From MONEX to the global monsoon: A review of monsoon system research

Substantial progress has been made over the past three decades since the Monsoon Experiments (MONEX) of 1978-79. Here, we review these achievements by highlighting four breakthroughs in monsoon research: (1) The identification of the coupled ocean-land-atmosphere nature of the monsoon in the process of the annual cycle of solar heating; (2) new understanding of the changes in the driving forces of monsoon systems, with anthropogenic factors (climate effects of increased greenhouse gas and aerosol emissions) playing an important role in the regulation of monsoons; (3) detection of the interdecadal- and centennial-scale variability of monsoon systems, and its attribution to the combined impact of global warming and natural (especially oceanic) effects; and (4) the emerging concept of the global monsoon and its long-term variation under the impact of global climate change. All the observational and model-derived evidence demonstrates that the monsoon system, as an important component of the global climate system, has already changed and will continue to change in the future. This picture of an evolving monsoon system poses great challenges for near-term prediction and long-term projection.