# Tag Info

78

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 µm and 2 µm. This wavelength is determined by the temperature of the Sun, in the order of 6000 K. For visible radiation (roughly between 0.4 µm and 0.7 µm), ...

45

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 nearly all of its elements. Earth does lose hydrogen and helium and cosmic rays will split water molecules leading to a loss of an impressive amount of ...

38

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 directions, so you see more colors. See below for the HMS Smoke Polygons for the day, which clearly shows smoke over your region from the intense smoke/wildfire ...

35

"So much work"? Actually, compared to the global rate of greenhouse gas emissions, it's a case of "so little work"! From a scientific perspective the 'economists' solution' of carbon trading was always unlikely to achieve the required carbon cuts, as has been verified by their ineffectiveness over the last decade or so. As farrenthorpe points out, the rate ...

31

According to Wikipedia an approximate average surface temperature for a bare earth is 274.5 K. This scenario is quite reasonable in my opinion as stripping the atmosphere without changing much else would (on a geological timescale) rather quickly result in a bare earth without ice caps or vegetation, causing circumstances quite close to those on the moon. (I ...

30

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 bigger than the cooling rate, the Earth is net warming (positive net flux – we can imagine it like heat is travelling "to us"), as opposed to the ...

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Absolutely not. While the answers by casey and farrenthorpe correctly state that the blue color is due to Rayleigh scattering, the composition of the atmosphere varies considerably from place to place - and with different composition come different degrees of scattering, and different color / intensity. Typically regions of greater industrial activity will ...

28

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 you are interested in the winds in areas clear of surface obstacles, otherwise the answer would a be a cave or a dense forest somewhere. To figure out what is ...

25

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 is predicted to lose almost all of its water in a billion or so years from now. It rains because temperature decreases with altitude. This lapse rate means ...

25

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 something else, and the hotter material transfers some of its heat to the colder material. It's why you rapidly lose heat if you wade into cold waters: your ...

24

The butterfly is a colourful illustration of Chaos Theory, and the word butterfly came from the diagram of the state space (see below). A system that is chaotic is extremely sensitive on its initial value. In principle, if you know exactly how the state of the universe is now, you could calculate how it develops (but due to other reasons, it is ...

24

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 the same way that for the Earth to lose mass, that mass have to go somewhere. For the Earth to lose angular momentum, it'd have to go somewhere. Earth's ...

23

First, to describe El Niño as a Pacific Ocean event seems overly simplistic. The effects of El Niño are felt worldwide as can be seemed by a principal component (EOF) analysis (e.g., Alexander et al., 2002). Also, using the term "El Niño" to describe the entire oscillation (ENSO, El Niño Southern oscillation) can lead to confusions as the term "El Niño" ...

23

Earth's atmosphere does escape over time, albeit very slowly. The distribution of kinetic energies of molecules in a gas obeys (more or less) a Maxwell-Boltzmann distribution. Notice that the graph is asymptotic, so in a suitably large population of gas molecules, there is a non-zero probability that some of those molecules will have a an arbitrarily large ...

23

Your premises are flawed due to the lack of two critical details: Population rise; the sheer number of people on the planet that are consuming resources has risen to 7 billion people. Standard of Living; a greater percentage of people in the world live a "Western" style, which consumes more goods per capita. You should study something like the Global ...

22

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 in the visible range*. It also shows the thermal radiation from the earth in blue. This is in the infrared range. Below, it shows how different gases allow ...

21

Electricity from waves, from hydro (both run-of-river and storage) and from wind, are all indirect forms of solar power. Electricity from tides is different, and we can deal with that in a separate question. Global tidal electricity generation is not yet at the scale of gigawatts, so it's tiny for now. Winds come about from the sun heating different parts ...

21

According to the recent paper in Nature Geoscience: Nitrogen speciation in upper mantle fluids and the origin of Earth's nitrogen-rich atmosphere, $N_2$ originates from regions of the Earth where plates are converging. Venus and Mars lack plate tectonics and therefore lack $N_2$ in their atmospheres. In other regions of Earth upper mantle, and in Venus and ...

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We don't really know. Climate models agree that the feedback is profound. Significant. Unfortunately, they do not agree about the magnitude of the feedback. Nor about the sign. The problem is that there are competing feedbacks. Clouds act similar to greenhouse gases, because they absorb and re-emit terrestrial radiation. But they also reflect solar ...

20

What's the minimum "uprightness" for it to not get obscured by snow and stay readable throughout the year? The answer to this problem is not in the angle at all. No amount of math will give you an angle at which you can reasonably presume your surface will remain clear. Snow can (and does) accumulate on vertical and even negatively sloped surfaces....

19

The major differences between weather and climate models are many. At their core lie the same set of primitive equations, but from here there are many differences. A weather model only (skillfully) predicts about 10 days into the future, while a climate model integrates forward in time for hundreds of years. The main difference here is that in a weather ...

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The subtropical jetstream The subtropical jetstream can be explained with angular momentum arguments. In an idealized circulation model of the atmosphere, there is a hadley cell that circulates upward at the equator, poleward along the tropical tropopause, downward around 30 N/S and equatorward at the surface. Parcels rising at the equator have a fair bit ...

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Don't think of the Coriolis force as deflecting motion clockwise/counter clockwise, but to the right (NH) or left (SH), when looking in the direction of the motion. So this is sort of 'by definition'. A cyclone is a low pressure system, and air will move from a location with high pressure towards a location with low pressure. The Coriolis force will deflect ...

19

There is more to phase change than just what you see on that graph. At temperatures and pressures that support multiple states (e.g. solid and gas) you have to look at the saturation vapor pressure of the gas and the actual vapor pressure (partial pressure) of the gas -- the line on the graph represents equilibrium between the states. The differences ...

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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 the reputation of the Volokin and ReLlez, so we will investigate that one first. The science of Volokin and ReLlez The traditional way to determine the '...

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Wind is caused by pressure differences. Think of a balloon full of air; poke a hole in it and the air comes out. Why? Because the pressure in the balloon is higher than outside, and so to regain equal pressure, mass moves and that is the wind. There is a bit more to this in the atmosphere as the Earth rotates and near the surface friction also plays a ...

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The lowest reaches of an aurora is ~100 km in the air. Your problem won't be the ionized gas, it'll be that the air pressure is close to zero. Also, aurora are very diffuse, with at most a few glowing molecules per square centimeter. I'm not sure at that density that you could tell you were actually in something. If you're in a spacesuit to survive the ...

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