The scientific importance of the Asian monsoon cannot be overemphasized. The giant Asian monsoon system dominates the entire Eastern Hemisphere tropics and subtropics. It interacts with the El NiSo-Southern Oscillation (ENSO) and extratropical circulations, and has far-reaching impacts on global climate and environment. The Asian monsoon exemplifies the most complex interactions between the Earth's land surface,ocean, atmosphere, hydrosphere, cryosphere and biosphere including human activities.

The Asian Monsoon Years (AMY 2007--2012)is a cross-cutting initiative as part of the International Monsoon Study (IMS), a coordinated observation and modeling effort under the leadership of the World Climate Research Programme (WCRP). The long-term goal of AMY is to improve Asian monsoon prediction for societal benefits through coordinated efforts to improve our understanding of Asian monsoon variability and predictability. It is believed that coordination and cooperation of individual participating and partner projects will greatly facilitate the efforts to reach this goal.

The specific objectives of AMY are:

· To better understand the ocean-atmosphere-land-biosphere interactions,the multi-scale interactions among time scales ranging from diurnal, intraseasonal to interannual, and the aerosol-cloud-water cycle interactions in the Asian monsoon system;

· To improve the physical representations of these interactions in coupled climate models, and to develop data assimilation of the ocean-atmosphere-land system in the Asian monsoon region.

· To determine predictability of the Asian monsoon on intraseasonal and seasonal time scales, and the roles of land initialization in continental seasonal rainfall prediction.

· To better understand how human activities in the Asian monsoon region interact with monsoon and its related environment.

These objectives will be fulfilled through coordination of the ongoing and planned field experiments and modeling projects in the Asian monsoon region which form contributions to AMY.

The AMY stems from. grass-root scientific and societal imperatives. It has been endorsed by the Joint Scientific Committee (JSC) of WCRP as well as the WCRP Climate Variability and Predictability (CLIVAR) Project and the Global Energy and Water Cycle Experiment (GEWEX). It has been identified as a cross-cutting weather and climate activity by WMO World Weather Research Programme (WWRP) Monsoon Panel in the WWRP Strategic Plan. The AMY program is gaining increasing support within the broad community represented by many national projects, operational, centers and monsoon research scientists at large.

The planned activity consists of field observations, data management, and modeling components. A Science Steering Committee, International Program Office,and three Working Groups have been set up as an outcome of the first AMY workshop at Beijing, April 23--25, 2007 hosted by State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (lAP). A draft of this science plan was discussed at the Second AMY workshop jointly hosted by CLIVAR and GEWEX and BPPT, Indonesia at Bali,Indonesia, September 3---4, 2007. This final version also facilitated the working groups in formulating the Implementation plan.

Summary

1 Introduction

1.1 Programmatic development

1.2 Participants

2 Background

2.1 Observational and process studies

2.2 Modeling and prediction

2.3 The monsoon environment and its future change

3 Science foci

3.1 Cross-cutting themes

3.2 Overarching science questions

4 Goals and objectives

4.1 The overarching goals

4.2 Objectives

5 Strategy

5.1 Balanced and integrated approach

5.2 Development of monsoon prediction system

5.3 Geographic foci and capacity building

5.4 Utilization of satellite observations

5.5 Organization

5.6 Collaboration and linkages

6 Planned activity

6.1 Observations

6.2 Data management and data assimilation

6.3 Modeling and prediction

7 Expectations

8 References

Appendix I. Acronyms

Appendix II. List of participants

Appendix III. AMY organization

Appendix IV. Funding and sponsors

Appendix V. The AMY Workshops