Climate Prediction Program for the Americas(CPPA)

Jin Huang and Annarita MariottiNOAA Climate Program Office

April 16, 2008

Padua, Italy

Outline:• CPPA program

• General overview• Activities relevant to HE

• Outstanding HE issues for North America• CPPA future priorities

NOAA Climate Goal Understand Climate Variability and Change to Enhance Society’s Ability to Plan and Respond

OUTCOMES

• A predictive understanding of the global climate system on time scales of weeks to decades with quantified uncertainties sufficient for making informed and reasoned decisions

• Climate-sensitive sectors and the climate-literate public effectively incorporating NOAA’s climate products into their plans and decisions

PR

OG

RA

MS

PROGRAMS• Observations and Monitoring • Climate Research and Modeling• Climate Services Development

CPPACPPA

Climate Prediction Program for the Americas

CPPA Science Objectives:• Improve the understanding and

model simulation of ocean, atmosphere and land-surface processes

• Quantify the predictability of climate variations on intra-seasonal to interannual time scale

• Advance NOAA’s operational climate forecasts, monitoring, and analysis systems

• Develop climate-based hydrologic forecasting capabilities for decision support and water resource applications.

GAPP PACSPACS

Mission: Improve operational intra-seasonal to interannual hydroclimatic predictions for the Americas

Research Components

Climate Predictability & Prediction

Atmosphere-Ocean Interactions

Land-Atmosphere Interactions

Operational Climate Prediction,Monitoringand Analysis

Climate-Based Hydrologic Forecasting and Water Resources Applications

CPPA Interests in Mountain Hydroclimate Studies

- Climate Predictability at intraseasonal to interannual time scales- seasonal predictability in mountain regions (local and remote forcing)

- Land-Atmosphere Interactions- cold-season processes in western mountains- representation of subgrid variability of hydrologic variables in climate models

- Operational Climate Prediction, Monitoring, and Analysis- improved prediction skill in mountainous areas- orographic precipitation- drought monitoring and prediction in mountain regions;- downscaling climate forecasts from large scale to sub-basin in mountain regions

- Hydrologic Forecasting for Water Resource Applications- hydrologic prediction in mountain regions

The North American Monsoon The North American Monsoon Experiment (NAME)Experiment (NAME)

NAME Accomplishments:- NAME 2004 Field Program and

Datasets Archive

- Diagnostic and Modeling Studies

Study of warm season hydroclimate and convective processes over complex terrain (Tier I):- NAME Event Rain gauge Network (NERN) 87 rain gauges and 14 T/RH sensors along 6 major W-E transects traversing SMO- Analyses of complex interactions over western Mexico between land-sea, mountain-plan circulations and low-level jets.

CPPA Drought Predictability Studies

Tropical influences on drought North America

OBS GLOBAL T.E. Pacific

January-May precipitation anomalies over the U. S. for 1998-2002 (Huang and Seager)

P-E trends for the southwest U.S. from IPCC AR4 simulations (Seager)

Future droughts in the southwest

New FY08 Projects: • Roles of SST modes• Role of remote convection• Influences of multi-ocean basins• Roles of vegetation and sub- surface water and drought impact on phenology;• Diagnosis of water budget and moisture sources during drought• Hydrological predictability in the West under drought conditions

VOCALS Program (VAMOS Ocean-Cloud-Atmosphere-Land-Studies)

OBJECTIVE:

• Improve numerical model simulations of the coupled climate system in the SEP

SCIENCE QUESTIONS:

• Why is SE Tropical Pacific so cold & cloudy?

• What are roles of:– Topography (Andes Cordillera)?– Ocean eddies & upwelling?– Natural and anthro. aerosol?

“To better understand physical and chemical processescentral to the climate system of the Southeast Pacific region,involving poorly understood interactions between the ocean, the atmosphere, and the land.”

VOCALS-REx field campaign Oct-Nov ‘08

WCRB

LSOSRCEW

MCRB

North American Cordilleran TransectIntegrated Measurement and modelling study

(PIs: Marks, Pomeroy, Link, Hardy)

LSOS

RCEW

MCRB

WCRB

Yukon Territory, Canada

Alberta, Canada

Idaho, USA

Colorado, USA

• Measurement of surface fluxes and hydro-meteo conditions during snowmelt

• Model development:- Vegetation-snowcover interactions- Scaling in complex terrain

Measured H, LvE & SublimationExposed & Sheltered Sites (2004-2006)

SnowAssim

Data Assimilation Sub-Model

Time evolution of SWE at a sample site, for initial and assimilation runs. Shown is the assimilation model’s ability to pass through the observations when and where they exist.

Modelling of snow processes and snow data assimilationA snow evolution modeling system (SnowModel) and A Simple Data Assimilation System For Complex Snow Distributions (SnowAssim)

-SnowModel simulations using SnowAssim have improved snow-water-equivalent (SWE) distributions.

-More realistic spatial heterogeneity than that provided by the observations alone. (Liston, and Hiemstra, 2007)

General Characteristics:- Based on NCEP’s ETA/EDAS/Noah- 3D Var assimilation system- Assimilation of observed

precipitation - 32 km/45 lvls, 3hr resolution- 1979 to 2002..

A long-term, consistent, high-resolution climate datasetfor the North American domain,as

a major improvement upon the earlier global reanalysis datasets in both resolution and accuracy

The North American Regional Re-analyses (NARR)

Evaluation of the North American Regional Reanalyses over Complex Terrain

CPPA Drought Monitor and Seasonal Prediction

NLDAS-based Drought Monitor is based on realtime and retrospective National Land Data Assimilation System (NLDAS) with multiple land models.

Compared to the existing operational US Drought Monitor, NLDAS-based Monitor System is 1) objective2) quantifiable3) reproducible

NLDAS-Based Drought Monitor

New Drought Prediction

MultipleLand/Hydrologic

Models

Climate Forecasts (GCMs and Official)

Initial land conditions

Downscaling & bias correction

Development of an experimental seasonal hydrologic prediction system for the continental U.S.

Nowcasts of Snow Water Equivalent for western U.S. and soil moisture for eastern U.S. from University of Washington Westwide Hydrologic Forecast System and Princeton Forecast System, respectively. White circles in western U.S. and red circles in eastern U.S. are streamflow forecast points, at which seasonal streamflow forecasts are issued twice-monthly (UW) and monthly (Princeton). Insert shows seasonal streamflow forecasts as of March 1 for Columbia River at the Dalles, OR from UW system. (D. Lettenmaier and E. Wood)

Outstanding mountain hydroclimate issues and CPPA’s near-term priorities

North American Mountain Hydroclimate Workshop - Oct 07

1) Improvement in hydrologic forecast in mountainous regions.

Includes improvement in precipitation forecast.

2) Development of a regional integrated modeling system (atmosphere, hydrology, ecosystem, etc,) as a tool to diagnose

and predict the mountains water balance.

3) Need for more data in the mountainous regions.

Recommendations include field projects for critical measurements along

mountain transects, and data assimilation products for the mountains (e.g.,

NARR does not adequately resolve mountain processes).

4) There is a need to quantify the limits of predictability in mountainous

regions (e.g., the relative importance of large-scale vs regional-scale

forcing, etc).

Recommandations:

Cascades

Sierra

Moist

Dry

Impact of Downscaling on simulation and prediction

- Typical GCM resolution does not allow to resolve effects of individual mountains

- E.g. Impact of downscaling in simulating ENSO precipitation anomalies.

Composite El Nino Precipitation Anomaly. After Leung et al.

RCM SimulationObservation

NCEP Reanalyses

180 km 80km 32 km

After Lawford

A New CPPA Project:Multi-RCM Ensemble Downscaling of multi-GCM Seasonal Forecasts

Objective: Demonstrate the usefulness of multi-RCM downscaling of global seasonal forecasts for hydrologic applications.

Linkage to NOAA’s operations:

• To examine the role of downscaling in improving GCM (CFS first) prediction skill

• To provide predictions at higher resolution and regional level for hydrologic applications

• contributing to better climate services• comparison of dynamic downscaling and statistical downscaling

CPPA near-term Priorities concerning mountain hydroclimate

• Impact of large scale climate variability on mountain hydroclimate

• Sources of climate predictability in mountainous areas • Cold-season process studies and modeling improvements

• Hydrologic prediction in mountainous areas.

• Orography provides a scale transfer mechanism that focuses large scale features into regional scale responses

• Predicting climate variability/change in the mountains requires prediction of large scale variations/change and their interactions with the mountains

• Large scale variations that influence the mountain regions of North America include:- ENSO (seasonal to interannual)- Tropical modes (intraseasonal) - Upper level flow (weekly and beyond)

• Climate change:– Drought in the southwest

HE-climate interactions over North America