5 ms·
There are tens (if not hundreds) of thousands of land based weather stations, bouys and floats, weather balloons, radiosondes, observatories, and satellites aro
by akiselev 3y ago
There are tens (if not hundreds) of thousands of land based weather stations, bouys and floats, weather balloons, radiosondes, observatories, and satellites around the world that form a lot of different sensor networks like Argo, ASOS, AWOS, etc. operated by a bunch of government agencies around the world. The World Meteorological Organization at the UN coordinates the sharing of all this data and there are too many players to list but the most important global datasets produced by the US are the GHCN v4 for land and ERSST v5 for sea.
Each organization creates their own models and often compare with each other but most methods start by defining a grid that divides the planet, then use a model to estimate the average temperature for each cell given available sensor data. Many cells, especially in the middle of the ocean, don't have any direct measurements so have to be filled in using satellite based estimates or kriging (interpolation). They average over all of the grid cells in each hemisphere separately then apply some sort of formula to account for the fact that the northern hemisphere has significantly better coverage.
It's not the most precise calculation and what most people are looking for is the rate of change over time using the same model and dataset (which are also versioned based on changes in methodology).
- fdsajkfdskl 3y ago[flagged]
- comfypotato 3y agoClimate science has always acknowledged this. The rate of rise is unprecedented. This is based on non-man-made evidence we gather from the world around us. Concentration of pollen in layers of ice cores for example.
- fdsajkfdskl 3y ago[flagged]
- slater 3y ago> Then who are these kind of headlines (ie, "Hottest day ever!") for? Given they are factually incorrect how so?
- fdsajkfdskl 3y ago[flagged]
- slater 3y agoi mean, yeah, back when the earth was formed i'm sure it was VERY much hotter than it has been in recent millennia (are you attempting a "global warming isn't real and/or not human-induced and/or 'just part of the regular cycle of things'"...?)
- wizofaus 3y agoThe headline doesn't say "ever", it says "on record". That's widely understood to mean "since accurate temperature records began", and doesn't include the fact that the earth was known to be far warmer in former aeons (we certainly don't have any records of what the average temperature was on any given day then).
- fdsajkfdskl 3y ago[flagged]
- wizofaus 3y ago> HN's editorialised version does not say that. True, "on record" was elided, but nor does it say "ever". And given the readership of HN I doubt it was done for sensationalist purposes, purely space-saving. > So the problem is? None, that I can see - it was you that claimed the headline was "factually incorrect".
- comfypotato 3y agoFor me, in the context of the climate change discussion, I knew exactly what it was trying to communicate. I did not find it particularly sensationalized. > Would love to see a source for that. False. If you’d love to you would have at least given it a quick Google and found plenty of relevant papers. There are thousands of studies that would communicate what I just said with a basic Google Scholar search. If you’re a climate change denier just say that so we can move on with our lives.
- fdsajkfdskl 3y ago[flagged]
- akiselev 3y agoIt's literally in the first paragraph of TFA: > This Monday, 3 July 2023, was the hottest day ever recorded globally, according to data from the US National Centers for Environmental Prediction. Key phrase: "ever recorded globally" It's obviously not the hottest day ever because four and a half billion years ago during the Hadean [1] the surface temperature of the earth would have been hundreds of degrees centigrade. [1] https://en.wikipedia.org/wiki/Hadean https://en.wikipedia.org/wiki/Hadean
- rfdsaljfds 3y ago[flagged]
- akiselev 3y agoOf course not. The Hadean was a tropical paradise known for its diversity of life. That's why it was named after the Greek god of fertility (Poe's law applies).
- rfdsaljfds 3y ago[flagged]