Ocean current hemisphere due to imposed wind stresses. In these wind-driven currents, the Ekman spiral effect results in the currents flowing at an angle to the driving winds. In addition, the areas of surface ocean currents move somewhat with the seasons; this is most notable in equatorial currents. Deep ocean basins generally have a non-symmetric surface current, in that the eastern equatorward-flowing branch is broad and diffuse whereas the western poleward flowing branch is very narrow. These western boundary currents (of which the Gulf Stream is an example) are a consequence of the rotation of the Earth. Deep ocean currents are driven
Atlantic Europe in close cultural contact from at least the mid 3rd millennium BC, contributing to what would emerge as the Celtic culture of the West/Central European Iron Age. Archaeologists have noted that the prehistoric peoples of Atlantic Europe presented common traits, as shown by artifacts, artistic and architectural styles found in the region which attest to at least some form of trade and/or cultural link. In addition, a number of genetic studies seem to interrelate specific groups of population in parts of Atlantic Europe in contrast with, for example, Central or Mediterranean Europe. Some examples of early cultural contact are the