What forces are reshaping our oceans?
Climate change is intensifying weather extremes, with warmer seas driving more frequent and severe marine heatwaves, stronger tropical cyclones, and heavier rainfall over the oceans. Rising sea levels and shifting storm patterns also amplify storm surge and extreme wave events, increasing risks for coastal and island regions.
Temperature and weather extremes can happen anywhere in the global ocean. They affect everything from shallow coastal seas, where ecosystems like coral reefs are especially vulnerable, to the open ocean.
Our research into these extreme events is closely linked to other critical areas like climate modelling and carbon cycling. To understand extremes, we have to bring together knowledge from across physical oceanography, marine ecology, and climate science, which reflects just how interconnected our ocean systems are.
How do temperature extremes affect our global climate?
Temperature extremes can influence how heat and carbon move between the ocean and the atmosphere, which in turn affects our weather patterns and long-term climate trends. The ocean has absorbed more than 90% of the excess heat from our greenhouse gas emissions. When extreme events disrupt this buffering role, the consequences are felt far beyond the ocean.
What happens without this research?
Without dedicated research into these extreme events, our communities and industries would be unprepared for the potential ecological damage, the economic losses from occurrences such as fishery collapse, and the more severe climate impacts that could follow. By studying these processes, NOC provides vital insights into how events like marine heatwaves are shaping both the ocean and the wider Earth system.
Research
Our research tackles the full range of ocean temperature and weather extremes. We use a combination of cutting-edge technologies and traditional observation methods to fully understand the situation.
We use a fleet of marine robots, including gliders and floats, alongside our research ships and fixed observatories to gather data. We also use satellite data to get a global view in real time.
Our state-of-the-art ocean models provide reliable predictions that help us understand what drives these extreme events, forecast when they might happen, and assess their potential impacts.
We archive observations in line with FAIR principles, integrating cutting-edge technologies with established methods to ensure long-term accessibility, reproducibility, and leadership in best practice for marine data archival that supports future research.
People
Our scientists, engineers, and researchers are driven by a mission to deepen understanding of ocean health amid a changing climate. Our temperature and weather extremes work shapes global policies and fosters industry collaboration to protect the ocean and tackle the pressing challenges of our time.
Podcasts
Our award-winning podcast, Into the Blue focus on the biggest topics and challenges the ocean faces today such as temperature and weather extremes.
Impacts
Our studies have shown that both unusually warm and cold events can cause rapid ecological changes. In places like the southern North Sea, these events can influence oxygen levels, the distribution of essential nutrients, and even the timing of the spring phytoplankton bloom. These shifts can cascade through the food web, affecting fisheries and the coastal communities that depend on them.
This is a huge challenge, and it requires a major team effort. Our researchers contribute to several major programmes, including AtlantiS, which brings together experts to understand how extremes affect the Atlantic Ocean, and CANARI, which is investigating how temperature extremes interact with other environmental changes in the North Atlantic and Arctic. We are also using digital twin technology in the MAS-DT programme to improve our prediction capabilities.
In May 2025, the UK experienced an unprecedented marine heatwave, with sea surface temperatures reaching up to 4°C above average. The event affected regions including the southwest UK and the waters west of Ireland, highlighting just how vulnerable our marine ecosystems are.
During the May 2025 marine heatwave, we were a trusted voice, providing rolling updates that tracked the event and explained its impacts. NOC scientists monitored the event closely, providing near-real-time analysis and interpretation. Our research demonstrated how temperature extremes can disrupt the base of the marine food web by influencing plankton reproduction, and how these changes can in turn affect fish breeding cycles.
In the seas around the UK, our research has shown that areas like the southern North Sea and the English Channel are particularly sensitive to prolonged warming or cooling. These events often happen at the same time as periods of low oxygen near the seafloor, which creates a double-whammy of stress that ecosystems struggle to withstand.
By combining data from satellites, gliders, floats, and our research ships, we can track and understand these extreme events as they are happening, and put these events into a long-term perspective. This network of observations provides the crucial data we need for both an immediate response and for long-term analysis.
The Urgent Importance of This Research
The results of our research feed directly into the development of improved forecasting tools and early warning systems. This allows for a proactive rather than a reactive response. This science also helps to shape management strategies that can minimise the impacts on fisheries and ecosystems, and supports long-term planning for climate adaptation.
Marine and ocean-driven weather extremes are becoming more frequent, more intense, and longer-lasting. Alongside rising ocean temperature extremes such as marine heatwaves, changes in storms, rainfall, and air–sea interactions mean that what were once rare events are now increasingly common, pushing marine ecosystems toward lasting—sometimes permanent—transformation.
What tipping points might we cross?
Some ecosystems are facing thresholds beyond which recovery might become impossible. For example, coral reefs that experience annual bleaching can't recover between events, and some kelp forests that are lost might never grow back. Understanding these tipping points is essential for protecting marine life before irreversible changes happen.
How does this research support climate action?
By documenting how ocean extremes are affecting marine systems, our research provides clear evidence for the urgent need to reduce greenhouse gas emissions. It also identifies which ecosystems and communities are most at risk, allowing for targeted adaptation strategies.
The ocean's temperature extremes are a clear symptom of a planet that is warming. By tracking, understanding, and predicting these events, our research is shining a light on the challenges we face and the pathways we can take to protect both marine life and human communities.
Want to stay informed about the ocean temperature extremes affecting UK waters? Follow NOC's real-time monitoring and discover how our cutting-edge research is revealing the ocean's response to our changing climate.
Publications
Lifting the lid on marine heatwaves
Malan, Neil 
ORCID: https://orcid.org/0000-0001-7568-3908; Gupta, Alex Sen ORCID: https://orcid.org/0000-0001-5226-871X; Schaeffer, Amandine ORCID: https://orcid.org/0000-0002-8320-4951; Zhang, Shujing ORCID: https://orcid.org/0000-0001-8830-7565; Doblin, Martina A. ORCID: https://orcid.org/0000-0001-8750-3433; Pilo, Gabriela Semolini ORCID: https://orcid.org/0000-0002-8590-8645; Kiss, Andrew E. ORCID: https://orcid.org/0000-0001-8960-9557; Everett, Jason D. ORCID: https://orcid.org/0000-0002-6681-8054; Behrens, Erik ORCID: https://orcid.org/0000-0002-9713-7227; Capotondi, Antonietta ORCID: https://orcid.org/0000-0002-3594-5472; Cravatte, Sophie ORCID: https://orcid.org/0000-0002-2439-8952; Hobday, Alistair J. ORCID: https://orcid.org/0000-0002-3194-8326; Holbrook, Neil J. ORCID: https://orcid.org/0000-0002-3523-6254; Kajtar, Jules B. ORCID: https://orcid.org/0000-0003-0114-6610; Spillman, Claire M. ORCID: https://orcid.org/0000-0003-0853-8190.
2025
Lifting the lid on marine heatwaves.
Progress in Oceanography, 239, 103539.
1, pp.
10.1016/j.pocean.2025.103539
2025
Article
Marine heatwaves and cold-spells, and their impact on fisheries in the southern North Sea
Wakelin, Sarah ORCID: https://orcid.org/0000-0002-2081-2693; Townhill, Bryony; Engelhard, Georg; Holt, Jason ORCID: https://orcid.org/0000-0002-3298-8477; Renshaw, Richard.
2021
Marine heatwaves and cold-spells, and their impact on fisheries in the southern North Sea.
In: EGU General Assembly 2021, Online, 19-30 April 2021.
2021
Conference item