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umsonst.bsky.social
@umsonst.bsky.social
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Earth-System Nerd
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umsonst.bsky.social
Southern Hemisphere marine heatwaves update - difference the last 5 days

How intense will be the marine heatwave signal in 2025/26 during summer?
November 9, 2025 at 4:33 PM
umsonst.bsky.social
Next study that we do not have a significant weakening of the AMOC till today

The whole climate system is now collapsing or shifting into a feedback driven state. That is the real story...

And AMOC collapse will have catastrophic effects, but till that happens it won't matter anymore much...
The graph shows AMOC strength modeled which show a gradual decline from out times onward till 2100. RAPID measurement array shows no decline till 2024. Two reanalysis datasets are also show no decline. Here what they write: Observed AMOC exhibits significant variability on timescales ranging from days to decades, masking long-term trends (Figure 1A). Generally, The RAPID array shows that decadal-mean subtropical AMOC exhibited a statistically significant weakening from 2005 to 2014, and virtually no trend since the early 2010s (Figure 1A), probably representing decadal variability rather than ongoing long-term weakening.3 Similarly, the OSNAP array has yet to exhibit any clear trend due to its relatively short observational duration. "Toward an integrated framework on AMOC stability: Combining theory, observations, paleoclimate records, model simulations and AI"; https://www.the-innovation.org/article/doi/10.59717/j.xinn-geo.2025.100167
November 9, 2025 at 12:35 PM
umsonst.bsky.social
We underestimated Southern Ocean outgassing by 40% around Antarctica >40°S

"Substantially underestimated winter CO2 sources of the Southern Ocean"; www.science.org/doi/10.1126/...
Shows three circumpolar bands around Antarctica where net carbon uptake (outer band) and outgassing (middle band 40°S-60°S) happens.
November 7, 2025 at 9:46 PM
umsonst.bsky.social
This one:

For ridge blocks, diabatic heating enhances the upstream wave activity, thus contributing to the persistence of blocks.

"Blocking diversity causes distinct roles of diabatic heating in the Northern Hemisphere"; www.nature.com/articles/s41...
November 7, 2025 at 9:08 PM
umsonst.bsky.social
And this happens while aerosols increase over the SH - this summer will be another important data point - will it further intensify like the last years? If so we are definitely in an extinction level event, as we warmed the oceans way too fast...

And aerosol reduction certainly reinforced it...
November 6, 2025 at 1:01 AM
umsonst.bsky.social
Its a model study while lots of MHW studies and their effects on clouds are observational - with the intensification of MHWs clouds are reduced while weak winds and blocking patterns induce them and strong stratification and shallow upper mixed layer depth precondition the upper ocean for MHWs...
This signal in 2023/24 had not been aerosols and their effect on clouds but a feedback between the upper ocean and atmosphere suddenly going off charts also driven by the SST pattern effect on cloud cover...
November 6, 2025 at 12:52 AM
umsonst.bsky.social
As cooling the planet via re-greening gains attraction here some important key publications on this issue - graph study...

#climate #Earth
Pictures show the affect of vegetation from the local to the global on circulation in four steps of scale. The abstract of the most recent review: Vegetation often understood merely as the result of long-term climate conditions. However, vegetation itself plays a fundamental role in shaping Earth's climate by regulating the energy, water, and biogeochemical cycles across terrestrial landscapes. It exerts influence by altering surface roughness, consuming significant water resources through transpiration and interception, lowering atmospheric CO2 concentration, and controlling net radiation and its partitioning into sensible and latent heat fluxes. This influence propagates through the atmosphere, from microclimate scales to the entire atmospheric boundary layer, subsequently impacting large-scale circulation and the global transport of heat and moisture. Understanding the feedbacks between vegetation and atmosphere across multiple scales is crucial for predicting the influence of land use and cover changes and for accurately representing these processes in climate models. This short review aims to discuss the mechanisms through which vegetation modulates climate across spatial and temporal scales. Particularly, we evaluate the influence of vegetation on circulation patterns, precipitation and temperature, both in terms of trends and extreme events, such as droughts and heatwaves. The main goal is to highlight the state of science and review recent studies that may help advance our collective understanding of vegetation feedbacks and the role they play in climate. Vegetation-climate feedbacks across scales"; https://arxiv.org/abs/2409.04872 Shows how forests help to bring water more inland - the animate precipitation, evaporate it and thereby help to transport it more inland. "Trees, forests and water: Cool insights for a hot world"; https://www.sciencedirect.com/science/article/pii/S0959378017300134 Shows a map of global vegetation cover and water risk - where it is high there is lower drought and water risk. "Managing Forests for Both Downstream and Downwind Water"; https://www.frontiersin.org/journals/forests-and-global-change/articles/10.3389/ffgc.2019.00064/full
November 5, 2025 at 7:55 PM
umsonst.bsky.social
Just went a little bit through the literature I did not know and found this passage - so it could be shallower than in the picture.

Actually this is what I remember gas hydrates can be quite shallow in the Arctic self regions where once glaciers existed...
Unlike results from the synthetic seismic data (Figure 5), we did not identify reflections indicating the top of gas hydrates either intra-permafrost or sub-permafrost. Possible reasons are insufficient impedance contrasts for intra-permafrost gas hydrates and sub-permafrost gas hydrate thicknesses that are smaller than the seismicresolution. For example, gas hydrate zones at the Mallik gas hydrate field on Richards Island on the coast ofthe Beaufort Sea (Figure 1) show thicknesses between 37 and 51 m (Dallimore & Collett, 2005). There, zone B(51 m thick) consists of a “series of 5–10 m thick gas hydrate-bearing sand units separated by 0.5–1 m thick gashydrate-free silt layers,” which possess heterogeneous gas hydrate saturations. A seismic response from such gashydrate-composed layers may not be explicit, particularly with our seismic resolution of c. 17–23 m (λ/4: 28 Hz;2,000–2,600 m/s). H "Revealing the Extent of Submarine Permafrost and Gas Hydrates in the Canadian Arctic Beaufort Sea Using Seismic Reflection Indicators"; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GC010884
November 4, 2025 at 6:38 PM
umsonst.bsky.social
But as there exist always a but - while one seems not as bad as feared there exist a real kicker in the system :D

Could be intensifying groundwater channels opening up UNDER the ESAS - question: is this shit new or old? This study things old...

www.pnas.org/doi/full/10....
November 4, 2025 at 5:51 PM
umsonst.bsky.social
Here the observations from some studies - could it be that oxygen saturation are a good proxy for AMOC strength?
November 4, 2025 at 12:56 PM
umsonst.bsky.social
Question on fig. 5 The oxygen saturation signal. It went up down to 1000m depth. Is it due to enhanced vertical mixing towards the end of the time line increasing?

In 2012-2016 we had the largest freshwater influx and a restrengthening signal of the AMOC towards 2017

Do you have an interpretation?
November 4, 2025 at 12:55 PM
umsonst.bsky.social
How can models simulate the warming of a chaotic getting feedback system if they can not even do it for an undisturbed state?

The spread is some 1.5°C above and below mean warming levels...
But hey, do not do one thing: evaluate the models ability to simulate the feedbacks on their ability to simulate the mean feedback state of a undisturbed state. Its the most prominent case of ignoring physics as the interplay of all systems constitutes the mean temperature. Anyhow how could there exist a physical problem with models if they can not simulate historic mean temperatures??? Morons who think so...
November 3, 2025 at 5:00 PM
umsonst.bsky.social
AMOC decline from a subsequent study on Atlantic heat content build up

This time a significant weakening

The AMOC discussion is a big fuck up with two opposing camps

Equatorial Atlantic mid-depth warming indicates Atlantic meridional overturning circulation slowdown www.nature.com/articles/s43...
This study on AMOC decline using also as a proxy Atlantic heat content changes sees a significant weakening starting in the 90s. while the previous I posted from July does not sees it. In my opinion the whole AMOC study discussion is a big fuck up! Its a heavily biased discussion with two camps: one it has already weakened while the other it has not significantly weakened till now - the later is a result of direct measurements showing no weakening... So lets see if the weakening really will start now... I'm 70/30 for another increase in warm water transport northward driven by intensifying and more northward moving storms in the NA and then a weakening or we get now a signal...
November 1, 2025 at 10:33 PM
umsonst.bsky.social
As there exist so much fuss about a substantially weakened AMOC here another one:

"The observed heat storage indicates an overall AMOC slowdown by only 1.31 ± 0.39 Sv since the 1950s. Considering the pronounced natural variability, this weak anthropogenic AMOC slowdown probably has not emerged yet"
Graphs shows AMOC strength declined somewhat in observations but only weakly. Still things can become interesting up there in the North Atlantic. Here the study: "Heat Storage Pattern Linked to the Atlantic Meridional Overturning Circulation Slowdown"; https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025GL116801 Shows warming patterns across the North Atlantic basin. What is interesting and important that the global oceans channel heat into the Atlantic. This is the reason it gains heat much faster than any other great basin. Important: the whole basins upper water column is warming, especially the first 700m. This picture shows the upper water transport from the Indian and Southern Ocean into the Atlantic basin from the South. The circumpolar winds strengthened driving the speed of the subtropical gyres in the South Atlantic and in the Indian Ocean basin which increased the warm water transport into the Atlantic Basin. Most seems to come from the Indian Ocean, but I'm not up to date as this study was from 2011 - want to check how that still holds but could be possible as in 2024 massive amounts of heat had been channeled into the Atlantic which gained a massive amount of heat - should have come from the western Pacific which gained massive amounts of heat prior to the El Nino in 2023...
November 1, 2025 at 10:17 PM
umsonst.bsky.social
Just this one shows how fast the Amazon could go up in flames - if this happens already what will happen along the way or after we reached 2°C of mean warming?

This thing can make puff and whoosh...

Also amplification between drought and tropical Atlantic SSTs is now discussed by a new preprint...
November 1, 2025 at 7:47 PM
umsonst.bsky.social
Not too much of a decline - here the table: psl.noaa.gov/cgi-bin/data...
November 1, 2025 at 7:20 PM
umsonst.bsky.social
@zohrankmamdani.bsky.social‬ - this one is also highly important to understand: you have a heat buildup in the Northwestern Atlantic right off New York...

"Recent warming and decadal variability of Gulf of Maine and Slope Water"; aslopubs.onlinelibrary.wiley.com/doi/10.1002/...
October 31, 2025 at 7:38 PM
umsonst.bsky.social
Slowly its entering main stream discussion:

"A dangerous hothouse Earth trajectory may now be more likely due to accelerated warming, self-reinforcing feedbacks, and tipping points."

"The 2025 state of the climate report: a planet on the brink"; academic.oup.com/bioscience/a...
October 31, 2025 at 8:53 AM
umsonst.bsky.social
also 2025 is astonishing as we have very high rates of outgoing longwave radiations - should cool more but it does not - but lets see what the next Ceres data shows...
October 30, 2025 at 11:39 PM
umsonst.bsky.social
You only have to find the right metric to find the non-linear signals in all this noise. Sadly, not seldomly the opposite is done...

This one I Iove as it shows so nicely that this system goes now nuts:
October 30, 2025 at 1:26 AM
umsonst.bsky.social
This graph of ocean heat content increase shows nicely how the upper ocean heat uptake starts to decouple from the deeper ocean

One preprint comes to the conclusion that ocean heat uptake efficiency was declining since the 2000s but they analyzed it only till 2010.

#climate #ocean #Earth
The graph shows at which layers the oceans take up heat. The share of the upper 300m is increasing with time the last ~25 years, while in recent years this development seems to accelerate. One preprint comes to the conclusion that ocean heat uptake efficiency was declining since the 2000s but they analyzed it only till 2010. The least years it seems to accelerate that heat is increasingly being stored in the upper ocean as stratification is increasing decoupling the deeper ocean from the upper one. This can be only seen in the data of 2023 and 2024 by this publication series from which also the first graph is. In 2024 about 75% of the ocean heat increase happened in the upper 300m. There will be some El Nino effect, as El Ninos shift heat towards the upper ocean. So 2025 will show if we have here a robust signal emerging... "Ocean heat content in 2024"; https://www.nature.com/articles/s43017-025-00655-0 The next years this development will move into the focus of climate science as it holds enormous feedback potential... This graph shows how heat uptake efficiency had been declining since the 200os till 2010 the end of their study period. A declining heat uptake efficiency means that heat is increasingly being stored in the upper ocean.
October 27, 2025 at 10:57 PM
umsonst.bsky.social
@climatenews.bsky.social next indication that we could have actually a massive amount of warming in the pipeline...

And it could already start to being tapped if we look at the North Pacific or around Antarctica where the warm water comes up again in recent years:
October 27, 2025 at 5:45 PM
umsonst.bsky.social
Here you have where the tropical overshooting into the stratosphere by convection takes places which is projected to increase - its also expanding poleward - mid latitude events are now happening regularly and also even in the Arctic - its one trend of a warming world - stronger convective activity
October 27, 2025 at 4:15 PM
umsonst.bsky.social
This one is important as the picture is actually more mixed - intensifying convection with overshoot - into the stratosphere - which is increasing in the atmosphere pumps water vapor into it which increases the lower stratosphere temperature over distinct regions.
Shows the upper troposphere- lower stratosphere temperature field over all latitudes - lower stratosphere temperatures are increasing over the tropics indication stronger convective activity which is a good proxy that indeed the rising branch of the Hadley cell - north/south tropical circulation cell - is indeed intensifying which means a intensification of the poleward upper "hot" air transport that intensifies heatwaves under high pressure in the subtropical high pressure belt where the "hot" upper air descends and warms again as the air pressure compresses the air parcels when they sink down...
October 27, 2025 at 4:07 PM
umsonst.bsky.social
Next worst case: Amazon droughts can form a vicious mutual enhancing cycle with tropical Atlantic SSTs

Just this feedback loop could be enough to switch the terrestrial carbon sink into a source as we came already close in 2024...

Link to the preprint in the alt text

#earth #climate
Next worst case: Amazon droughts can form a vicious mutual enhancing cycle with tropical Atlantic SSTs We are now in the process to trigger ever more self-reinforcing feedbacks in the system. How Amazon drought couple with tropical Atlantic sea surface temperatures in the form of a positive feedback loop is just another example of how fast things could spiral out of control in the Earth systems as the intensifications of such couplings are difficult to quantify... Furthermore, this feedback loop would be able to enhance tropical storms over the North Atlantic and would trigger distant knock-on effects. Last just this feedback could be enough that the terrestrial carbon sink switches into a source as we came already close in 2024... Here what they write: There is evidence suggesting that the Amazon interannual hydrological variability is getting more extreme (Fu et al. 2013; Gloor et al. 2013; Yin et al. 2014; Zou et al. 2015). According to our results, a continuous warming of the TNA SST’s may be amplified by a drier Amazon, and may affect the region’s ocean-atmosphere dynamics and diverse mechanisms and processes such as tropical easterly waves, tropical storms, which might induce more frequent and intense hurricanes over the TNA and the Caribbean Sea, that in turn could cause positive feedbacks into the continent, thus accelerating desiccation and vegetation dieback of Amazonia, which in turn could lead to a tipping point in the Amazonian hydroclimate (Lenton et al. 2008), with significant consequences at continental and global scales. As suggested by our results, future anomalies in rainfall over the Amazon River basin possibly caused by climate change, climate variability, deforestation and land use/land change might thus be related to anomalous future stages of TNA’s SSTs. Our results also suggest that the Amazon plays a key role in the TNA warming, reinforcing the feedback and triggering more severe droughts, such as the well-studied two one-in-a-century record breaking events of 2005 and 2010in the Amazon. "Nonlinear interactions between the Amazon River basin and the Tropical North Atlantic at interannual timescales"; https://arxiv.org/pdf/2504.02102 A schematic of how tropical convection over the Amazon is connected to surface winds over the tropical Atlantic which induce a control function for sea surface temperatures
October 26, 2025 at 9:03 PM