The Kuroshio Current (黒潮; "Black Stream"), 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. Since the early 20th century, anthropologists have debated the role of the current in Japanese culture. Today, historians are reevaluating the role of the current as a factor in Japan's economic development.
History The Kuroshio current was discovered in 1565 by Andrés de Urdaneta, a native of Guipuzcoa, colonial administrator, supervisor of nautical expeditions, Corregidor, Augustinian monk and loyal navigator in the service of King Philip II, when, aboard the nao San Pedro, he was the first to open the "tornaviaje" between Cebu (Philippines) and the coasts of Old California (New Spain). The secret of the tornaviaje gave Spain absolute hegemony over the Pacific Ocean for centuries, a hegemony that was embodied in the so-called "Manila galleon". The existence of the Kuroshio Current was known to Europeans from as early as 1650. This was shown in a map drawn by Bernhardus Varenius. As well as this, it was also noted by Captain J. King during a British expedition under Captain James Cook. Historians have debated the current’s role in structuring the economic geography of Japan, especially at the time before steam navigation. The current’s path influenced the development of fisheries and whaling businesses that grew in the early modern period in specific regions. Its movement was also a factor in the development of maritime routes for domestic shipping as well as international navigation along the shores of Japan. In the mid-19th century, the current became an object of oceanographic interest both in Japan and abroad. The ideological effect of scientific conquest and industrial appropriation of the Kuroshio by the Japanese Empire has been likened to a frontier incorporation.
Physical properties
The Kuroshio is a relatively warm ocean current with an annual average sea-surface temperature of about 24 °C (75 °F), is approximately 100 kilometres (62 mi) wide, and produces frequent small to meso-scale eddies. The Kuroshio originates from the Pacific North Equatorial Current, which splits in two at the east coast of Luzon, Philippines, to form the southward-flowing Mindanao Current and the more significant northward-flowing Kuroshio Current. East of Taiwan, the Kuroshio enters the East China Sea through a deep break in the Ryukyu island chain known as the Yonaguni Depression. The Kuroshio then continues northwards and parallel to the Ryukyu islands, steered by the deepest part of the East China Sea, the Okinawa Trough, before leaving the East China Sea and re-entering the Pacific through the Tokara Strait. It then flows along the southern margin of Japan but meanders significantly. At the Bōsō Peninsula, the Kuroshio finally separates from the Japanese coast and travels eastward as the Kuroshio Extension. The Kuroshio Current is the Pacific analogue of the Gulf Stream in the Atlantic Ocean, transporting warm, tropical water northward toward the polar region. The Kuroshio's counterparts associated with the North Pacific Gyre are the: east flowing North Pacific Current to the north, the south flowing California Current to the east, and the west flowing North Equatorial Current to the south. The warm waters of the Kuroshio Current sustain the coral reefs of Japan, the northernmost coral reefs in the world. The part of the Kuroshio that branches into the Sea of Japan is called Tsushima Current (対馬海流, Tsushima Kairyū).
… excerpt ends here. Continue reading the full article.
