The Coriolis effect is a phenomenon that describes the pattern of deflection taken by objects that are not firmly connected to the ground as they travel long distances around the Earth. It is an inertial or fictitious force that acts on objects in motion within a frame of reference that rotates with respect to an inertial frame. The Earths rotation means that we experience an apparent force known as the Coriolis effect. The Coriolis effect influences the global wind patterns and gives rise to the prevailing south-westerlies in the UK.

The Coriolis effect is caused by the Earths rotation, which causes circulating air to be deflected toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. The Coriolis effect strongly affects the large-scale oceanic and atmospheric circulation, leading to the formation of robust features like jet streams and western boundary currents. It also affects weather patterns, ocean currents, and air travel.

The Coriolis effect is a complex phenomenon that has many practical applications. It is instrumental in the establishment of the large-scale ocean flow pattern called the Sverdrup balance, and it is responsible for the propagation of many types of waves in the ocean and atmosphere, including Rossby waves and Kelvin waves. The Coriolis effect is also responsible for the deflection of winds on Earth, which is a major factor in explaining why winds blow anticlockwise around low pressure and clockwise around high pressure in the northern hemisphere and vice versa in the southern hemisphere.