- Research Article
- 10.1175/jcli-d-25-0288.1
Changes in Seasonal Front Frequency and Precipitation over East Asia under SSP5-8.5 Scenario
- May 15, 2026
- Journal of Climate
- Chia-Chi Wang + 2 more +2
Abstract This study evaluates the performance of CMIP6 models in simulating synoptic-scale fronts and their associated precipitation over East Asia, with a focus on winter, spring, and the Taiwan mei-yu season. A modified front detection method incorporating low-level cyclonic shear improves the identification of mei-yu fronts. Results show that CMIP6 models reasonably reproduce the spatial distribution of frontal activity but underestimate the frequency of fronts and frontal precipitation in southern China, while overestimating frontal activity over Japan during the Taiwan mei-yu season. Future projections under shared socioeconomic pathway 5-8.5 (SSP5-8.5) indicate a decline in front frequency and frontal precipitation over key regions, particularly southern China and Taiwan, especially during winter and spring. In contrast, the Taiwan mei-yu season exhibits an increasing front frequency near Taiwan through the midcentury, followed by a growing intermodel spread. Frontal precipitation generally follows these trends, while total precipitation increases more broadly across East Asia. The discrepancy between frontal and total precipitation suggests a shift in dominant precipitation regimes, with a decreasing contribution from frontal systems and a potential increase in convective or nonfrontal rainfall. These changes, linked to weakened temperature gradients and altered moisture transport, present challenges for regional water security and highlight the need for improved frontal representation to support reliable hydrological projections and climate adaptation in East Asia. Significance Statement Frontal systems play a crucial role in shaping seasonal rainfall; however, their frequency, location, and hydrological impacts remain difficult to simulate in global climate models. This study presents an improved front detection method that enhances the identification of mei-yu fronts. Using CMIP6 simulations, we evaluate model performance and future projections under a high-emission scenario. While frontal activity and precipitation are projected to decrease over regions of frequent fronts during winter and spring, mei-yu frontal precipitation is expected to increase over southern China and Taiwan. These results underscore the importance of enhancing frontal representation in climate models and provide valuable insights for water resource planning and climate adaptation in East Asia.
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