In 1992, a cargo ship carrying bath toys got caught in a storm. Shipping containers washed overboard, and the waves swept 28,000 rubber ducks and other toys into the North Pacific. But they didn’t stick together. Quite the opposite– the ducks have since washed up all over the world, and researchers have used their paths to chart a better understanding of ocean currents.
Mwaka 1992 Meli ya mizigo iliyobeba shehena ya Vichezeo vya kuogea ilipatwa na dhoruba. Makontena ya kusafirishia shehena yakapotea kwenye maji, Mawimbi yalisomba bata wa raba na vichezeo vinginevyo kwenye bahari ya Pacific ya kaskazini. Lakini havikukaa pamoja. Tofauti kabisa-- Bata hao wametapakaa Dunia nzima, Na wachunguzi wametumia njia yao Kuelewa zaidi mikondo ya Bahari.
Ocean currents are driven by a range of sources: the wind, tides, changes in water density, and the rotation of the Earth. The topography of the ocean floor and the shoreline modifies those motions, causing currents to speed up, slow down, or change direction.
Mikondo ya bahari inaendeshwa na vitu vingi: Upepo,mawimbi,mabadiliko kwenye wiani, Na mzunguko wa Dunia. Topografia ya sakafu ya bahari na ufukwe vinaongeza hiyo mizunguko, Kusababisha mikondo iongeze spidi, Kupunguza spidi au kubadili muelekeo.
Ocean currents fall into two main categories: surface currents and deep ocean currents. Surface currents control the motion of the top 10 percent of the ocean’s water, while deep-ocean currents mobilize the other 90 percent. Though they have different causes, surface and deep ocean currents influence each other in an intricate dance that keeps the entire ocean moving.
Mikondo ya bahari imegawanyika kwenye makundi makuu mawili: Mikondo ya juu na mikondo ya ndani ya bahari. Mikondo ya juu ina dhibiti mwendo Wa asilimia 10 ya maji ya bahari, Wakati mikondo ya ndani inadhibiti asilimia 90 iliyobaki. Japo yanasababishwa na vitu tofauti, Mikondo ya juu na ya ndani inashabiana Ni dansi ambayo inaifanya bahari itembee.
Near the shore, surface currents are driven by both the wind and tides, which draw water back and forth as the water level falls and rises. Meanwhile, in the open ocean, wind is the major force behind surface currents. As wind blows over the ocean, it drags the top layers of water along with it. That moving water pulls on the layers underneath, and those pull on the ones beneath them. In fact, water as deep as 400 meters is still affected by the wind at the ocean’s surface.
Karibu na fukwe, Mikondo ya bahari ya juu inaendeshwa na upepo na mawimbi, Ambayo inavuta Maji ndani na Nje pale ambapo kiwango cha maji kinapungua na kuongezeka. Wakati huo huo,kwenye bahari upepo ndio nguvu kubwa ya mikondo ya juu. Upepo unapovuma juu ya bahari, Unaenda na maji ya juu, Maji yanayotembea yavuta vilivyomo chini, Na hizo zinavuta za chini yake. Maji yenye kina kirefu cha Mita 400 Bado yana athiriwa na upepo wa juu ya bahari.
If you zoom out to look at the patterns of surface currents all over the earth, you’ll see that they form big loops called gyres, which travel clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere. That’s because of the way the Earth’s rotation affects the wind patterns that give rise to these currents.
Ukiangalia kwa karibu muundo wa mikondo ya juu ya bahari ya Dunia nzima, Utaona kwamba inatengeneza vitanzi vikubwa vinavyoitwa gyre, Inayosafiri upande wa saa kaskazini mwa ulimwengu Na kwa kurudi kusini mwa ulimwengu. Hiyo ni sababu ya jinsi Dunia inavyozunguka Inaingilia muundo wa upepo inayoleta hii mikondo.
If the earth didn’t rotate, air and water would simply move back and forth between low pressure at the equator and high pressure at the poles. But as the earth spins, air moving from the equator to the North Pole is deflected eastward, and air moving back down is deflected westward. The mirror image happens in the southern hemisphere, so that the major streams of wind form loop-like patterns around the ocean basins. This is called the Coriolis Effect. The winds push the ocean beneath them into the same rotating gyres. And because water holds onto heat more effectively than air, these currents help redistribute warmth around the globe.
Kama Dunia isingezunguka, Maji na hewa vingeenda mbele na nyuma Kutoka sehemu yenye presha ndogo ikweta Na presha kubwa kwenye fito. Lakini Kadri Dunia inavyozunguka, Hewa kutoka ikweta kwenda kwenye fito ya kaskazini inageukia mashariki, Na hewa inayoelekea chini inageukia magharibi. Tofauti yake inatokea kwenye ulimwengu wa kusini, Ili kusudi mito mikubwa ya upepo Inatengeneza miundo ya vitanzi karibu na mabonde ya bahari. Hii inaitwa ifekti ya coriolis. Upepo unasukuma bahari chini yake kwenye gyre za kuzunguka. Na sababu maji yanashika moto upesi kushinda hewa, Hii mikondo inasaidia kugawanya joto duniani.
Unlike surface currents, deep ocean currents are driven primarily by changes in the density of seawater. As water moves towards the North Pole, it gets colder. It also has a higher concentration of salt, because the ice crystals that form trap water while leaving salt behind. This cold, salty water is more dense, so it sinks, and warmer surface water takes its place, setting up a vertical current called thermohaline circulation.
Tofauti na mikondo ya juu, Mikondo ya ndani inaendeshwa na tofauti ya wiani wa maji ya bahari. Maji yanavyoelekea fito ya kaskazini, Yanakuwa na baridi. Pia yanakuwa na chumvi nyingi, Sababu ile barafu inayoshikilia maji wakati inaacha chumvi nyuma. Haya Maji ya baridi yenye chumvi ni mazito zaidi Kwahiyo yananuka, Na Maji ya uvugu vugu yanachukua nafasi yake. Kutengeneza mkondo wa wima unaoitwa mzunguko wa thermohaline
Thermohaline circulation of deep water and wind-driven surface currents combine to form a winding loop called the Global Conveyor Belt. As water moves from the depths of the ocean to the surface, it carries nutrients that nourish the microorganisms which form the base of many ocean food chains.
Mzunguko wa thermohaline wa maji ya ndani na yanayoendeshwa na upepo wa Mkondo wa bahari wa juu Unajiunga kutengeneza kitanzi cha upepo kinachoitwa Global Conveyor Belt. Maji yanavyohama kutoka ndani ya bahari kwenda juu. Yanabeba virutubishi ambavyo vinasaidia kukuza viumbe hai Ambayo inatengeneza msingi wa cheni nyingi za chakula baharini.
The global conveyor belt is the longest current in the world, snaking all around the globe. But it only moves a few centimeters per second. It could take a drop of water a thousand years to make the full trip. However, rising sea temperatures are causing the conveyor belt to seemingly slow down. Models show this causing havoc with weather systems on both sides of the Atlantic, and no one knows what would happen if it continues to slow or if it stopped altogether. The only way we’ll be able to forecast correctly and prepare accordingly will be to continue to study currents and the powerful forces that shape them.
Mkondo wa Global Conveyor belt ndo mrefu zaidi duniani, Ukizunguka dunia nzima. Lakini unazunguka sentimita chache kwa sekunde. Inaweza ichukua tone la maji miaka 1000 kufanya safari yote. Japokuwa Levo za joto la bahari zinazopanda zinasababisha ukanda wa conveyor Kupunguza spidi. Modeli zinaonesha hii inasabisha ma tatizo kwenye hali ya hewa Kwenye pande zote za Atlantic, Na hamna anayejua nini kitatokea ikiendelea kupunguza spidi Au ikisimama kabisa Njia pekee tutakayoweza tabiri sawasawa na kujiandaa vizuri Ni Kwa kuendelea kusoma mikondo na nguvu zote zinazosababisha mikondo kuwepo.