What is air-sea coupling?
The ocean and atmosphere are in a constant dance, forming a coupled system that continually exchanges energy, momentum, gases, and particles. Understanding these exchanges, both in the past and how they might change in the future, is key to understanding our oceans and the entire planet.
This coupling has a huge influence on ocean circulation. For example, in the high-latitude Atlantic and Arctic seas, strong cooling at the ocean surface makes the water denser, causing it to sink. This process helps power the global 'conveyor belt' that redistributes heat, salt, and carbon around the world, including the circulation that brings warm water northwards in the Atlantic. Over the tropics, the opposite happens. The sun heats the surface, causing strong evaporation, rising air, and towering clouds. We research these critical exchanges using observations from ships and satellites, as well as complex computer simulations. This work is vital for tackling the climate crisis, as these exchanges transfer much of the excess heat and carbon from the atmosphere into the ocean.
What are the impacts of air-sea coupling research?
Understanding how the ocean and atmosphere interact is absolutely critical for monitoring, modelling, and predicting our entire Earth system. This coupling controls how much heat and carbon stays in the atmosphere and how much is absorbed by the ocean, which in turn drives global climate change. It affects sea level, rainfall patterns, temperature, and the water cycle on a planetary scale.
Regionally and locally, this interaction influences both the air and the sea, and can lead to hazards like flooding, wave damage, and extreme temperatures or winds. Our researchers are especially focused on the role these exchanges play in the development and severity of hurricanes, the formation of marine heatwaves, and the dramatic decline of Arctic and Antarctic sea ice.
Our Current Research Projects
We are actively involved in several major projects to better understand these processes:
- A project funded by the European Space Agency (ESA) is monitoring the Earth's energy cycle to better understand climate change. We're contributing by improving how we estimate air-sea heat exchange, combining satellite data with traditional measurements from ships and buoys.
- Another ESA project is developing an "essential climate variable" (ECV) dataset for ocean surface heat flux.
- Under our AtlantiS funding, we're developing an update to the NOC Surface Flux and Meteorological Variables dataset. So far, this has produced new long-term estimates of near-surface air temperature over the ocean, sea surface temperature data, and a new software package to create smooth, globally complete fields from scattered observations.
- This work is also a key part of the Climate Change in the Arctic and North Atlantic Region and Impacts on the UK project (CANARI).
- Air-sea coupling is at the heart of vital research into forecasting a major climate tipping point: the potential collapse of the Atlantic Subpolar Gyre. Through the AEROSTATS project, we're exploring the use of novel platforms like airships or high-altitude pseudo-satellites to determine the risk of such a collapse.
- We've also recently been funded for the SO-SIMMER project, working with the British Antarctic Survey to investigate the drivers of heat accumulation beneath the sea-ice in the Southern Ocean, including the role of air-sea fluxes.
Our Research
Our current work builds on several major research projects:
- Under the ORCHESTRA (and partly AtlantiS) projects, we developed a software package that makes it easy to compare different methods for parameterizing heat exchange between the atmosphere and ocean.
- We also contributed to the design of the global air-sea coupling observing system as part of OceanObs2019 globally, and with a special focus on the Southern Ocean.
- The EU-funded SO-CHIC project gave us new insights into how heat and carbon accumulate in the Southern Ocean by combining observations and modeling.
- This research was also a key component of the UK's ArctiCONNECT project, led by the University of Exeter, which aimed to understand how accelerating Arctic warming affects European climate and extreme weather.
Our research has produced tangible results and critical insights.
- We've developed a software package for calculating air-sea exchange that is available to the community.
- An in-press Journal of Climate paper led by Dr. Jeremy Grist explores how the low ocean surface salinity from Arctic melt is impacting Eurasian winter climate. This change in salinity alters the ocean-atmosphere coupling, leading to more storminess and rainfall over the Atlantic, close to the UK.
- Furthermore, a recent Nature paper led by Prof. Simon Josey examined the impacts of Antarctic sea-ice decline. This work revealed a doubling of the normal ocean heat loss to the atmosphere in these regions, which causes major changes to both the ocean and atmosphere, including an increase in storms. Both the sea-ice decline and the increase in storminess have negative consequences for a wide range of marine life, including Emperor Penguin colonies.
We believe it's vital to share this science far and wide. Our experts are regularly featured in the media, explaining these complex topics to the public. Recent examples include:
- 2025: A BBC News interview on the record-low global sea-ice cover.
- 2024/25: A wide range of global media coverage on the impacts of Antarctic sea-ice decline, including in Le Figaro and La Vanguardia.
- 2024: An ITV News interview explaining the ocean's role in the explosive development of Hurricane Milton.
Interested in learning more about air-sea coupling research or accessing NOC's datasets and tools?
Explore our software packages and discover how ocean-atmosphere exchanges shape climate and weather.