[HN Gopher] Global decline in ocean memory over the 21st century
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Global decline in ocean memory over the 21st century
Author : gumby
Score : 89 points
Date : 2022-05-10 12:08 UTC (10 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| shrubble wrote:
| I think this needs a lot more scrutiny.
|
| What did we really know about the ocean in 1899, which is when
| part of the data starts? Are they just using mathematical models
| of 1899? What's the margin of error for such a case?
| gumby wrote:
| The British admiralty has maintained data on ocean currents and
| temperatures since the mid 19th century. They operated a number
| of scientific studies (cf Darwin on the Beagle). I'm mildly
| surprised the time series starts as late as 1870.
| londons_explore wrote:
| Whenever an abstract uses the word "noise" it has one of two
| meanings:
|
| * An unpredictable component of a signal, due to things that are
| inherently theoretically unpredictable, such as Johnson-Nyquist
| noise.
|
| * Part of a signal that the writers do not understand or cannot
| model due to shortcomings of the model. Describing such signals
| as 'noise' generally indicates a poor or incomplete paper.
|
| I suspect in this case, it's the latter sadly.
| waterthrowaway wrote:
| I believe noise here just refers to high frequency variation in
| atmospheric forcing. The ocean can be thought of as adding
| inertia to the climate system like a massive flywheel. This
| means it reacts slowly to change. This paper is arguing the
| ocean is becoming quicker to respond to changes it sees (or
| that's my interpretation after a first read)
|
| This paper is tangentially related
| https://onlinelibrary.wiley.com/doi/10.1111/j.2153-3490.1976...
| waterthrowaway wrote:
| Quick clarification: the noise is applied as a perturbation
| of their model which is meant to tease out its response to
| high frequency variation in sst. It is not really a
| limitation of their model but part of its design.
| nonrandomstring wrote:
| Dither [1]
|
| [1] https://en.wikipedia.org/wiki/Dither
| abrax3141 wrote:
| The specific term shouldn't be "Climate Change" but rather
| "Climate Chaos" - both accurate and appropriately ominous-
| sounding.
| Natfan wrote:
| I've seen "Climate Crisis" a lot more recently, which I think
| is an apt descriptor. I've also seen "Climate Emergency", but
| it doesn't alliterate as well.
| abrax3141 wrote:
| Climate Crisis is technically incorrect. For some places the
| climate is, perhaps temporarily, improved with respect to
| their local goals. Climate Chaos provides the desired
| omenisity while accurately describing the physics.
| [deleted]
| photochemsyn wrote:
| Conceptually, this is just about that warming a body of water
| from above tends to result in a thin layer of warm water sitting
| atop the larger colder body. Anyone who has gone swimming in a
| temperate lake in summer will experience this; there's a thin
| warm layer on top. This greatly reduces mixing with the lower
| body. In winter, such lakes typically 'overturn', i.e. the
| temperature gradient disappears and the surface water mixes
| freely with the deep water.
|
| A feature of a shallower warm layer with less deep mixing in the
| ocean is that it's going to be more susceptible to atmospheric
| forcing (clouds blocking sunlight, or winds driving surface
| currents, or a warm wet air mass driving heating). This paper
| presents modeling runs in support of that hypothesis. Since long-
| term (months) climate forecasts (El Nino estimates etc) rely
| heavily on sea surface temperature forecasts (SSTs being fixed
| data fed into short-term forecasts), this will reduce the
| accuracy of the long-term forecasts (but not of the short-term
| forecasts, which are based in part on real-time satellite
| measurements of SSTs).
|
| One of the more likely long-term effects of this shallower,
| warmer mixed layer is a reduction in deep-ocean mixing rates, and
| what that means is less oxygen gets delivered to the deep ocean,
| so oceanic anoxia and hypoxia events are more likely to become
| widespread over time. This is a complex situation, however, as
| nutrient inputs (i.e. fertilizer runoff from intensive
| agriculture) can cause a massive drawdown of oxygen in the deeper
| ocean, due to amplification of local biological breakdown of
| biomass.
|
| https://oceanservice.noaa.gov/podcast/feb18/nop13-hypoxia.ht...
|
| Global oceanic anoxia events have happened in the past, but would
| really require hundreds-to-thousands of years to develop; what we
| see now are more regional events linked to the dieoff of large
| numbers of bottom-dwelling animals. We are definitely headed in
| that direction under current practices, however:
|
| https://en.wikipedia.org/wiki/Ocean_deoxygenation
| tejohnso wrote:
| So more loss of stability. Decreased predictability. Typical for
| the climate emergency we're in, and typical precursor for a
| significant state change event in complex systems.
|
| I hadn't heard of the term ocean memory before. For something
| more specific and slightly related, check out the Atlantic
| Meridional Overturning Circulation. Another complex system or
| subsystem that is being affected with potential for significant
| impact.
| lm28469 wrote:
| > and typical precursor for a significant state change event in
| complex systems.
|
| We're about to rediscover food chains and the domino effect
| sprinkled with a heavy dose of "told you so"
| nonrandomstring wrote:
| Sadly, there is no "told you so". The kind of people who are
| impervious to reason before they create a catastrophe are
| equally impervious in its wake. They're either dead, along
| with all the other people they got killed, or intransigent to
| the last.
|
| Carlo Cipolla developed the "Basic Laws of Human Stupidity"
| as a quadrant model, positing Intelligence, Helplessness,
| Predation and Stupidity as four individual types [1]. Of all
| dark human qualities, including malicious psychopathy Cipolla
| thought that "the stupid person is the most dangerous person
| that exists".
|
| [1] This paper offers an insightful analysis: https://www.sci
| rp.org/journal/PaperInformation.aspx?PaperID=...
| jvanderbot wrote:
| Oh man that is a fun read:
|
| > A large class of stupid agents are those who act only "on
| principle", thereby frustrating the work of others without
| gaining any personal benefits, as often occurs in board
| meetings, on faculty or departmental committees, in
| political parties, assemblies with unanimous voting
| regulations, even in international associations of nations
| when a nation vetoes a proposition "based on principle".
| doublerabbit wrote:
| OT, your comment was intellectual pleasing, that I read it
| twice.
| robocat wrote:
| > the stupid person is the most dangerous person that
| exists
|
| But everybody is relatively stupid compared against others,
| if multiple dimensions of intelligence are measured.
|
| Or use an absolute scale, and I think we can round
| everybody's intelligence down to zero. Humans are surely
| not that smart - certainly in my experience.
| nonrandomstring wrote:
| > But everybody is relatively stupid compared against
| others, if multiple dimensions of intelligence are
| measured.
|
| Absolutely true. And, to go further, "intelligence" is
| almost impossible to measure.
|
| Look more closely at Cipolla's theory though, and you'll
| see it is not about *measurement".
|
| He doesn't set up a (diametric) scale of intelligent
| <---> stupid.
|
| It's about behaviour between people who transact. He
| labels the behaviours (results of transaction) as one of
| four types.
|
| The one labelled "stupidity" is the lose-lose quadrant,
| where the parties act in such a way as to destroy value
| for them both!
|
| So, I guess in theory two rather low IQ people (measured
| intelligence) could interact in a way that is
| "intelligent" behaviour.
|
| Does that help explain it in a useful way?
| robocat wrote:
| Thanks. The "theory" would perhaps be better served by
| using clearer, less inflammatory, terms from
| transactional games like the prisoner's dilemma, or from
| evolutionary strategies.
|
| "Intelligence" just mean "cooperate" in a win-win
| situation (non-zero sum game)?
|
| "1) Intelligent people, 2) Helpless/Naive people, 3) the
| Bandit and 4) the Stupid person" seem like terrible
| categorisations to me, because they imply fairly
| unchangeable attributes. Who wants to live in a world of
| being labelled? Defecting can be intelligent. Learning
| how to play tit-for-tat is worthwhile.
|
| Edit: disclaimer: I didn't read much of the link, because
| the little I saw triggered my bogus limit. And I hope
| Cipolla isn't Spanish - they would get a lot of ribbing.
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