Fredrick H. M. Semazzi North Carolina State University

Emerging Research Opportunities at the Climate Modeling

Laboratory

NC State University (Presentation at NIA Meeting: 9/04/03)

Fredrick H. M. SemazziNorth Carolina State University

Department of Marine, Earth and Atmospheric Sciences

&Department of Mathematics

Emerging Research Opportunities at the Climate Modeling

Laboratory

NC State University

For Details

http://climlab4.meas.ncsu.edu

•High Resolution Nested Regional Climate Prediction Models

•High Resolution Global Atmospheric Prediction Models

MAIN AREAS OF EMERGING RESEARCH OPPORTUNITIES

Equations of Motion

rFgvΩv

pDt

D

1

2

01

vDt

D

JDt

Dp

Dt

DTcv

MODEL NUMERICAL-DOMAIN

PERFORMANCE IN AN SIMULATING

CLIMATOLOGY (IRI)1970-1995 AVERAGE

• Observations• ENCHAM GCM• RCM-Low Resolution

Model• RCM-High Resolution

Model

OND ACTUAL RAINFALL (MM/DAY)

1970-95 AVERAGE

Comparison of models performance

Adaptation of RegCM2 for EA

0

50

100

150

200

250

TF KH SC TZ SA EA

Homogeneous climate sub-regions

rain

fall(

mm

)

Obs

Exp.1

Exp.2

Exp.3

Exp.4

Exp.5(Optimum)

Optimization of Regional Numerical Models Based on

Useable Prediction Skill

Useable Skill(Palmer et al, 1999)

Fig.2: Algorithm for computation of forecast value (V) & optimization

USER SECTOR PREDICTION MODELCLIMATE OBSERVATIONS

Define (E)Identity C & L

Set ParametersForecast E

Observe E Compute

o (E)

observed

Fst No Yes No Yes

Region 1

Region 2

Region 9ROC

Hit rate H / False alarm F Perfect Prediction

Model

Mper o CL

oL

CoHo

L

CFM

11

Climatology Prediction Model

MCli minCL

,o

HF

V pt MCli M

MCli Mper

Vopt max V

Savings$ MCli Mopt NL

See fig.3

Parameter updateand optimization

Global Atmospheric Model

==================Variable Resolution

Nonhydrostatic Global

Semi-implicit Semi-Lagrangian

Global Variable Resolution Grid

• No lateral boundary conditions

• Multiple scales

• Single code for multiple problems

• Flexible (easy to customize for different regions)

• Simplifies maintenance and optimization with only one code

Variable Resolution Grid

Nonhydrostatic Dymanics

• Increasing resolutions of atmospheric models

• Little additional computational cost

• Some atmospheric phenomena are nonhydrostatic (e.g. tropical cyclones)

BatesNASA GODDARD

GCM

Bates et al (1993)

NC STATE UNIVERSITY

GCM

Semazzi et al (2003)

Day 2 - 500 hPa

400 m resolution-courant#=3

Hydrostatic Non-Hydrostatic

2 km resolution

Hydrostatic Non-Hydrostatic

Future Work•Optimization of Regional Numerical Models Based on Useable Prediction Skill•Efficiency improvements to semi-implicit semi-Lagrangian (SISL) numerical scheme: solver, interpolation•Physical parameterization: heating, friction, convection, moisture, etc.•Parallel version

in collaboration with NASA and other organizations …