Papers on ocean temperature
Posted by Ari Jokimäki on August 10, 2009
This list of papers contains evidence of the warming of the world ocean. The list is not complete, and will most likely be updated in the future in order to make it more thorough and more representative.
UPDATE (February 25, 2016): Abraham et al. (2013) added. Thanks to Tapani Linnaluoto for pointing it out. Also some dead links corrected.
UPDATE (September 24, 2012): Levitus et al. (2012) added. Thanks to Barry for pointing it out.
UPDATE (November 24, 2010): Lyman et al. (2010) added. Thanks to Anander for pointing it out, see the comment section below.
UPDATE (September 22, 2010): Roemmich & Gilson (2009) and Gregory et al. (2004) added.
UPDATE (September 12, 2010): Purkey & Johnson (2010) added.
UPDATE (April 24, 2010): Page updated. Some papers got new full text links and DiNezio & Goni (2010) was added.
UPDATE (November 19, 2009): Douglass & Knox (2009) added, thanks to Magnus W for pointing it out, see the comment section of “Papers on Earth’s radiation budget”.
UPDATE (October 11, 2009): von Schuckmann et al. (2009) and Church et al. (2009) added.
A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change – Abraham et al. (2013)
Abstract: “The evolution of ocean temperature measurement systems is presented with a focus on the development and accuracy of two critical devices in use today (expendable bathythermographs and conductivity-temperature-depth instruments used on Argo floats). A detailed discussion of the accuracy of these devices and a projection of the future of ocean temperature measurements are provided. The accuracy of ocean temperature measurements is discussed in detail in the context of ocean heat content, Earth’s energy imbalance, and thermosteric sea level rise. Up-to-date estimates are provided for these three important quantities. The total energy imbalance at the top of atmosphere is best assessed by taking an inventory of changes in energy storage. The main storage is in the ocean, the latest values of which are presented. Furthermore, despite differences in measurement methods and analysis techniques, multiple studies show that there has been a multidecadal increase in the heat content of both the upper and deep ocean regions, which reflects the impact of anthropogenic warming. With respect to sea level rise, mutually reinforcing information from tide gauges and radar altimetry shows that presently, sea level is rising at approximately 3 mm yr−1 with contributions from both thermal expansion and mass accumulation from ice melt. The latest data for thermal expansion sea level rise are included here and analyzed.”
Citation: Abraham, J. P., et al. (2013), A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change, Rev. Geophys., 51, 450–483, doi:10.1002/rog.20022. [Full text]
World ocean heat content and thermosteric sea level change (0–2000 m), 1955–2010 – Levitus et al. (2012) “We provide updated estimates of the change of ocean heat content and the thermosteric component of sea level change of the 0–700 and 0–2000 m layers of the World Ocean for 1955–2010. Our estimates are based on historical data not previously available, additional modern data, and bathythermograph data corrected for instrumental biases. We have also used Argo data corrected by the Argo DAC if available and used uncorrected Argo data if no corrections were available at the time we downloaded the Argo data. The heat content of the World Ocean for the 0–2000 m layer increased by 24.0 ± 1.9 × 1022 J (±2S.E.) corresponding to a rate of 0.39 W m−2 (per unit area of the World Ocean) and a volume mean warming of 0.09°C. This warming corresponds to a rate of 0.27 W m−2 per unit area of earth’s surface. The heat content of the World Ocean for the 0–700 m layer increased by 16.7 ± 1.6 × 1022 J corresponding to a rate of 0.27 W m−2 (per unit area of the World Ocean) and a volume mean warming of 0.18°C. The World Ocean accounts for approximately 93% of the warming of the earth system that has occurred since 1955. The 700–2000 m ocean layer accounted for approximately one-third of the warming of the 0–2000 m layer of the World Ocean. The thermosteric component of sea level trend was 0.54 ± .05 mm yr−1 for the 0–2000 m layer and 0.41 ± .04 mm yr−1 for the 0–700 m layer of the World Ocean for 1955–2010.” Levitus, S., et al. (2012), World ocean heat content and thermosteric sea level change (0–2000 m), 1955–2010, Geophys. Res. Lett., 39, L10603, doi:10.1029/2012GL051106. [Full text]
Robust warming of the global upper ocean – Lyman et al. (2010) “A large (~1023 J) multi-decadal globally averaged warming signal in the upper 300 m of the world’s oceans was reported roughly a decade ago and is attributed to warming associated with anthropogenic greenhouse gases. The majority of the Earth’s total energy uptake during recent decades has occurred in the upper ocean, but the underlying uncertainties in ocean warming are unclear, limiting our ability to assess closure of sea-level budgets, the global radiation imbalance and climate models. For example, several teams have recently produced different multi-year estimates of the annually averaged global integral of upper-ocean heat content anomalies (hereafter OHCA curves) or, equivalently, the thermosteric sea-level rise. Patterns of interannual variability, in particular, differ among methods. Here we examine several sources of uncertainty that contribute to differences among OHCA curves from 1993 to 2008, focusing on the difficulties of correcting biases in expendable bathythermograph (XBT) data. XBT data constitute the majority of the in situ measurements of upper-ocean heat content from 1967 to 2002, and we find that the uncertainty due to choice of XBT bias correction dominates among-method variability in OHCA curves during our 1993–2008 study period. Accounting for multiple sources of uncertainty, a composite of several OHCA curves using different XBT bias corrections still yields a statistically significant linear warming trend for 1993–2008 of 0.64 W m-2 (calculated for the Earth’s entire surface area), with a 90-per-cent confidence interval of 0.53–0.75 W m-2.” John M. Lyman, Simon A. Good, Viktor V. Gouretski, Masayoshi Ishii, Gregory C. Johnson, Matthew D. Palmer, Doug M. Smith & Josh K. Willis, Nature 465, 334-337 (20 May 2010) | doi:10.1038/nature09043. [Full text]
Warming of Global Abyssal and Deep Southern Ocean Waters Between the 1990s and 2000s: Contributions to Global Heat and Sea Level Rise Budgets – Purkey & Johnson (2010) “We quantify abyssal global and deep Southern Ocean temperature trends between the 1990s and 2000s to assess the role of recent warming of these regions in global heat and sea level budgets. We compute warming rates with uncertainties along 28 full-depth, high-quality, hydrographic sections that have been occupied two or more times between 1980 and 2010. We divide the global ocean into 32 basins defined by the topography and climatological ocean bottom temperatures and estimate temperature trends in the 24 sampled basins. The three southernmost basins show a strong statistically significant abyssal warming trend, with that warming signal weakening to the north in the central Pacific, western Atlantic, and eastern Indian Oceans. Eastern Atlantic and western Indian Ocean basins show statistically insignificant abyssal cooling trends. Excepting the Arctic Ocean and Nordic seas, the rate of abyssal (below 4000 m) global ocean heat content change in the 1990s and 2000s is equivalent to a heat flux of 0.027 (±0.009) W m−2 applied over the entire surface of the Earth. Deep (1000–4000 m) warming south of the Sub-Antarctic Front of the Antarctic Circumpolar Current adds 0.068 (±0.062) W m−2. The abyssal warming produces a 0.053 (±0.017) mm yr−1 increase in global average sea level and the deep warming south of the Sub-Antarctic Front adds another 0.093 (±0.081) mm yr−1. Thus warming in these regions, ventilated primarily by Antarctic Bottom Water, accounts for a statistically significant fraction of the present global energy and sea level budgets.” Sarah G. Purkey and Gregory C. Johnson, Journal of Climate 2010, doi: 10.1175/2010JCLI3682.1. [Full text]
Identifying and Estimating Biases between XBT and Argo Observations Using Satellite Altimetry – DiNezio & Goni (2010) “A methodology is developed to identify and estimate systematic biases between expendable bathythermograph (XBT) and Argo observations using satellite altimetry. … The depth-dependent XBT-minus-Argo differences suggest a global positive bias of 3% of the XBT depths. The fact that this 3% error is robust among the different ocean basins provides evidence for changes in the instrumentation, such as changes in the terminal velocity of the XBTs. The value of this error is about the inverse of the correction to the XBT fall-rate equation (FRE) implemented in 1995, suggesting that this correction, while adequate during the 1990s, is no longer appropriate and could be the source of the 3% error. This result suggests that for 2000–07, the XBT dataset can be brought to consistency with Argo by using the original FRE coefficients without the 1995 correction.” [Full text]
The 2004–2008 mean and annual cycle of temperature, salinity, and steric height in the global ocean from the Argo Program – Roemmich & Gilson (2009) “The Argo Program has achieved 5 years of global coverage, growing from a very sparse global array of 1000 profiling floats in early 2004 to more than 3000 instruments from late 2007 to the present. Using nearly 350,000 temperature and salinity profiles, we constructed an upper-ocean climatology and monthly anomaly fields for the 5-year era, 2004–2008. A basic description of the modern upper ocean based entirely on Argo data is presented here, to provide a baseline for comparison with past datasets and with ongoing Argo data, to test the adequacy of Argo sampling of large-scale variability, and to examine the consistency of the Argo dataset with related ocean observations from other programs. The Argo 5-year mean is compared to the World Ocean Atlas, highlighting the middle and high latitudes of the southern hemisphere as a region of strong multi-decadal warming and freshening. Moreover the region is one where Argo data have contributed an enormous increment to historical sampling, and where more Argo floats are needed for documenting large-scale variability. Globally, the Argo-era ocean is warmer than the historical climatology at nearly all depths, by an increasing amount toward the sea surface; it is saltier in the surface layer and fresher at intermediate levels. Annual cycles in temperature and salinity are compared, again to WOA01, and to the National Oceanography Center air–sea flux climatology, the Reynolds SST product, and AVISO satellite altimetric height. These products are consistent with Argo data on hemispheric and global scales, but show regional differences that may either point to systematic errors in the datasets or their syntheses, to physical processes, or to temporal variability. The present work is viewed as an initial step toward integrating Argo and other climate-relevant global ocean datasets.” Dean Roemmich, and John Gilson, Progress In Oceanography, Volume 82, Issue 2, August 2009, Pages 81-100, doi:10.1016/j.pocean.2009.03.004. [Full text]
Changes in global upper-ocean heat content over the last half century and comparison with climate models – Church et al. (2009) Apparently an update to Domingues et al. (2008). “Here, we present updates of our previous estimates of global upper ocean heat content annual anomalies from 1961 to 2008. These updates will allow for spatial and instrumental biases in the historical data base and include improved upper-ocean heat content estimates from recent Argo data.”
Global hydrographic variability patterns during 2003–2008 – von Schuckmann et al. (2009) “Monthly gridded global temperature and salinity fields from the near-surface layer down to 2000 m depth based on Argo measurements are used to analyze large-scale variability patterns on annual to interannual time scales during the years 2003–2008. … Global mean heat content and steric height changes are clearly associated with a positive trend during the 6 years of measurements.” [Full text]
Ocean heat content and Earth’s radiation imbalance – Douglass & Knox (2009) “Earth’s radiation imbalance is determined from ocean heat content data and compared with results of direct measurements. Distinct time intervals of alternating positive and negative values are found: 1960–mid-1970s (−0.15), mid-1970s–2000 (+0.15), 2001–present (−0.2 W/m2), and are consistent with prior reports. These climate shifts limit climate predictability.” [Full text]
Global ocean heat content 1955–2008 in light of recently revealed instrumentation problems – Levitus et al. (2009) “We provide estimates of the warming of the world ocean for 1955–2008 based on historical data not previously available, additional modern data, correcting for instrumental biases of bathythermograph data, and correcting or excluding some Argo float data. The strong interdecadal variability of global ocean heat content reported previously by us is reduced in magnitude but the linear trend in ocean heat content remain similar to our earlier estimate.” Addresses also the issues raised by Gouretski & Koltermann (2007). [Full text]
Reevaluation of historical ocean heat content variations with time-varying XBT and MBT depth bias corrections – Ishii & Kimoto (2009) “In comparison with the previous temperature analysis, large differences are found in the present analysis as follows: the duration of large ocean heat content in the 1970s shortens dramatically, and recent ocean cooling becomes insignificant.” [Full text]
Improved estimates of upper-ocean warming and multi-decadal sea-level rise – Domingues et al. (2008) “Our ocean warming and thermal expansion trends for 1961–2003 are about 50 per cent larger than earlier estimates but about 40 per cent smaller for 1993–2003, which is consistent with the recognition that previously estimated rates for the 1990s had a positive bias as a result of instrumental errors” [Full text]
In Situ Data Biases and Recent Ocean Heat Content Variability – Willis et al. (2008) “Two significant instrument biases have been identified in the in situ profile data used to estimate globally integrated upper-ocean heat content. A large cold bias was discovered in a small fraction of Argo floats along with a smaller but more prevalent warm bias in expendable bathythermograph (XBT) data. These biases appear to have caused the bulk of the upper-ocean cooling signal reported by Lyman et al. between 2003 and 2005.” [Full text]
How much is the ocean really warming? – Gouretski & Koltermann (2007) “Using bias-corrected XBT data we argue reduces the ocean heat content change since the 1950s by a factor of 0.62. Our estimate of the ocean heat content increase (0–3000 m) between 1957–66 and 1987–96 is 12.8·1022 J.” [Full text]
Simulated and observed variability in ocean temperature and heat content – AchutaRao et al. (2007) “For all major ocean basins, there was good agreement between the simulated and observed sampling distributions of OHC changes on 2-, 5-, and 10-year time scales (see SI Figs. 6–8). … Our analysis shows that the cooling found by Lyman et al. is spurious. At least five lines of evidence support this conclusion.” [Full text]
Isolating the signal of ocean global warming – Palmer et al. (2007) “We present a new analysis of millions of ocean temperature profiles designed to filter out local dynamical changes to give a more consistent view of the underlying warming. Time series of temperature anomaly for all waters warmer than 14°C show large reductions in interannual to inter-decadal variability and a more spatially uniform upper ocean warming trend (0.12 Wm−2 on average) than previous results.” [Full text]
Is the World Ocean Warming? Upper-Ocean Temperature Trends: 1950–2000 – Harrison & Carson (2007) “Where there are sufficient observations for this analysis, there is large spatial variability of 51-yr trends in the upper ocean, with some regions showing cooling in excess of 3°C, and others warming of similar magnitude.” [Full text]
Recent cooling of the upper ocean – Lyman et al. (2006) Reports an apparent cooling of the oceans after 2003, but later it turned out to be a problem in observations (See Willis et al., 2008 given above). [Full text]
Anthropogenic Warming of the Oceans: Observations and Model Results – Pierce et al. (2006) “Comparing the observations with results from two coupled ocean–atmosphere climate models [the Parallel Climate Model version 1 (PCM) and the Hadley Centre Coupled Climate Model version 3 (HadCM3)] that include anthropogenic forcing shows remarkable agreement between the observed and model-estimated warming.” [Full text]
Penetration of Human-Induced Warming into the World’s Oceans – Barnett et al. (2005) “A warming signal has penetrated into the world’s oceans over the past 40 years. The signal is complex, with a vertical structure that varies widely by ocean; it cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models.” [Full text]
Warming of the world ocean, 1955–2003 – Levitus et al. (2005) “During 1955–1998 world ocean heat content (0–3000 m) increased 14.5 x 1022 J corresponding to a mean temperature increase of 0.037°C at a rate of 0.20 Wm-2 (per unit area of Earth’s total surface area).” [Full text]
Simulated and observed decadal variability in ocean heat content – Gregory et al. (2004) “Previous analyses by Levitus et al.  (“Levitus”) of ocean temperature data have shown that ocean heat content has increased over the last fifty years with substantial temporal variability superimposed. The HadCM3 coupled atmosphere–ocean general circulation model (AOGCM) simulates the Levitus trend if both natural and anthropogenic forcings are included. In the relatively well-observed northern hemisphere upper ocean, HadCM3 has similar temporal variability to Levitus but, like other AOGCMs, it has generally less variability than Levitus for the world ocean. We analyse the causes of this discrepancy, which could result from deficiencies in either the model or the observational dataset. A substantial contribution to the Levitus variability comes from a strong maximum around 500 m depth, absent in HadCM3. We demonstrate a possibly large sensitivity to the method of filling in the observational dataset outside the well-observed region, and advocate caution in using it to assess AOGCM heat content changes.” Gregory, J. M., H. T. Banks, P. A. Stott, J. A. Lowe, and M. D. Palmer (2004), Geophys. Res. Lett., 31, L15312, doi:10.1029/2004GL020258. [Full text]
Warming of the World Ocean – Levitus et al. (2000) “The heat content of the world ocean increased by ~2 × 1023 joules between the mid-1950s and mid-1990s, representing a volume mean warming of 0.06°C. This corresponds to a warming rate of 0.3 watt per meter squared (per unit area of Earth’s surface).” [Full text]