biases in nsipp simulations

BIASES IN NSIPP SIMULATIONS

• COMPARE AMIP AND COUPLED RUNS WITH SAME ATMOSPHERIC MODEL– CLIMATOLOGY– TROPICAL BIASES– INTERANNUAL VARIABILITY– SENSITIVITY

Credits: Sonya Miller, Phil Pegion, Augustin Vintzelios

MODELS

• NSIPP 1 AGCM (2 x 2.5 x 34L resolution)– RAS Convection (w/ autoconv. And reevap)– Louis turbulence– M-D Chou Radiation

• Poseidon OGCM (1/3 x 5/8 resolution)– Schopf’s quasi-isopycnal dynamics– Reduced gravity– Global (no Arctic or Med)

• Mosaic LSM• Direct coupling – no flux correction

SEASONAL ANOMALIES AT THE EQUATOR

2 DEG ATMO

1 DEG ATMOS

DIFFERENCE

CONTROL

CU FRIC

SUMMARY

• Model has many of the same biases as other coupled models.

• Clear indications of many of these are already apparent in AMIP mode.

• Though some like, the bias in the SPCZ (double ITCZ), are much worse in coupled mode.

• Upper air features (stationary waves, zonal mean biases) not very affected by coupling.

• Both AMIP and coupled models have reasonable stratus, but generic coupled problems in the East Equatorial Pacific still present