Ai2 reposted this
Ai2 Climate Modeling’s director Chris Bretherton wrote a great blog post summarizing our group’s recent work on AI-based climate model emulators. Reading the whole post is worthwhile (https://lnkd.in/gPPV-79Z) but I will also summarize here. The post describes two preprints recently on arxiv: 📃 ACE2: Accurately learning subseasonal to decadal atmospheric variability and forced responses (https://lnkd.in/gWSxdwHH) • Introduces the ACE2-ERA5 model—the Ai2 Climate Emulator version 2 trained on the ERA5 reanalysis dataset • This is the first fully AI-based autoregressive atmospheric model to show accurate historical (past 80-year) trends in atmospheric temperature • At the same time as getting long-term trends right, ACE2-ERA5 also generates realistic features like tropical cyclones, stratospheric sudden warmings and the Madden Julian Oscillation—all essential atmospheric phenomena for extreme weather and sub-seasonal to seasonal prediction 📃 ACE2-SOM: Coupling an ML atmospheric emulator to a slab ocean and learning the sensitivity of climate to changed CO2 (https://lnkd.in/gBsi7CKj) • Here we use a simple thermodynamic (“slab”) ocean model to do climate change simulations where carbon dioxide concentrations are increased (up to quadrupled) from present-day conditions • Trained on a physics-based model (SHiELD-SOM) forced with a range of CO2 concentrations, we show that ACE2-SOM is able to accurately capture the expected response of surface temperature to increasing CO2 (see image) • ACE2-SOM also accurately predicts the changes in frequency of extreme precipitation up to the top ten-thousandth percentile There is still work to be done: for example, while the equilibrium climate predictions are accurate, ACE2-SOM does not correctly predict the initial response to a large abrupt increase in CO2. It’s exciting to push AI+weather to climate time scales. The speed of these models really shines—being able to do 1000-year simulations (over a million 6-hour steps!) in less than a day still blows me away. Excited to see what 2025 brings for AI and climate modeling. These models are publicly released and simulations are fast and easy to run, even on your MacBook. See our ACE codebase: https://lnkd.in/g88qk2fp where you can find documentation and links to the models described above. Tagging the team: Spencer Clark, Brian Henn, Anna Kwa, Jeremy McGibbon, W. Andre Perkins, Elynn Wu, James Duncan, Lucas Harris (NOAA GFDL) and Chris Bretherton.