Current Subseasonal-to-Seasonal Prediction System and On-going Activities at NASA’s Global Modeling and Assimilation Office Myong-In Lee, Siegfried Schubert, Max Suarez, Randy Koster, Michele Rienecker, and David Adamec Global Modeling and Assimilation Office Earth Sciences Directorate Workshop on monthly-to-seasonal climate prediction Taipei, Taiwan October 2003

Global Modeling and Assimilation Office NASA/GSFC GMAO Merger of NSIPP and the DAO Science areas: Subseasonal-to-Seasonal-to-Decadal Prediction Weather prediction Chemistry-climate connections Hydrological Cycle Technical areas: satellite data assimilation: usage, new mission design, instrument team products Agency Partnerships: NOAA/NCEP, JCSDA, ESMF, NCAR, GFDL, NOAA/CDEP Merger of NSIPP and the DAO Science areas: Subseasonal-to-Seasonal-to-Decadal Prediction Weather prediction Chemistry-climate connections Hydrological Cycle Technical areas: satellite data assimilation: usage, new mission design, instrument team products Agency Partnerships: NOAA/NCEP, JCSDA, ESMF, NCAR, GFDL, NOAA/CDEP

The GMAO/NSIPP Forecast/Analysis System

NSIPP CGCMv1 Forecast Ensembles 12 month Coupled Integrations: 19 ensemble members AGCM (AMIP forced with Reynolds SST) Ocean DAS (Surface wind analysis from R. Atlas, Reynolds SST, Temperature profiles by TAO) Ocean state estimate perturbations:  ’s randomly from snapshots Atmospheric state perturbations:  ’s randomly from previous integrations AGCM: NSIPP1 AGCM, 2 x 2.5 x L34 LSM: Mosaic (SVAT) OGCM: Poseidon v4, 1/3 x 5/8 x L27, with embedded mixed layer physics CGCM: Full coupling, once per day ODAS: Optimal Interpolation of in situ temperature profiles - daily, salinity adjustment (Troccoli & Haines), Jan1993-present, starting in every month

Ensemble mean precipitation and ground temperature anomalies forecast for NDJ 2003 Rienecker, Suarez, et al. GSFC/GMAO (NSIPP) Seasonal forecasts with NSIPP CGCMv1: High resolution: 2° AGCM & 1/3° OGCM Ocean initial states from ocean data assimilation Ensembles used to indicate uncertainty Nino3 SST forecast, initialized in September 2003

Observations Ensemble member Ensemble mean April 1 starts September 1 starts Niño-3 Forecast SST anomalies up to 9-month lead NSIPP Coupled Model Hindcasts

Impact of Ocean Assimilation

Seasonally Varying Correlation Skill (1993 – 2002) BSLN (bi-monthly) : (3 member ensemble) ASSIM (bi-monthly) : (6 member ensemble) May July ~ August June PERS. Forecast (monthly)

Anomaly correlation of forecast SSH with TOPEX data May starts Altimeter data not used in initializationAltimeter data used in initialization Lag 1 Lag 3 Lag 6 Lag 9 Kurkowski, Keppenne, Kovach

Impact of Soil Moisture Initialization

1. Development of Model System -- Construct models -- Couple models; ensure proper behavior -- Continue model evolution 3. Develop Strategy for Producing Initial Conditions (ICs) for Forecasts -- TYPE 1: ICs based on met. forcing -- TYPE 2: ICs based on met. forcing and satellite data assimilation(MSR) 4. Establish Baseline of Forecast Skill Without Data Assimilation -- Forecast experiments using TYPE 1 ICs -- Optimize forecast skill; resolve key issues of forecast strategy 5. Determine Impacts of Satellite soil moisture Assimilation on Forecast Skill -- Forecast experiments using TYPE 2 ICs -- Compare forecasts with baseline established in #4 -- Idealized predictability experiments 2. Establish Predictability in System NSIPP’s overall strategy for demonstrating the usefulness of satellite land data for seasonal forecasts completed work ongoing work future work

ObservationsPredicted: AMIPPredicted: Scaled LDAS 1988 Midwestern U.S. Drought (JJA precipitation anomalies, in mm/day) Without soil moisture initialization With soil moisture initialization Koster et al 2003

ObservationsPredicted: AMIP 1993 Midwestern U.S. Flood (JJA precipitation anomalies, in mm/day) 10 Without soil moisture initialization Predicted: Scaled LDAS With soil moisture initialization

ENSO Response and Weather Extremes

Skill of Z500mb: North America (NDJFM) NSIPP_AGCM ave corr = 0.46 Multi_AGCM ave corr = 0.44 CCA_OBSER ave corr = M. Hoerling: CDC NSIPP Science Team

The differences between the 1983 and 1989 January, February, March (JFM) mean fields ( ) for the model simulations (top panels) and the observations (bottom panels). The left panels consist of the differences in the 200mb heights (color), and the differences in the 200mb variance in the daily meridional winds (contour intervals: 40 (m/s) 2 ). The right panels are the differences in the precipitation. The model values are the averages of 36 ensemble members for each year.  JFM  odel (36 members) Observations

San Francisco Tampa Bay Histograms of the daily precipitation rates for January, February, March (JFM) for 1983 (red bars), and 1989 (blue bars). The left panel is for a grid point near San Francisco (38°N, 122.5°W), and the right panel is for a grid point near Tampa Bay (28°N, 82.5°W). Bins are every 4mm/day. The results are based on 36 JFM NSIPP model hindcasts.

Probability Density Functions of Extreme Winter Storms that form in the Gulf of Mexico (DJF ) Red - El Nino winters Blue - La Nina winters Maximum value of the principal components associated with storms that form in the Gulf of Mexico. Thin curves are the NSIPP model results (9 ensemble members). Thick dashed curves are from the observations. Values are scaled so that the model and observed values have the same total variance. Units are arbitrary. The PDFs are the fits to a Gumbel Distribution. Schubert et al (2003) Observations

Subseasonal predictions-MJO

200 mb EEOF of velocity potential NSIPP-2.0NSIPP-1NCEP Rean. Julio Bacmeister (2003)

Plans

New approach: - weather capable climate model and climate-reliable weather model –Unified Goddard modeling system AGCM: FVcore + evolving physics: combining GSFC developments with NCAR, GFDL collaborations Working to include GISS under a common Goddard model “toolkit” (with Code 930) LSM: Catchment LSM + features required for carbon, NWP, long- term climate –Development and validation in collaboration with other centers and general community –Next generation model –Modular, ESMF-based development of atmospheric model and subcomponents New approach: - weather capable climate model and climate-reliable weather model –Unified Goddard modeling system AGCM: FVcore + evolving physics: combining GSFC developments with NCAR, GFDL collaborations Working to include GISS under a common Goddard model “toolkit” (with Code 930) LSM: Catchment LSM + features required for carbon, NWP, long- term climate –Development and validation in collaboration with other centers and general community –Next generation model –Modular, ESMF-based development of atmospheric model and subcomponents

Forecast System Evolution –Analysis system (EKF, multi-variate OI) –Unified model –Higher Resolution (. 1°, 1/2° regional issues -e.g. NAME) –Observations (altimetry, soil moisture, snow, …) Science –Link between weather and climate –Impact of other ocean basins –Subseasonal problem (MJO, soil moisture, etc.) – decadal focus on droughts and ENSO variability –evolution of full PDF

“Snapshot” of water vapor (white) and precipitation (orange) from a simulation with the NASA Seasonal-to-Interannual Prediction Project (NSIPP) AGCM run at 1/2 degree lat/lon resolution.