THIS SECTION IS DEDICATED TO STUDENTS OF ALL LEVELS (FROM UNDERGRADUATE TO MSc AND PhD) AS WELL AS TO YOUNG RESEARCHERS AND PROFESSIONALS WHICH WOULD LIKE TO FIND OUT MORE ABOUT THE COASTAL CURRENTS. INDIVIDUALS UNDER THE EFFECT OF THE MOST IMPORTANT DRIVER OF KNOWLEDGE – CURIOSITY – ARE ALSO AMONG THE TARGET OF THIS SECTION.

Coastal Currents

Coastal currents are among the most significant factors which model the land – sea interaction areas (the coastal environments). They are one of the main vectors for sediment circulation and settlement in the coastal areas. Nevertheless, the coastal currents are only a part of the marine currents.
Marine currents play a major role for the general climate, by carrying water of different temperatures towards various environments world wide (e.g. Gulfstream – which carries warm waters from the central part of the Atlantic towards its northwards – cooler – part - but also cold water in warmer environments).

There are four processes which cause the marine currents: tides, wind – water interactions, differences of water density and wave induced currents.

1. Currents induced by tides. The tides form due to interaction between the gravity of the Sun, the Earth and the Moon. The currents caused by tides form in oceans and open seas usually, where the effects of the Son and Moon are most effective. They are controlled by pressure gradients, bottom friction (only in shallow waters) and Coriolis force. Their speed varies between 0.05 m/s in deep ocean to 0.1 – 1 m/s in coastal waters.

2. Currents induced by winds. The energy of the wind blowing over the sea surface transfer to the water forming waves and currents. The currents can be induced by two types of wind: local winds (storms) or large scale atmospheric circulation (Gulfstream, Equatorial winds etc.)

3. Currents induced by differences in water density. Usually, the differences in density are given by variation of temperature, salinity or sediment concentration. The most common example of mixture of waters with different densities is the discharge of the river into the sea. The fresh, sediment loaded river water outflow into the sea causing formation of density driven currents.

4. Currents induced by the waves. These currents form, basically, by two processes: drifting and wave breaking. In the case of drifting a current is formed by the non-breaking waves. Wave breaking occurs close to the shore (up to 20 m water depth) and generates a longshore current. When waves break, much of their energy is transferred to the longshore current. This current is very important for the dynamic of the coast because is the main way for the sediment movement.

The CLASS Project website presents to those who are interested (especially MSc and PhD students, as well as young researchers and professionals) the chapters dedicated to the coastal currents from the prestigious Coastal Engineer Manual, written and published by the United States Army Corps of Engineers, one of the world`s most significant institutions specialized in coastal studies: http://chl.erdc.usace.army.mil/cem

[download CEM_Part-II_Chap-4.pdf]
[download CEM_Part-II_Chap-8.pdf]