Sun Yat-Sen University launches SYCIM2.0: A new climate model poised to join CMIP7

Accurately predicting regional climate—especially the East Asian summer monsoon—remains one of the toughest challenges in climate science today. While recent generations of global models, like those from the Coupled Model Intercomparison Project Phase 6 (CMIP6) project, have made big strides, many still struggle with some stubborn issues. These include a common error in simulating rainfall near the equator, called the "double ITCZ problem," and inaccuracies in representing key systems like the Western Pacific Subtropical High. These limitations reduce the models' reliability in projecting weather extremes and long-term climate risks across Asia.

Now, scientists at Sun Yat-Sen University have stepped in with a powerful new solution. Their team has developed SYCIM2.0, a next-generation Earth system model built to push the boundaries of climate simulation. Description of SYCIM2.0 is now detailed in a paper published in Advances in Atmospheric Sciences.

Developed in partnership with Tsinghua University—whose homegrown coupler technology, C-Coupler3, forms the backbone of the system—SYCIM2.0 brings together three advanced components: an ocean–sea ice model (FVCOM), an atmospheric model (GAMIL3), and a land surface model (CoLM2014). What makes it stand out? A key innovation lies in its use of a non-structured ocean grid, which gives the model the flexibility to zoom in on complex, climate-sensitive regions like the Indo-Pacific and coastal East Asia—areas that are often underrepresented in older models.

But SYCIM2.0 isn't just about what it's made of—it's about what it can do. One of its major goals is to offer “seamless” climate prediction, meaning it can simulate everything from daily weather events to long-term climate trends using the same framework. In a 250-year baseline test, the model showed impressive stability and energy balance, keeping global temperatures and radiation levels in check. That kind of performance is a big step forward, especially since some CMIP6 models still struggle with maintaining balance over long runs.

In terms of accuracy, SYCIM2.0 is already showing clear strengths. It closely matches real-world patterns of sea surface temperature, rainfall, and wind circulation, especially in East Asia and the equatorial Pacific. It significantly reduces the double ITCZ issue and does a better job at capturing the timing and structure of the summer monsoon. The model also reflects the complex relationship between the monsoon system and ENSO—the El Niño–Southern Oscillation—which is key to predicting extreme events like droughts or floods in the region. Of course, no model is perfect. SYCIM2.0 still shows a slightly weakened and eastward-shifted version of the Western Pacific Subtropical High. But researchers have already identified this issue, and future improvements are planned. Thanks to its modular design and flexible architecture, the model can quickly evolve with new data, physics, or technological upgrades.

Looking ahead, SYCIM2.0 is well-positioned to become part of CMIP7, the next major phase in global climate model coordination. CMIP7 is expected to focus more on high-resolution modeling, regional climate detail, and models that can bridge short-term forecasting and long-term projection. With its advanced coupling system, adaptability, and strong performance in monsoon simulation, SYCIM2.0 is ready to play a key role in that future. The team behind SYCIM2.0 welcomes international collaboration and hopes the model will be widely cited in future studies—especially those focused on East Asia, monsoon dynamics, and Indo-Pacific climate variability.

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