Final answer:
The Gulf Stream is the warm surface-ocean current that flows along the Atlantic coast of the United States, playing a crucial role in the climate of Western Europe.
Step-by-step explanation:
The surface-ocean current that flows along the Atlantic coast of the United States is known as the Gulf Stream. This is a warm current that originates in the Gulf of Mexico, where its waters are warmed before it follows the Eastern Seaboard of the United States and eventually crosses the Atlantic Ocean toward Europe. The Gulf Stream has a significant impact on the climate of Western Europe, contributing to the moderate type C climate that most of Western Europe experiences. Additionally, the Gulf Stream's warm waters are responsible for allowing some forms of tropical flora to survive in the western coastal islands of Scotland, despite its northern latitude.