ABSTRACT
Viewed as a whole the lecture series can be seen to have a basic symmetry. Its beginning and end primarily cover important but familiar ground: the parameterizations which the models must make to cope with the complexities of nonlinear systems, and the pitfalls that must be skirted in separating skilled from lucky forecasts. In the intervening lectures, the persistent theme is the importance of events on the synoptic time and space scales which must be resolved to establish clear causal relationships. Since such events are unpredictable beyond a few days, their contributions to the development, maintenance, and destruction of climatic anomalies can be assessed only with probability statements and continual reevaluation. Joe Fletcher has pointed out that the maximum extent of the Antarctic sea ice coincides with the most rapid seasonal change in insolation. This tends to magnify the climatic effects of year-to-year changes in sea ice extent.
