Atomosphere Flashcards
What are the 5 layers of the Atmosphere?
Troposphere Stratosphere Mesosphere Thermosphere Exosphere
How High dose the Troposphere extend?
Between 25,000ft-35,000ft at the polls and 50,000ft-65,000ft at the equator.
How is the atmosphere heated?
The atmosphere is not directly heated by the sun’s radiation. The sun’s radiation which is primarily short wave radiation is first directly absorbed by the surface of the earth. This heats the earth which in turn re-radiates the heat at a much longer wavelength which is absorbed by the atmosphere.
What are the 4 factors to unequal heating on the earth?
- Seasonal variations which expose one hemisphere to more sunlight than another depending on the time of the year
- Latitude variations
- Diurnal (day/night) variations
- Different surfaces on the earth absorbing and reflecting heat differently. For example, a dark rocky surface will absorb more sunlight directly than a surface covered in vegetation
is a standard atmosphere what is the environmental lapse rate?
1.98°C per 1,000 ft.
What is the standard lapse rate for calculations?
2°C per 1,000 ft
What is the dry adiabatic lapse rate?
3°C per 1,000 ft.
What is the wet or saturated adiabatic lapse rate?
1.1 to 2.8°C per 1,000 ft
What is the wet adiabatic lapse rate for calculations?
1.5°C per 1,000 feet
In a stable atmosphere what dose the lapse rate look like?
A stable atmosphere occurs when the environmental lapse rate is shallow or even negative. In this condition, it will be less than either the dry or wet adiabatic lapse rates. When the lapse rate is negative, the condition is known as an inversion. The atmosphere is stable because any air which rises will cool adiabatically and in doing so will cool more rapidly than the surrounding air which cools at the environmental lapse rate. Because rising air cools faster than its surroundings it will sink back after rising. This is a stable situation.
In an unstable atmosphere what dose the lapse rate look like?
An unstable atmosphere arises when the environmental lapse rate is steeper than both the dry adiabatic lapse rate and the wet adiabatic lapse rate. Under these conditions, any air which is forced to rise and cools adiabatically will end up being warmer than the surrounding atmosphere. As a consequence, it will then be lighter than the surrounding air which will then cause it to rise further and in doing so increase the temperature difference between itself and the surrounding air and so on.
in a conditionally or potentially unstable atmosphere what dose the lapse rate look like?
A conditionally (or potentially) unstable atmosphere arises when the environmental lapse rate is somewhere between the dry and adiabatic lapse rates. Under these conditions, air which is forced to rise a short amount, will cool at the dry adiabatic lapse rate and end up cooler than the surrounding air. This will cause it to sink back. In other words the situation will be stable. If however the air is forced to rise a considerable amount causing it to cool adiabatically to the dew point and beyond, where it then cools at the slower wet adiabatic lapse rate, it may end up warmer, and as a result lighter, than the surrounding air. This is then the familiar unstable situation.
What is the International Standard Atmosphere?
- Temperature at sea level is 15°C
- Environmental lapse rate is 2°C/1,000’
- Pressure at sea level is 29.92” Hg
- Atmospheric pressure drops by approximately 1” of mercury for every 1,000 feet that you climb in the lower atmosphere
- The height of the tropopause is 36,090 feet
What is HUMIDITY?
The higher the temperature of the air, the greater the quantity of water which it can hold
What is RELATIVE HUMIDITY?
RELATIVE HUMIDITY is the amount of water in the air relative to the maximum which it can hold at that temperature and pressure
What is DEWPOINT?
DEWPOINT: If air is cooled at constant pressure the temperature at which condensation begins is known as the dewpoint. The closer the dewpoint temperature is to the outside air temperature, the more likely it is that clouds will form.
What is Convection?
Convection - is the vertical movement of air
