En ota kantaa väitteisiin Potsdam -instituutin luotettavuuteen koska en tunne asiaa, mutta sen verran lisäisin että viimeisen parin vuoden aikana on tullut vahvistavia tutkimustuloksia tuon P-atlantin virran heikkenemisestä. Alla spoilerissa erittäin lyhyt tiivistelmä ( vuodelta 2023 )
Tuossa paperissa käytetään virheellistä dataa, jonka vuoksi tulos näyttää heikkenevää Golf-virtaa. Kun tuo virhe korjataan, on lopputuloksena hyvinkin muuttumaton Golf-virran voimakkuus vuodesta 1982 nykypäivään. Naturessa julkaistu tutkimus vuodelta 2024:
Florida Current transport observations reveal four decades of steady state
The study shows that the Florida Current, an important contributor to the Atlantic Meridional Overturning Circulation, has not declined as previously suggested, but remained steady over the past 40-years of observations.
www.nature.com
Abstract
The potential weakening of the Atlantic Meridional Overturning Circulation (AMOC) in response to anthropogenic forcing, suggested by climate models, is at the forefront of scientific debate. A key AMOC component, the Florida Current (FC), has been measured using submarine cables between Florida and the Bahamas at 27°N nearly continuously since 1982. A decrease in the FC strength could be indicative of the AMOC weakening. Here, we reassess motion-induced voltages measured on a submarine cable and reevaluate the overall trend in the inferred FC transport. We find that the cable record beginning in 2000 requires a correction for the secular change in the geomagnetic field. This correction removes a spurious trend in the record, revealing that the FC has remained remarkably stable. The recomputed AMOC estimates at ~26.5°N result in a significantly weaker negative trend than that which is apparent in the AMOC time series obtained with the uncorrected FC transports.
Paperin johtopäätöksistä:
The 2000–2023 cable record was reprocessed by first correcting the cable voltages for the secular change in the EMF and then recalibrating the FC transports using ship section data. The corrected FC transport time series is made freely available through the WBTS project’s web page (
https://www.aoml.noaa.gov/phod/wbts/). The most important outcome of this study is that the overall trend of the FC volume transport since 1982 has been revised. The updated trend estimate for the 1982–2023 period is −0.1 ± 0.2 Sv per decade, which is not statistically different from zero and 3–4 times smaller than it was thought previously before accounting for the EMF change. This result impacts the recently made assertion of the robust weakening of the FC<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" title="Piecuch, C. G. & Beal, L. M. Robust weakening of the Gulf Stream during the past four decades observed in the Florida Straits. Geophys. Res. Lett. 50, e2023GL105170 (2023)." href="
Florida Current transport observations reveal four decades of steady state - Nature Communications">39</a>. Rather, it appears that the FC has remained remarkably stable over the 40 years of nearly continuous observations.
Ja tuo referenssi 39 on juurikin tuo linkittämäsi tutkimus.
Sinänsä hyvinkin tunnettu AMO-sykli edellyttäisi Golf-virran hidastumista aivan luonnollisista syistä. Tämän hidastumisen pitäisi jo vähitellen käynnistyä.
