on the north pacific reduced skill in near-term climate predictions of sea surface temperatures
DESCRIPTION
On the North Pacific reduced skill in near-term climate predictions of sea surface temperatures. Virginie Guemas With the collaboration of : Francisco Doblas-Reyes, Fabian Lienert, Hui Du, Yves Soufflet. Our focus : Seasonal to decadal prediction. Francisco J Doblas-Reyes : The Head - PowerPoint PPT PresentationTRANSCRIPT
Climate Forecasting Unit
On the North Pacific reduced skill in near-term climate predictions of
sea surface temperatures
Virginie Guemas
With the collaboration of : Francisco Doblas-Reyes, Fabian Lienert, Hui Du, Yves Soufflet
Climate Forecasting Unit
Francisco J Doblas-Reyes : The Head
Hui Du : Initial perturbations, sea ice
Javier García-Serrano : AMO, African monsoon
Virginie Guemas : Sea ice, North Pacific skill
Fabian Lienert : regionalisation, PDO
Melanie Davis : climate services
Danila Volpi : initialisation techniques
Luis Ricardo Rodrigues : ENSO, statistical models
Aida Pintó : extremes
Muhammad Asif : EC-Earth
Oriol Mula-Valls : system administrator
Domingo Manubens : autosubmit developer
Our focus : Seasonal to decadal prediction
We share, on request :
1) Autosubmit
2) Our decadal hindcasts
3) Monthly sea ice restarts
4) R diagnostic functions
We run on :
1) Marenostrum ( Spain )
2) ECMWF
3) HECTOR ( Scotland )
4) Lindgren ( Sweden )
5) Our local cluster
Climate Forecasting Unit
On the North Pacific reduced skill in near-term climate predictions of
sea surface temperatures
Virginie Guemas
With the collaboration of : Francisco Doblas-Reyes, Fabian Lienert, Hui Du, Yves Soufflet
Climate Forecasting Unit
The climate prediction exercise
Fig. 2 of Meehl et al. (2009, BAMS)
Climate Forecasting Unit
Nov 60 Nov 65 Nov 70 Nov 75 Nov 80 ...
Multi-model ensemble system with coupled initialized GCMs
Model 1 Model 2 Model 3 Model 4 Model 5 Model 6
Leadtime = 10 years
Obs
The climate prediction exercise
Climate Forecasting Unit
Multi-model ensemble system with coupled initialized GCMs
Model 1 Model 2 Model 3 Model 4 Model 5 Model 6
Nov 60 Nov 65 Nov 70 Nov 75 Nov 80 ...
Obs
Leadtime = 5 years
The climate prediction exercise
Climate Forecasting Unit
Model 1 Model 2 Model 3 Model 4 Model 5 Model 6
Leadtime = 2-5 years
Obs
Multi-model ensemble system with coupled initialized GCMs
Nov 60 Nov 65 Nov 70 Nov 75 Nov 80 ...
The climate prediction exercise
Climate Forecasting Unit
Model 1 Model 2 Model 3 Model 4 Model 5 Model 6
Leadtime = 2-5 years
Obs
Multi-model ensemble system with coupled initialized GCMs
Nov 60 Nov 65 Nov 70 Nov 75 Nov 80 ...
The climate prediction exercise
Climate Forecasting Unit
Model 1 Model 2 Model 3 Model 4 Model 5 Model 6
Leadtime = 2-5 years
Obs
Multi-model ensemble system with coupled initialized GCMs
Nov 60 Nov 65 Nov 70 Nov 75 Nov 80 ...
The climate prediction exercise
Climate Forecasting Unit
CERFACS UKMO IFM-GEOMAR
ECMWF DePreSys EC-Earth
2m atmospheric temperature skillCorrelation modelled and ERA40 T2M. Leadtimes : 2-5 years
Climate Forecasting Unit
CERFACS UKMO IFM-GEOMAR
ECMWF DePreSys EC-Earth
Correlation modelled and ERSST SST. Leadtimes : 2-5 years
Sea Surface Temperature skill
Climate Forecasting Unit
Correlation between multi-model ensemble-mean and ERSST SST
Sea Surface Temperature skill
Climate Forecasting Unit
CERFACS UKMO IFM-GEOMAR
ECMWF DePreSys EC-Earth
Which major events are missed ?Sea Surface Temperature anomalies (155°E-235°E, 10°N-45°N)
Climate Forecasting Unit
Outline
Links with well-known variability modes ?
Mechanism explaining the 1963 event
Mechanism explaining the 1968 event
Possible cause for the failure of forecasting systems
Climate Forecasting Unit
Outline
Links with well-known variability modes ?
Mechanism explaining the 1963 event
Mechanism explaining the 1968 event
Possible cause for the failure of forecasting systems
Climate Forecasting Unit
Two major warmings in the North Pacific Ocean in
1963 and 1968
Da Silva et al. (1994) turbulent
Da Silva et al. (1994) total
OAFluxes turbulent
ERSST
Sea Surface Temperature anomalies (155-235°E 10-45°N )
Upward surface heat fluxes anomalies (155-235°E 10-45°N )
155-235°E 10-45°N
Climate Forecasting Unit
No links with the main modes of variability
http://www.esrl.noaa.gov/psd/data/climateindices/
Monthly values
12-month running mean
Climate Forecasting Unit
Outline
Links with well-known variability modes ?
Mechanism explaining the 1963 event
Mechanism explaining the 1968 event
Possible cause for the failure of forecasting systems
Climate Forecasting Unit
1963: 3-dimensional structure of the anomaly
Pattern of ERSST anomalies (155-235°E 10-45°N )
NEMOVAR temperature anomaly profile (180-205°E – 35-45°N)°C
Climate Forecasting Unit
1963: advection of the anomaly
Hoevmuller ERSST anomalies ( 35°N-45°N latitude band)
NEMOVAR backward trajectories computed with ARIANE
ARIANE ( http://stockage.univ-brest.fr/~grima/Ariane/)
April 1963November 1960
°C
Climate Forecasting Unit
1963: modulation of the amplitude by mixing
Hoevmuller ERSST anomalies ( 35°N-45°N latitude band) °C
NEMOVAR climatological mixed layer depth ( 35°N-45°N ) m
Climate Forecasting Unit
Outline
Links with well-known variability modes ?
Mechanism explaining the 1963 event
Mechanism explaining the 1968 event
Possible cause for the failure of forecasting systems
Climate Forecasting Unit
1968: 3-dimensional structure of the anomaly
Pattern of ERSST anomalies (155-235°E 10-45°N ) °C
NEMOVAR temperature anomaly profile (170-235°E – 10-35°N)
Climate Forecasting Unit
1968: upward transfer of the anomaly
NEMOVAR temperature anomaly profile (170-235°E – 10-45°N)
Climate Forecasting Unit
1968: amplification by the atmosphere forcing
Wind speed anomalies (170-235°E, 10-35°N)
DFS4.3NCEP
NEMOVAR temperature anomaly profile (170-235°E – 10-45°N)
Climate Forecasting Unit
Outline
Links with well-known variability modes ?
Mechanism explaining the 1963 event
Mechanism explaining the 1968 event
Possible cause for the failure of forecasting systems
Climate Forecasting Unit
Stratification in the Pacific Ocean
NE
MO
VA
R-C
OM
BIN
EC
ER
FA
CS
IFM
-GE
OM
AR
EC
-Earth
v2
FMA mixed layer depth (density criteria) in m
Climate Forecasting Unit
Conclusion
North Pacific region = region of lowest skill in near-term climate predictions ( 2- 5 years )
Major warm events around 1963 and 1968 missed by every forecasting systems = main cause for the low skill
1963 : heat anomaly advected along the Kuroshio-Oyashio and confined to an increasingly thinnner mixed layer
1968 : deep heat anomaly transferred toward the surface and then amplified by the atmospheric noise
Biases in the Pacific ocean stratification could be responsible for the failure of the forecasting systems
Climate Forecasting Unit
Thanks for your attentionThanks for your attention
[email protected]@ic3.cat