COMMERCIAL PILOT LICENCE (CPL)
METEOROLOGY - CMET
THERMAL ENERGY
● Feeling of heat is the transfer of thermal energy
● Contained within any object with a temperature above absolute zero
● Transfer of energy flows from hot to cold
CONDUCTION
● Flow of heat via contact between two objects
CONVECTION
● Vertical movement of hot and cold due its buoyancy relative to the
surrounds
● Hot air is lighter than the surrounding air, and therefore rises
● Cold air is denser than the surrounding air, and therefore sinks
ADVECTION
● Horizontal movement of hot and cold
● Wind
RADIATION
● Flow of heat via electromagnetic radiation, without contact
● Can travel without an atmosphere
LATENT HEAT
● Flow of heat via phase change of an object
● Either absorbed into the object or released into the environment
,SPECIFIC HEAT
● Energy required to change its temperature by 1 degree
● High specific heat means a large amount of energy is required to
change its temperature
● Low specific heat means only a small amount of energy is required to
change its temperature
HEIGHT
● Vertical distance above a datum, usually above ground level
ALTITUDE
● Vertical distance above mean sea level
ELEVATION
● Vertical distance of some point on the ground, above mean sea level
QNH
● Air pressure at any point on the earth, measured at mean sea level
QFE
● Air pressure at field elevation, measured at some point on the ground
PRESSURE HEIGHT
● Vertical distance above the international standard atmosphere mean
sea level, 1013.25 hPA
● 1 hPA is lost for every 30 ft of height gained
ISA TEMPERATURE
● 15 degrees at mean sea level
● 2 degrees is lost for every 1,000 ft of height gained
,THE ATMOSPHERE
● 78% nitrogen, 20% oxygen, 2% carbon dioxide and other gases
● Broken up into layers defined by the behaviour of temperature with
increasing height
● Water vapour present in lower level of atmosphere in amounts
varying from trace to 3% of total mass
TROPOSPHERE
● First layer of the atmosphere
● Temperature decreases as height increases
● About 60,000 ft (18 km) over the equator and 30,000 ft (8 km) over
the poles
● Contains virtually all convection, water vapour, weather and clouds
TROPOPAUSE
● Boundary between the troposphere and stratosphere
● Marked by the change to an isothermal temperature lapse rate
● Convection of air weakens due to the converging buoyancy of the
surrounding air
STRATOSPHERE
● Second layer of the atmosphere
● Temperature is constant as height increases to a point, and then
temperature increases as height increases given the proximity to the
ozone
● Little to no vertical mixing of air due to the increase in the ambient
temperature preventing convection
● Only towering cumulus or cumulonimbus may be found here due to
very strong convection
ISOTHERMAL LAYER
● Temperature is constant as height increases
, SOLAR RADIATION
● Ozone gas absorbs large amounts of solar radiation, producing
temperatures similar to that on the ground
○ Concentrated at 50 km above ground
● Remaining can be reflected back to space from cloud tops
● Some is scattered by air particles, producing the blue colour of the
sky
● What’s left is arrives at the surface and may be absorbed or
reflected
● Equatorial regions receive radiation at a greater intensity than the
poles
○ Therefore equatorial regions have higher surface temperatures
○ During summer in the southern hemisphere, due to the tilt, the
most intense solar heating occurs south of the equator
○ During winter in the southern hemisphere, due to the tilt, the
most intense solar heating occurs north of the equator
TROPICAL CELL
● Equatorial regions with high surface temperatures heat the air via
conduction
● Hot air rises due to convection until it can rise no further
● Air moves laterally towards the poles
● Air begins to cool (not at the poles) and sinks to the surface
POLAR CELL
● Polar regions with low surface temperatures cool the air via
conduction
● Sinking cold air pushes air below it towards the equator
● Transversing air warms as it moves to lower latitudes
● Once warm enough, it rises and returns to the polar regions where it
then sinks
METEOROLOGY - CMET
THERMAL ENERGY
● Feeling of heat is the transfer of thermal energy
● Contained within any object with a temperature above absolute zero
● Transfer of energy flows from hot to cold
CONDUCTION
● Flow of heat via contact between two objects
CONVECTION
● Vertical movement of hot and cold due its buoyancy relative to the
surrounds
● Hot air is lighter than the surrounding air, and therefore rises
● Cold air is denser than the surrounding air, and therefore sinks
ADVECTION
● Horizontal movement of hot and cold
● Wind
RADIATION
● Flow of heat via electromagnetic radiation, without contact
● Can travel without an atmosphere
LATENT HEAT
● Flow of heat via phase change of an object
● Either absorbed into the object or released into the environment
,SPECIFIC HEAT
● Energy required to change its temperature by 1 degree
● High specific heat means a large amount of energy is required to
change its temperature
● Low specific heat means only a small amount of energy is required to
change its temperature
HEIGHT
● Vertical distance above a datum, usually above ground level
ALTITUDE
● Vertical distance above mean sea level
ELEVATION
● Vertical distance of some point on the ground, above mean sea level
QNH
● Air pressure at any point on the earth, measured at mean sea level
QFE
● Air pressure at field elevation, measured at some point on the ground
PRESSURE HEIGHT
● Vertical distance above the international standard atmosphere mean
sea level, 1013.25 hPA
● 1 hPA is lost for every 30 ft of height gained
ISA TEMPERATURE
● 15 degrees at mean sea level
● 2 degrees is lost for every 1,000 ft of height gained
,THE ATMOSPHERE
● 78% nitrogen, 20% oxygen, 2% carbon dioxide and other gases
● Broken up into layers defined by the behaviour of temperature with
increasing height
● Water vapour present in lower level of atmosphere in amounts
varying from trace to 3% of total mass
TROPOSPHERE
● First layer of the atmosphere
● Temperature decreases as height increases
● About 60,000 ft (18 km) over the equator and 30,000 ft (8 km) over
the poles
● Contains virtually all convection, water vapour, weather and clouds
TROPOPAUSE
● Boundary between the troposphere and stratosphere
● Marked by the change to an isothermal temperature lapse rate
● Convection of air weakens due to the converging buoyancy of the
surrounding air
STRATOSPHERE
● Second layer of the atmosphere
● Temperature is constant as height increases to a point, and then
temperature increases as height increases given the proximity to the
ozone
● Little to no vertical mixing of air due to the increase in the ambient
temperature preventing convection
● Only towering cumulus or cumulonimbus may be found here due to
very strong convection
ISOTHERMAL LAYER
● Temperature is constant as height increases
, SOLAR RADIATION
● Ozone gas absorbs large amounts of solar radiation, producing
temperatures similar to that on the ground
○ Concentrated at 50 km above ground
● Remaining can be reflected back to space from cloud tops
● Some is scattered by air particles, producing the blue colour of the
sky
● What’s left is arrives at the surface and may be absorbed or
reflected
● Equatorial regions receive radiation at a greater intensity than the
poles
○ Therefore equatorial regions have higher surface temperatures
○ During summer in the southern hemisphere, due to the tilt, the
most intense solar heating occurs south of the equator
○ During winter in the southern hemisphere, due to the tilt, the
most intense solar heating occurs north of the equator
TROPICAL CELL
● Equatorial regions with high surface temperatures heat the air via
conduction
● Hot air rises due to convection until it can rise no further
● Air moves laterally towards the poles
● Air begins to cool (not at the poles) and sinks to the surface
POLAR CELL
● Polar regions with low surface temperatures cool the air via
conduction
● Sinking cold air pushes air below it towards the equator
● Transversing air warms as it moves to lower latitudes
● Once warm enough, it rises and returns to the polar regions where it
then sinks
