Ocean heat content

Ocean heat content (OHC) 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. Integrating the areal density of ocean heat over an ocean basin or entire ocean gives the total ocean heat content.^[2] Between 1971 and 2018, the rise in ocean heat content accounted for over 90% of Earth’s excess thermal energy from global heating.^[3][4] The main driver of this increase was anthropogenic forcing via rising greenhouse gas emissions.^[5]: 1228 By 2020, about one third of the added energy had propagated to depths below 700 meters.^[6][7] In 2022, the world’s oceans were again the hottest in the historical record and exceeded the previous 2021 record maximum.^[8] The four highest ocean heat observations occurred in the period 2019–2022. The North Pacific, North Atlantic, the Mediterranean, and the Southern Ocean all recorded their highest heat observations for more than sixty years.^[9] Ocean heat content and sea level rise are important indicators of climate change.^[10]

There has been an increase in ocean heat content during recent decades as the oceans absorb most of the excess heat created by human-induced global warming.^[1]

Ocean water absorbs solar energy efficiently. It has far greater heat capacity than atmospheric gases.^[6] As a result, the top few meters of the ocean contain more thermal energy than the entire Earth's atmosphere.^[11] Since before 1960, research vessels and stations have sampled sea surface temperatures and temperatures at greater depth all over the world. Since 2000, an expanding network of nearly 4000 Argo robotic floats has measured temperature anomalies, or the change in ocean heat content. Ocean heat content has been increasing at a steady or accelerating rate since at least 1990.^[3][12] The net rate of change in the upper 2000 meters from 2003 to 2018 was +0.58±0.08 W/m² (or annual mean energy gain of 9.3 zettajoules). It is challenging to measure temperatures over decades with sufficient accuracy and covering enough areas. This gives rise to the uncertainty in the figures.^[10]

Changes in ocean heat content have far-reaching consequences for the planet's marine and terrestrial ecosystems; including multiple impacts to coastal ecosystems and communities. Direct effects include variations in sea level and sea ice, shifts in intensity of the water cycle, and the migration and extinction of marine life.^[13][14]

Calculations

Definition

 

Graph of different thermoclines (depth versus ocean temperature) based on seasons and latitude

Ocean heat content is "the total amount of heat stored by the oceans".^[15] To calculate the ocean heat content, measurements of ocean temperature at many different locations and depths are required.

Integrating the areal density of ocean heat over an ocean basin, or entire ocean, gives the total ocean heat content. Thus, total ocean heat content is a volume integral of the product of temperature, density, and heat capacity over the three-dimensional region of the ocean for which data is available. The bulk of measurements have been performed at depths shallower than about 2000 m (1.25 miles).^[16]

The areal density of ocean heat content between two depths is defined as a definite integral:^[17][2]

${\displaystyle H=c_{p}\int _{h2}^{h1}\rho (z)T(z)dz}$ 

where ${\displaystyle c_{p}}$  is the specific heat capacity of sea water, h2 is the lower depth, h1 is the upper depth, ${\displaystyle \rho (z)}$  is the seawater density profile, and ${\displaystyle T(z)}$  is the temperature profile. In SI units, ${\displaystyle H}$  has units of Joules per square metre (J·m⁻²).

In practice, the integral can be approximated by summation of a smooth and otherwise well-behaved sequence of temperature and density data. Seawater density is a function of temperature, salinity, and pressure. Despite the cold and great pressure at ocean depth, water is nearly incompressible and favors the liquid state for which its density is maximized.

Measurements of temperature versus ocean depth generally show an upper mixed layer (0–200 m), a thermocline (200–1500 m), and a deep ocean layer (>1500 m). These boundary depths are only rough approximations. Sunlight penetrates to a maximum depth of about 200 m; the top 80 m of which is the habitable zone for photosynthetic marine life covering over 70% of Earth's surface.^[18] Wave action and other surface turbulence help to equalize temperatures throughout the upper layer.

Unlike surface temperatures which decrease with latitude, deep-ocean temperatures are relatively cold and uniform in most regions of the world.^[19] About 50% of all ocean volume is at depths below 3000 m (1.85 miles), with the Pacific Ocean being the largest and deepest of five oceanic divisions. The thermocline is the transition between upper and deep layers in terms of temperature, nutrient flows, abundance of life, and other properties. It is semi-permanent in the tropics, variable in temperate regions (often deepest during the summer), and shallow to nonexistent in polar regions.^[20]

Measurements

 

The global distribution of active floats in the Argo array^[21]

See also: Argo (oceanography) and Ocean temperature

Ocean heat content measurements come with difficulties, especially before the deployment of the Argo profiling floats. Due to poor spatial coverage and poor quality of data, it has not always been easy to distinguish between long term global warming trends and climate variability. Examples of these complicating factors are the variations caused by El Niño–Southern Oscillation or changes in ocean heat content caused by major volcanic eruptions.^[10]

Argo is an international program of robotic profiling floats deployed globally since the start of the 21st century.^[22] The program's initial 3000 units had expanded to nearly 4000 units by year 2020. At the start of each 10-day measurement cycle, a float descends to a depth of 1000 meters and drifts with the current there for nine days. It then descends to 2000 meters and measures temperature, salinity (conductivity), and depth (pressure) over a final day of ascent to the surface. At the surface the float transmits the depth profile and horizontal position data through satellite relays before repeating the cycle.^[23]

Starting 1992, the TOPEX/Poseidon and subsequent Jason satellite series have observed vertically integrated OHC, which is a major component of sea level rise.^[24] The partnership between Argo and Jason measurements has yielded ongoing improvements to estimates of OHC and other global ocean properties.^[21]

Causes for heat uptake

Oceanographer Josh Willis discusses the heat capacity of water, performs an experiment to demonstrate heat capacity using a water balloon and describes how water's ability to store heat affects Earth's climate.

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.^[11][25] This high percentage is because waters at and below the ocean surface - especially the turbulent upper mixed layer - exhibit a thermal inertia much larger than the planet's exposed continental crust, ice-covered polar regions, or atmospheric components themselves. A body with large thermal inertia stores a big amount of energy because of its volumetric heat capacity, and effectively transmits energy according to its heat transfer coefficient. Most extra energy that enters the planet via the atmosphere is thereby taken up and retained by the ocean.^[26][27][28]

 

Earth heat inventory (energy accumulation) in ZJ for the components of the Earth's climate system relative to 1960 and from 1960 to 2018. The upper ocean (0–300 m, light blue line, and 0–700 m, light blue shading) accounts for the largest amount of heat gain.^[3]

Planetary heat uptake or heat content accounts for the entire energy added to or removed from the climate system.^[29] It can be computed as an accumulation over time of the observed differences (or imbalances) between total incoming and outgoing radiation. Changes to the imbalance have been estimated from Earth orbit by CERES and other remote instruments, and compared against in-situ surveys of heat inventory changes in oceans, land, ice and the atmosphere.^[3][30][31] Achieving complete and accurate results from either accounting method is challenging, but in different ways that are viewed by researchers as being mostly independent of each other.^[30] Recent increases in planetary heat content obtained from the two methods are in overall agreement and are thought to exceed measurement uncertainties.^[25]

From the ocean perspective, the more abundant equatorial solar irradiance is directly absorbed by Earth's tropical surface waters and drives the overall poleward propagation of heat. The surface also exchanges energy that has been absorbed by the lower troposphere through wind and wave action. Over time, a sustained imbalance in Earth's energy budget enables a net flow of heat either into or out of greater ocean depth via thermal conduction, downwelling, and upwelling.^[32][33] Releases of OHC to the atmosphere occur primarily via evaporation and enable the planetary water cycle.^[34] 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.^[16][35] 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.^[26]

 

Surface air temperatures over land masses have been increasing faster than the sea surface temperature because the ocean has been absorbing most of the heat from global warming.

From the perspective of land and ice covered regions, their portion of heat uptake is reduced and delayed by the dominant thermal inertia of the ocean. Although the average rise in land surface temperature has exceeded the ocean surface due to the lower inertia (smaller heat-transfer coefficient) of solid land and ice, temperatures would rise more rapidly and by a greater amount without the full ocean.^[26] Measurements of how rapidly the heat mixes into the deep ocean have also been underway to better close the ocean and planetary energy budgets.^[36]

The ocean also functions as a sink and source of carbon, with a role comparable to that of land regions in Earth's carbon cycle.^[37][38] In accordance with the temperature dependence of Henry's law, warming surface waters are less able to absorb atmospheric gases including oxygen and the growing emissions of carbon dioxide and other greenhouse gases from human activity.^[39][40]

Recent observations and changes

 

Map of the ocean heat anomaly in the upper 700 meters for year 2020 versus the 1993–2020 average.^[41] Some regions accumulated more energy than others due to transport drivers such as winds and currents.

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.^[3][42] 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.^[5]: 1228 The heat uptake results from a persistent warming imbalance in Earth's energy budget that is most fundamentally caused by the anthropogenic increase in atmospheric greenhouse gases.^[43]: 41 The rate in which the ocean absorbs anthropogenic carbon dioxide has approximately tripled from the early 1960s to the late 2010s, a scaling proportional to the increase in atmospheric carbon dioxide.^[44] There is very high confidence that increased ocean heat content in response to anthropogenic carbon dioxide emissions is essentially irreversible on human time scales.^[5]: 1233

Studies based on Argo measurements indicate that ocean surface winds, especially the subtropical trade winds in the Pacific Ocean, change ocean heat vertical distribution.^[45] This results in changes among ocean currents, and an increase of the subtropical overturning, which is also related to the El Niño and La Niña phenomenon. Depending on stochastic natural variability fluctuations, during La Niña years around 30% more heat from the upper ocean layer is transported into the deeper ocean. Furthermore, studies have shown that approximately one-third of the observed warming in the ocean is taking place in the 700-2000 meter ocean layer.^[46]

Model studies indicate that ocean currents transport more heat into deeper layers during La Niña years, following changes in wind circulation.^[47][48] Years with increased ocean heat uptake have been associated with negative phases of the interdecadal Pacific oscillation (IPO).^[49] This is of particular interest to climate scientists who use the data to estimate the ocean heat uptake.

The upper ocean heat content in most North Atlantic regions is dominated by heat transport convergence (a location where ocean currents meet), without large changes to temperature and salinity relation.^[50] Additionally, a study from 2022 on anthropogenic warming in the ocean indicates that 62% of the warming from the years between 1850 and 2018 in the North Atlantic along 25°N is kept in the water below 700 m, where a major percentage of the ocean's surplus heat is stored. ^[51]

Although the upper 2000 m of the oceans have experienced warming on average since the 1970s, the rate of ocean warming varies regionally with the subpolar North Atlantic warming more slowly and the Southern Ocean taking up a disproportionate large amount of heat due to anthropogenic greenhouse gas emissions.^[5]: 1230

Deep-ocean warming below 2000 m has been largest in the Southern Ocean compared to other ocean basins.^[5]: 1230

Impacts

Further information: Ocean temperature and Effects of climate change on oceans

Warming oceans are one reason for coral bleaching^[52] and contribute to the migration of marine species.^[53] Marine heat waves are regions of life-threatening and persistently elevated water temperatures.^[54] Redistribution of the planet's internal energy by atmospheric circulation and ocean currents produces internal climate variability, often in the form of irregular oscillations,^[55] and helps to sustain the global thermohaline circulation.^[56][57]

The increase in OHC accounts for 30–40% of global sea-level rise from 1900 to 2020 because of thermal expansion.^[58][59] It is also an accelerator of sea ice, iceberg, and tidewater glacier melting. The ice loss reduces polar albedo, amplifying both the regional and global energy imbalances.^[60] The resulting ice retreat has been rapid and widespread for Arctic sea ice,^[61] and within northern fjords such as those of Greenland and Canada.^[62] Impacts to Antarctic sea ice and the vast Antarctic ice shelves which terminate into the Southern Ocean have varied by region and are also increasing due to warming waters.^[63][64] Breakup of the Thwaites Ice Shelf and its West Antarctica neighbors contributed about 10% of sea-level rise in 2020.^[65][66]

A study in 2015 concluded that ocean heat content increases by the Pacific Ocean were compensated by an abrupt distribution of OHC into the Indian Ocean.^[67]

Warming of the deep ocean has the further potential to melt and release some of the vast store of frozen methane hydrate deposits that have naturally accumulated there.^[68]

See also

• Ocean acidification
• Ocean reanalysis
• Ocean stratification
• Special Report on the Ocean and Cryosphere in a Changing Climate
• Tropical cyclones and climate change

•   Climate change portal
•   Ecology portal
•   Oceans portal

References

1. Top 700 meters: Lindsey, Rebecca; Dahlman, Luann (6 September 2023). "Climate Change: Ocean Heat Content". climate.gov. National Oceanic and Atmospheric Administration (NOAA). Archived from the original on 29 October 2023. ● Top 2000 meters: "Ocean Warming / Latest Measurement: December 2022 / 345 (± 2) zettajoules since 1955". NASA.gov. National Aeronautics and Space Administration. from the original on 20 October 2023.
2. Kumar, M. Suresh; Kumar, A. Senthil; Ali, MM (10 December 2014). "Computation of Ocean Heat Content" (PDF). Technical Report NRSC-SDAPSA-G&SPG-DEC-2014-TR-672. National Remote Sensing Centre (ISRO), Government of India.
3. von Schuckmann, K.; Cheng, L.; Palmer, M. D.; Hansen, J.; et al. (7 September 2020). "Heat stored in the Earth system: where does the energy go?". Earth System Science Data. 12 (3): 2013-2041. Bibcode:2020ESSD...12.2013V. doi:10.5194/essd-12-2013-2020.   Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
4. Cheng, Lijing; Abraham, John; Trenberth, Kevin; Fasullo, John; Boyer, Tim; Locarnini, Ricardo; et al. (2021). "Upper Ocean Temperatures Hit Record High in 2020". Advances in Atmospheric Sciences. 38 (4): 523–530. Bibcode:2021AdAtS..38..523C. doi:10.1007/s00376-021-0447-x. S2CID 231672261.
5. Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G.  Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021: Chapter 9: Ocean, Cryosphere and Sea Level Change 2022-10-24 at the Wayback Machine. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change 2021-08-09 at the Wayback Machine [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L.  Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1211–1362.
6. LuAnn Dahlman and Rebecca Lindsey (2020-08-17). "Climate Change: Ocean Heat Content". National Oceanic and Atmospheric Administration.
7. "Study: Deep Ocean Waters Trapping Vast Store of Heat". Climate Central. 2016.
8. Cheng, Lijing; Abraham, John; Trenberth, Kevin E.; Fasullo, John; Boyer, Tim; Mann, Michael E.; Zhu, Jiang; Wang, Fan; Locarnini, Ricardo; Li, Yuanlong; Zhang, Bin; Yu, Fujiang; Wan, Liying; Chen, Xingrong; Feng, Licheng (2023). "Another Year of Record Heat for the Oceans". Advances in Atmospheric Sciences. 40 (6): 963–974. Bibcode:2023AdAtS..40..963C. doi:10.1007/s00376-023-2385-2. ISSN 0256-1530. PMC 9832248. PMID 36643611.   Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
9. NOAA National Centers for Environmental Information, Monthly Global Climate Report for Annual 2022, published online January 2023, Retrieved on July 25, 2023 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202213.
10. Cheng, Lijing; Foster, Grant; Hausfather, Zeke; Trenberth, Kevin E.; Abraham, John (2022). "Improved Quantification of the Rate of Ocean Warming". Journal of Climate. 35 (14): 4827–4840. Bibcode:2022JCli...35.4827C. doi:10.1175/JCLI-D-21-0895.1. 2017-10-16 at the Wayback Machine
11. "Vital Signs of the Plant: Ocean Heat Content". NASA. Retrieved 2021-11-15.
12. Abraham, J. P.; Baringer, M.; Bindoff, N. L.; Boyer, T.; et al. (2013). "A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change". Reviews of Geophysics. 51 (3): 450–483. Bibcode:2013RvGeo..51..450A. CiteSeerX 10.1.1.594.3698. doi:10.1002/rog.20022. hdl:11336/25416. S2CID 53350907.
13. Dean Roemmich (18 March 2014). "How long until ocean temperature goes up a few more degrees?". Scripps Institute of Oceanography.
14. "Ocean warming : causes, scale, effects and consequences. And why it should matter to everyone. Executive summary" (PDF). International Union for Conservation of Nature. 2016.
15. US EPA, OAR (2016-06-27). "Climate Change Indicators: Ocean Heat". www.epa.gov. Retrieved 2023-02-28.
16. "OHC reaches its highest level in recorded history". National Centers for Environmental Information. 22 January 2020.
17. Dijkstra, Henk A. (2008). Dynamical oceanography ([Corr. 2nd print.] ed.). Berlin: Springer Verlag. p. 276. ISBN 9783540763758.
18. "photic zone (oceanography)". Encyclopædia Britannica Online. Retrieved 2021-12-15.
19. MarineBio (2018-06-17). "The Deep Sea". MarineBio Conservation Society. Retrieved 2020-08-07.
20. "What is a thermocline?". National Oceanic and Atmospheric Administration. Retrieved 2021-12-23.
21. "About Argo". Scripps Institute of Oceanography, UC San Diego. Retrieved 27 January 2023.
22. Toni Feder (2000). "Argo Begins Systematic Global Probing of the Upper Oceans". Physics Today. 53 (7): 50. Bibcode:2000PhT....53g..50F. doi:10.1063/1.1292477.
23. Dale C.S. Destin (5 December 2014). "The Argo revolution". climate.gov.
24. "Ocean Surface Topography from Space: Ocean warming estimates from Jason". NASA Jet Propulsion Laboratory. 29 January 2020.
25. Trenberth, Kevin E; Cheng, Lijing (2022-09-01). "A perspective on climate change from Earth's energy imbalance". Environmental Research: Climate. 1 (1): 013001. doi:10.1088/2752-5295/ac6f74. ISSN 2752-5295.
26. Michon Scott (24 April 2006). "Earth's Big Heat Bucket". NASA Earth Observatory.
27. "Transfer and Storage of Heat in the Oceans". UCAR Center for Science Education. Retrieved 17 November 2023.
28. Hansen, J.; Russell, G.; Lacis, A.; Fung, I.; Rind, D.; Stone, P. (1985). "Climate response times: Dependence on climate sensitivity and ocean mixing" (PDF). Science. 229 (4716): 857–850. Bibcode:1985Sci...229..857H. doi:10.1126/science.229.4716.857. PMID 17777925.
29. "CERES Science". NASA. Retrieved 17 November 2023.
30. Loeb, Norman G.; Johnson, Gregory C.; Thorsen, Tyler J.; Lyman, John M.; et al. (15 June 2021). "Satellite and Ocean Data Reveal Marked Increase in Earth's Heating Rate". Geophysical Research Letters. 48 (13). Bibcode:2021GeoRL..4893047L. doi:10.1029/2021GL093047.
31. Hakuba, M.Z.; Frederikse, T.; Landerer, F.W. (28 August 2021). "Earth's Energy Imbalance From the Ocean Perspective (2005–2019)". Geophysical Research Letters. 48 (16). doi:10.1029/2021GL093624.
32. "Air-Sea interaction: Teacher's guide". American Meteorological Society. 2012. Retrieved 2022-02-22.
33. "Ocean Motion : Definition : Wind Driven Surface Currents - Upwelling and Downwelling". Retrieved 2022-02-22.
34. "NASA Earth Science: Water Cycle". NASA. Retrieved 2021-10-27.
35. Laura Snider (2021-01-13). "2020 was a record-breaking year for ocean heat - Warmer ocean waters contribute to sea level rise and strengthen storms". National Center for Atmospheric Research.
36. "Deep Argo Mission". Scripps Institution of Oceanography, UC San Diego. Retrieved 17 November 2023.
37. Friedlingstein, M., O'Sullivan, M., M., Jones, Andrew, R., Hauck, J., Olson, A., Peters, G., Peters, W., Pongratz, J., Sitch, S., Le Quéré, C. and 75 others (2020). "Global carbon budget 2020". Earth System Science Data. 12 (4): 3269–3340. Bibcode:2020ESSD...12.3269F. doi:10.5194/essd-12-3269-2020.{{cite journal}}: CS1 maint: multiple names: authors list (link)
38. Riebeek, Holli (16 June 2011). "The Carbon Cycle". Earth Observatory. NASA. from the original on 5 March 2016. Retrieved 26 February 2022.
39. Woolf D. K., Land P. E., Shutler J. D., Goddijn-Murphy L.M., Donlon, C. J. (2016). "On the calculation of air-sea fluxes of CO2 in the presence of temperature and salinity gradients". Journal of Geophysical Research: Oceans. 121 (2): 1229–1248. Bibcode:2016JGRC..121.1229W. doi:10.1002/2015JC011427.{{cite journal}}: CS1 maint: multiple names: authors list (link)
40. Riebeek, Holli (1 July 2008). "The Ocean's Carbon Cycle". Earth Observatory. NASA. Retrieved 26 February 2022.
41. Jessica Blunden (25 August 2021). "Reporting on the State of the Climate in 2020". Climate.gov. National Oceanic and Atmospheric Administration.
42. Abraham; et al. (2013). "A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change". Reviews of Geophysics. 51 (3): 450–483. Bibcode:2013RvGeo..51..450A. CiteSeerX 10.1.1.594.3698. doi:10.1002/rog.20022. S2CID 53350907.
43. Arias, P.A., N. Bellouin, E. Coppola, R.G. Jones, G. Krinner, J. Marotzke, V. Naik, M.D. Palmer, G.-K. Plattner, J. Rogelj, M. Rojas, J. Sillmann, T. Storelvmo, P.W. Thorne, B. Trewin, K. Achuta Rao, B. Adhikary, R.P. Allan, K. Armour, G. Bala, R. Barimalala, S. Berger, J.G. Canadell, C. Cassou, A. Cherchi, W. Collins, W.D. Collins, S.L. Connors, S. Corti, F. Cruz, F.J. Dentener, C. Dereczynski, A. Di Luca, A. Diongue Niang, F.J. Doblas-Reyes, A. Dosio, H. Douville, F. Engelbrecht, V.  Eyring, E. Fischer, P. Forster, B. Fox-Kemper, J.S. Fuglestvedt, J.C. Fyfe, N.P. Gillett, L. Goldfarb, I. Gorodetskaya, J.M. Gutierrez, R. Hamdi, E. Hawkins, H.T. Hewitt, P. Hope, A.S. Islam, C. Jones, et al. 2021: Technical Summary 2022-07-21 at the Wayback Machine. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change 2021-08-09 at the Wayback Machine [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 33−144.
44. Gruber, Nicolas; Bakker, Dorothee; DeVries, Tim; Gregor, Luke; Hauck, Judith; Landschützer, Peter; McKinley, Galen; Müller, Jens (24 January 2023). "Trends and variability in the ocean carbon sink". Nature Reviews Earth & Environment. 4 (2): 119–134. Bibcode:2023NRvEE...4..119G. doi:10.1038/s43017-022-00381-x. hdl:20.500.11850/595538. S2CID 256264357.
45. Balmaseda, Trenberth & Källén (2013). "Distinctive climate signals in reanalysis of global ocean heat content". Geophysical Research Letters. 40 (9): 1754–1759. Bibcode:2013GeoRL..40.1754B. doi:10.1002/grl.50382. Essay 2015-02-13 at the Wayback Machine
46. Levitus, Sydney (17 May 2012). "World ocean heat content and thermosteric sea level change (0–2000 m), 1955–2010". Geophysical Research Letters. 39 (10): 1–3. Bibcode:2012GeoRL..3910603L. doi:10.1029/2012GL051106. ISSN 0094-8276. S2CID 55809622. Retrieved 28 April 2023.
47. Meehl; et al. (2011). "Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods". Nature Climate Change. 1 (7): 360–364. Bibcode:2011NatCC...1..360M. doi:10.1038/nclimate1229.
48. Rob Painting (2 October 2011). "The Deep Ocean Warms When Global Surface Temperatures Stall". SkepticalScience.com. Retrieved 15 July 2016.
49. Rob Painting (24 June 2013). "A Looming Climate Shift: Will Ocean Heat Come Back to Haunt us?". SkepticalScience.com. Retrieved 15 July 2016.
50. Sirpa Häkkinen; Peter B Rhines; Denise L Worthen (2015). "Heat content variability in the North Atlantic Ocean in ocean reanalyses". Geophys Res Lett. 42 (8): 2901–2909. Bibcode:2015GeoRL..42.2901H. doi:10.1002/2015GL063299. PMC 4681455. PMID 26709321.
51. Messias, Marie-José; Mercier, Herlé (17 May 2022). "The redistribution of anthropogenic excess heat is a key driver of warming in the North Atlantic". Communications Earth & Environment. 3 (1): 118. Bibcode:2022ComEE...3..118M. doi:10.1038/s43247-022-00443-4. ISSN 2662-4435. S2CID 248816280. Retrieved 27 April 2023.
52. "The Great Barrier Reef: a catastrophe laid bare". The Guardian. 6 June 2016.
53. Poloczanska, Elivra S.; Brown, Christopher J.; Sydeman, William J.; Kiessling, Wolfgang; Schoeman, David S.; Moore, Pippa J.; et al. (2013). "Global imprint of climate change on marine life". Nature Climate Change. 3 (10): 919–925. Bibcode:2013NatCC...3..919P. doi:10.1038/nclimate1958.
54. "So what are marine heat waves? - A NOAA scientist explains". National Oceanic and Atmospheric Administration. 2019-10-08.
55. "El Niño & Other Oscillations". Woods Hole Oceanographic Institution. Retrieved 2021-10-08.
56. Rahmstorf, Stefan (2003). "The concept of the thermohaline circulation". Nature. 421 (6924): 699. Bibcode:2003Natur.421..699R. doi:10.1038/421699a. PMID 12610602. S2CID 4414604.
57. Rahmstorf, Stefan; Box, Jason E.; Feulner, George; Mann, Michael E.; Robinson, Alexander; Rutherford, Scott; Schaffernicht, Erik J. (2015). "Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation" (PDF). Nature Climate Change. 5 (5): 475–480. Bibcode:2015NatCC...5..475R. doi:10.1038/nclimate2554.
58. Frederikse, Thomas; Landerer, Felix; Caron, Lambert; Adhikari, Surendra; Parkes, David; Humphrey, Vincent W.; et al. (2020). "The causes of sea-level rise since 1900". Nature. 584 (7821): 393–397. doi:10.1038/s41586-020-2591-3. PMID 32814886. S2CID 221182575.
59. "NASA-led study reveals the causes of sea level rise since 1900". NASA. 2020-08-21.
60. Garcia-Soto, Carlos (2022-10-20). "An Overview of Ocean Climate Change Indicators: Sea Surface Temperature, Ocean Heat Content, Ocean pH, Dissolved Oxygen Concentration, Arctic Sea Ice Extent, Thickness and Volume, Sea Level and Strength of the AMOC (Atlantic Meridional Overturning Circulation)". Frontiers in Marine Science. 8. doi:10.3389/fmars.2021.642372.
61. Rebecca Lindsey and Michon Scott (2021-09-21). "Climate Change: Arctic sea ice". National Oceanic and Atmospheric Administration.
62. Maria-Jose Viñas and Carol Rasmussen (2015-08-05). "Warming seas and melting ice sheets". NASA.
63. Slater, Thomas; Lawrence, Isobel R.; Otosaka, Inès N.; Shepherd, Andrew; et al. (25 January 2021). "Review article: Earth's ice imbalance". The Cryosphere. 15 (1): 233–246. Bibcode:2021TCry...15..233S. doi:10.5194/tc-15-233-2021.
64. Michon Scott (2021-03-26). "Understanding climate: Antarctic sea ice extent". National Oceanic and Atmospheric Administration.
65. Carly Cassella (2021-04-11). "Warm Water Under The 'Doomsday Glacier' Threatens to Melt It Faster Than We Predicted". sciencealert.com.
66. British Antarctic Survey (2021-12-15). "The threat from Thwaites: The retreat of Antarctica's riskiest glacier". phys.org.
67. Lee, Sang-Ki; Park, Wonsun; Baringer, Molly O.; Gordon, Arnold L.; Huber, Bruce; Liu, Yanyun (June 2015). "Pacific origin of the abrupt increase in Indian Ocean heat content during the warming hiatus". Nature Geoscience. 8 (6): 445–449. Bibcode:2015NatGe...8..445L. doi:10.1038/ngeo2438. hdl:1834/9681.
68. Adam Voiland and Joshua Stevens (8 March 2016). "Methane Matters". NASA Earth Observatory. Retrieved 26 February 2022.

External links

• NOAA Global Ocean Heat and Salt Content