Download - Recent S/I Prediction Activities at IRI
Recent S/I Prediction Activities at IRI
IRI Climate Predictability Tool (CPT)
• Simon Mason
What is CPT?
Climate Predictability Tool (CPT) is an easy-to-use Windows-based
software package for making downscaled seasonal climate forecasts.
It runs on Windows 95+. A
source code version,
which has no GUI or any
of the graphics
capabilities, is available for
other platforms.
What is CPT?
Specifically, CPT is designed to produce statistical forecasts of seasonal
climate using either the output from a GCM, or fields of sea-surface
temperatures.
The program
provides extensive
tests indicating
forecast
performance.
Comparison of Coupled and Uncoupled Simulations on Simulation of Indian Monsoon
Precipitation
• Andrew Robertson
• Vincent Moron
• David DeWitt
correlations (%) with CPC GSOD daily rainfall amount
1980–2003
coupled uncoupled
Effect of Coupling on Simulated Indian Summer Monsoon
Effect of Coupling on Simulated Indian Summer Monsoon
correlations (%) with CPC GSOD 1980–2003
coupled uncoupled
obs daily rainfall frequency
AGCM-Based Coupled Modeling at IRI
• Initial Coupled System:– ECHAM4.5-MOM3 Fully Coupled
COLA (Kirtman, Min) Provides ODA
Documented in:
Schneider et al. (2004)
DeWitt (2004)
DeWitt (2005)
DeWitt, Goddard, Li (In Preparation)
Issues with Initial Forecast System
• ODA and OGCM are run at 2 different resolutions• ODA has large salinity drift due to mistreatment of
fresh water flux • ODA system not parallel and historic records are not
set up for operational usage.• Not apparent that direct coupling is best approach
despite fact that it is methodology employed by all operational centers
• Open question whether OGCM based systems are best tool to use for S/I forecasting– Computationally Expensive– Large systematic errors even in ocean only integrations
(diffuse thermocline)
Development Path for Next Coupled Models
AGCM- ECHAM4.5
Ocean Models:
MOM4 –
Postdoc (Galanti)
New postdoc (to be hired)
KKZ – Multi-mode reduced gravity model
LDEO (State Dependent Bias Corrected Models)
CZ(K) ocean
INC ocean
MOM4
Thermodynamic Ocean Models (Donna Lee)
Enhanced Predictive Skill by Selective Coupling
• Dong Eun Lee
• David DeWitt
NCEP/NCAR ReanalysisEnsemble mean ECHAM 1st month lead forecast
Feedback Parameters
(Wm-2K-1)
ECHAM forecast 24 ensemble
Ocean Mixed LayerFixed MLD at mean annual cycle (Levitus94)
Climatological dynamics through flux correction
Seager ATM
SSTLatent, sensible heat fluxesand long wave radiation
surface wind velocity,cloud fraction
Off-line SST prediction model
wind stressesfor Ekman effects
1st mon Lead 1st mon Lead
Seager heat flux