# Tag Info

52

Water is a rather strange substance. With most substances, the solid phase is denser than is the liquid phase. This is not the case with water. Ice is less dense than liquid water. A side effect of this effect is that liquid water very close the the freezing point is less dense than is slightly warmer water. That very cool water sinks. Liquid fresh water ...

51

Water melts at 0 °C (32 °F) but freezing is a more complicated affair. It is safe to say water gains the ability to freeze at 0 °C, but it can get much cooler before it actually does so resulting in supercooled water. Water in this state can rapidly solidify when suitable ice nuclei are introduced. For example, in convective clouds, liquid water can be ...

50

Your middle school physics perhaps hasn't gotten to thermodynamics yet. The three laws of which can be summarized as 1) You can't win; 2) You can't even break even; 3) You can't leave the game. The crucial point here is that heat engines don't actually work on heat, they work on temperature differences. So you can't really "collect" heat and turn it into ...

32

Quoting from John Russell's response to this article, "This is arrant nonsense!" Russell concludes with How did this paper get through the peer-review and editorial review processes? What technical standards were applied to determine the apparent merit of its contents so as to justify its inclusion in a reputable journal? Just because something is ...

27

Collecting thermal energy is really hard. As others have said, things like heat pumps exist for moving heat around, but the laws of thermodynamics (which are fairly fundemantal in physics) require that moving heat around will always generate more heat. Now, the amount of extra heat generated can be less than the amount of heat that's being moved - so if we ...

21

Due to convection (the cold water sinks while the warm water rises), the entire pond needs to be brought to near-freezing temperatures before the surface can freeze. With only the top of the pond in contact with the cold air, this takes a long time. ​‌‍​‌‍Additionally, the ground (which is not cooled by convection) will take even longer to cool down, ...

15

What neither the authors nor the response by John Russell takes into account is that all underground oil and gas is stored inside tiny pores of rocks. An oil reservoir is not a big underground cave, it is a very fine-grained sponge made of stone filled with oil. In essentially all cases, there is more stone than oil (by volume). This means that since oil is ...

14

The water in a pond is in contact with the ground and the ground is not even close to freezing even if the air temperature is 27° below freezing.

13

Disclamer: I am not an atmospheric or climate scientist; corrections are welcome if I have anything wrong. Human heat production According to the IEA, world primary energy consumption in 2012 was 13370 million tons of oil equivalent, which works out to being $5.6 \times 10^{20}$ Joules. Averaged over a year, this equates to $17.8\,\mathrm{TW}$. Wind, solar,...

13

The first part of the association is that increasing levels of greenhouse gases in the atmosphere will cause rising temperatures on earth. Here is some information on why that is so, if you are interested. Now assuming that temperatures are currently going up (they are), there are two mechanisms that will connect this to rising sea level, melting of ice on ...

12

Basically, we can ignore the heat we release compared to the effect of the $\ce{CO2}$ we release. To be more specific: Heat we release has only a temporary effect because heat is radiating out to space. In fact you can get an idea of how long it takes for newly released heat to radiate away by checking how quickly temperatures drop when the sun sets. It'...

11

It doesn't stay frozen. Ice evaporates (or sublimates is the correct term) under direct sunlight, but that's at a molecular level, it doesn't melt, it goes from solid to gas under sunlight and in the cold, some of this newly formed water vapor goes back being to ice. In an absolutely dry climate, well below freezing, ice would slowly sublimate and ...

11

Like passive radiative cooling? The new materials reflect a broad spectrum of light, in much the same way as mirrors or white paint do. In the crucial 8–13-µm part of the infrared spectrum, however, they strongly absorb and then emit radiation. When the materials point at the sky, the infrared rays can pass straight through the atmosphere and into space. ...

10

As your diagram shows, the jet stream actually has two circulating components: one is "around the earth" (which is why the transatlantic crossing is so much faster going East than going West), while the second is more like a vortex, with a circulating flow "around" the main direction. This circulating flow is vertical in two places: North of the jet stream ...

10

First off, your observation that Tamil Nadu gets more rainfall in the evening is partially backed by records. Sahany, Venugopal, and Nanjundiah, 2010 provide data on diurnal scale rainfall distribution during the Southwest monsoon season shows that Tamil Nadu is dry from 0530-1430 each day, and likely to be wet from 1730-0230: The Northeast monsoon is ...

9

Latent heat is a factor, but is completely eclipsed by the rate of global warming. For example, since 1978 the April (maximum) Arctic sea ice has decreased in volume by about $11,000$ cubic km. The latent heat absorbed by the ice to achieve this is about $3.7(10)^{18}$ Joules. Compare this to the amount of excess heat, which has been absorbed by the oceans,...

8

This could be because the air cools and heats faster than water. Air has a lower Specific Heat than water. It may take some time for the water to freeze.

7

First of all, the Earth does not receive heat from the Sun, it receives visible light that is absorbed by the surface of the Earth and then heat is re-radiated back into the atmosphere. If the surface is ice/snow, most of the light from the sun is reflected back to space. Sunlight will sublimate a little bit of the ice, but it is normally replenished at a ...

7

...the submerging plate is always drawn as deep (seemingly tens of km) into molten rock... It's actually hundreds of kilometres, not tens of them. But let me correct a common misconception: The mantle is solid rock. It is not molten rock. So subduction leads solid rock into more solid rock. the surrounding medium is hot enough to melt rock The ...

6

There is a convention for moist air entropy built from dry air entropy being 0 at T = 273.15K and P = 101325Pa, and liquid water entropy being 0 at its triple point. See the page numbered 47 of this NIST document: http://www.nist.gov/calibrations/upload/5241.pdf Entropy is not measured directly. Entropy $S$ is defined as $dS \equiv dQ_{rev}/T$ ...

6

The lifting condensation level (LCL) is the level at which a rising particle reaches 100 % relative humidity by adiabatic cooling. Please have a look at Wikipedia: LCL and LFC (level of free convection!).

6

userLTK has explained that not all of the ice in the Antarctic stays frozen all the time. But perhaps there's a more basic view needed : sunlight in temperate areas melts all of the ice quite quickly, so why doesn't the same happen in Antarctica? There are a number of reasons, but the simplest (and probably most important?) is one of geometry, and the way ...

6

You cannot leave "temperature outside", as temperature is the key factor to know if the balloon would pop or not. Let's set up some assumptions about the problem so we can calculate something: The gas inside the balloon behave according the ideal gas law: $PV=nRT$ That the balloon can hold a differential pressure of 30 mmHg (=4000 Pa) as found in this ...

5

It's a harder direct relation to show that it appears. On the surface, warmer = less ice, file under "duh", but while it probably is that simple, showing a causal relation is a more difficult. The thermal expansion aspect of the question is easy enough. Warmer air warms the ocean surface which slowly warms the ocean. About 90% of the heat trapped by ...

5

No-one has mentioned fish yet. Do you have fish or other animals in your pond? Not only do they provide a small amount of warming, their movement will help prevent ice forming.

5

First let me start by saying that redox buffers are a made-up thing. All these QFM (actually FMQ) or NNO or other abbreviations don't exist in nature. They were developed as a way to "cheat" in experiments to get the desired Fe(II)/Fe(III) ratio, and later extended for more uses. High temperature and pressure experiments are permeable to hydrogen: it just ...

5

First some definitions: Latent heat is the heat that leaves or enters a system during a process where the temperature of the system stays constant. Phase changes are prime examples where latent heat leaves (exothermic) or enters (endothermic) a system. Ice melts (endothermic) and water freezes (exothermic) at constant temperature. Sensible heat is the heat ...

5

As others have pointed out, if you use the energy, it turns right back into heat. Radiating it back to space is at least theoretically possible. But there is a problem with scale. The Earth receives about a 100 petawatts of energy from the sun. And it radiates almost exactly the same amount back out. Everything humanity do with energy is about 0.02 ...

4

This IPCC graph (discussed here) shows the amounts of heat going into oceans, atmosphere, land and ice melting. Plot of energy accumulation in zettajoules within distinct components of Earth’s climate system relative to 1971 and from 1971–2010 unless otherwise indicated. Ocean warming (heat content change) dominates, with the upper ocean (light blue, ...

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