the Amazon river and in Colombia (both reach more than 1°C/°C), and a negative teleconnection (around -0.4°C/°C) over southern South America (Uruguay & Argentina). Here, the model simulates a pattern close to the observed one but the teleconnections are too weak (divided by two) and the negative teleconnection over southern South America does not reach the southern end of the continent. 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 in India, Indochinese peninsula, Indonesia (up to 0.4°C/°C), and a negative teleconnection over southwestern China (up to -0.4°C/°C). Here, the model simulates a pattern close to the observed one but the positive teleconnection India and the Indochinese peninsula is too strong by a factor of two. 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 positive teleconnections over this region with maxima western and eastern Australia (both up to 1°C/°C). Here, the model simulates a too strong teleconnection centered in the middle of 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.