Climate and Earth Systems Models using Scientific Computing Eigil Kaas Professor in Meteorology and Climate Dynamics Niels Bohr Institute University of.

Climate and Earth Systems Models using Scientific Computing

Eigil Kaas

Professor in Meteorology and Climate Dynamics

Niels Bohr Institute

University of Copenhagen.

In front of the ENIAC, April 4, 1950: H.Wexler, J. von Neumann, M. H. Frankel, J. Namias, J. C. Freeman, R. Fjortoft, F. W. Reichelderfer, and J. G. Charney.

The Development of Electronic Computers

The new DMI-computer: Cray XT5

(in a bigger configuration).

3-dimensional dynamic Earth system models

Applications:

• Simulating basic processes and changes in the entire Earth system.

• Ocean and land-surface carbon cycle

• Interactive aerosol module

• Interactive chemistry (mostly gas phase)

• Ice sheets

• Biology

• …

Navier-Stokes equation (Unit mass version of “Newton's second law) expressed in the accelerated coordinate system of the Earth

12

d

dp

dt

VV g F

Equation of state for ideal gases (i.e. no particle density included in ρ). p

RT

v p

dT d dT dpc p c Qdt dt dt dt

The first equation of thermodynamics

Continuity equation for dry aird

d

d

dt

V

Continuity equation for various tracers including water vapour

t

tt

d+S

dt V

t

tq

dqS

dt

non particles

tt

Governing dynamical equations for the atmosphere

Hybrid sigma theta

Example of validation of atmospherec models:Precipitation

SST Errors: ECHAM5/MPI-OM

Systematic errors in sea surface temperature (SST)

Observed (black line) anthropogenic + natural forcings (red lines), anthropogenic forcings only (blue lines), anthroponegic (- effects of black carbon) + natural forcings (green line).

Hadley Centre simulations with HADGEM1 in ENSEMBLES

Circulation changes II

CLIMAP SSTs MOD SSTs

topographycontrol

CLIMAP+topo MOD+topo