Timeline for Can the previous weather be computed from the current situation?
Current License: CC BY-SA 4.0
17 events
| when toggle format | what | by | license | comment | |
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| Jul 10, 2018 at 17:24 | answer | added | Metlam | timeline score: 3 | |
| Jul 10, 2018 at 6:48 | comment | added | BmyGuest | @ToivoSäwén Ah, makes sense. Didn’t know it is done like this though, so thanks for adding this info. | |
| Jul 10, 2018 at 6:37 | comment | added | Toivo Säwén | Not enough info for an additional answer, but worth noting is the reason why we can still somewhat trust weather forecasts is because rather than performing one state-of-the-art-technology simulation, several are performed with slightly differing initial conditions (accounting for the fact that the current state of the atmosphere can never be faithfully measured). This technique is called ensemble forecasting and may further explain why we can't simply use the algorithms backwards to find out what the weather was like in the past. | |
| Jul 9, 2018 at 20:49 | answer | added | BoredBsee | timeline score: 1 | |
| Jul 9, 2018 at 17:03 | vote | accept | BmyGuest | ||
| Jul 9, 2018 at 15:43 | answer | added | leftaroundabout | timeline score: 19 | |
| Jul 9, 2018 at 12:52 | vote | accept | BmyGuest | ||
| Jul 9, 2018 at 17:03 | |||||
| Jul 9, 2018 at 12:52 | answer | added | gerrit♦ | timeline score: 13 | |
| Jul 9, 2018 at 12:21 | history | edited | BmyGuest | CC BY-SA 4.0 |
Edit for clarity.
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| Jul 9, 2018 at 12:18 | comment | added | BmyGuest | @gerrit 99% the answer I want (-I agree to the practical point, still would be curious if there is mathematical forking point in the alogirthm which would prevents it from working or not. Or rather: Can one - given the current system - compute the previouse system (f.e. if some planet atmosphere on a remote planet would be 'snap-shot' visited, could one compute "backwards"?. but can you make your comment into an answer so that I can accept and close? | |
| Jul 9, 2018 at 12:05 | comment | added | user1066 | @BmyGuest Gerrit's is the right answer. | |
| Jul 9, 2018 at 11:58 | comment | added | gerrit♦ | Validation is done by hindcasting, not by reversing the time axis, which seems to be what you're asking about. Reversing the time axis would involve water falling up to the clouds and cyclones moving equatorward and turning into potential vorticity. It seems involved and I'm not sure what benefit would be. | |
| Jul 9, 2018 at 10:27 | comment | added | BmyGuest | @JeopardyTempest Sure, but some mathematical algorithms are reversible, some within limits and some simply aren’t. I don’t know into which category the ones used for weather predictions fall - hence me asking. | |
| Jul 9, 2018 at 10:25 | comment | added | JeopardyTempest | The problem I'd think is A definitely causes B, but the inverse, B can often have many causes of A, C, D, etc. I'd think that's a problem in most mathematical modeling of time? | |
| Jul 9, 2018 at 9:35 | comment | added | BmyGuest | @Communisty No, but from a programmers/mathematicians perspective that would be an interesting idea to validate forecast methods, I think. And I was also interested if these methods are invertible or not. So, I assumed somebody else might have had this idea as well (for sure) and at least tried it. Unless, of course, it is not doable. Which would be the other answer... | |
| Jul 9, 2018 at 9:32 | comment | added | Communisty | I've never heard that anyone would do this. Any sources implying that someone does? I would guess that most models can't do this. | |
| Jul 9, 2018 at 8:39 | history | asked | BmyGuest | CC BY-SA 4.0 |