Downwelling is a process in oceanography where surface water sinks into the deeper layers of the ocean. This typically occurs in areas where water becomes denser, often due to cooling temperatures or increased salinity. As the surface water sinks, it carries oxygen and nutrients down, which can support marine life in deeper waters. This process is essential for the global ocean circulation system, known as the thermohaline circulation. Downwelling helps regulate climate by distributing heat and nutrients throughout the ocean, influencing weather patterns and supporting ecosystems. It plays a crucial role in maintaining the health of the ocean and its inhabitants.