Results from a study focusing on the development of physical-empirical models for prediction of East Asia wintertime temperature appropriate to APEC Climate Center (APCC) operational practices are presented in this report. The developed statistical tool, which is based on a multiple regression scheme with flexible construction of the predictors, has been proven efficient in the tests simulating real-time forecasts for 30 winters (1983/84–2012/13). The tests have shown the ability of the developed method to construct physically plausible predictors based on the fields of atmospheric and surface variables. Predictions of the wintertime Arctic Oscillation Index with the use of Z500 fields as a basis for predictor construction yield the skill in terms of temporal unadjusted correlation coefficient (TCC) > 0.60 and mean square skill score (MSSS) > 0.35. Prediction for East Asia comprising forecast of the leading principal components of the wintertime temperature anomalies with further composition of the predicted anomaly fields yields prevailing skill for South Korea characterized by TCC = 0.40–0.60 and MSSS = 0.20-0.30. Since the predictability underlying prediction for East Asia with the developed method mainly originates from extratropical processes, it is concluded that improvement can be achieved by combination of forecasts from the developed physical-empirical model with seasonal forecasts from dynamic models that are mainly governed by tropical sea surface temperature anomalies.

1. INTRODUCTION

2. DATA AND METHODOLOGY

2.1 Data

2.2 Methodologies

3. RESEARCH RESULTS

3.1 South Korea Wintertime Temperature: Relationships and Pre-Prediction Analysis

3.1.1 South Korea Temperature Time Series Peculiarities

3.1.2 Relationships between October Temperature and Wintertime Temperature: Is Prediction of Wintertime Temperature Based on Persistence Possible?

3.1.3 Concurrent Relationships of Wintertime Temperature with Circulation and Surface Properties

3.1.4 Lag Relationships of Wintertime Temperature with October Circulation and Surface Properties

3.2 Prediction of the Wintertime Arctic Oscillation Based on Autumn Circulation: Prediction of Wintertime East Asia Temperature with the Use of the Arctic Oscillation- Selected Predictors

3.2.1 Introduction

3.2.2 Data and Methods

3.2.3 Results

3.2.4 Discussion Discussion

3.2.5 Conclusion

3.3 Prediction of East Asia Wintertime Temperature for 1984–2013: Simulating Real-Time Mode with the Use of the Whole Series (1959–2013)

3.3.1 Prediction of East Asia Temperature Fields

3.3.2 Prediction of South Korea Temperature Fields

3.3.3 Prediction of Korean Peninsula Temperature Fields

3.3.4 Prediction of South Korea Temperature Fields in Cross-Validation Mode: Examples

3.4 Prediction of the East Asia Winter Monsoon Indices

3.5 Preliminary Tests: Wintertime Monthly Temperature and Seasonal Total Precipitation

4. CONCLUDING REMARKS

REFERENCES

APPENDIX 1. PREDICTION TECHNIQUES

APPENDIX 2. VERIFICATION ASSESSMENTS