My colleagues and I have been pushing the idea that
ENSO forecasts should be broadly integrated into economic, security and social policies in the tropics and subtropics. In a talk to policy folks yesterday, I tried to point them towards an excellent resource provided by the
International Research Institute for Climate and Society (at Columbia) that aggregates ENSO forecasts across many modeling groups (
here). Their current forecast for 2012 (Sep-Nov) is a 27% chance of El Nino, a 52% chance of neutral conditions and a 21% chance of La Nina.
More resources
here.
Historical projections from many different models (both physics-based dynamical models and statistical models) with actual observations overlaid in black:
Forecasts from various models going out until October of next year:
For a reference on our ability to forecast ENSO, see
Chen et al. They reconstruct forecasts using the LDEO model going back more than a century:
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Time series of SST anomalies averaged in the NINO3.4 region (5° S–5° N, 120–170° W). The red curve is monthly analysis of [reconstructed observations] and the blue curve is the LDEO5 prediction at 6-month lead. Source: Nature. |
and show, somewhat incredibly, that strong El Nino events can be reasonably forecast (corr ~ 0.75) up to twenty months in advance:
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These are shown as a function of start month and lead. The straight green lines denote the verification month of May. The left panel is based on all monthly anomalies, while the right panel is for anomalies with amplitudes greater than 0.7 °C. The colour bar shows the range of correlation coefficients. Source: Nature. |
Here is another link to ENSO forecasts: http://www.ubilava.com/ENSO.html .
ReplyDeleteThese forecasts are based on estimates from the Smooth Transition Autoregressive (STAR) modeling framework. Of course, I will be happy to hear any suggestions or criticism regarding the suggested forecasts.
Thanks David!
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