S.-Y. Simon Wang, Lawrence Hipps, Robert R Gillies,(Utah State U) &
J.-H. Yoon (PNNL)
Fire and Ice California drought and "polar vortex" with
the changing climate
2013-14: A TWO-FACE WINTER
2013-14 winter
normal
geopotential height @ 250 hPa
anomaly
X anomaly
the “dipole”!
Not an isolated event!
X
one-point correlation map
geopotential height @ 250 hPa
SST
X
2013-14 El Nino
“Precursor”
El Nino “Precursor”
X
optimal pattern
PMM WNP SPMM
What’s an El Nino Precursor?
IndO
NPO
wait till Wed morning.
ENSO precursor Nino#(Y+1)
correlation with Nino4 (Y+1)
Function of the ridge
W/m^2
Wave flux (250 hPa)
OLR
NDJ 2013-14
W/m^2
Wave flux (850 hPa)
OLR
evolution
active convection
WNP
Composite for one year before an El Nino
ENSO Precursor - has it changed?
1951-1979
1980-2008
Forecasting CESM large ensemble (x30)
WNP composite:
CCSM4 (x6)
WNP composite:
CCSM4 (x6)
WNP composite:
greenhouse gas (GHG)
natural forcing (NAT) Attribution
1 yr before
El Niño
1 yr before
El Niño (simulated)
GHG
NAT
OBS
1 yr before
El Niño
GHG
NAT
Z250 anomalies
OBS X X
X X
X X GHG
OBS
NAT
Sliding correlation:
dipole vs. Nino4(Y-1)
GHG
NAT
X X
18 models
X X
El Nino Precursor
El Nino Precursor
Dipole’s 30-yr running variance
CMIP5 projection
Looking ahead
Kim et al. (2014)
X X
♨ ️
Arctic forcing?
- well developed water markets - modernize irrigation infrastructure - clear water entitlements
vs.
PDSI
Ground- water
sliding correlation
Oct 2013 SSTA
teleconnection
1 yr before
El Niño
“Dipole”
CMIP5 performance on ENSO precursor
Spatial correlation of SSTA