78 votes

How do 'greenhouse gases' let heat in, but not let it out?

In a nutshell: The radiation that enters is shortwave radiation from the sun. Solar radiation is dominated by visible (as well as UV and near infrared) radiation with a wavelength mostly between 0.2 ...
gerrit's user avatar
  • 11.7k
46 votes

Why doesn't the 71% water of the earth dry or evaporate?

There are two ways this problem needs to be looked at. The first is more astronomy than Earth science. The Earth as an entire system is largely contained. Its gravity and magnetic field retains ...
userLTK's user avatar
  • 5,857
39 votes
Accepted

Why were both the sun and the moon red today?

Smoke. There was significant smoke across the USA, which attenuated the light from the sun/moon due to increased scattering. The smoke particles effectively cause the light to reflect in different ...
f.thorpe's user avatar
  • 13.6k
35 votes
Accepted

Why aren't weather balloons left in the atmosphere permanently?

In addition to radiosondes that do a single ascent over a few hours, there are also driftsondes that stay in atmosphere for days or weeks, typically with their buoyancy set up to track a particular ...
Deditos's user avatar
  • 3,950
30 votes
Accepted

Why are mornings cooler than nights?

The Earth is always radiating heat to the space. But in the day the Sun delivers some heat. The net heat flux is then defined as the sum of those two factors. If the energy delivered by the Sun is ...
User123's user avatar
  • 638
28 votes
Accepted

Where is the calmest place on Earth?

The main resistance that winds have to their movements comes from the topography and surface obstacles. Therefore, as a general rule the closer to the surface the less wind you will find. But I guess ...
Camilo Rada's user avatar
  • 17.7k
25 votes

Why doesn't the 71% water of the earth dry or evaporate?

Why doesn't 71% water of the earth dry or evaporate? The simple answer: Because it rains. The not so simple answer: By some estimates, the Earth has already lost about a quarter of its water, and it ...
David Hammen's user avatar
  • 23.6k
25 votes

How do 'greenhouse gases' let heat in, but not let it out?

Gerrit's got the technical answer; I'm going to answer for a layperson. There are two ways objects lose heat. The first, and the way people are most familiar with, is conduction. Something touches ...
Kevin's user avatar
  • 351
24 votes
Accepted

What is the fastest the Earth has ever spun?

The speed of rotation of Earth is controlled by its angular momentum. And the conservation of angular momentum is a very serious law of physics (perhaps even stricter than conservation of mass). So in ...
Camilo Rada's user avatar
  • 17.7k
24 votes

Why aren't weather balloons left in the atmosphere permanently?

It depends on what each weather balloon is measuring; what data they are capturing. Most weather balloons are released as specific times during a 24 hour cycle. Such balloons measure altitude, ...
Fred's user avatar
  • 24.7k
23 votes

How do 'greenhouse gases' let heat in, but not let it out?

To add to Gerrit's excellent answer, I'd like to add a couple more Images. Images always help clarify things for me. Firstly, this one shows the spectrum light coming from the sun in red. The peak is ...
craq's user avatar
  • 327
22 votes
Accepted

Why is CO₂ abundance in the atmosphere still small?

The mass of the atmosphere is 5.1 × 1018 kg, which is 5.1 × 1015 t. As stated in the edited question, industries emits 1.5 billion metric tons of carbon dioxide each year, That's 1.5 × 109 t. The ...
Fred's user avatar
  • 24.7k
20 votes

Why is CO₂ abundance in the atmosphere still small?

As well as the atmosphere having a lot of mass, there are many processes which remove CO2 from the atmosphere, see the wikipedia article for the carbon cycle. Plants sequester it as biomass, some of ...
llama's user avatar
  • 309
19 votes

Is the Unified Theory of Climate (Nikolov & Zeller) compatible with the AGW/GHG theory in any respect?

The paper you linked lists as its first reference Volokin and ReLlez, 2014; a paper that addresses the magnitude of the Earth's greenhouse effect. The validity of the paper you found largely hinges on ...
kingledion's user avatar
  • 3,376
17 votes
Accepted

Why is WRF most often configured at 3:1 nesting ratio?

To understand why the nesting ratio of 3 is preferred to the nesting ratio of 2, it is important to understand the following two features of WRF: 1) Grids are Arakawa C-staggered: mass points are at ...
milancurcic's user avatar
  • 4,983
17 votes
Accepted

Where do bad smells eventually go?

If you are smelling something, you are inhaling gases, particles, or a combination of the two. They don't normally build up in the atmosphere because of three reasons: transport/dilution (which you ...
f.thorpe's user avatar
  • 13.6k
17 votes

Why does warm air "hold" more moisture?

Saying that warm air "holds" more moisture is technically incorrect, but is a common colloquialism. Let's break it down to the technicalities. Let's consider a glass of water with a vacuum (no air) ...
BarocliniCplusplus's user avatar
16 votes
Accepted

Why snow is white?

Normal ice (as in refrigerated ice cubes) mostly has uniform crystalline structure - water molecules are in a perfect hexagonal grid, which enables it to be transparent. Not all ice is like that - ...
Jack White's user avatar
15 votes

What keeps the different gases mixed in the atmosphere?

It's because gases also diffuse. If you separate two gases of different densities by a horizontal membrane, and then slowly remove the membrane, then the interface will diffuse. You can try this with ...
Wolfgang Bangerth's user avatar
15 votes

Why snow is white?

Snow has a very high albedo. Actually, it reflects all wavelengths of the visible spectrum, whilst absorbing no particular wavelength. Hence the eye averages out the multiple reflected wavelengths as '...
Gordon Stanger's user avatar
15 votes
Accepted

Why (actually) is the night sky so bright in the city? How far up is that happening?

What's actually happening is scattering of light, both off of aerosol particles and nitrogen and oxygen molecules. For a review of quantitative models of light pollution as a function of distance ...
DavePhD's user avatar
  • 5,972
15 votes
Accepted

Is Earth getting heavier or lighter?

tl;dr: The Earth receives 40,000 tons of dust from space every year, but looses 95,000 tons of Hydrogen and 1,600 tons of Helium every year as well. After all additional effects are balanced, the ...
uhoh's user avatar
  • 7,148
14 votes
Accepted

What causes a rainbow, its colours and its shape?

Short answer: A rainbow is formed when light enters a drop of water or an ice crystal and gets refracted and reflected back into an observer's eye. Longer Answer: Light travels at different ...
BillDOe's user avatar
  • 2,187
14 votes

Why is it colder in the mountains than at sea level?

The traditional answer basically comes down to the physics concept of adiabatic cooling, a description of which is: There is less pressure as you go up in the atmosphere (basically due to less air ...
JeopardyTempest's user avatar
14 votes
Accepted

What is the explanation of using pressure units (hPa) to express height when dealing with wind speeds?

There are several reasons. From the theoretical point of view it is beneficial to use isobaric coordinates, due to the vanishing density in the equations of motion. While in cartesian coordinates the ...
Joscha Fregin's user avatar
13 votes
Accepted

How much water is the atmosphere losing to space?

It is not actual water what is lost to space, because in the high atmosphere water usually dissociate into other molecules or ions. The oxygen ion outflow is frequently assumed to be a proxy for the ...
Camilo Rada's user avatar
  • 17.7k
13 votes

Is the Mauna Loa CO$_\mathsf{2}$ record affected by the nearby mantle plume?

How is ist possible that Mauna Loa Observatory is the International Reference Observatory for CO2 Global Meassurments I don’t know that it is ‘the International Reference Observatory’. The Mauna Loa ...
Pont's user avatar
  • 5,429
13 votes
Accepted

Is volume of air increasing as CO2 levels increase?

[Major edits below] In short the answer is NO. Before we get into volume changes, I have to say that volume is a tricky measure to apply to the atmosphere as a whole, because there is no clear limit ...
Camilo Rada's user avatar
  • 17.7k
13 votes
Accepted

Why is Earth's density gradient a step-function, rather than smooth?

Roughly put, it's the same thing that makes a density step function when you try to combine oil and water: Source The components do not mix with or dissolve into each other, so gravity makes the ...
Oscar Lanzi's user avatar
  • 3,831
13 votes

Why aren't weather balloons left in the atmosphere permanently?

There are several reasons for this. One of them is air traffic concerns. The parts of the atmosphere that are interesting for weather (namely, the troposhere and lower stratosphere) also happen to be ...
reirab's user avatar
  • 303

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