Questions tagged [atmosphere]

The gaseous envelope surrounding the *Earth*, and retained by the Earth's gravitational field. If your question is about the atmosphere on another celestial body or is more astronomy related, please ask on Astronomy.SE.

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Why is the Ozone Layer 'hole' more pronounced in the Southern Hemisphere?

Lots of people comment that you have to use more sunscreen in Australia compared to European countries due to the hole in the ozone layer. (Even for roughly equivalent latitudes). What would cause ...
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What causes these banded clouds?

A set of banded clouds can be seen in MODIS imagery during several days in January and February over the Gulf of Maine. They tend to occur with very cold winds from the NW following storms. There are ...
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Why (actually) is the night sky so bright in the city? How far up is that happening?

The recent news reported by the New York Times, the BBC and the NPR web sites (for example) as well as in the Iceland Review and Iceland Magazine sites, about the shutting-off of Reykjavik's ...
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Dry atmospheric temperature profile (dry adiabatic vs. isothermal)

I'm trying to understand why there are differing predictions of the atmospheric temperature profile. It is well established that the dry adiabatic lapse rate (DALR) is: $$ \frac{\mathrm{d}T}{\mathrm{...
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Are clouds significantly easier to simulate in weather models than climate models?

Cloud forcing is still one of the major uncertainties of radiative forcing in climate modeling because there are so many uncertainties in it (and parametrizations). But also because the timescale of ...
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Why air do not suffer density stratification of its gaseous components?

The different gases that make up the air have different densities. So, naively, one would expect the heavier gasses to pool in the lower atmosphere and the light ones at the top. I asked myself this ...
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What is the difference between roughness length and zero plane displacement?

Both roughness length $z_0$ and zero plane displacement $d$ seemed to be defined as the height above the ground at which wind speed theoretically becomes zero. But wind speed is also supposed to go to ...
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How do Kelvin waves determine surface temperature variations?

Kelvin waves are basically waves that balance out the Coriolis force against topographic boundaries like coastlines and mountains. It seems very important in the oceans, for example. My question is ...
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How big does a lake have to be to have its own Sea Breeze?

How big does a body of water need to have a sea breeze? Is there a chart on sea breezes wind speed that include lakes? Could a circular lake create enough sea breeze to create a wind vortex in the ...
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Why snow is white?

Snow is precipitation in the form of flakes of crystalline water ice that falls from clouds. Why is it not another colour?
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Weak flashes of light in the sky

On a recent, late-evening flight from New York City to San Fransisco, I was seated on the right side of the plane. We were flying over lake Michigan - about 2 hours into the flight. When we were over ...
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How does radiogenic argon-40 get into the atmosphere?

There's an awful lot of argon in the atmosphere: about 0.93% of the atmosphere is argon[1], making it the third-most abundant gas after N2 and O2. As I understand it, most of it is produced by the ...
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How is it possible that a Hurricane such as Alex forms in the Atlantic in winter?

Hurricane Alex (developed from an area of low pressure which began in the Atlantic near Bahamas in January 2016, and developed subtropical and later tropical storm characteristics to the south of the ...
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Why is WRF most often configured at 3:1 nesting ratio?

In WRF application, nested domain has always been used for weather/air quality modeling for the place of interest in a better resolution. The figure below illustrates this: I have noticed that the ...
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What determines how fast clouds move?

Do cirrus clouds in the upper troposphere move faster than cumulus and stratus clouds in the lower atmosphere? What about clouds associated with extratropical systems, compared with clouds in the ...
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What atmospheric radiative effects, if any, do contrails cause?

First of all, this question is not about the conspiracy theory based chemtrails as in the linked question, from the answers there and from the question Equation for predicting contrail formation I ...
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Bifurcation Scenarios in the Atmosphere

I read that the mathematical definition of bifurcation is that, at a critical value of a parameter that governs the dynamical system, the system changes to a topologically different system than the ...
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Why does El Niño enhance the jet stream?

As quoted over here. This is especially interesting to me because El Niño tends to warm up the climate, and warmer climates are generally associated with weaker jet streams. El Niño has other ...
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Is there any evidence for higher air pressures in the geological past?

I was curious about how the Earth's overall air pressure has varied over time, and tried to take a look around the internet. However, Google pops up a lot of sites with questionable science proposing ...
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What are baroclinic and barotropic waves?

I have a basic understanding of what baroclinic and barotropic mean but cannot seem to get my head around baroclinic waves and barotropic waves.
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Why are methane spectroscopic parameters harder to determine and relatively poorly known, compared to other Earth trace gases?

In atmospheric remote sensing of methane, a dominant source of error is the uncertainty in spectroscopic parameters. For example, in the retrieval algorithms described by Batchelor et al. (2009), the ...
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Does the gravitational pull of the moon affect the composition of Earth's atmosphere?

In particular, does the pull of the moon affect the amount of water vapour in the Earth's atmosphere? In other words, if the moon were larger, or orbiting more closely to the earth, would the ...
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Does the magnetic field really protect Earth from anything?

Many topics discussed here in Earth Science SE, tend to be about facts that are of consensus in the scientific community but not widely accepted by the general public. Instead, this one is widely ...
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What woud happen to me if I touched the aurora?

The Aurora Borealis (commonly known as the northern lights) is a mesmerizing and captivating sight to behold, so beautiful that I just want to touch it and feel it. Should I? Could it harm me?
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What is the fastest the Earth has ever spun?

How fast can the Earth rotate and support life? In prehistoric times, dinosaurs were so massive that archeologists wonder how they were not crushed under their own weight. Could a faster spinning ...
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Wind profile below the aerodynamic roughness length

The vertical profile of horizontal windspeed is often given by the so-called "log-law": $$u(z)=(u^*/k)\ln(z/z_0),\ \mathrm{for}\ z>z_0,$$ which can be found here. As can be seen from the ...
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Is it possible for a natural fluorescent mineral to glow from the sun's rays?

I have been searching certain fluorescent minerals, such as Andersonite, and all websites are saying how the mineral will glow if exposed to Ultraviolet light. Does enough ultraviolet light come ...
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Winds in a northern hemisphere hurricane

In the Northern Hemisphere, do surface winds around the center of a hurricane move counterclockwise and inward or counterclockwise and outward? I'm guessing they move inward.
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Why does the meandering pattern of the jet stream itself propagate?

It is well known that the jet stream follows an overall meandering pattern, but what is less well known is that this meandering pattern itself moves as a wave with a velocity much slower than the ...
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How to remove 'silk braid' noise in satellite data?

Satellite remote sensing data is a powerful tool for researching the spatial distribution and temporal variation of atmospheric species. Aura is one satellite owing to NASA which meaning ...
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Why is ocean surface velocity around 3% of wind velocity?

Many introductory level textbooks suggest that, as a rule of thumb, the velocity of the ocean surface is around 3% the wind velocity at 10 meters above the sea surface. For instance, Ocean ...
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What caused a fall in atmospheric oxygen about 1.9 billion years ago?

Using chromium isotopes geochemistry, Frei et al. 2009, describe in the article Fluctuations in Precambrian atmospheric oxygenation recorded by chromium isotopes that after the Great Oxidation Event (...
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How do we measure (or empirically calculate) the amount of entropy in the atmosphere and oceans?

Here's a paper on the entropy budget1, where moist entropy is defined in equation (8) as $$ s = (1-q_t)(C_{pd} \ln T - R_d \ln p_d) + q_t C_l \ln T + \frac{q_v L_v}{T} - q_v R_v \ln \mathcal{H} $$ ...
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Is increase in atmospheric $\mathrm{CO}_2$ concentration affecting Earth's atmospheric pressure?

It's well known that the $\mathrm{CO}_2$ levels around the world are increasing, leading to an increase in overall surface temperature, etc. But I'm wondering, are these gases (or the effects from ...
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Synoptic weather predictibility under climate change scenarios

Under climate change scenarios, it is quite certain that high latitude regions will experience more warming than at low latitudes. For example, in winter the reduced area of sea ice and snow cover ...
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What does the notation “kg kg-1” for units mean for specific humidity

I am using a data set from Justin Sheffield at Princeton that includes specific humidity. The description is as follows: "Reanalysis 6-hourly specific humidity interpolated to 1.0deg with account ...
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Why does warm air “hold” more moisture?

It is often explained that warm air holds more water because warmer water is less likely to condense. This and other explanations just seem to be circular arguments. If the warmer air picks up enough ...
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How do current pollution levels in Los Angeles compare to the 1970s?

As I understand it there are two key kinds of air pollution: ozone and fine particles. Are there any long-term data series that chart average ozone levels and/or fine particulates over time going ...
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Why are there no CO2 snowfalls on Earth?

The CO2 phase diagram shows that at atmospheric pressure and about -78 °C temperature CO2 becomes solid: Wikipedia confirms this: At 1 atmosphere (near mean sea level pressure), the gas deposits ...
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What keeps the different gases mixed in the atmosphere?

Consider a gas centrifuge holding two different gases. After spinning for a while, the heavier gas will move to the outside, and the lighter gas will be on the inside. In other words, we have ...
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Is the atmosphere becoming thicker?

Is the atmosphere getting more dense with various gases, car pollution (200 million cars just in North America), factory pollution, more water vapor and denser cloud cover? If so could a "thicker" ...
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Resources for learning the technical parts of atmospheric modeling

I'm a computer/atmospheric science undergrad and I'm trying to get into atmospheric modeling. Any recommendations for resources to get going or to learn about approaches? I can handle fairly technical ...
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Why does the rising of high clouds due to climate change impart positive radiative feedback on radiative forcing?

As seen in the figure below. The larger the temperature difference between surface and cloud, the more positive the radiative forcing is from the cloud. So as the cloud moves up, it supposedly ...
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How do I calculate Per capita $\ce{CO2}$ emissions?

I need to find the per capita $\ce{CO2}$ emissions for Canada in 2010 (expressed in kg/day). I know that Canada had $\ce{CO2}$ emissions of 0.55 (Gt) and a population of 34 million in 2010. I am just ...
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Does natural plant decomposition release more greenhouse gases than burning

I understand that all plant matter releases CO2 as it decomposes and also when it burns in, for example, a forest fire. My assumption, upon which this question is based, is that the CO2 release is the ...
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A rough picture about the ground-level ammonia (NH3)

Ammonia is the only alkaline gas in the atmosphere. It is one of the key features to control the acidity of aerosols and the formation of ammonium salts. In the environment of $NH_3$-rich and $NH_3$-...
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Optimal vertical coordinate for complex topography

There are plenty of choices in models in so far as choice of vertical coordinate is concerned for meteorological models. Five that I know of: The sigma coordinate system - Hybrid coordinate system(...
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Electricity in clouds and induced magnetism

This is well known to everyone that clouds carry electric charges and cumulonimbus clouds contain huge amount of electricity. It is also known from Maxwell's equations that moving particles induce ...
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Are there any high-resolution urban CO2 concentration data sets?

I gather that higher-than-ambient CO2 "domes" can form above urban areas, enhancing other local air pollution. Are there papers or datasets of average CO2 concentrations down at ground level (say 0-20 ...
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Technique to delete spin-up frames from WRF

I'm a user of WRF V3.5 aiming at meteorological simulation. Sometimes, I'll run the model for a long period. My attempt I split the long period(e.g 1 year) into serval short ones. For ...