| environmental lapse rate atmospheric stability | greater than the DALR (eg. 11 o C/km) absolutely unstable |
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What causes an unstable atmosphere?
To be “unstable”, the lowest layers of an air mass must be so warm and/or humid that, if some of the air rises, then that air parcel is warmer than its environment, and so it continues to rise . ... This condensation releases heat, which warms the air parcel, which can cause the parcel to rise higher still.
Is the atmosphere likely to be more unstable in mid afternoon or early morning?
Is the atmosphere likely to be more unstable in mid-afternoon or in early morning? Why? Mid-afternoon . Incoming solar radiation heats air during the day near the surface, causing the air to become less dense and more buoyant, resulting in rising parcels and potentially cumulus clouds.
How do you know if a air is stable or unstable?
If the air comes back to where it started, the atmosphere is stable . If the air continues to rise the atmosphere is unstable. In the figure above the air in the parcel has ended up colder and denser than the surrounding air. In this case the parcel would sink back to the ground.
What is the most unstable layer of the atmosphere?
The lowest layer is the troposphere where most of the atmospheric gases and all of the planet’s weather are located. The troposphere is heated from the ground, so temperature decreases with altitude. Because warm air rises and cool air sinks, the troposphere is unstable.
What are the characteristics of an unstable atmosphere?
Poor visibility, intermittent precipitation, and cumulus-type clouds. C) Poor visibility, steady precipitation, and stratus type clouds. What are some characteristics of unstable air? A) Turbulence and poor surface visibility .
What happens when unstable air rises?
In an unstable environment, the weather can change suddenly and can be violent. When rising air, through expansion, cools to the point where some of the water vapor molecules compact together at a faster rate than they are torn apart , some of the water vapor condenses (change from a gas to liquid) and forms clouds.
How do you know if atmosphere is stable?
In order to determine the stability of the atmosphere, meteorologists compare the temperature of a rising air parcel with the temperature of the air around it at the same level . To describe the temperature of the atmosphere surrounding air parcels, meteorologists use the environmental lapse rate.
How can the atmosphere be made more stable more unstable?
Warming the air above the ground and /or cooling the air next to the ground will make the atmosphere more stable. The ground and the air above it cool during the night. ... This steepens the environmental lapse rate and makes the atmosphere more unstable. Cooling air above the ground has the same effect.
What is conditionally unstable?
The state of a layer of unsaturated air when its lapse rate of temperature is less than the dry-adiabatic lapse rate but greater than the moist-adiabatic lapse rate . The choice of usage of the term “conditional instability” has been uncertain and sometimes controversial for at least 50 years. ...
How does air move in general?
Air in the atmosphere moves around the world in a pattern called global atmospheric circulation. ... When the air cools, it drops back to the ground, flows back towards the Equator, and warm again . The, now, warmed air rises again, and the pattern repeats. This pattern, known as convection, happens on a global scale.
Is warm air stable or unstable?
Air is considered unstable , in the lowest layers of an air mass when the air is warmer and or more humid than the surrounding air. When this occurs the air will rise, as that air parcel is warmer than the air surrounding it.
Is cold air more stable?
A stable air mass is one in which there is warm air overlying cold air. Why is that called stable? It is stable because if something should bump the underlying cold air and push it up, the colder air, being more dense than the air above it, will sink right back down to the ground.
What is the coldest layer of the atmosphere?
Mesosphere , coldest layer of Earth’s atmosphere.
What are the 7 layers of atmosphere?
- The Troposphere. This is the lowest part of the atmosphere – the part we live in. ...
- The Stratosphere. This extends upwards from the tropopause to about 50 km. ...
- The Mesosphere. The region above the stratosphere is called the mesosphere. ...
- The Thermosphere and Ionosphere. ...
- The Exosphere. ...
- The Magnetosphere.
Why the layers of atmosphere become thinner with altitude?
Long answer – The gravity causes the upper layers of atmosphere to exert force on the lower ones due to their weight . This causes the air to compress and hence the air become dense at the lower level(closer to surface) while in comparison the air at heights( far from surface) is rarer or thinner.
