Would you happen to have some references reæated the these statements? I would like to read more about recent developments.
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humanspiral@lemmy.ca 2 weeks ago
Even if current weakens it won’t make Europe cold. Main effect will be extreme hot subtropical ocean and stronger hurricanes in Caribbean and south US. Those hotter sea levels will still distribute heat along the main current path. But Europe will get warmer because Atlantic gets warmer without current. Hot water spreads naturally, and hot air temperatures make water warmer. Continuous dropping of Artic ice levels, especially the winter maximums, means very long summer warming periods and very high fall arctic ocean temps, means steady ocean temperatures at UK level.
AMOC collapse theory is based on accelerated Artic melting. But what’s happening so far, last decade or so, is less freezing happening each year. At the time the theory was developed, global warming was led by Arctic region, warming 3-4x faster than rest of planet. Rest of planet has caught up without maintaining that ratio.
DigitalMus@feddit.dk 2 weeks ago
magiccupcake@lemmy.world 2 weeks ago
AMOC is weakening because of salinity changes, not temperature. There’s still a lot of glacier ice on Greenland that melt and disrupt the current.
AMOC carries a lot of heat that is not likely to be replaced if it fails. Atmosphere convection doesn’t have the heat capacity, so only logical conclusion is that temperatures in europe must drop. And based on research people have done, it’s not gonna be a small amount.
If you want a fun math (and a little physics) exercise, we can estimate how much heat AMOC carries from the equator to northern europe, and also try to see how much air it’s heating in the atmosphere. From here it gets a bit more complicated as we have to estimate the the incoming solar radiation and earths radiative cooling. But from there you could compare estimated temperatures with and without AMOC heating.
humanspiral@lemmy.ca 2 weeks ago
temperature melt driven salinity changes.
the physics experiment should include heat in oceans trapped below surface. The different heat flow from 35C Florida oceans in October vs what used to be 28C even at slower flow rate. How a 2 delta melt rate one season could reduce the melt rate next season, how Greenland melt into 10C water instead of 2C water would increase the southward flow rate that increases/maintains the north flow. Salinity normalizes within 3 months. Early summer melt will be low at low winter freeze rates, by theory increasing Carribean north flow, late summer south flow will be warmer.
Observations since 2016 data paper have been the opposite warming of Europe in winter.
magiccupcake@lemmy.world 2 weeks ago
Yeah your just missing two key facts here. One, yeah europe is still getting warmer, AMOC hasn’t collapsed. Two, the conditions for maintaining a convective current are significantly easier than starting one. So if AMOC collapses and Greenland ice stops melting, there’s no guarantee AMOC will restart. And even if it does, it could take centuries.