2/
And now that we have all read the explainer above on #ACC , the Antarctic Circumpolar Current(s),
we can better appreciate what Matt England explains here from about minute 50 onwards
https://www.youtube.com/live/39T7bW7KA18
He actually answers a question I put to him beforehand on Bluesky, regarding my confusion about salinification versus freshening.
The beginning of this #ClimateChat episode hosted by Dan Miller and Leon Simons
is all about Matt's paper with Rahmstorf and others about the 2023 bananas in the North Atlantic. You may recall: low wind speed as primary cause by far for the marine heatwaveS 2023 that gripped regions of the North Atlantic one after the other.
Matt explains the multiple ways wind over oceans contribute to cooling.
a) mixing b) white caps on the waves = albedo increase c) ocean spray or fog = albedo increase, and one more I now forget.
As is Dan Miller's habit, he also quickly asks Matt about #geoengineering, bringing SO2 into the #stratosphere .
Matt's reply: 1) angry that fossil fuel industry should be let off the hook by this
2) realistically, the political mindset lets Matt expect that geo engineering will be done.
3) whether he supports this is not answered.
4) as an afterthought, he adds that ocean acidification from relentless CO2 emissions does continue despite geo-engineering, and also the CO2 take-up and later re-release into the atmosphere continues.
Dan Miller also grazes his pet topic #ShippingSO2 . Matt politely agrees that it is a bananas factor – but a small one.
Then comes the Southern Ocean part (thank you!).
At which point the question is also raised and answered with a NO: whether seafloor #clathrate on Antarctica's continental shelf might thaw and cause a methane bomb.
And only one short moment at the end on #AMOC collapse, about which Matt also published a paper recently, namely the #collapse impacts non-Europe areas, such as teleconnections to adjacent basins and into the Southern Hemisphere
https://www.nature.com/articles/s41558-022-01380-y
I think, my question stole precious time from the AMOC part. 😬
Read this article about #methane #hydrates observed off the coast of Africa moving 40km from deep-cold waters to the continental shelf:
https://scitechdaily.com/fire-ice-time-bomb-discovered-climate-changes-deep-ocean-threat/
Relevant because one of the leading theories for what caused the #PETM (jump in #CO2 and #temperatures at 55 Ma) is the #clathrate gun-- frozen methane in the abyssal ocean thawing & causing sudden warming.
https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis
But it hinges on methane being shallow enough to being vulnerable to melt.
Not time to panic, but wow.
Research indicates that oceanic fire-ice, or frozen methane, is vulnerable to melting from climate change, posing a significant threat of methane release into the atmosphere. An international team of researchers led by Newcastle University found that as frozen methane and ice melts, methane — a p
How methane studies on Earth could inform the search for alien life in our solar system https://www.space.com/methane-deposits-earth-proteins-search-for-alien-life
Molecular basis for inhibition of #methane clathrate growth by a deep subsurface bacterial protein https://academic.oup.com/pnasnexus/article/2/8/pgad268/7242427
"Results showed a class of #proteins called the bacterial #clathrate-binding proteins (CbpAs) influenced the growth of clathrate by interacting directly with its structure."
#Tegtmeier
🎶 What you don't know you'll need to explain on your own.
Was man nicht selber weiß, das muss man sich erklären. 🎶
When I was a teenager, Tegtmeier was a German TV figure 1984-85, played by Jürgen von Manger. In the show, he travelled Europe and explained to himself and his audience all kinds of stuff he found curious. His explanations were based on his common sense alone.
And he sang that little tune "Was man nicht selber weiß, das muss man sich erklären." 🎶
Now, since I became #climate aware, my guilty conscience (WHY didn't I get it earlier?!?!?) and natural curiosity has me tegtmeiern a lot. See? I used the name as verb, with the German infinitive "n" at the end ! Cause that's what I'm doing when I go on a quest to figure out how stuff works in the big eco and climate clusterfuck: I tegtmeiere ("e" = suffix for verb in presence, first person singular).
Using my common sense alone isn't enough, of course.
But still, having to catch up in soo many areas unknown to me until 2018, I feel the need to preserve my self-image at least a little bit. Not knowing stuff wasn't a prominent part of my self-image before – unless coupled with successful tegtmeiern. It's a
personally disorienting experience, having ignored for most of my life THE most existential topic of all time, and now, based on that big unknown, having to re-design all of my philosophy and values.
So when I come across something I don't know and find curious enough to explain to myself, I apply my uneducated, unfactual common sense as first pointer to where to search for answers. Humming #Tegtmeier 's silly, little tune to myself: 🎶 What I don't know myself, I'll find an explanation 🎶
And I decided that I'll be using #Tegtmeier as hashtag for my quests here in the Fediverse.
Next two #Tegtmeier topics: #clathrate #ClathrateBomb
and #AMOC slowdown.
I pulled ocean temperature measurements from the World Ocean Database for the topic of the clathrate scare.
And once I had gotten a feel for the data and what I can and can not do with it, I pulled some more data for the wider region around the #ColdBlob
When I get around posting about the two things, watch out for the hashtag #Tegtmeier .
💃 🎶
Read 2 papers about what happens to CH4 in the water column. One from onsite inspection after #DeepWaterHorizon. But that's in 800-1200m. Needless to say, CH4 doesn't make it to the surface. Bacteria eat methane, CH4 is oxidised to CO2 (which acidifies the ocean. Bad!).
The other paper is about CH4 seeps in 240m from thawed (!) #clathrate
https://www.sciencedirect.com/science/article/pii/S0278434313002604
Winter currents may drive some CH4 up to the atmo but summer stratification def-o holds CH4 down.
Take away: don't fret💃🏼 much😁
https://www.science.org/doi/full/10.1126/sciadv.aaz1346
Miller et al 2020 charted 65million years of #sealevel with CO2 and temperature. The Pliocene at the very top and the blue curve in the centre chart shows that sea level in the Pliocene undulated between 30m and -40m.
Noteworthy is also that sea level was never lower than in the last #IceAge with -120m. I wonder what that means for #clathrate #hydrate on continental shelves – and for potential fossil CH4 gas pockets beneath them I mentioned elsewhere. Hm. Hm.🤔
@SusanKraemer
It's methane from ~ contemporary microbes digesting what trickles down to the ocean floor as dead sea creatures. Pressure and ºC freezes CH4 + H2O Why those microbes live on relatively shallow continental shelves (and produce methane): only there sea creatures are abundant. In deeper seas, the ocean floor is scarce living for these microbes or otherwise uninhabitable for them.
The potential gas pockets beneath the #clathrate are old fossil gas, tho, like on land in permafrost.
@SusanKraemer
Ja #clathrate or methane #hydrate are CH4 and water frozen ~ solid. And under this solid ice lid, gazeous methane bubbles may exist, as well.
A lot like the round permafrost holes that appear when the lid on the gazeous bubbles thaws and the gas escapes.
In the first 20 years, emitted methane has a warming effect 80x that of CO2.
In the decade 2010-2019 the average concentration of 1830ppb (or 1.8ppm) CH4 caused 0.51ºC warming.
Whereas Ø 400ppm CO2 caused 0.7ºC, see #AR6-WG1
#Clathrate
To stay stable, clathrates require pressure. Ocean depths of >350m provide enough pressure.
The top map shows ocean depths as white which are shallower than 280m.
The bottom map shows known clathrate reservoirs in brown.
Puzzling difference: many ocean regions near costs are white but appear to have clathrate? Eg., north of Siberia and Alaska, South of Indonesia, West of Ireland.
One of my sources must be wrong. Which one?
Anyway. +1ºC in 500m depth breaks the ice cap and WAM.
anlomedad
Matt Willemsen
legraLeGra
Lukas VFN 🇪🇺
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