2859: Oceanography Gift

Explain xkcd: It's 'cause you're dumb.
Revision as of 21:20, 24 November 2023 by 172.71.178.23 (talk) (Explanation: Starting it off, as it seems stil to be empty... does someone else want to do something about extreme dilution/etc?)
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Oceanography Gift
Shipping times vary. Same-ocean delivery may only take a few years, but delivery from the Weddell Sea in Antarctica may take multiple decades, and molecules meant for inland seas like the Mediterranean may be returned as undeliverable by surface currents.
Title text: Shipping times vary. Same-ocean delivery may only take a few years, but delivery from the Weddell Sea in Antarctica may take multiple decades, and molecules meant for inland seas like the Mediterranean may be returned as undeliverable by surface currents.

Explanation

Ambox notice.png This explanation may be incomplete or incorrect: Created by a WATER CURRENT - Please change this comment when editing this page. Do NOT delete this tag too soon.
If you can address this issue, please edit the page! Thanks.

In this comic, Randall seems inspired by the timing of ocean currents, much as he has previously been with air currents, although he may even have already considered some of the technicalities prior to that.

Transcript

Ambox notice.png This transcript is incomplete. Please help editing it! Thanks.

Happy birthday! I got you these water molecules. (click) (pour)

[10 years pass]

Aww, thank you! (scoop)

Global surface ocean connectivity times are ≤10 years (Jönsson & Watson, 2016, DOI:10.1038/ncomms11239), so if you're willing to plan ahead, you can pour water into the ocean while wishing someone a happy birthday, and then in 10 years let them know they can pick up their gift at the nearest coastline.

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Discussion

The explanation for inland seas is incorrect. What Randall refers to is that with some (or many) of them, the surface currents work against letting any water flow in, because those currents flow outward. Thus, water poured into the Atlantic won't enter the Mediterranean, but water poured into the Med will move outward and then join the general ocean exchange. What the explanation says does apply to (for instance) the Dead Sea. Of course, water molecules added to that have a high chance of evaporation, which would then get them into the global circulation anyway. 172.71.98.97 (talk) 07:04, 25 November 2023 (please sign your comments with ~~~~)

This is incorrect anyway, since the Mediterranean has a net inflow of water from the Atlantic (inflow from its rivers can't make up for evaporation). 172.70.38.34 08:20, 25 November 2023 (UTC)
I would not have called the Med an "inland sea", either.
Though I haven't read the main article/its history, since I put the very first paragraph there and invited others to add more. I presume someone took that literally (like Dead, Aral, Caspian or Salton, each with their own characteristics) rather than with the perhaps rather over-broad definition of having a single relatively narrow 'neck' connection.
But the caveat in the Title Text of undeliverable by surface waters does apply, depending upon where you're sampling, as the Levantine sink of water takes inflowing water (that hasn't reversed around Corsica and gone straight back out) and feeds it round to the depths (and out again into the Atlantic) to a large degree. If you're relying on the 2D circulation, you lose such connectivity through the depths as well as it attaining atmospheric height...
i.e. complex, and I think Randall's wording is not perfect. And yet to see if I can go back and improve/correct/support the Explanation. 172.71.178.134 18:47, 25 November 2023 (UTC)
...and, re: the later edit about the Suez, yes. That too. Meant to consider it, in my re-edit, but forgot to finish checking which way the flow was (or tended to be). Good catch, though. 172.71.94.193 15:06, 26 November 2023 (UTC)
I am not inclined to call the Mediterranean an "inland sea" either, at first thought... but upon inspection, perhaps only because Europe and Africa are separate continents, which makes it feel less "enclosed" and more of a "border", which is not a very good reason. Terdragontra (talk) 20:23, 13 January 2024 (UTC)
Well, (very-pre-)historically, it was the Tethys Ocean, before the continents started to close up like they have done. 172.69.79.139 21:09, 13 January 2024 (UTC)
Randall says that molecules intended for the Med may be returned as undeliverable - not that they will. I would read that to mean that they're more likely to end up back where they started than they are to make it to a destination in the Med, in which case the current explanation is a bit off base.172.71.242.37 09:26, 27 November 2023 (UTC)
I'm not sure the overall premise is accurate; the paper is dependent on very low probability pathways, using the ability of algae to reproduce in those regions to give billions of chances of hitting those difficult pathways. The water in the bottle doesn't reproduce. 172.69.194.70 (talk) 09:51, 27 November 2023 (please sign your comments with ~~~~)
<mumble mumble>...homeopathy...</mumble mumble> 172.71.178.32 12:00, 27 November 2023 (UTC)