/sci/ - Science & Math

>>9528784
There is some evidence that climate models may be overestimating AMOC stability by wrong small-scale mixing parameterization and an incorrect Atlantic salt budget
see
>http://advances.sciencemag.org/content/3/1/e1601666

There is plenty of evidence of AMOC collapse in the paleoclimate archives. The most salient examples are the Dansgaard-Oeschger events and the Younger Dryas climate events, which were all associated with an interhemispheric "seesawing" of warming. However, those examples come from a much colder glacial climate state, so they may not directly translate into the modern world.

Are there examples of AMOC collapse in a warmer world? The most immediate paleo-analogue may be the last interglacial ("Eemian") 120,000 years ago, which was marginally warmer than modern times. Far-field sea level reconstructions suggest a very rapid sea level rise late in the Eemian towards a highstand of +9 meters above the present sea level. See
>https://www.nature.com/articles/ngeo1890

Both Greenland ice cores and North Atlantic ocean sediments document a rapid cooling event at the same time. See
>https://www.sciencedirect.com/science/article/pii/S0277379102000781

Lake sediments from Central Europe point towards a pronounced aridity pulse. See
>https://www.nature.com/articles/nature03905

There is even geologic evidence of significantly intensified storm activity in the subtropics. See
>https://www.sciencedirect.com/science/article/pii/S0025322717302700

This is internally consistent with an orbitally induced collapse of ice sheets, an ensuing freshwater forcing and subsequent collapse of overturning in the ocean.