(1) Professor, University of California, Los Angeles
(2) Senior Research Scientist, Columbia University
Title: Subseasonal-to-Seasonal (S2S) Prediction: Theoretical and Practical Aspects
Abstract: How to predict for 30–100 days when we can’t do so for 10 days? It’s a truism that weather and climate variability involves many space and time scales, and that the processes that give rise to these scales interact nonlinearly. What is less obvious is that we are starting to come to grips with various aspects of modeling, simulating and predicting certain aspects of weather and climate on longer and longer time scales. An important toolkit for doing so is provided by dynamical systems theory and its applications to large systems.
Michael Ghil will provide a description of so-called low-frequency variability (LFV) of the atmosphere, on S2S scales, and of ways to assess its theoretical predictability. Andrew Robertson will present some of the practical difficulties and of the ways these are being overcome in an international program that he is leading.