Timeline for Why does ice form on bridges even if the temperature is above freezing?
Current License: CC BY-SA 3.0
8 events
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| Jan 29, 2014 at 20:06 | comment | added | gerrit | @AJMansfield But that's not the bridge having a conductive heat sink, that's the bridge lacking a conductive heat source. In other words, the road is heated from below, but the bridge isn't. But the bridge does not lose heat through conduction (it is, to a first order, only in contact with air, and air is a bad heat conductor). | |
| Jan 29, 2014 at 18:01 | comment | added | AJMansfield | @gerrit yes It would; a more obvious instance of this is the use of thermal wells in some HVAC systems. The further down you go, the less variation in temperature with outside conditions. When the surface is cool, the not-quite-as-cool dirt and rocks below it warm it up considerably. For the same reason, snowfall does not typically accumulate immediately upon starting, as the ground is not yet at the freezing point. Lower material is able to source enough heat to keep the surface above freezing unless it is particularly cold out, or particularly high wind. | |
| Jan 29, 2014 at 10:51 | history | edited | Krazer | CC BY-SA 3.0 |
nixed conduction reason; grammar.
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| Jan 29, 2014 at 10:03 | comment | added | gerrit | Heat loss via conduction won't cause bridges to cool down faster than the surrounding land. I think the radiative effect is dominant. | |
| Jan 28, 2014 at 22:23 | review | First posts | |||
| Jan 28, 2014 at 22:27 | |||||
| Jan 28, 2014 at 22:12 | history | edited | Krazer | CC BY-SA 3.0 |
edited body
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| Jan 28, 2014 at 22:07 | vote | accept | CommunityBot | ||
| Jan 28, 2014 at 22:06 | history | answered | Krazer | CC BY-SA 3.0 |