climate research

CELLO brings together international experts in ocean turbulence, air-sea-ice interactions, and computational methods to model and better understand ocean dynamics. The meeting will take place from September 16th to 18th, 2025, at Bucerius Law School in Hamburg.

Nearly 50 years ago, the Max Planck Institute for Meteorology, under the leadership of Klaus Hasselmann, recognized the ocean's crucial role in the climate system. Since then, advances in computational power and observational techniques have dramatically enhanced our ability to observe and simulate dynamics that were previously beyond our reach. These advancements now offer deeper insights into Earth's climate and its potential future changes, including how, where, and to what extent these changes might occur.

CELLO seeks to convene leading scientists from our field to share the latest research findings, explore future directions, and foster opportunities for collaboration.

To learn more about the conference themes and convenors please refer to the Conference Program. Submissions and registration will open on this website in Spring 2025.

Recent advances in machine learning have revolutionized dynamical modeling, yet AI weather and climate models often suffer from instability and unphysical drift when integrated over long timescales. This talk unifies three complementary works addressing this challenge. First, we present a theoretical eigenanalysis of neural autoregressive models that establishes a semi-empirical framework linking inference-time stability to the spectrum of the model’s Jacobian. This analysis reveals how integration-constrained architectures suppress unstable eigenmodes and enable predictable error growth. Building on this foundation, we identify spectral bias—a universal tendency of deep networks to under-represent high-wavenumber dynamics—as the root cause of instability in AI weather models. We demonstrate how higher-order integration schemes and spectral regularization, implemented in the FouRKS framework, mitigate this bias and produce century-scale stable emulations of turbulent flows. Finally, we translate these theoretical insights into practice with LUCIE-3D, a data-driven climate emulator trained on reanalysis data that captures forced responses to CO₂, reproduces stratospheric cooling and surface warming, and remains computationally efficient. Together, these results chart a rigorous pathway from mathematical theory to physically consistent AI climate models capable of stable, interpretable, and trustworthy long-term Earth-system emulation.

Institutions

• AI for Good

Despite the huge success of foundation models across fields, they still suffer from hallucinations and can produce physically inconsistent outputs. To leverage foundation models for climate science, it is critical to integrate first principles and physical laws to the learning and reasoning of these models.  In this talk, I will discuss our on-going effort to ground foundation models, including diffusion models and large language models for climate science. In particular, I will discuss dynamics-informed diffusion models for emulating complex fluids and an adaptive framework for LLM agents to use scientific tools. I will demonstrate the use cases of our methods on building an autonomous LLM agent as a climate co-scientist.

Learning Objectives:

By the end of this session, participants will be able to:

• Identify the limitations of current foundation models in climate science.
• Understand how integrating first principles and physical laws can ground diffusion models and LLMs for reliable scientific use.
• Recognize emerging applications of autonomous LLM agents as climate co-scientists for simulation, reasoning, and tool use.

Institutions

• AI for Good

Welcome to the 2025 edition of the WarmWorld-ESiWACE3 Summer School, in the old town of Lauenburg near Hamburg!

The Summer School will give an insight into ICON , one of the state-of-the-art weather and climate science models. The students will learn basic meteorology concepts and will be invited to tackle code challenges using intermediate and advanced approaches from software engineering, high-performance computing and data analysis, all under the guidance of experienced lecturers from these various fields.

Important dates

• Apr 15, 2025 – Deadline for travel grants requests
• Apr 30, 2025 – Registration closes
• until May 15, 2025 – Notification of acceptance
• Jul 28 - Aug 7, 2025 – Summer School

Institutions

• IT Center for Science (CSC-IT)
• Deutsches Klimarechenzentrum (DKRZ)
• Deutscher Wetterdienst (DWD)
• Technical University of Munich (TUM)
• University of Cologne , Center for Earth System Observation and Computational Analysis (CESOC)
• Max Planck Institute for Meteorology (MPI-M) 

Climate change research today relies on climate information from the past. Historical climate records of temperature observations form global gridded datasets that are examined, for example, in IPCC reports. However, the datasets combining measurement records are sparse in the past. Even today, they contain missing values. We found that recently successful image inpainting technologies, such as those found on smartphones to get rid of unwanted objects or people in photos, are useful here. The derived AI networks are able to reconstruct artificially cropped versions in the grid space for any given month using the missing values observation mask. So herewith we have found with AI a technique that gives us data from the past that we never measured with instruments.  Other important datasets used in the Assessment Report 6 of the IPCC to study climate change, as well as advanced applications such as downscaling in atmosphere and ocean, a hybrid (AI&ESM) data assimilation approach within ICON, or precipitation in broken radar fields are shown in this presentation.

Climate research, including the study mentioned in the previous paragraph, often requires substantial technical expertise. This involves managing data standards, various file formats, software engineering, and high-performance computing. Translating scientific questions into code that can answer them demands significant effort. The question is, why? Data analysis platforms like Freva (Kadow et al. 2021, e.g., gems.dkrz.de) aim to enhance user convenience, yet programming expertise is still required. In this context, we introduce a large language model setup and chat bot interface based on GPT-4/ChatGPT, which enables climate analysis without technical obstacles, including language barriers. This approach is tailored to the needs of the broader climate community, which deals with massive data sets from kilometer-scale modeling and requires a processing environment utilizing modern technologies, but addressing society after all - such as those in the Earth Virtualization Engines (EVE eve4climate.org).

Kadow, C., Hall, D.M. & Ulbrich, U. Artificial intelligence reconstructs missing climate information. Nat. Geosci. 13, 408-413 (2020)

Climate variability and weather extremes pose profound challenges for prediction, preparedness, and resilience. Traditional approaches often rely on predefined indices or supervised learning methods, which can overlook unexpected patterns or reinforce biases inherent in labeled datasets. This keynote explores how unsupervised learning techniques can uncover hidden patterns in high-dimensional climate data. I will highlight recent innovations that adapt established methods to reveal properties not captured by conventional architectures, offering new perspectives on modes of variability and extreme events. For instance, a knowledge-guided autoencoder can disentangle distinct Pacific climate modes with differing spectral signatures, while a custom hyperparameter search can optimize self-organizing maps to produce smooth, interpretable pathways among weather regimes. Together, these advances help uncover processes and mechanisms that may underlie established climate and weather phenomena. Ultimately, unsupervised learning provides a powerful lens for scientific discovery, with implications for understanding, prediction, and decision-making in a changing climate.

Institutions

• AI for Good

Anselm Fehnker, Senior AI Projektmanager am Artificial Intelligence Center Hamburg (ARIC) e.V.
Louisa Rockstedt, Projektmanagerin am Artificial Intelligence Center Hamburg (ARIC) e.V.

Künstliche Intelligenz gilt als Schlüsseltechnologie der Zukunft. Doch was kann sie beitragen, wenn es um eines unserer wichtigsten und zugleich am stärksten bedrohten Güter, dem Wasser, geht? Und worauf müssen wir achten, um technologische Innovation mit ökologischer Verantwortung zu verbinden?