Simulated Rapid Warming of Abyssal North Pacific Waters

Masuda, Shuhei; Awaji, Toshiyuki; Sugiura, Nozomi; Matthews, Janice R.; Toyoda, Takahiro; Kawai, Yoshimi; Doi, Toshimasa; Kouketsu, Shinya; Igarashi, Hiromichi; Katsumata, Katsuro; Uchida, Hiroshi; Kawano, Takeshi; Fukasawa, Masao

doi:10.1126/science.1188703

Cited by 119 publications

(121 citation statements)

References 24 publications

Supporting

Mentioning

114

Contrasting

Order By: Relevance

“…Kusahara et al [2011b] have estimated a substantial reduction of 23% of the dense export out of the Ad elie Depression following the 2010 Mertz calving. This is about the same amount as the interannual variability (25-45% of the mean) found in a precalving simulation over the period 1979-2008[Kusahara et al, 2011b. In the present study, we use observations to estimate the interannual variability of the dense shelf water prior to 2010 and evaluate the abrupt changes following the calving with regards to this variability.…”

Section: Introductionmentioning

confidence: 75%

“…The thin ice production is here assumed to represent the MGP production. Several algorithms to retrieve thin ice thickness from passive radiometer observations have been recently developed and evaluated [Tamura et al, 2007;Naoki et al, 2008;Kaleschke et al, 2012]. In the present study, the thin ice thickness was estimated following a methodology adapted from the Tamura et al [2007] algorithm.…”

Section: Sea Ice and Atmospheric Datamentioning

confidence: 99%

“…The AAB has indeed the largest chlorofluorocarbon concentrations of the Southern Ocean [Orsi et al, 1999], in agreement with the ALBW and the RSBW being the most important contributors to AABW renewal. At the global scale, the AABW from the AAB has been recently recognized as responsible for changes observed in the abyssal layers of the North Pacific Ocean [Masuda et al, 2010].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dense shelf water production in the Adélie Depression, East Antarctica, 2004–2012: Impact of the Mertz Glacier calving

et al. 2014

View full text Add to dashboard Cite

Summer repeated hydrographic surveys and 4 years of mooring observations are used to characterize for the first time the interannual variability of the bottom water in the Mertz Glacier Polynya (MGP) on the East Antarctic shelf (142 E-146 E). Until 2010, large interannual variability was observed in the summer bottom salinity with year-to-year changes reaching 0.12 in Commonwealth Bay, the region with the highest sea ice production. The summer variability was shown to be linked to the efficiency of the convection during the preceding winter. The recent freshening of the bottom waters subsequent to the Mertz Glacier calving was well beyond the range of the precalving interannual variability. Within 2 years after the event, the bottom water of the shelf became too light to possibly contribute to renewal of the Antarctic Bottom Water. Rough estimates of the freshwater budget of the Ad elie Depression indicate that the freshening necessary to compensate for net sea ice production in the MGP did not change drastically after the Mertz calving. The year-to-year salinity changes appeared to respond to the MGP activity. Yet, prior to the calving, the convective system in the polynya was also partly controlled by the late winter bottom salinity through a mechanism leading to a sequence of alternatively fresher and more saline bottom waters over the period [2007][2008][2009][2010]. Exceptional events like the Mertz calving seem to be able to switch over the system into a less stratified state where convection responds more directly to changes in the surface forcing. IntroductionAntarctic Bottom Water (AABW), the densest water mass of the world ocean, occupies the abyssal layer of the Southern Ocean as a relatively well-oxygenated, cold and fresh product, which spreads north into the Atlantic, Indian, and Pacific oceans. Surface water transformation on the continental margins around Antarctica and subsequent sinking of the dense shelf waters along the slope supply the bottom limb of the ocean thermohaline circulation. It has been argued that changes in the properties or formation rate of the AABW could affect the strength of the thermohaline circulation, and therefore the global climate [Stouffer et al., 2007;Purkey and Johnson, 2012].The production of AABW is considered to originate on the Antarctic shelf in coastal polynyas where nearfreezing water (the so-called High-Salinity Shelf Water, HSSW) is formed through ocean surface cooling and brine drainage from growing sea ice. Upon mixing with ambient waters on the shelf and subsequent sinking and entrainment of Circumpolar Deep Water down the continental slope, these waters eventually acquire final AABW properties when reaching the abyssal layer of the Southern Ocean. While this process is suspected to occur at many locations around Antarctica, observations have unambiguously identified some primary formation sites: the Weddell Sea, the Ross Sea [Carmack, 1977], and the Ad elie-George V Land [Gordon and Tchernia, 1972;Rintoul, 1998]. Estimates of the relative im...

show abstract

Section: Introductionmentioning

confidence: 75%

Section: Sea Ice and Atmospheric Datamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dense shelf water production in the Adélie Depression, East Antarctica, 2004–2012: Impact of the Mertz Glacier calving

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Rapid signal transmission can also be achieved via oceanic pathways through the action of internal ocean waves (e.g. Masuda et al, 2010). In the conceptual model of Stocker and Johnsen (2003), a rapid, wave-mediated seesaw in the Atlantic is coupled to a Southern Ocean heat reservoir.…”

Section: Resultsmentioning

confidence: 99%

The last deglaciation: timing the bipolar seesaw

et al. 2011

View full text Add to dashboard Cite

Abstract. Precise information on the relative timing of north-south climate variations is a key to resolving questions concerning the mechanisms that force and couple climate changes between the hemispheres. We present a new composite record made from five well-resolved Antarctic ice core records that robustly represents the timing of regional Antarctic climate change during the last deglaciation. Using fast variations in global methane gas concentrations as time markers, the Antarctic composite is directly compared to Greenland ice core records, allowing a detailed mapping of the inter-hemispheric sequence of climate changes. Consistent with prior studies the synchronized records show that warming (and cooling) trends in Antarctica closely match cold (and warm) periods in Greenland on millennial timescales. For the first time, we also identify a sub-millennial component to the inter-hemispheric coupling. Within the Antarctic Cold Reversal the strongest Antarctic cooling occurs during the pronounced northern warmth of the Bølling. Warming then resumes in Antarctica, potentially as early as the Intra-Allerød Cold Period, but with dating uncertainty that could place it as late as the onset of the Younger Dryas stadial. There is little-to-no time lag between climate transitions in Greenland and opposing changes in Antarctica. Our results lend support to fast acting inter-hemispheric coupling mechanisms, including recently proposed bipolar atmospheric teleconnections and/or rapid bipolar ocean teleconnections.

show abstract

“…Both slow advective processes and comparatively fast wave-like dynamics can lead to deep and abyssal OHC trends (e.g. [41]). Multiple factors have accordingly been proposed to explain the decadal warming of AABW, including freshening of the Ross Sea Shelf Water and the associated downward heave of isopycnal surfaces, as well as wind-driven variability of the Weddell gyre [32,53,55].…”

Section: Tackling Uncertainties: a Deep Ocean Perspectivementioning

confidence: 99%

Observational Advances in Estimates of Oceanic Heating

Desbruyères

McDonagh

King

2016

Curr Clim Change Rep

View full text Add to dashboard Cite

Since the early twenty-first century, improvements in understanding climate variability resulted from the growth of the ocean observing system. The potential for a closure of the Earth's energy budget has emerged with the unprecedented coverage of Argo profiling floats, which now provide a decade (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015) of invaluable information on ocean heat content changes above 2000 m. The expertise gained from Argo and repeat hydrography sections motivated the extension of the array toward the ocean bottom, which will progressively reveal the poorly known deep ocean and reduce the uncertainty of its presumed 10-15 % contribution to the 2006-2015 global ocean warming trend of 0.65-0.80 W m −2 . The sustainability and synergy of various observing systems helped to corroborate numerical models and decipher the internal variability of distinct ocean basins. Due to unique observations of the circulation in the North Atlantic, particular attention is paid to heat content changes and their relationship to dynamic variability in that region.

show abstract

Simulated Rapid Warming of Abyssal North Pacific Waters

Cited by 119 publications

References 24 publications

Dense shelf water production in the Adélie Depression, East Antarctica, 2004–2012: Impact of the Mertz Glacier calving

Dense shelf water production in the Adélie Depression, East Antarctica, 2004–2012: Impact of the Mertz Glacier calving

The last deglaciation: timing the bipolar seesaw

Observational Advances in Estimates of Oceanic Heating

Contact Info

Product

Resources

About