LONG-RANGE FORECASTING [INACTIVE]
Earlier in my career, while at Rutgers, the project which supported me was geared towards the prediction of short-term (monthly and seasonal) climate anomalies over the U.S. using advanced statistical techniques. I assisted in the issuance of operational winter season long-range U.S. temperature forecasts using a statistical model. One objective of this multi-year project was to expand the existing scheme to other seasons and to precipitation as well. A summary of some of the methods and results were given in Harnack et al. (1986a/b/c) for temperature forecasts, in Lanzante and Harnack (1982) and Harnack and Lanzante (1985) for precipitation, and in Harnack and Lanzante (1984) for atmospheric circulation.
The basic philosophy of the schemes was to use Empirical Orthogonal Functions (EOF's) to extract the important signal contained in predictor fields and to use these to build statistical models for the prediction of U.S monthly and seasonal temperature, precipitation or atmospheric circulation. Most frequently the models were constructed using screening multiple linear regression, however other techniques such as the "analog approach" and discriminant analysis were employed as well. In addition we used Monte Carlo and resampling schemes to evaluate the practical utility of our models.
The principal predictor fields included tropical and extratropical SST's,, 700 hPa heights and sea-level pressure, along with antecedent conditions of the predictands. We also performed specification studies in which regression models were based on zero lag (simultaneous) relationships. The idea here was to assess an upper limit on predictive capabilities. Although this project terminated about ten years ago many of the methods and relationships found to be useful, as well as the general level of skill of the forecasts have not dramatically changed!
Although I am no longer active in this area some of my research is geared towards diagnostics which may have relevance towards climate prediction. Particularly in this regard is an ongoing project related to the discontinuous nature of the seasonal cycle of temperature (see also SEASONAL CYCLE). I hope to demonstrate its relation to both medium and long-range forecasting.
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