ARCHER2 Calendar May 2024

Gravity current propagating past a cylinder

Peter Brearley, Imperial College London, Department of Aeronautics

Gravity currents are fluid flows driven by density differences, causing the denser fluid to propagate across a surface through the less dense fluid. They are the means of a range of oceanic, atmospheric and geological flows that shape and regulate the environment that we live in. Oceanic gravity currents include the vast deep sea currents caused by differences in temperature or salinity. In the atmosphere, gravity currents occur as cold fronts, where cold, dense air displaces warm, light air. When interacting with physical objects such as geological formations, submarine structures or city landscapes, gravity currents can exhibit complex behaviours. A two-way interaction occurs where the object disrupts the flow while the flow is exerts considerable force on the object. This mutual interaction is of particular importance when considering the durability of offshore structures, pipelines and buildings.

This image was published on the May page of the ARCHER2 2024 printed calendar.