Thread by @EleanorFrajka

Will the #AMOC collapse by 2025? Here’s what we know from direct observations (since 2004).
Image from Srokosz & Bryden (2015)
A 🧵 https://t.co/mzTLMObRRrshorturl.at/ryB34

The #AMOC is highly variable. More variable than scientists expected when the observations was started. @RAPID_AMOC @NOCnews @MiamiRosenstiel https://t.co/KjBGWcIr2wrapid.ac.uk/data.php

@RAPID_AMOC @NOCnews @MiamiRosenstiel Atmospheric variability can ‘imprint’ on the #AMOC strength. We expected that cooling would matter, but finding out that wind also matters didn’t fit our classical view of the AMOC as a slowly varying circulation.

Jackson et al. (2022) sums it up https://t.co/LZhpNwKKogshorturl.at/dnFY6

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson The #AMOC can temporarily reverse. In 2009/10, and again later, the northward heat flux of the AMOC stopped and even reversed. Temporarily! (These reversals were due to changing winds.)

@ger_the_sea et al. 2012 https://t.co/dcgVkQAk6sshorturl.at/adgiM

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson @ger_the_sea Metrics for the strength of the #AMOC at different latitudes give different numbers.

On the one hand, this is unsurprising. The AMOC is a complex system of currents. But it does complicate the picture when talking about a collapse.
https://t.co/mIoVuFL8CBshorturl.at/tFW49

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson @ger_the_sea The latest study () is based on a statistical analysis of SST fingerprints not #AMOC measurements (remember, only available since 2004). It cites increases in variability as indicating that the system is moving towards a tipping point. https://t.co/asFLXo7jbrshorturl.at/fqyO8

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson @ger_the_sea Statistical tools can be helpful, but run the risk of over-simplifying relationships in the climate system (i.e., how the #AMOC responds to freshwater, or the net effect of small-scale eddies on large-scale circulation).

Johnson et al. 2019 () https://t.co/70cBxKIb9jshorturl.at/qMW28

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson @ger_the_sea More complex models don’t necessarily represent those relationships either. On account of models missing key processes, the @IPCC_CH AR6 report reduced confidence to 50% that the #AMOC won't collapse by 2100.

IPCC AR6 WG1 Chap9 Executive summary (2021)

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson @ger_the_sea @IPCC_CH Scientists gathered in @CENunihh to discuss the state of #AMOC research and observations. From the observational (rather than proxy) record, a majority agreed that we don’t yet know how the AMOC will respond to future anthropogenic change.

#AMOC2023 https://t.co/pImBt28LXfshorturl.at/adewO

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson @ger_the_sea @IPCC_CH @CENunihh @EpocProject @PatrickHeimbach @ShaneKahn @fmkdejong @JohannesKarst @sunke_tk @np_holliday @David_Smeed Summary report in progress. Sneak peak:
- A need to reconcile missing key processes
- New approaches for basin-scale #AMOC understanding
- Compound impacts of AMOC with carbon and cryosphere
- Articulation of societal impacts

Maybe education too. AMOC is not the Gulf Stream.

@RAPID_AMOC @NOCnews @MiamiRosenstiel @kieloben @BenMoat1 @JonIRobson @ger_the_sea @IPCC_CH @CENunihh @EpocProject @PatrickHeimbach @ShaneKahn @fmkdejong @JohannesKarst @sunke_tk @np_holliday @David_Smeed See also @EpocProject where we dive deeper into #AMOC proxies, high resolution coupled modelling for missing key processes, and latitude-spanning (34°S to Arctic) approaches and new sensors for carbon/AMOC transports. @HorizonEurope https://t.co/F4VQmoavFhepoc-eu.org