This study describes the newly developed APCC in-house model, Seamless Coupled Prediction System (SCoPS). Using 32-year (1982–2013) ensemble hindcast runs produced with SCoPS and CCSM3, which is current operation system in APCC, this study evaluates the spatial and temporal structure of hindcast climatology, large-scale features, and prediction skills for major climate variability in both systems. A special focus is on the fidelity of the systems to reproduce and forecast phenomena that are closely related to the East Asian monsoon system. Overall, both CCSM3 and SCoPS exhibit realistic representations of the basic climate, although systematic biases are found for surface temperature and precipitation. Also, the SCoPS simulation provides a more realistic representation than CCSM3 for Walker and monsoon circulations based on analysis of upper tropospheric velocity potential, although it tends to overestimate the intensity of the Hadley circulation. Notably, SCoPS also captures the northward migrating rain band in May to August related to the Changma. In the case of East Asian monsoon index prediction, SCoPS show a higher correlation coefficient between observed and predicted indices than CCSM3 for both summer and winter seasons. The SCoPS simulation also demonstrates a useful skill in prediction of the wintertime Arctic Oscillation index based on EOF analysis. Based on results, it is clear that SCoPS is more skillful than CCSM3 in prediction of seasonal climate variability including ENSO, East Asian summer and winter monsoon, and the Arctic Oscillation. Consequently, this provides criteria for understanding the characteristics of CCSM3 and SCoPS for providing

seasonal climate forecasts. Also, it is clear that the SCoPS seasonal climate forecast will be useful for simulating the East Asian monsoon system within the MME prediction system.

1. INTRODUCTION

2. MODEL AND PREDICTION SYSTEM

2.1 Overview of APCC CCSM3

2.2 Overview of SCoPS

2.3 Hindcast simulation

3. RESEARCH RESULTS

3.1 Systematic bias

3.2 Large-scale tropical circulation

3.3 Seasonal prediction skill

3.4 East Asia summer monsoon

3.5 East Asia winter monsoon

4. SUMMARY AND CONCLUSIONS

REFERENCE