{"id":486990,"date":"2026-11-11T10:49:43","date_gmt":"2026-11-11T17:49:43","guid":{"rendered":"https:\/\/climatescience.press\/?p=486990"},"modified":"2026-11-11T10:49:46","modified_gmt":"2026-11-11T17:49:46","slug":"unexpected-stability-antarctic-shelf-processes-leave-no-fingerprint-on-deep-ocean-carbon-reservoir","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=486990","title":{"rendered":"Unexpected Stability: Antarctic Shelf Processes Leave No Fingerprint on Deep-Ocean Carbon Reservoir"},"content":{"rendered":"\n
\"Research
AI generated by Grok<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

A recent study (published November 10, 2026, in Nature Communications<\/em>) found that dissolved organic matter (DOM) in Antarctic waters<\/em> remains remarkably stable in both amount and molecular composition<\/em> as water forms Antarctic Bottom Water on the continental shelf, despite intense biological activity.<\/strong><\/p>\n\n\n\n

The press release and related coverage (often under titles highlighting \u201cunexpected stability\u201d or \u201cvanished without a trace\u201d) come from the Alfred Wegener Institute (AWI)<\/strong>.<\/p>\n\n\n\n

The lead author is Dr. Gonzalo V. Gomez- Saez (formerly at AWI, now leading a group at Ludwig- Maximilians- Universit\u00e4t M\u00fcnchen), with joint senior authors Dr. Moritz Holtappels (AWI) and Prof. Dr. Thorsten Dittmar (University of Oldenburg\/ICBM). Folke Mehrtens is associated with the AWI communications and press release.<\/p>\n\n\n\n

Researchers analyzed water samples from two Polarstern<\/em> expeditions (2016 and 2021) in the southern Weddell Sea. They used advanced molecular techniques (including ultrahigh-resolution mass spectrometry at ICBM) and radiocarbon dating (via AWI\u2019s MICADAS facility).<\/p>\n\n\n\n

Despite seasonal phytoplankton blooms producing labile (easily degradable) organic matter and significant changes in water masses, the concentration and chemical makeup of the vast DOM reservoir showed almost no detectable change as dense water sank into the deep ocean. Shelf processes left essentially no \u201cfingerprint\u201d<\/strong>.\u2060<\/a><\/p>\n\n\n\n

The explanation is residence time: dense waters stay on the Weddell Sea shelf (including under the Filchner- Ronne Ice Shelf) for 6- 12 years. This gives microbes enough time to fully remineralize newly produced surface organic carbon into dissolved inorganic carbon before the water exits the shelf.<\/p>\n\n\n\n

DOM is highlighted as a stable component of the regional Southern Ocean carbon cycle<\/strong>. Because this large organic carbon reservoir is largely unaffected by shelf processes, it may remain relatively buffered against climate change impacts in this region (even as warming reaches Antarctic shelf seas). Other carbon pools (e.g., sinking particulate organic matter or dissolved inorganic carbon) may respond more strongly to temperature, sea-ice, and biological changes.\u2060<\/a><\/p>\n\n\n\n

The paper is: Gomez-Saez et al., \u201cConserved molecular properties of dissolved organic matter during Weddell Sea Deep Water formation,\u201d Nature Communications<\/em> (2026), DOI: 10.1038\/s41467-026-79040-4.<\/p>\n\n\n\n

Further work is planned under initiatives like Antarctica InSync, including a 2028 Polarstern<\/em> winter expedition to the Weddell Sea.<\/p>\n\n\n\n

<\/p>\n\n\n\n

\"Schematic
Diagram of the seven water masses involved in WSDW formation. Credit: Nature Communications (2026). DOI: 10.1038\/s41467-026-79040-4<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

<\/p>\n\n\n\n

Antarctic Bottom Water (AABW) <\/strong>is the coldest, densest water mass in the open ocean. It forms primarily around the Antarctic continental margin and sinks to the abyssal depths, where it spreads northward as a key part of the global overturning circulation (the \u201cgreat ocean conveyor belt\u201d<\/strong>). It ventilates the deep ocean by supplying oxygen and helps sequester heat and carbon for centuries to millennia.<\/p>\n\n\n\n

Main Formation Regions<\/strong><\/h3>\n\n\n\n

AABW forms mainly in a few key areas:<\/p>\n\n\n\n