In which regions do the westerlies affect surface currents and in which regions do the trade winds affect surface currents?

The westerlies primarily affect surface currents in mid-latitude regions, typically between 30° and 60° latitude in both hemispheres, where they drive ocean currents eastward. In contrast, the trade winds influence surface currents in tropical regions, generally between 0° and 30° latitude, by pushing currents westward towards the equator. Together, these wind patterns help establish the major ocean gyres in various ocean basins.