The atmosphere is
conditionally unstable
. A rising parcel of unsaturated air ends up cooler and denser than the surroundings. A parcel of saturated air, which cools at a slower rate, ends up warmer than the air around it. The condition for instability is that the air must be saturated.
Which layer is unstable for unsaturated air?
Eventually the rising air cools to its dew point, condensation begins, and a cumulus cloud forms. The vertical stretch of the unsaturated layer cools the
top of the layer more than the bottom
—conditionally unstable. unsaturated layer cools the top of the layer more than the bottom— absolutely unstable.
What is atmospheric stability and instability?
Stability is
the state in which an air parcel finds itself colder than the air surrounding it at the same pressure
(elevation). … Instability is the state in which an air parcel finds itself warmer than the air surrounding it at the same pressure (elevation).
Are clouds stable or unstable?
Clouds with extensive vertical development are indicative of
absolute instability
. Conditional instability is a state of instability that depends upon whether or not the rising air is saturated. Conditional stability occurs when the environmental lapse rate is between the moist and dry adiabatic rates.
What makes 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.
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 are characteristics of a stable air?
What are the characteristics of stable air? A—
Good visibility; steady precipitation
; stratus clouds. B—Poor visibility; steady precipitation; stratus clouds. C—Poor visibility; intermittent precipitation; cumulus clouds.
Why does saturated air cool at a slower rate?
When rising air parcels are saturated, they cool at a slower rate
because of the release of latent heat
. Unlike the DALR, the saturated adiabatic lapse rate (SALR) is not constant, but we often use 6°C/km as an average value.
What is saturated air parcel?
SATURATED PARCEL OF AIR. As a saturated parcel of
air rises condensation is taking place
. The condensed moisture leaves the parcel as rain. The relative humidity remains 100% as the saturated parcel rises. The temperature and dewpoint fall together at the same lapse rate as the saturated air rises.
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.
What causes air instability?
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. In an unstable environment, the weather can change suddenly and can be violent.
What affects air stability?
Stability is determined by
comparing the temperature of a rising or sinking air parcel to the environmental air temperature
. Imagine the following: at some initial time, an air parcel has the same temperature and pressure as its environment.
What are the 4 atmospheric lifting mechanisms?
– There are four lifting mechanisms that form clouds:
Orographic Lifting, Convection, Convergence, and Updraft
.
What is the rarest type of cloud?
Nacreous clouds
are some of the rarest clouds on the planet. They are a form of polar stratospheric cloud, which is a main culprit in chemical destruction of the ozone layer.
Are stratiform clouds stable air?
SKYbrary Wiki
Stratiform, or layer clouds, are cloud formations that are not vertically developed. They are
formed in relatively stable conditions
, where lifted air will be restricted, and instead be spread out horizontally.
Do altostratus clouds rain?
Altostratus clouds are “strato” type clouds (see below) that possess a flat and uniform type texture in the mid levels. … However,
altostratus clouds themselves do not produce significant precipitation at the surface
, although sprinkles or occasionally light showers may occur from a thick alto- stratus deck.
