climate state
Robustness of AI-based weather forecasts in a changing climate
Rackow, Thomas, Koldunov, Nikolay, Lessig, Christian, Sandu, Irina, Alexe, Mihai, Chantry, Matthew, Clare, Mariana, Dramsch, Jesper, Pappenberger, Florian, Pedruzo-Bagazgoitia, Xabier, Tietsche, Steffen, Jung, Thomas
Data-driven machine learning models for weather forecasting have made transformational progress in the last 1-2 years, with state-of-the-art ones now outperforming the best physics-based models for a wide range of skill scores. Given the strong links between weather and climate modelling, this raises the question whether machine learning models could also revolutionize climate science, for example by informing mitigation and adaptation to climate change or to generate larger ensembles for more robust uncertainty estimates. Here, we show that current state-of-the-art machine learning models trained for weather forecasting in present-day climate produce skillful forecasts across different climate states corresponding to pre-industrial, present-day, and future 2.9K warmer climates. This indicates that the dynamics shaping the weather on short timescales may not differ fundamentally in a changing climate. It also demonstrates out-of-distribution generalization capabilities of the machine learning models that are a critical prerequisite for climate applications. Nonetheless, two of the models show a global-mean cold bias in the forecasts for the future warmer climate state, i.e. they drift towards the colder present-day climate they have been trained for. A similar result is obtained for the pre-industrial case where two out of three models show a warming. We discuss possible remedies for these biases and analyze their spatial distribution, revealing complex warming and cooling patterns that are partly related to missing ocean-sea ice and land surface information in the training data. Despite these current limitations, our results suggest that data-driven machine learning models will provide powerful tools for climate science and transform established approaches by complementing conventional physics-based models.
- Southern Ocean > Weddell Sea (0.04)
- North America (0.04)
- Asia (0.04)
- (8 more...)
Differentiable Physics-based Greenhouse Simulation
Nguyen, Nhat M., Tran, Hieu T., Duong, Minh V., Bui, Hanh, Tran, Kenneth
We present a differentiable greenhouse simulation model based on physical processes whose parameters can be obtained by training from real data. The physics-based simulation model is fully interpretable and is able to do state prediction for both climate and crop dynamics in the greenhouse over very a long time horizon. The model works by constructing a system of linear differential equations and solving them to obtain the next state. We propose a procedure to solve the differential equations, handle the problem of missing unobservable states in the data, and train the model efficiently. Our experiment shows the procedure is effective. The model improves significantly after training and can simulate a greenhouse that grows cucumbers accurately.
Make Mars Great Again - Issue 43: Heroes
Mars is currently inhabited by an estimated 1 million microbes. They coat the surfaces and crowd the innards of our robotic landers and rovers, which international policy requires to be cleaned, but not fully sterilized. The bugs are dormant, but viable. If Mars warmed up and water began to flow again, these microorganisms would revive and reproduce. And it is within our power to make that happen.