Meteo

The temperature lapse rate with increasing height within the troposphere according ISA is...

0,65° C / 100 m

The saturated adiabatic lapse rate should be assumed with a mean value of:

0,6° C / 100 m

What temperatures are most dangerous with respect to airframe icing?

0°to-12°C

What is the mass of a "cube of air" with the edges 1 m long, at MSL according ISA?

1,225 kg

What clouds and weather can typically be observed during the passage of a cold front?

Strongly developed cumulus clouds (Cb) with showers of rain and thunderstorms, gusting wind followed by cumulus clouds with isolated showers of rain

What danger is most immenent when an aircraft is hit by lightning?

Surface overheat and damage to exposed aircraft parts

Which of the following conditions are most favourable for ice accretion?

Temperatures between 0° C and -12° C, presence of supercooled water droplets (clouds)

What factor may affect the top of cumulus clouds?

The presence of an inversion layer

What is the ISA standard pressure at FL 180 (5500 m)?

500 hPa

The "spread" is defined as...

difference between actual temperature and dew point.

The movement of air flowing apart is called...

divergence

An inversion layer close to the ground can be caused by...

ground cooling during the night.

The barometric altimeter with QNH setting indicates...

height above MSL

The barometric altimeter with QFE setting indicates...

height above the pressure level at airfield elevation.

The saturated adiabatic lapse rate is...

lower than the dry adiabatic lapse rate.

With regard to thunderstorms, strong up- and downdrafts appear during the...

mature stage.

Heavy downdrafts and strong wind shear close to the ground can be expected...

near the rainfall areas of heavy showers or thunderstorms.

Extensive high pressure areas can be found throughout the year...

over oceanic areas at latitues around 30°N/S.

Above the friction layer, with a prevailing pressure gradient, the wind direction is...

parallel to the isobars.

Regarding the type of cloud, precipitation is classified as...

rain and showers of rain.

Cold air inflow in high tropospheric layers may result in...

showers and thunderstorms.

"Foehn" conditions usually develop with...

stability, widespread air blown against a mountain ridge.

A boundary between a cold polar air mass and a warm subtropical air mass showing no horizontal displacement is called...

stationary front.

The formation of medium to large precipitation particles requires...

strong updrafts.

The barometric altimeter indicates height above...

a selected reference pressure level.

What weather conditions can be expected in high pressure areas during summer?

Calm weather and cloud dissipation, few high Cu

What weather conditions can be expected in high pressure areas during winter?

Calm winds and widespread areas with high fog

Clouds in high layers are referred to as...

Cirro-

What cloud sequence can typically be observed during the passage of a warm front?

Cirrus, thickening altostratus and altocumulus clouds, lowering cloud base with rain, nimbostratus

Which type of ice forms by large, supercooled droplets hitting the front surfaces of an aircraft?

Clear ice

What process causes latent heat being released into the upper troposphere?

Cloud forming due to condensation

What weather phenomena have to be expected around an upper-level trough?

Development of showers and thunderstorms (Cb)

How do dew point and relative humidity change with decreasing temperature?

Dew point remains constant, relative humidity increases

What clouds and weather may result from an humid and instable air mass, that is pushed against a chain of mountains by the predominant wind and forced to rise?

Embedded CB with thunderstorms and showers of hail and/or rain.

What pressure pattern can be observed during the passage of a polar front low?

Falling pressure in front of the warm front, constant pressure within the warm sector, rising pressure behind the cold front

What pressure pattern may result from cold-air inflow in high tropospheric layers?

Formation of a low in the upper troposphere

What weather conditions can be expected during "Foehn" on the windward side of a mountain range?

Layered clouds, mountains obscured, poor visibility, moderate or heavy rain

Which answer contains every state of water found in the atmosphere?

Liquid, solid, and gaseous

Winds blowing uphill are defined as...

anabatic winds

Light turbulence always has to be expected...

below cumulus clouds due to thermal convection.

The movement of air flowing together is called...

convergence

With other factors remaining constant, decreasing temperature results in...

decreasing spread and increasing relative humidity

The term "tropopause" is defined as...

the boundary area between the troposphere and the stratosphere.

What visual flight conditions can be expected after the passage of a cold front?

Good visiblity, formation of cumulus clouds with showers of rain or snow

What phenomenon is caused by cold air downdrafts with precipitation from a fully developed thunderstorm cloud?

Gust front

Which processes result in decreasing air density?

Increasing temperature, decreasing pressure

What weather conditions in Central Europe are typically found in high pressure areas during summer?

Large isobar spacing with calm winds, formation of local wind systems

What factors may indicate a tendency to fog formation?

Low spread, decreasing temperature

Which of the stated wind phenomena will increase in speed since its path is narrowed by mountains?

Mistral

What visual flight conditions can be expected within the warm sector of a polar front low during summer time?

Moderate to good visibility, scattered clouds

What factors are required for the formation of precipitation in clouds?

Moderate to strong updrafts

Which of the stated surfaces will reduce the wind speed most due to ground friction?

Mountainous areas, vegetation cover

Which type of cloud is associated with prolonged rain?

Nimbostratus

What type of fog emerges if humid and almost saturated air, is forced to rise upslope of hills or shallow mountains by the prevailling wind?

Orographic fog

What is the gas composition of "air"?

Oxygen 21 % Nitrogen 78 % Noble gases / carbon dioxide 1 %

What is the usual direction of movement of a polar front low?

Parallel to the the warm-sector isobars

What are the air masses that Central Europe is mainly influenced by?

Polar cold air and tropical warm air

What frontal line divides subtropical air from polar cold air, in particular across Central Europe?

Polar front

Which force causes "wind"?

Pressure gradient force

The pressure which is measured at a ground station and reduced to mean sea level (MSL) by means of the actual atmospheric conditions is called...

QFF

The altimeter can be checked on the ground by setting...

QNH and comparing the indication with the airfield elevation.

Which type of ice forms by very small water droplets and ice crystals hitting the front surfaces of an aircraft?

Rime ice

What cloud type can typically be observed across widespread high pressure areas during summer?

Scattered Cu clouds

What pressure pattern can be observed when a cold front is passing?

Shortly decreasing, thereafter increasing pressure

How do spread and relative humidity change with increasing temperature?

Spread increases, relative humidity decreases

The height of the tropopause of the International Standard Atmosphere (ISA) is at...

36000 ft

When air masses meet each other head on, how is this referred to and what air movements will follow?

Convergence resulting in air being lifted

Clouds are basically distinguished by what types?

Cumulus and stratiform clouds

Which stage of a thunderstorm is dominated by updrafts?

Cumulus stage

How does inflowing cold air affect the shape and vertical distance between pressure layers?

Decrease in vertical distance, lowering in height (low pressure)

What has to be considered when taking off in a ground inversion?

During climb, a sudden decrease in speed and climb performance has to be expected

What condition may prevent the formation of "radiation fog"?

Overcast cloud cover

What type of turbulence is typically found close to the ground on the lee side during Foehn conditions?

Turbulence in rotors

What wind conditions can be expected in areas showing large distances between isobars?

Variable winds, formation of local wind systems

What change of wind direction can be expected during the passage of a polar front low in Central Europe?

Veering wind during passage of the warm front, veering wind during passage of the cold front

Winds blowing downhill are defined as..

katabatic winds

Moderate to severe turbulence has to be expected...

on the lee side of a mountain range when rotor clouds are present.

At what rate does the temperature change with increasing height according to ISA (ICAO Standard Atmosphere) within the troposphere?

Decreases by 2° C / 1000 ft

Which process may result in an inversion layer at about 5000 ft (1500 m) height?

Widespread descending air within a high pressure area

The dry adiabatic lapse rate has a value of...

1,0° C / 100 m

The character of an air mass is given by what properties?

Region of origin and track during movement

The pressure at MSL in ISA conditions is...

1013.25 hPa

What is the mean height of the tropopause according to ISA

11000 m

What danger is most imminent during an approach to an airfield situated in a valley, with strong wind aloft blowing perpendicular to the mountain ridge?

Wind shear during descent, wind direction may change by 180°

What is meant by "inversion layer"?

An atmospheric layer where temperature increases with increasing height

What is meant by "isothermal layer"?

An atmospheric layer with constant temperature with increasing height

What weather development will result from convergence at ground level?

Ascending air and cloud formation

With regard to global circulation within the atmosphere, where does polar cold air meets subtropical warm air?

At the polar front

What is the name of the the cold, katabatic wind phenomena blowing from northeast into the Adriatic Sea?

Bora

How can wind speed and wind direction be derived from surface weather charts?

By alignment and distance of isobaric lines

What conditions are mandatory for the formation of thermal thunderstorms?

Conditionally unstable atmosphere, high temperature and high humidity

How is an air mass described when moving to Central Europe via the Russian continent during winter?

Continental polar air

What weather conditions may be expected during conditionally unstable conditions?

Towering cumulus, isolated showers of rain or thunderstorms

Weather phenomena are most common to be found in which atmospheric layer?

Troposphere

What situation is called "over-development" in a weather report?

Vertical development of Cumulus clouds to rain showers

What conditions are favourable for the formation of thunderstorms?

Warm humid air, conditionally unstable environmental lapse rate

Which conditions are likely for the formation of advection fog?

Warm, humid air moves over a cold surface

What process results in the formation of "orographic fog" ("hill fog")?

Warm, moist air is moved across a hill or a mountain range

What process results in the formation of "advection fog"?

Warm, moist air is moved across cold ground areas

What situation may result in the occurrence of severe wind shear?

When a shower is visible close to the airfield