Zadnji dan ali dva se povsod ponavljajo objave po redditu in poročanje, ki počasi pronica tudi k nam iz tujih medijev, tako da je to bilo na hitro napisano za kontekstualizacijo zadeve, pa da se morebiti odgovori na par vprašanj – ker je področje pri nas na splošno precej manj znano v javnosti, ker ni tako relevantno, kot za nekatere oboceanske države. Pa da imamo še mal druge vsebine, ne samo “*fill the blank*”;
It might be tremendously helpful to further clarify due to the reporting on the issue of the past few days (e.g. [Guardian](https://www.theguardian.com/environment/2023/jul/25/gulf-stream-could-collapse-as-early-as-2025-study-suggests), [Live Science](https://www.livescience.com/planet-earth/climate-change/gulf-stream-current-could-collapse-in-2025-plunging-earth-into-climate-chaos-we-were-actually-bewildered), [n1info](https://n1info.si/novice/svet/nova-studija-morski-tok-ki-ogreva-evropo-bi-lahko-razpadel/), [zurnal24](https://www.zurnal24.si/svet/zalivski-tok-bi-lahko-zamrl-ze-leta-2025-kaze-studija-kaj-bi-to-pomenilo-za-nas-409529), etc.) basic distinctions between (i) wind-driven circulation (Gulf Stream included – wind-induced Ekman transports leads to SSHA – leads to geostrophic balance with Coriolis force – and western boundary intensification is due to Earth´s rotation and vorticity conservation of sverdup transport. With subsurface, thermal wind balance, observable in [tilted isopycnals](http://sam.ucsd.edu/ltalley/talley_old_atlas/atl_sections/natl_36n/plots/natl_36n_sig1.gif) (upper left subsurface at 36N in Atlantic), comes into play for estimates. In any case, oceans have subtropical and subpolar gyres due to this, with addition of ACC in Southern Ocean) and (ii) thermohaline circulation (which is nevertheless crucially dependant on other forcings, wind included, that influences buoyancy and upwellings). This obviously makes this reporting utterly atrocious, and physically impossible. Predictions about Gulf Stream weakening are a reflection of predicted AMOC weakening over the next century (per IPCC report), but *at worst* it would lose an eighth of its net transport, as [/u/TheProfessorO](https://www.reddit.com/u/TheProfessorO/) says, beside often accompanying climatological overstatements (without denying the seriousness of consequences). (For introduction into physical oceanography that covers fundamental mechanisms above, [Huang 2009](https://www.cambridge.org/si/universitypress/subjects/earth-and-environmental-science/oceanography-and-marine-science/ocean-circulation-wind-driven-and-thermohaline-processes?format=HB), [Talley et al. 2011](https://www.sciencedirect.com/book/9780750645522/descriptive-physical-oceanography)).
Further, the state of AMOC is, as indicated, hotly debated, and continuous in situ monitoring has not detected any discernable trends yet ([Latif et al. 2022](https://www.nature.com/articles/s41558-022-01342-4), [Worthington et al. 2021](https://os.copernicus.org/articles/17/285/2021/), [Le Bras et al. 2023](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101931), [Cainzos et al. 2022](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021GL096527#:~:text=We%20have%20analyzed%20hydrographic%20data%20collected%20for%20the%20last%2030,freshwater%20leaving%20the%20South%20Atlantic), comparable situation is with the surface Gulf Stream, e.g. [Rossby et al. 2014](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013gl058636), [Chi et al. 2021](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021GL093113), slightly more qualified, [Dong et al. 2019](https://www.nature.com/articles/s41598-019-42820-8)) past intraannual, annual, decadal, and multidecadal variabilities (e.g. data [from RAPID array](https://rapid.ac.uk/data.php) at 26N, which e.g. will show even temporary reversals even at that latitude, because other forcings can overcome the current), which are responsive to multiple and different non-linear (internal and external) forcings, e.g. seasonal buoyancy sensitivity due to heat and freshwater fluxes ([Kostov et al. 2019](https://link.springer.com/content/pdf/10.1007/s00382-019-04802-4.pdf)), even the sensitivity of the latter is far from clear ([Spence et al. 2008](https://journals.ametsoc.org/view/journals/clim/21/11/2007jcli2103.1.xml), [Swingedouw et al. 2015](https://link.springer.com/article/10.1007/s00382-014-2270-x), [He et al. 2022](https://www.nature.com/articles/s41558-022-01328-2), or against common view, even anticorrelated, e.g. [Cael et al. 2020](https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lol2.10125)) – those that have observed such weaking, rely on models run on various proxies. The recent statistical study itself that is currently circulating, which relies (solely) on SSTA as a direct proxy for AMOC strength – its mechanism and correlation (let alone strength of it) are not settled (e.g. see [Holliday response](https://www.sciencemediacentre.org/expert-reaction-to-paper-warning-of-a-collapse-of-the-atlantic-meridional-overturning-circulation/) here), and for a recent overview of AMOC literature, which showcases the divergences on these issues ([Zhang et al. 2019](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019RG000644), [Buckley et al. 2016](https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2015RG000493)) – it needs to be put into context within that (this is not saying it is meritless at all, but it is pretty clear what it is and *what it is not*), inevitably, the jurnalistic malpractice ultimately does a disservice here, again.
All of this skims over some very important issues about LSW and NADW (which is further differentiated, and the term is more applicable when differentiation between different masses loses significance due to mixing) and site-formation, actual DWBC and abyssal (re)circulation, ACC role, et al.
[Prirejeno in izvzeto it od tu.](https://www.reddit.com/r/askscience/comments/159j3wd/comment/jtih50g/?utm_source=share&utm_medium=web2x&context=3) Our resident earth-related, /u/ayahuasca274.
Morski tokovi, mehanizmi in poročanje.
by u/PhiloSpo in Slovenia
by PhiloSpo