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Post by Deleted on Feb 28, 2019 4:29:55 GMT -5
Just found out (using calculus) that half of the Earth's surface area is located within 30° from the Equator assuming the Earth is a perfect sphere ( which is not completely true). The formula for the amount of surface area within x degrees from the equator is actually surprisingly simple. Just sin(x) when x is in degrees and 0°≤x≤90°. But the average temperature of the Earth's land area in the most recent times is about 9.6°C ( source). Of course it would be about 15°C including oceans. Now, I'm interested in the median land temperature of the earth. That would have to take account where the land is. Here is a map, but according to this source, the median land is 33.3° away from the equator, which sounds about right looking at the map. That means the poles and high altitudes of the earth skew the average very strikingly. I would guess that the median climate of the Earth's land would have an average annual temperature of around 15°C, slightly less than what you'd expect at 33.3°N or 33.3°S due to high elevations. So if we have an average around 9.6°C and a median around 15°C, should that be any sign of how we see the earth's climate overall? We often see the earth as a cold planet where the colder areas are uninhabitable. It is true that the poles are uninhabitable while even the hottest areas can be habitable, but the poles occupy such a small area. The median climate actually seems mild in terms of average annual temperature, and "temperate" climates in a scientific sense are significantly colder than the median climate. Thoughts? |
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Post by Lommaren on Feb 28, 2019 5:07:43 GMT -5
It's true that Antarctica heavily changes the general land temperature. Having said that, it would be rather difficult to estimate general mean temperature because the earth is not a flat planet, but rather has very strong elevation changes and therefore those areas like you say also skew the general averages. Having said that, Antarctica is a landmass still large enough to probably draw the land median well down below 15°C; since the colder areas of Greenland's ice cap, Siberia and North America would have to be included in the bottom tier of land temperature and we're definitely talking in between 1/4 and 1/3 of the land area being "latitudal" subarctic or polar even though the earth's surface is smaller near the Poles. Then another few percentage points of high mountain ranges must be added onto that.
To just throw in a number would seem a bit exaggarated given I've got no real evidence, but I think the land median would be lower than 15°C courtesy of the Southern Hemisphere having so little land. All that aside, then a lot of the humid continental and oceanic climates are also below 10°C in means and they cover a vast portion of the Northern Hemisphere. Then that would require really advanced calculations to figure out at what point in between 10°C and 15°C the actual median is. I'd venture the truth is somewhere in between there, but I'm not qualified to say exactly where.
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Post by tij on Feb 28, 2019 5:10:02 GMT -5
@qidb602 elevation is also a quite important factor to consider. Think I remember some chart calculating the median annual average temperature per latitude and will post it.
Totally right that temperate climates tend to be on the cooler side for global standards, if that excludes the subtropics. Subtropics have far more population than the subarctic and tropics to polar regions.
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Post by Deleted on Feb 28, 2019 5:21:30 GMT -5
I kind of looked at this map when saying the average is ~15C. Note that elevation only matters when it pushes the average annual temperature below the median. Even though Medellin has 1500m of elevation, it still belongs to the "warmer than the median" group. I would definitely like to see a map with median temperature by latitude, though. However, it must be land temperature only. Also, because the chart is split by latitude, the "median of the medians" is not exactly what I'm looking for, but it will certainly help.  Source: www.climate-charts.com/World-Climate-Maps.html |
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Post by Deleted on Feb 28, 2019 5:35:53 GMT -5
It's true that Antarctica heavily changes the general land temperature. Having said that, it would be rather difficult to estimate general mean temperature because the earth is not a flat planet, but rather has very strong elevation changes and therefore those areas like you say also skew the general averages. Having said that, Antarctica is a landmass still large enough to probably draw the land median well down below 15°C; since the colder areas of Greenland's ice cap, Siberia and North America would have to be included in the bottom tier of land temperature and we're definitely talking in between 1/4 and 1/3 of the land area being "latitudal" subarctic or polar even though the earth's surface is smaller near the Poles. Then another few percentage points of high mountain ranges must be added onto that.
To just throw in a number would seem a bit exaggarated given I've got no real evidence, but I think the land median would be lower than 15°C courtesy of the Southern Hemisphere having so little land. All that aside, then a lot of the humid continental and oceanic climates are also below 10°C in means and they cover a vast portion of the Northern Hemisphere. Then that would require really advanced calculations to figure out at what point in between 10°C and 15°C the actual median is. I'd venture the truth is somewhere in between there, but I'm not qualified to say exactly where.
I know I made a rough estimate, but I said that there is actually 50% of the Earth's land between 33.3°S and 33.3°N from a source I posted in the original post (not reliable but the best I could find). That means the lack of land in the Southern Hemisphere shouldn't matter because my estimate for 33.3 degrees away from the equator is 15C. Since half of the world's land is within 33.3 degrees away from the equator, about half should also be warmer than the median land temperature at 33.3°N/33.3°S. |
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Post by Lommaren on Feb 28, 2019 5:48:06 GMT -5
I know I made a rough estimate, but I said that there is actually 50% of the Earth's land between 33.3°S and 33.3°N from a source I posted in the original post (not reliable but the best I could find). That means the lack of land in the Southern Hemisphere shouldn't matter because my estimate for 33.3 degrees away from the equator is 15C. Since half of the world's land is within 33.3 degrees away from the equator, about half should also be warmer than the median land temperature at 33.3°N/33.3°S. Approaching the tropics, temperatures indeed warm very fast. That being said, the Himalayan influence will, like you said, cool that latitude a bit. That being said, both Los Angeles and Dallas have an annual mean of about 18-19°C and then the Middle East is very warm due to desert influences too so it's really hard to say what any sort of median would be. It may be above 15°C if the median latitude is so low. Keep in mind that the SH low-latitude oceans are well below the general temperature of the North Atlantic too with the antarctic influence. So without computer programs it would be an impossible estimation really. Anyway, the median human definitely lives in a climate with 20°C means at least. Just look at the population spread... |
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Post by tij on Feb 28, 2019 6:25:06 GMT -5
Lommaren maybe a touch below 20C? 18-19C? Regions (mostly) below 20c: N Am, Europe, East Asia Regions (mostly) above 20c: South Asia, Southeast Asia, Subsaharan Africa The Middle East appears to straddle the line--- Maghreb, Iran, and Turkey are mostly below the line while Egypt and Arabia are mostly above. LatAm does as well due to elevation, but maybe a touch above due to Brazil.
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Post by Cadeau on Mar 1, 2019 0:18:11 GMT -5
Just found out (using calculus) that half of the Earth's surface area is located within 30° from the Equator assuming the Earth is a perfect sphere ( which is not completely true). The formula for the amount of surface area within x degrees from the equator is actually surprisingly simple. Just sin(x) when x is in degrees and 0°≤x≤90°. I've always wondered how to figure out the surface area of certain latitude in a sphere shape. I knew cos(x) works for the length of each latitude but had no idea for sin(x). Inspired by that, I created a chart for how many areas covered by each latitude. Very interesting to see within the tropic region constituted about 40% surface of the whole Earth, while the temperate region takes 52% and the polar region takes ONLY 8%.  |
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Post by nei on Mar 16, 2019 12:06:02 GMT -5
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Post by Deleted on Mar 29, 2019 22:29:29 GMT -5
So now that nei made a thread for median climate by latitude, we can find the median climate at 33.3°N, which would be similar to the median climate of the Earth's land area. I will assume that cooler areas within 33.3°N/S will be equally compensated by warmer areas outside of 33.3°N/S. The median climate at 30°N has a 19.6°C annual mean and the median climate at 35°N has a 14.15°C annual mean. The median latitude of land is 33/50 of the way between the two latitudes, so in that case the annual mean of the median climate would be 19.6-((19.6-14.15)*(33/50)) = 16.003°C. I would guess that the Southern Hemisphere at 33.3°S is cooler due to having less hot desert areas like the Sahara. So all in all, it should be pretty close to my original estimate of 15°C, but for a completely accurate number we would have to take into account the area of cooler places within 33.3°N/S vs. warmer places outside of 33.3°N/S. |
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