General > General Technical Chat
The 8-Bit Guys house in Texas
Siwastaja:
--- Quote from: rsjsouza on February 27, 2021, 04:54:38 pm ---I don't either. Regarding foundation, whwre I live the typical construction here is built on a slab of concrete that "floats" on the soil. It would be somewhat self-leveling if it wasn't for the fact the soil has a pesky tendency of becoming porous when dry. That brings tremendous forces that crack the slab and cost thousands of dollars to fix. That or you keep dripping water all around your house year round, with the cavest that you may have accumulated moist that seeps through the slab.
Builders don't give a crap to a problem that will take 15, 20 years to manifest itself.
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Here, the great idea that was followed (and forced) for over 30 years was: excavate some soil, maybe one foot deep. Pour some concrete here, so the top is still under the top soil. Leave placeholder gaps for all outside and inside walls; add styrofoam thermal insulation and then pour another layer of concrete on the top of that insulation, so that the top of this upper slab is on the ground level or an inch above it. Now fix some timber in the gaping canyons so that the wood lies directly on the lower slab, which is cold and moist below the ground level. Build the walls on the top of this wet timber.
Why do it like this? No one knows. Oh and the result looks so ugly that people ask why this building is lacking the foundation. The solution: create a decorative concrete "fake foundation" on the front of the building so it looks like the building is founded above ground, yet you can walk in through the cutout in this fake foundation. It was even explicitly called fake, yet someone thought it's a good idea!
Zero999:
--- Quote from: Nominal Animal on February 25, 2021, 12:50:31 am ---
--- Quote from: Zero999 on February 24, 2021, 10:47:59 pm ---The west of England is milder and wetter, than the east, because the west is closer to the Atlantic and the east is nearer to the continent. A similar pattern repeats over North America, from west to east.
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Not very similar, though:
https://nelson.wisc.edu/sage/data-and-models/atlas/maps/avgwintemp/atl_avgwintemp.jpg
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The basic pattern of warmer in the west and colder in the east prevails over north America and Eurasia. The main difference is the mild temperatures extend further west into Europe, than they do into North America. There are a few reasons for this. Europe is a peninsula, with inland seas, America has the Rocky Mountains, which block the prevailing mild westerlies, so they don't get so far inland. The Rockies also send the jet stream on a north-west, to south-east trajectory, which results in the generation of intense low pressure systems and an increase in strength, as it hits the Atlantic, on eastern seaboard. This intense jet stream powers across the Atlantic, delivering mild air into Europe.
--- Quote ---I do not know what is the main driver, but I definitely would not claim the Gulf Stream is irrelevant. (Note, neither did Zero999; they just said it is not the main driver.) The average winter temperature difference between Nunavut, Canada; Southern Greenland; and Iceland, breaks the "east-west part of continent dictates it" assertion, as they are all surrounded by ocean.
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They're surrounded by cold ocean and are downwind of the frozen Arctic ocean and continent. Greenland has a mountainous interior and cold air sinking and flowing to the exterior makes it extremely cold. The Russian Far East is also very cold, despite being a peninsular.
--- Quote ---The main reason I am wary of any simple explanations, is that Medieval Warm Period occurred, between c. 950 and 1100 Common Era. During this time, Vikings in (the southernmost tip of) Greenland had cattle, sheep, and goats, and only a quarter of their diet was seafood. By 1300, three quarters of their diet came from seal hunting, as livestock just couldn't handle the harsh winters. We do not know why it occurred: all we know is correlation, and can only guess (and try to simulate to ascertain) the causation.
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I agree. I don't like simple explanations, which is why it makes no sense when people say Europe is mild because of the Gulf Stream. The reality is much more complex than that. Ocean currents play a role, but only a small part.
--- Quote ---I grew up in Finland, north of the arctic circle (so about 6° further north), and for example potatoes, carrots, rutabaga, and onions grow just fine even at 330m above sea level there. (At the bottom of a couple of fell lakes, well above the treeline, there are still rather large tree trunks from the Medieval Warm Period, too.) So, it is not a small difference in winter temperatures; it is a clear difference that affects the entire biome.
The exact circulation patterns in the North Atlantic are rather interesting,
https://upload.wikimedia.org/wikipedia/commons/1/1e/North_Atlantic_currents.svg
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Yes, interesting how the North Atlantic current misses all but most Northern Europe. The cold currents around Greenland and Eastern Canada help to push the July 10°C isotherm further south, although that's not he only reason.
--- Quote ---Finally, comparing to the 10°C July mean isotherm (red line),
we can see that the summer mean temperature differs quite a bit from the winter mean temperatures in eastern Siberia and Alaska. This supports the reasoning for continental effect on the climate (continental winters being colder, summers hotter). However, the way Bering Sea summers are much colder than say Iceland clearly undermines that reasoning. In other words, simple theories based only on the polar jet stream, or only on the Gulf Stream, are doomed to fail even a cursory examination.
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The pattern of colder on the east coasts fits the summer pattern quite well though:the Labrador Sea is pretty cold in summer.
The atmospheric circulation patterns for January and July are very revealing. Note how the high and low pressure areas are influenced by the landmasses? In the northern hemisphere wind blows clockwise around high pressure and anti-clockwise around low pressure.
In the northern winter, the strong Icelandic (polar) low, Bermuda (also often called the Azores high in Europe) (subtropical) and Siberian high help to push south-westerly winds over Eurasia. Areas to the east of the large landmasses experience a much colder climate because the polar lows deliver northerly winds. In North America, the pressure pattern is similar, but not exactly the same, which accounts for the differences in temperatures.
In summer the areas of high pressure in the subtropics move northwards and the polar lows weaken, giving more settled weather. Areas of low pressure sit in the middle of the continents, bringing about the monsoons.
Also note that there's very little land in the mid-latitudes in the southern hemisphere, so there's less blocking and the wind direction is just flat westerly.
Here's the site I got the charts from. It has a lot more information about the global atmospheric circulation pattern.
https://slideplayer.com/slide/677125/
--- Quote from: JohnnyMalaria on February 24, 2021, 11:19:43 pm ---
--- Quote from: Zero999 on February 24, 2021, 10:47:59 pm ---It's been disproven a long time ago that the Gulf Stream is the main driver for mild European winters. The west of England is milder and wetter, than the east, because the west is closer to the Atlantic and the east is nearer to the continent. A similar pattern repeats over North America, from west to east.
Yes, it's the jet stream which governs our weather. It's true it's affected by sea surface temperatures, but the correlation isn't direct. A warm North Atlantic doesn't necessarily mean milder winters for Europe. The temperature of the North Pacific, has a greater impact.
Links to sea surfaces temperature anomalies, at the end of Novembers 2010 and 2015, which preceded the coldest and mildest Decembers ever recorded in the UK. The Atlantic was much warmer at the end of 2010, than 2015. The difference was the Pacific was much colder in 2010, especially the north.
https://www.ospo.noaa.gov/data/sst/anomaly/2010/anomnight.11.29.2010.gif
https://www.ospo.noaa.gov/data/sst/anomaly/2015/anomnight.11.30.2015.gif
Of course there are many other factors. The weather has changed from cold in the first half of February, to near record breaking warm this week, because the jet stream has moved northwards, due to the North Atlantic oscillation flipping to the positive phase and now the wind is now coming from the Azores, rather than Svalbard. The sea surface temperatures haven't changed much and Gulf Stream didn't go way when it was cold and return now it's milder.
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NOAA seems quite convinced of the importance of the Gulf Stream: https://scijinks.gov/gulf-stream/
And you can't really decouple the two: http://www.actforlibraries.org/jet-stream-gulf-stream-polar-shifts-and-climate-changes/
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On the other hand, there's a lot of new evidence to show the Gulf Stream doesn't have as much effect, as previously thought.
https://www.google.com/search?client=firefox-b-d&q=gulf+stream+myth
I agree it's impossible to decouple the two, but noting the above about how the land & sea interface, govern the global air circulation patten, suggests it's not so important. I agree that if the Gulf stream changed, it would affect the European climate, I very much doubt it would plunge us into the freezer, as many scaremongers say. The land and sea won't move that much, so the basic atmospheric circulation pattern won't change drastically.
Renate:
I see "Canadian high", but I don't see any "Rocky Mountain High".
Zero999:
--- Quote from: Renate on February 28, 2021, 08:04:50 pm ---I see "Canadian high", but I don't see any "Rocky Mountain High".
--- End quote ---
What you mean by that statement?
Mountains can block winds and affect the jet stream, if they're high enough. Another example of this is, the Himalayas block cold air from North Asia, preventing it from reaching South Asia, which is why such places have much milder winters, than southern Texas, which is on a similar parallel. It's also another reason why the US west coast doesn't experience the same level of extreme cold, as the south.
Cubdriver:
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