Pacific Ocean Warming increased at an accelerating rate, heated with so much zettajoule. Heat Content in ocean change it current Climate Change phenomenon trends

The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on the definition, to Antarctica) in the south, and is bounded by the continents of Asia and Australia in the west and the Americas in the east.

At 165,250,000 square kilometers (63,800,000 square miles) in area (as defined with a southern Antarctic border), the largest division of the World Ocean and the hydrosphere covers about 46% of Earth's water surface and about 32% of the planet's total surface area, larger than its entire land area (148,000,000 km² (57,000,000 sq mi)). The centers of both the water hemisphere and the Western Hemisphere, as well as the oceanic pole of inaccessibility, are in the Pacific Ocean.

The Pacific Ocean's mean depth is 4,000 meters (13,000 feet). The Challenger Deep in the Mariana Trench, located in the northwestern Pacific, is the deepest known point in the world, reaching a depth of 10,928 meters (35,853 feet). The Pacific also contains the deepest point in the Southern Hemisphere, the Horizon Deep in the Tonga Trench, at 10,823 meters (35,509 feet). The third deepest point on Earth, the Sirena Deep, is also located in the Mariana Trench.

Due to the effects of plate tectonics, the Pacific Ocean is currently shrinking by roughly 2.5 cm (1 in) per year on three sides, roughly averaging 0.52 km² (0.20 sq mi) a year. By contrast, the Atlantic Ocean is increasing in size.

Along the Pacific Ocean's irregular western margins lie many seas, the largest of which are the Celebes Sea, Coral Sea, East China Sea (East Sea), Philippine Sea, Sea of Japan, South China Sea (South Sea), Sulu Sea, Tasman Sea, and Yellow Sea (West Sea of Korea). The Indonesian Seaway (including the Strait of Malacca and Torres Strait) joins the Pacific and the Indian Ocean to the west, and Drake Passage and the Strait of Magellan link the Pacific with the Atlantic Ocean on the east. To the north, the Bering Strait connects the Pacific with the Arctic Ocean.

The Pacific Ocean has most of the islands in the world. There are about 25,000 islands in the Pacific Ocean. Many tropical storms batter the islands of the Pacific. The lands around the Pacific Rim are full of volcanoes and often affected by earthquakes. Unknown Tsunamis, caused by underwater earthquakes, have devastated many islands and in some cases destroyed entire towns.

Pacific Oceans and Heat Uptake

Ocean heat content (OHC) or ocean heat uptake (OHU) is the energy absorbed and stored by oceans. To calculate the ocean heat content, it is necessary to measure ocean temperature at many different locations and depths. The North Pacific, North Atlantic, the Mediterranean, and the Southern Ocean all recorded their highest heat observations for more than sixty years of global measurements.

Numerous independent studies in recent years have found a multi-decadal rise in OHC of upper ocean regions that has begun to penetrate to deeper regions. The upper ocean (0–700 m) has warmed since 1971, while it is very likely that warming has occurred at intermediate depths (700–2000 m) and likely that deep ocean (below 2000 m) temperatures have increased. There is very high confidence that increased ocean heat content in response to anthropogenic carbon dioxide emissions and waste pollution is essentially irreversible on human time scales.

In 2021 scientists from around the world revealed that, per their measurement, the world oceans are hotter than ever recorded for the sixth straight year. “One way to think about this is the oceans have absorbed heat equivalent to seven Hiroshima atomic bombs detonating each second, 24 hours a day, 365 days a year.” Scientifically, the data shows that the oceans heated up by about 14 zettajoules.

In 2023, the world's oceans were again the hottest in the historical record and exceeded the previous 2022 record maximum. The five highest ocean heat observations to a depth of 2000 meters occurred in the period 2019–2023.

With improving observation in recent decades, the heat content of the upper ocean has been analyzed to have increased at an accelerating rate. Changes in ocean temperature greatly affect ecosystems in oceans and on land.

Ocean heat uptake accounts for over 90% of total planetary heat uptake, mainly as a consequence of human-caused changes to the composition of Earth's atmosphere.

Concentrated releases in association with high sea surface temperatures help drive tropical cyclones, atmospheric rivers, atmospheric heat waves and other extreme weather events that can penetrate far inland. Altogether these processes enable the ocean to be Earth's largest thermal reservoir which functions to regulate the planet's climate; acting as both a sink and a source of energy. 

Current trends phenomenon of Climate Change

Marine Heatwave
A marine heatwave is a period of abnormally high sea surface temperatures compared to the typical temperatures in the past for a particular season and region. Unlike heatwaves on land, marine heatwaves can extend over vast areas, persist for weeks to months or even years, and occur at subsurface levels. It is clear that the ocean is warming as a result of climate change, and this rate of warming is increasing.

Scientists predict that the frequency, duration, scale (or area) and intensity of marine heatwaves will continue to increase. This is because sea surface temperatures will continue to increase with global warming, and therefore the frequency and intensity of marine heatwaves will also increase. Simply put, the more greenhouse gas emissions and waste pollution (or the less mitigation), the more the sea surface temperature will rise.

Many species already experience these temperature shifts during the course of marine heatwave events. There are many increased risk factors and health impacts to coastal and inland communities as global average temperature and extreme heat events increase.

The Blob

The Blob is a large mass of relatively warm water in the Pacific Ocean off the coast of North America that was first detected in late 2013 and continued to spread throughout 2014 and 2015. It is an example of a marine heatwave. Sea surface temperatures indicated that the Blob persisted into 2016, but it was initially thought to have dissipated later that year.

By September 2016, the Blob resurfaced and made itself known to meteorologists. The warm water mass was unusual for open ocean conditions and was considered to have played a role in the formation of the unusual weather conditions experienced along the Pacific coast of North America during the same time period. The warm waters of the Blob were nutrient-poor and adversely affected marine life.

In 2019 another scare was caused by a weaker form of the effect referred as "The Blob 2.0" and in 2021 the appearance of "The Southern Blob" at south of the equator near New Zealand has caused a major effect in South America, particularly Chile and Argentina.

The Blob was first detected in October 2013 and early 2014 by Nicholas Bond and his colleagues at the Joint Institute for the Study of the Atmosphere and Ocean of the University of Washington. It was detected when a large circular body of seawater did not cool as expected and remained much warmer than the average normal temperatures for that location and season.

Initially the Blob was reported as being 500 miles (800 km) wide and 300 feet (91 m) deep. It later expanded and reached a size of 1,000 miles (1,600 km) long, 1,000 miles (1,600 km) wide, and 300 feet (91 m) deep in. In February 2014, the temperature of the Blob was around 2.5 °C (4.5 °F) warmer than what was usual for the time of year. A NOAA scientist noted in September 2014 that, based on ocean temperature records, the North Pacific Ocean had not previously experienced temperatures so warm since climatologists began taking measurements.

In 2015 the atmospheric ridge causing the Blob finally disappeared. The Blob vanished shortly after in 2016. However, in its wake are many species that will take a long time to recover. Although the Blob is gone for now, scientists predict that similar marine heat waves are becoming more common due to the Earth's warming climate. Residual heat from the first blob in addition to warmer temperatures in 2019 lead to a second Blob scare. However, it was quelled by a series of storms that cooled the rising temperatures.

The reason for the phenomenon remains unclear, but it is speculated to partially be human caused climate change.

Caused of increasing heat in Pacific Ocean

Environment

The Northwestern Pacific Ocean is most susceptible to micro plastic pollution due to its proximity to highly populated countries like Japan and China. The quantity of small plastic fragments floating in the north-east Pacific Ocean increased a hundredfold between 1972 and 2012. The ever-growing Great Pacific Garbage Patch between California and Japan is three times the size of France. An estimated 80,000 metric tons of plastic inhabit the patch, totaling 1.8 trillion pieces.

Marine pollution is a generic term for the harmful entry into the ocean of chemicals or particles. The main culprits are those using the rivers for disposing of their waste. The rivers then empty into the ocean, often also bringing chemicals used as fertilizers in agriculture. The excess of oxygen-depleting chemicals in the water leads to hypoxia and the creation of a dead zone.

Marine debris, also known as marine litter, is human-created waste that has ended up floating in a lake, sea, ocean, or waterway. Oceanic debris tends to accumulate at the center of gyres and coastlines, frequently washing aground where it is known as beach litter.

In addition, the Pacific Ocean has served as the crash site of satellites, including Mars 96, Fobos-Grunt, and Upper Atmosphere Research Satellite.

Nuclear waste

From 1946 to 1958, Marshall Islands served as the Pacific Proving Grounds, designated by the United States, and played host to a total of 67 nuclear tests conducted across various atolls. Several nuclear weapons were lost in the Pacific Ocean, including one-megaton bomb that was lost during the 1965 Philippine Sea A-4 incident.

In 2021, the discharge of radioactive water from the Fukushima nuclear plant into the Pacific Ocean over a course of 30 years was approved by the Japanese Cabinet. The Cabinet concluded the radioactive water would have been diluted to drinkable standard. Apart from dumping, leakage of tritium into the Pacific was estimated to be between 20 and 40 trillion Bqs from 2011 to 2013, according to the Fukushima plant.

Deep sea mining

An emerging threat for the Pacific Ocean is the development of deep-sea mining. Deep-sea mining is aimed at extracting manganese nodules that contain minerals such as magnesium, nickel, copper, zinc and cobalt. The largest deposits of these are found in the Pacific Ocean between Mexico and Hawaii in the Clarion Clipperton fracture zone.

Deep-sea mining for manganese nodules appears to have drastic consequences for the ocean. It disrupts deep-sea ecosystems and may cause irreversible damage to fragile marine habitats. Sediment stirring and chemical pollution threaten various marine animals. In addition, the mining process can lead to greenhouse gas emissions and promote further climate change. Preventing deep-sea mining is therefore important to ensure the long-term health of the ocean.

Options for reducing impacts

To address the root cause of more frequent and more intense marine heatwaves, climate change mitigation methods are needed to curb the increase in global temperature and in ocean temperatures.

Better forecasts of marine heatwaves and improved monitoring can also help to reduce impacts of these heatwaves.