Download - El Nino and Southern Oscillation (ENSO)
El Nino and Southern Oscillation (ENSO)
Markus Jochum (NCAR)
ENSO – a modeler's perspective
● What is ENSO?● Why use models?● What are the challenges?
NOAA/PMEL
NOAA/PMEL
NOAA/PMEL
NOAA/PMEL
NOAA/PMEL
Why models?
● Philosophical aspect: proof of understanding comes from reproducing/predicting
● Practical aspect: seasonal weather forecast provides societal benefits
● Desperation: for the foreseeable future there will not be enough observations to determine the nature of ENSO - ENSO triggered by noise - ENSO, an ocean-atmosphere oscillation
Lengaigne et al., 2004
Thermocline anomaly from CCSM3
CHALLENGE I: the observations
CHALLENGE II: What is the source of a bias in a coupled model?
CHALLENGE III: Physics
CHALLENGE IV: the global solution
Over long time periods like decades midlatitude oceanic biases will affect ENSO.
Surface wind stress fromT42x1 and ERS satellite
Summary
● Neither ignore nor trust the observations● ENSO is not a solved problem● Don't believe everything your advisor
tells you● There is no well defined ocean-
atmosphere boundary● If you cannot laugh about it, it is not the
right way!