Fernseh-Meteorologen kämpfen um die Wahrheit: Weil sie über die Zusammenhänge von Wetter und Klimakrise aufklären, sehen sie sich immer häufiger Angriffen von Wissenschaftsleugnern ausgesetzt.
Fernseh-Meteorologen kämpfen um die Wahrheit: Weil sie über die Zusammenhänge von Wetter und Klimakrise aufklären, sehen sie sich immer häufiger Angriffen von Wissenschaftsleugnern ausgesetzt.
English “Everything” user here. Sorry.
Liters/meter^2
Is this a common unit for weather? I translated the post text and the climate/drought makes sense.
I just haven’t ever seen the USA national weather service use the volume over area units like that. Mostly like a depth measurement… X inches short of typical rainfall insert timeframe here…
I guess dimensionally it’s the same, it just hits differently IMO?
Liters / m^2 is common unit for the amount of rain. Other unit is mm/m^2 for rain. The units are exchangeable
Just mm, not mm/m^2.
If you get 10mm of rainfall over night, every level surface will have 10mm of water height added to it. So if you have a pool, the water level will be 10mm higher in the morning. Or if you just leave an empty drinking glass outside, it will also have 10mm of rain inside in the morning. If you imagine that there is no runoff, no evaporation, no percolation, then everything would be covered in a 10mm layer of water.
You are right. The poorly worded point I tried to make was: 1l of water is a volume of 1mm by 1m^2
Yes, as others have said, this is the standard outside of the US. The neat thing about metric units is the ability to convert stuff more easily.
If we take our rainfall example here: 1 sqm is a square with 1000 millimeters (mm) on each side. To go one order of magnitude up you just divide by 10, so you get 100 centimeters (cm). This is not necessary, but it is more common to calculate small liter amounts in cubiccentimeters (cm3), that’s what the cc/ccm on measuring jugs or the volume measurement of engines stands for. This is usually referred to as milliliters (ml). 1000 of these make up 1 liter (l) (that’s where the biggest irregularities of the metric system lie
So image that 1 sqm square in front of you (the scale compared to feet/inches isn’t that important). To fill that square up we would need 10.000 of our little cubiccentimeter-cubes, 100 on each side, 100*100=10.000. If we now fill up our little cubes with water we raise the water level in our square by 1 cm/10 mm. 10.000 ccm/ml are equal to 10. So 10 mm of rainfall would result in 10 l of water, 25,4 mm (1 inch) would be 25,4 l and so on. As I’m not familiar with American weather reports I don’t know how granular the reporting is if you have to work with fractions of an inch, but I guess down to 1/10 would still work for me, but don’t tell me to imagine something like 11/17" or somesuch.
That’s what makes the metric system so great. If you understand the underlying mechanic you can easily convert everything.
This would still work in imperial units in principle, but because length and volumetric measurements don’t align properly you would have trouble converting them in your head. 1 gallon would be 231 sqin, 1 cubic foot would be 7,481 gallons. There is no way to fit these into a system where you could easily convert the height of your water level into a volumetric measurement and that’s why the US sticks to just using inches for rainfall.
The beautiful thing about the metric system is also that it does not forbid to use more tangible measurements but makes it easier: So, you could imagine 1 liter per hour and m2 as the same amount of liquid as for example 3 canned beverages or 2 bottled beers. 1 beer if you’re Bavarian.
Yep, it’s pretty normal, though I also often see just plain mm and many weather apps/sites often only display the probability of rain.
It’s a global standard. You’re in Murica.
Maybe the us national weather service just assumes a volume and doesn’t say it? They kinda have to. If you say it rained x inches of rain in that hour, how do you know in what area? X inches over the whole country? Or per city? Per square inch? They have to measure the rainfall over a certain volume over a certain time. Otherwise you wouldn’t be able to compare it.
Inches or mm are a perfectly fine measurement for the amount of rain. Volume over area mathematically comes out as a unit of length.
It’s a lot more intuitive with snow. If you get five inches of snow over night, there’s no need for an area reference, because everything gets the same five inches of snow, no matter how big the area.
With rain it’s the same, everything gets the same “height” of rain, even though it usually doesn’t stay in place like the snow.
You don’t need the area to actually have a clue about the significance of a rain event. In the weather news you’ll find expressions like “20 mm of rain”. 20mm “water table” is the independent from the area as it means the same like 20mm/m² or 20mm/km².
You won’t actually calculate the total amount of water (volume) coming down by multiplying it with the area of the rain event.