Gulf Stream in the context of Boundary current

Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east. Europe shares the landmass of Eurasia with Asia, and of Afro-Eurasia with both Africa and Asia. Europe is commonly considered to be separated from Asia by the watershed of the Ural Mountains, the Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea, and the Turkish straits.

Europe covers approx. 10,186,000 square kilometres (3,933,000 sq mi), or 2% of Earth's surface (6.8% of Earth's land area), making it the second-smallest continent (using the seven-continent model). Politically, Europe is divided into about fifty sovereign states, of which Russia is the largest and most populous, spanning 39% of the continent and comprising 15% of its population. Europe had a total population of about 745 million (about 10% of the world population) in 2021; the third-largest after Asia and Africa. The European climate is affected by warm Atlantic currents, such as the Gulf Stream, which produce a temperate climate, tempering winters and summers, on much of the continent. Further from the sea, seasonal differences are more noticeable producing more continental climates.

Iceland is a Nordic island country between the Arctic Ocean and the North Atlantic Ocean, located on the Mid-Atlantic Ridge between Europe and North America. It is culturally and politically linked with Europe and is the region's westernmost and most sparsely populated country. Its capital and largest city is Reykjavík, which is home to about 36% of the country's roughly 390,000 residents (excluding nearby towns/suburbs, which are separate municipalities). The official language of the country is Icelandic. Iceland is on a rift between tectonic plates, and its geologic activity includes geysers and frequent volcanic eruptions. The interior consists of a volcanic plateau with sand and lava fields, mountains and glaciers, and many glacial rivers flow to the sea through the lowlands. Iceland is warmed by the Gulf Stream and has a temperate climate, despite being at a latitude just south of the Arctic Circle. Its latitude and marine influence keep summers chilly, and most of its islands have a polar climate.

According to the Landnámabók, an ancient manuscript, the settlement of Iceland began in 874 AD, when the Norwegian chieftain Ingólfr Arnarson became the island's first permanent settler. In following centuries, Norwegians and to a lesser extent other Scandinavians, immigrated to Iceland, bringing with them thralls (i.e., slaves or serfs) of Gaelic origin. The island was governed as an independent commonwealth under the native parliament, the Althing, one of the world's oldest functioning legislative assemblies. After a period of civil strife, Iceland acceded to Norwegian rule in the 13th century. In 1397, Iceland followed Norway's integration into the Kalmar Union along with the kingdoms of Denmark and Sweden, coming under de facto Danish rule upon its dissolution in 1523. The Danish kingdom introduced Lutheranism by force in 1550, and the Treaty of Kiel formally ceded Iceland to Denmark in 1814.

The Faroe Islands (/ˈfɛəroʊ/ FAIR-oh) (alt. the Faroes) are an archipelago in the North Atlantic Ocean and an autonomous territory of the Kingdom of Denmark. Located between Iceland, Norway, and the Hebrides and Shetland isles of Scotland, the islands have a population of 54,885 as of September 2025 and a land area of 1,393 km². The official language is Faroese, which is partially mutually intelligible with Icelandic. The terrain is rugged, dominated by fjords and cliffs with sparse vegetation and few trees. As a result of their proximity to the Arctic Circle, the islands experience perpetual civil twilight during summer nights and very short winter days; nevertheless, they experience a subpolar oceanic climate and mild temperatures year-round due to the Gulf Stream. The capital, Tórshavn, receives the fewest recorded hours of sunshine of any city in the world at only 840 per year.

Færeyinga saga and the writings of Dicuil place initial Norse settlement in the early 9th century, with Grímur Kamban recorded as the first permanent settler. As with the subsequent settlement of Iceland, the islands were mainly settled by Norwegians and Norse-Gaels who also brought thralls (i.e. slaves or serfs) of Gaelic origin. However, new study has found that Viking colonizers of the Faroe Islands and nearby Iceland had different origins.

An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength. Ocean currents move both horizontally, on scales that can span entire oceans, as well as vertically, with vertical currents (upwelling and downwelling) playing an important role in the movement of nutrients and gases, such as carbon dioxide, between the surface and the deep ocean.

Ocean currents are classified by temperature as either warm currents or cold currents. They are also classified by their velocity, dimension, and direction as either drifts, currents, or streams. Drifts, such as the North Atlantic Drift Current, involve the forward movement of surface ocean water under the influence of the prevailing wind. Currents, such as the Labrador Current, involve the movement of oceanic water in a more definite direction at a greater velocity than drifts. Streams, such as the Gulf Stream, involve movement of larger masses of ocean water with greater velocity than drifts or currents.

The Straits of Florida, Florida Straits, or Florida Strait (Spanish: Estrecho de Florida) is a strait located south-southeast of the North American mainland, generally accepted to be between the Gulf of Mexico and the Atlantic Ocean, and between the Florida Keys (U.S.) and Cuba. It is 93 mi (150 km) wide at the narrowest point between Key West and the Cuban shore, and has been sounded to a depth of 6,000 feet (1,800 m). The strait carries the Florida Current, the beginning of the Gulf Stream, from the Gulf of Mexico.

The North Atlantic Current (NAC), also known as North Atlantic Drift and North Atlantic Sea Movement, is a powerful warm western boundary current within the Atlantic Ocean that extends the Gulf Stream northeastward.

The North Atlantic Gyre of the Atlantic Ocean is one of five great oceanic gyres. It is a circular ocean current, with offshoot eddies and sub-gyres, across the North Atlantic from the Intertropical Convergence Zone (calms or doldrums) to the part south of Iceland, and from the east coasts of North America to the west coasts of Europe and Africa.

In turn it is chiefly subdivided into the Gulf Stream flowing northward along the west; its often conflated continuation, the North Atlantic Current across the north; the Canary Current flowing southward along the east; and the Atlantic's North Equatorial Current in the south. The gyre has a pronounced thermohaline circulation, bringing salty water west from the Mediterranean Sea and then north to form the North Atlantic Deep Water.

The climate of Ireland is mild, humid and changeable with abundant rainfall and a lack of temperature extremes. Ireland's climate is defined as a temperate oceanic climate, or Cfb on the Köppen climate classification system, a classification it shares with most of northwest Europe. The island receives generally warm summers and cool winters.

As Ireland is downwind of a large ocean, it is considerably milder in winter than other locations at the same latitude, for example Newfoundland in Canada or Sakhalin in Russia. The Atlantic overturning circulation, which includes ocean currents such as the North Atlantic Current and Gulf Stream, releases additional heat over the Atlantic, which is then carried by the prevailing winds towards Ireland giving, for example, Dublin a milder winter climate than other temperate oceanic climates in similar locations.

The Isthmus of Panama, historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. The country of Panama is located on the isthmus, along with the Panama Canal. Like several isthmuses on Earth, as a relatively narrow land bridge between close seas, it is a location of great geopolitical and strategic importance.

The isthmus is thought to have finally formed around 3 million years ago (Ma), separating the Atlantic and Pacific Oceans and causing the creation of the Gulf Stream, as first suggested in 1910 by Henry Fairfield Osborn. Osborn based the proposal on the fossil record of mammals in Central America, a conclusion that would provide a foundation for Alfred Wegener when he proposed the theory of continental drift in 1912. Some recent studies suggest an earlier formation of the isthmus than the recognized age of 3 Ma, potentially stretching as far back as 19 Ma.

The Sargasso Sea (/sɑːrˈɡæsoʊ/) is a region of the Atlantic Ocean bounded by four currents forming an ocean gyre. It is the only named sea without land boundaries. It is distinguished from other parts of the Atlantic Ocean by its characteristic brown Sargassum seaweed and often calm blue water.

The sea is bounded on the west by the Gulf Stream, on the north by the North Atlantic Current, on the east by the Canary Current, and on the south by the North Atlantic Equatorial Current, the four together forming a clockwise-circulating system of ocean currents termed the North Atlantic Gyre. It lies between 20° and 35° north and 40° and 70° west and is approximately 1,100 kilometres (600 nautical miles) wide by 3,200 km (1,750 nmi) long. Bermuda is near the western fringes of the sea. While all of the above currents deposit marine plants and refuse into the sea, ocean water in the Sargasso Sea is distinctive for its deep blue color and exceptional clarity, with underwater visibility of up to 60 m (200 ft).

The Kuroshio Current (黒潮; "Black Tide"), also known as the Black Current or Japan Current (日本海流, Nihon Kairyū), is a north-flowing, warm ocean current on the west side of the North Pacific Ocean basin. It was named for the deep blue appearance of its waters. Similar to the Gulf Stream in the North Atlantic, the Kuroshio is a powerful western boundary current that transports warm equatorial water poleward and forms the western limb of the North Pacific Subtropical Gyre. Off the East Coast of Japan, it merges with the Oyashio Current to form the North Pacific Current.

The Kuroshio Current has significant effects on both physical and biological processes of the North Pacific Ocean, including nutrient and sediment transport, major pacific storm tracks and regional climate, and Pacific mode water formation. Additionally, the current's significant nutrient transport results in a biologically rich ecoregion supporting an important fishing industry as well as diverse marine food webs. The South China Sea for example has relatively low nutrient concentrations in its upper waters, but experiences enhanced biological productivity due to the input from the Kuroshio Current Intrusion. Ongoing research centered around the Kuroshio Current's response to climate change predicts a strengthening in surface flows of this western boundary current which contrasts the predicted changes in the Atlantic Ocean's Gulf Stream.

The Neogene (/ˈniː.ədʒiːn/ NEE-ə-jeen,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period 23.04 Ma (million years ago) to the beginning of the present Quaternary Period 2.58 Ma. It is the second period of the Cenozoic and the eleventh period of the Phanerozoic. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). The earlier term Tertiary Period was used to define the span of time now covered by Paleogene and Neogene and, despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use.

During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first humans (Homo habilis) appeared in Africa near the end of the period. Some continental movements took place, the most significant event being the connection of North and South America at the Isthmus of Panama, late in the Pliocene. This cut off the warm ocean currents from the Pacific to the Atlantic Ocean, leaving only the Gulf Stream to transfer heat to the Arctic Ocean. The global climate cooled considerably throughout the Neogene, culminating in a series of continental glaciations in the Quaternary Period that followed.

A flow tracer is any fluid property used to track the flow velocity (i.e., flow magnitude and direction) and circulation patterns. Tracers can be chemical properties, such as radioactive material, or chemical compounds, physical properties, such as density, temperature, salinity, or dyes, and can be natural or artificially induced. Flow tracers are used in many fields, such as physics, hydrology, limnology, oceanography, environmental studies and atmospheric studies.

Conservative tracers remain constant following fluid parcels, whereas reactive tracers (such as compounds undergoing a mutual chemical reaction) grow or decay with time. Active tracers dynamically alter the flow of the fluid by changing fluid properties which appear in the equation of motion such as density or viscosity, while passive tracers have no influence on flow.

Thermohaline circulation (THC) is a part of the large-scale ocean circulation driven by global density gradients formed by surface heat and freshwater fluxes. The name thermohaline is derived from thermo-, referring to temperature, and haline, referring to salt content—factors which together determine the density of sea water.

Wind-driven surface currents (such as the Gulf Stream) travel polewards from the equatorial Atlantic Ocean, cooling and sinking en-route to higher latitudes - eventually becoming part of the North Atlantic Deep Water - before flowing into the ocean basins. While the bulk of thermohaline water upwells in the Southern Ocean, the oldest waters (with a transit time of approximately 1000 years) upwell in the North Pacific; extensive mixing takes place between the ocean basins, reducing the difference in their densities, forming the Earth's oceans a global system. The water in these circuits transport energy - as heat - and mass - as dissolved solids and gases - around the globe. Consequently, the state of the circulation greatly impacts the climate of Earth.

The Agulhas Current (/əˈɡʌləs/) is the western boundary current of the southwest Indian Ocean. It flows south along the east coast of Africa from 27°S to 40°S. It is narrow, swift and strong. It is suggested that it is the largest western boundary current in the world ocean, with an estimated net transport of 70 sverdrups (70 million cubic metres per second), as western boundary currents at comparable latitudes transport less — Brazil Current (16.2 Sv), Gulf Stream (34 Sv), Kuroshio (42 Sv).

The Labrador Current is a cold current in the North Atlantic Ocean which flows from the Arctic Ocean south along the coast of Labrador and passes around Newfoundland, continuing south along the east coast of Canada near Nova Scotia. Near Nova Scotia, this cold water current meets the warm northward moving Gulf Stream. The combination of these two currents produces heavy fogs and has also created one of the richest fishing grounds in the world.

In spring and early summer, the Labrador Current transports icebergs from the glaciers of Greenland southwards into the trans-Atlantic shipping lanes. The waters of the current have a cooling effect on the Canadian Atlantic provinces, and on the United States' upper northeast coast from Maine south to Massachusetts. South of Cape Cod, Massachusetts, the Gulf Stream becomes the dominant ocean current.