Atmospheric Layers and Gradient Winds

Meteorology Banks - Completed Questions

• The layer above the Tropopause in the Atmosphere is the Stratosphere.
• The layer closest to Earth is the Troposphere.
• Temperature decreases throughout the layer in the troposphere.
• Temperature increases in the Stratosphere.
• The layer that is closest to the earth is the Troposphere.
• For practical purposes, a pressure gradient is measured from high pressure to low pressure.
• Balance of pressure gradient force, centrifugal force and coriolis force resulting in curved winds blowing parallel to isobars are Gradient winds.
• Wind balanced out by Pressure Gradient Force, Coriolis Force and Centripetal Force and follows curved isobars going anti clockwise or clockwise is known as Gradient Wind.
• When Pressure Gradient Force and Coriolis Force are not equal, Centrifugal Force causes isobars to become a Curved path; the wind following this path is known as gradient winds.
• Gradient wind follows Curved isobars.
• Surface wind is reduced and hits the isobar at an angle compared to gradient wind due to Surface friction 2000ft - 5000ft.
• Clouds reflect some of the incoming solar radiation, which in turn decreases the daily temperature and maximises it.
• Clouds reflects solar radiation lowering the daily temperature to the maximum.
• When mid level clouds form above a mist, Fog forms.
• A thick layer of mid-level cloud forms over an aerodrome after mist has formed will Enhance condensation, resulting in fog.
• The relationship between pressure, temperature and density is that high pressure & cold temp = high density.
• Density increase, pressure increase and temperature decrease describes the relationship between pressure, temperature and density.
• Relationship of surface pressure centres and pressure centres aloft depends on Temperature of column of air.
• Relationship between surface pressure centres and pressure centres aloft is dependent on the Temperature of column of air.
• Diurnal variation is greatest when there are Clear skies, light winds (no clouds to reflect solar radiation/less thermal mixing of air).
• The greatest diurnal variation occurs in a Desert with clear skies.
• As compared to a lake and an ocean, desert areas Heat up faster in the day and cool faster in the night.
• The diurnal variation is greatest in a temperate region when there is Clear sky, light winds.
• The diurnal variation in temperature is Greatest in desert area.
• Cloud cover influences the diurnal variation of temperature near Earth's surface by Lowering daytime maximum temperature and increasing minimum night time temperature.
• The hottest time of the day is Mid afternoon.
• The coldest and hottest time of the day is After dawn and few hours after midday.
• The conditions when highest temperature range is Clear skies, light wind.
• Terrestrial heating is via Conduction and convection.
• After sunset, Terrestrial radiation over a plot of land with light wind effects causes Radiation inversion.
• At sunset, terrestrial radiation occurs and there is some light mixing of wind, Radiation inversion occurs.
• When the ground cools faster than the air above, causes Radiation Inversion.
• Atmospheric pressure Decrease, Increase as height.
• During a cloudy night with some light mixing winds, the Warmer air is brought down, thus causing the temperature to be Warmer.
• On a day with an overcast, as compared to a day with clear skies, temperature is Colder in the day and warmer at night.
• On a windy night, turbulent mixing in the lower atmosphere brings down air that is Warmer than the surface from above, causing the surface temperature to be Warmer than it otherwise would be - On land only.
• There are turbulent winds at night which bring down Warmer winds and makes the temperature Warmer than usual.
• Two graphs of temperature vs altitude represents a Subsidence inversion.
• An inversion created by descending air that is warmed adiabatically is called a Subsidence inversion.
• An inversion caused by sinking air that is warmed adiabatically is known as Subsidence inversion.
• The development of overnight conditions where land cools faster than the overlying air causes Surface inversion.
• Temperature increases with altitude in a temperature inversion.
• The unit the ICAO Standard Atmosphere use for temperature is Celsius.
• The measure of the intensity of heat, or degree, is associated with Temperature.
• In aviation terms, wind is defined as Movement of air in the atmosphere due to pressure differences, with speed and direction measured in km/h.
• Wind is defined by Horizontal movement of air by pressure difference, measured by anemometer.
• Wind is formed by and calculated by Horizontal movement of air by pressure difference, measured by anemometer.
• When the aircraft climbs out of the friction layer in the Southern Hemisphere, The wind remains relatively constant until it completely leaves the friction layer then speed increases and backs.
• Wind is formed by and calculated by Horizontal movement of air by pressure difference, measured by anemometer.
• When the aircraft climbs out of the friction layer in the Southern Hemisphere, it remains relatively constant until it completely leaves the friction layer then speed increases and backs.
• When the aircraft climbs out of the friction layer in the Southern Hemisphere, it remains relatively constant until friction layer is vacated then speed increases and backs.
• A low-level system with a cold air core typically intensifies with height because Air is denser.
• Area of low pressure in the summer is indicated by Low pressure and Divergence aloft.
• A barometer is used to Measure altitude.
• The Altimeter work by to Measure Altitude by calibrating Barometric pressure.
• Aircraft altimeter measures Altitude by calibrating magnitude of vertical pressure deviations and indicating altitude above sea level.
• ISA conditions are 15 Degrees C, 1013.2hPa.
• If an aircraft is flying at 10 000ft with the QNH of 1004hPa and clearance was given at FL100, Descend 270 ft to achieve this using the rule of thumb of 30ft / mb difference.
• If airfield altitude is set on the altimeter, the sub-scale corresponds to QNH.
• If an aircraft is operating at a constant indicated altitude at 1020hPa and outside air temperature continues to fall, true altitude will increase.
• If a pilot's aircraft is parked at 720ft above mean sea level, he can estimate the QNH Setting 720ft in the altimeter and reading off the subscale.
• At a pressure altitude of 180ft, the pressure is 1020hPa and the mean sea level pressure is 1026hPa.
• Mean sea level pressure of 1013 hPa at ISA lapse rate would have a pressure of 994 hPa at 570 ft utilising the fact that 1 mb = 30 ft.
• The pressure at mean sea level is 1020 hPa, the pressure at 1500ft is 970 hPa.
• QFE is Height above airfield.
• Measured pressure at an airfield utilises International Standard Atmosphere (ISA) to determine the QNH.
• The temperature at 10,000ft at ISA conditions is -5 degrees.
• Air pressure decreases by 1 hPa every 27ft in the troposphere.
• Above 5000 ft, the pressure decreases 1 hPa per 27ft.
• With a Mean sea level is 1013hPa and Aircraft parked at 570 ft, implies the QFE is 994 calculated by 994 (570/30 = 19, 1013 - 19 = 994).
• Using Standard Lapse Rate, when an airfield has an elevation of 570ft and mean sea level pressure is 1013hPa, it reveals the atmospheric pressure at the airfield of 984 utilising the fact that it is 994.
• Conditional Stability of the atmosphere is where the Environmental Lapse Rate (ELR) Lies between Saturated Adiabatic Lapse Rate & Dry Adiabatic Lapse Rate.
• Temperature Lapse Rate in troposphere in ISA is Decrease of 1.98 degrees /1000 feet up to 36090 AMSL
• Surface friction slows down the wind and deflects the wind, hitting isobar at an angle
• Wind flowing through a narrow valley Accelerates, decreases ambient pressure
• During day when turbulent mixing of lower atmosphere bring Cooler air from above, it causes a surface temperature to be lower than normal.
• The force that causes wind to change direction due to rotation of the Earth is known as Coriolis force.
• Coriolis force acts At 90 degrees to surface wind.
• Coriolis effect is proportional to The strength of wind and latitude.
• Heat is transferred from warm land mass to cool land mass through Conduction.
• Heat is transferred from a land mass to the atmosphere by Conduction and Convection.
• Temperature is transferred between a warm landmass and the atmospheric air above by Conduction and convection.
• Heat transfer happens by rising warmer air of lower density and falling of colder air of higher density through Convection.
• Wind direction changes from 340 to 230 is said to have backed.
• Seasonal changes on Earth happens because The Earth's spin axis is tilted at 23.5 deg to a line passing vertically through its orbital plane.
• On a graph showing 0 to 30km altitude on y-axis, the x-axis indicates Pressure.
• Most of the water vapour is in Troposphere.
• An ocean and lake will Heat up faster in the day and cool slower in the night, compared to a desert or beach sand.
• The relationship between temperature, pressure and density is that High Pressure, Low Temperature = High Density.
• Heat increases in a molecule without any transfer of heat energy through Adiabatic Energy.
• The degree or intensity of heat in a substance defines Temperature.
• Lines joining points of equal barometric pressures are isobars.
• Surface winds are measured at 10 metres above ground.
• On a cold day, an airfield with a elevation of 570ft will have a airfield pressure Higher than 994, provided that the mean sea-level QNH is 1013.
• Altitude increases by 27ft per 1mb until 20,000ft.
• When an aircraft is flying from Aerodrome A to Aerodrome B with QNH at Aerodrome A at 1010 and the QNH at Aerodrome B at 1020, the altitude the pilot will arrive at Aerodrome B with airfield elevation is 600ft if the pilot did not change the barometric pressure at Aerodrome A is 300ft.
• Coriolis Force is directly proportional to Latitude.
• The variation of temperatures in the day and night for a region of snow and ice is Generally constant throughout day and night when compared to a forested area.
• Pressure altitude = 1013.2mb is used to determine airfield elevation.
• The temperature lapse rate according to ISA is 2 degC per 1000ft up to 36090ft AMSL.
• The Saturated Adiabatic Lapse Rate is 1.5° per 1000 ft.
• On a warmer day, the altitude change per mb will Increase.
• The Dry Adiabatic Lapse Rate (DALR) is 3.0° per 1000 ft.
• Friction winds decreases in speed and backs.
• Colder columns of air indicate that it is Moist and increased change of rate of pressure.
• The correct option showing the order is (left is 1, right is 2): 1 - anemometer, 2- wind vane.
• In the troposphere it contains ¼ of atmosphere's weight.

Meteorology Banks - Incomplete Questions

• ISA is +15C 1013.25mb/HPA, 1225g/m3 or 1.225kg/m3.
• Temperature stays constant at -56 Degree Celsius in the lower Stratosphere.
• The density at MSL for ISA is 1225g/m^3.
• When the spacing of isobars is close with one another, there is a Great pressure change over short distances.
• Low Level Divergence in the Southern Hemisphere will cause Increasing pressure, Low turbulence and a lesser chance of precipitation and generally with clear skies.
• Deflection of wind flow from high to low pressure is caused by Coriolis Force because of Earth rotation.
• Air sinks and warms adiabatically due to Subsidence inversion.
• Coriolis force acts on The surface wind at 90 degrees.
• Surface friction layer reduces the speed of wind and changes its direction and crosses isobars toward Low pressure.
• Surface wind turns in the mid latitudes due to Coriolis force and Surface friction.
• Tropopause is the Layer between troposphere and stratosphere.
• Most weather occurs in the Troposphere.
• Troposphere is below the Tropopause.
• The friction layer is Ground to 2000 feet or from the Ground to the layer which it is affected by friction force.
• Friction layer is closest to the earth 's surface in the troposphere wherefriction affects wind speed and direction causing wind to be gusty (irregular flow).
• The standard ELR used in ISA atmosphere is 1.98 degree Celsius per 1000ft.
• When an aircraft climbs from ground to cruising altitude, wind speed will increase and veer due to lesser friction so wind speed increase veer if northern hemisphere.
• Surface friction causes the surface wind to hit the isobars at an angle instead of flowing parallel to it.
• FL240 corresponds to Pressure altitude of 24000.
• The altimeter must be reset to determine the altitude by accounting for the change in mean sea level atmospheric pressure (affected by change in pressure, hence affected by change in sea level atmospheric pressure).
• As an aircraft climbs out of the friction layer in the southern hemisphere, surface friction causes the wind direction It remains relatively constant until it completely leaves the friction layer then speed increases and backs.
• Low level convergence in Southern hemisphere ischaracterised by Increasing Turbulence, lowering air pressure, increasing clouds with possible precipitation.
• Temperature inversion is when Temperature increase with altitude.
• Land rapidly cools before the air above when there is a Surface inversion.
• With an Aircraft on aerodrome where it is 120ft above MSL and QFE 1010 implies that is 1 millibar for every 30 feet implies that 120/30=4 which produces that QNH = QFE + 4 = 1014 which corresponds with known graphs for temperature inversion.
• Minimum temperature is higher and diurnal variation decreases in areas with clouds.
• Clouds in desert Increase min temp and decrease diurnal variation.
• At standard ICAO mean sea level with a temperature of 15 degree, the temperature at 10000ft is -5 degree celsius.
• FL340 means Pressure altitude 34,000 ft (with reference to pressure altitude of QNH1013.25) or 34,000ft above MSL
• An L shape Graph showing altitude on x axis, indicates Pressure on the y axis
• Relationship between surface pressure centres and pressure centres Stability and Temperature of the column of air.
• Temperature lapse rate is 1.98degrees/1000feet until 36,090 feet AMSL according to
• Low level convergence in the southern hemisphere leads to low pressure, Increasing turbulence, increase in clouds and chance of precipitation.
• Clouds causes An increase in minimum temperature and decrease in maximum temperature.
• Aircraft climbing in the southern hemisphere will experience No significant change in speed until vacating the friction layer, Speed increase, Back or No significant change in speed until vacating the friction layer, Speed increase, Veer.
• Closely spaced isobars indicate Large change in pressure in a short distance where to Expect bad weather.
• Horizontal movement of air due to pressure difference and and is measured using an anemometer explains of how wind is formed and measured.
• Due to Earth rotation, the deflection of wind flow from high to low pressure is caused by Coriolis Effect and Pressure Gradient Force.
• Low level Divergence causes Low turbulence , high pressure, clear skies with less cloud
• Low level Convergence causes High Turbulence , low pressure , clouds and rain.
• With settled weather, the temperature of the air is the highest in Mid afternoon.
• 42.How does the wind change when the aircraft climbs out of the friction layer in the Southern Hemisphere? a. It remains relatively constant until it completely leaves the friction layer then speed increases and backs. During NIGHT, turbulent mixing of lower atmosphere bring Warm air from above, causing surface temperature to be higher than normal

44. At troposphere temperature why is it colder a. Air is thin and cannot hold onto hot molecules b. Air is heated by conduction from the earth
45. There are 15 knots of wind blowing into a ridge at 3,000ft. What should you do to fly safely from the Leeward side to the Windward side? a. Climb to 3,000ft or higher and fly at turbulence penetration speed until you passed the ridge b. Climb to 2,000ft until you reach the ridge and fly as low as possible at max cruising speed c. Fly as low as possible to avoid rotor turbulence and climb only when you reach the ridge d. Fly below 2,000ft and only climb at the ridge to avoid turbulence