Quick Review Flashcards - Click to flip and test your knowledge!
Question
What is the process by which water vapour enters the atmosphere upon heating?
Answer
Evaporation
Question
What term describes the process of water vapour forming water droplets on cooling?
Answer
Condensation
Question
The process by which water droplets fall to the ground in liquid, solid, or frozen form is known as _____.
Answer
Precipitation
Question
What is the definition of humidity?
Answer
The amount of water vapour present in the air.
Question
How many calories of heat are generally required to change one gram of liquid water into its vaporous state?
Answer
600 calories
Question
What is the name of the 'hidden' heat stored in water vapour during evaporation?
Answer
Latent heat
Question
Why does the temperature of the atmosphere rise slightly when condensation occurs?
Answer
The latent heat stored in the vapour is released back into the atmosphere.
Question
Why is evaporation relatively low in Equatorial regions despite high temperatures?
Answer
The sky often remains overcast with clouds.
Question
How does dry air promote greater evaporation compared to humid air?
Answer
Dry air has more capacity to hold water vapour than humid air.
Question
What effect do strong winds have on the rate of evaporation?
Answer
Strong winds promote evaporation.
Question
Term: Absolute Humidity
Answer
Definition: The actual amount of water vapour held by air at a certain temperature and volume.
Question
In what units is Absolute Humidity typically expressed?
Answer
$g/m^{3}$ (grams per cubic metre)
Question
Why is absolute humidity generally excluded from weather calculations?
Answer
Absolute humidity changes as air rises upward and its volume fluctuates.
Question
What is the definition of Relative Humidity?
Answer
The ratio between the absolute humidity of a mass of air and the maximum water vapour it can hold at that same temperature.
Question
In what format is Relative Humidity always expressed?
Answer
Percentage
Question
Formula: Relative Humidity (RH)
Answer
$RH = \frac{Actual\ amount}{Water\ holding\ capacity} \times 100$
Question
How does an increase in air temperature affect its water vapour capacity?
Answer
An increase in temperature increases the air's capacity to hold water vapour.
Question
Term: Dew point
Answer
Definition: The specific temperature at which a given mass of air becomes fully saturated.
Question
What is the Relative Humidity of air that has reached its dew point?
Answer
100%
Question
Why does a human feel warm and uncomfortable under conditions of high relative humidity?
Answer
The rate of sweat evaporation from the skin decreases.
Question
Which instrument is used to measure the humidity of the atmosphere?
Answer
Hygrometer
Question
What is the alternative name for a Hygrometer?
Answer
Dry and Wet Bulb Thermometer
Question
In a Hygrometer, what causes the temperature of the wet bulb to be lower than the dry bulb?
Answer
The evaporation of water from the wet cloth tied around the bulb.
Question
What does it indicate when the temperature readings on both the dry and wet bulbs of a hygrometer are the same?
Answer
The air is fully saturated and Relative Humidity is 100%.
Question
Condensation can only take place when water vapour is added to saturated air or when the _____.
Answer
Temperature falls below the dew point
Question
Term: Condensation nuclei
Answer
Definition: Minuscule particles of dust, salt, or smoke around which water vapour condenses.
Question
Why are condensation nuclei essential for the formation of clouds and precipitation?
Answer
Condensation cannot take place without these particles to support the droplets.
Question
Describe the appearance of Cirrus clouds.
Answer
They are fleecy like wool and generally found at high altitudes.
Question
What shape is characteristic of Cumulus clouds?
Answer
A cauliflower-like or dome-shaped top with a horizontal base.
Question
Which type of cloud is characterized by a layered structure?
Answer
Stratus clouds
Question
What form of condensation appears as tiny droplets of water on surfaces due to night-time cooling?
Answer
Dew
Question
Under what condition does frost form instead of dew?
Answer
When condensation occurs at or below freezing point ($0^{\circ}C$).
Question
What are droplets of water suspended in the atmosphere close to the earth's surface called?
Answer
Fog
Question
How is mist distinguished from fog in terms of visibility?
Answer
Mist is less dense and allows visibility up to two kilometres, whereas fog limits it to less than one kilometre.
Question
What is the most common form of precipitation?
Answer
Rain
Question
What is the term for raindrops of smaller size and less intensity?
Answer
Drizzle
Question
How is snow formed in the atmosphere?
Answer
Water droplets rise higher and freeze due to a drop in temperature.
Question
What causes the formation of hail?
Answer
Vertical air currents push water droplets or ice particles higher into freezing layers.
Question
What is the alternative name for Relief Rainfall?
Answer
Orographic Rainfall
Question
What causes the cooling of air in Relief Rainfall?
Answer
The ascent of moist air over a mountain barrier.
Question
In Orographic Rainfall, which side of the mountain receives heavy precipitation?
Answer
The windward side
Question
What happens to the relative humidity of air as it descends the leeward slope of a mountain?
Answer
Relative humidity drops as the air compresses and warms up.
Question
Term: Rain shadow area
Answer
Definition: The dry region on the leeward side of a mountain that receives little to no precipitation.
Question
Which specific region in India experiences heavy orographic rainfall from monsoon winds?
Answer
The Western Ghats
Question
In which global regions is Convectional Rainfall most common?
Answer
Equatorial regions
Question
Why is convectional rainfall in equatorial regions often called '4 O'clock Shower'?
Answer
It occurs daily in the afternoon around 4 o'clock following rapid heating of air.
Question
What weather phenomena typically accompany convectional rainfall?
Answer
Thunder and lightning
Question
What is the average annual rainfall amount in Equatorial regions?
Answer
More than $200\ cm$.
Question
What causes Cyclonic or Frontal Rainfall?
Answer
The convergence of two air masses with different temperatures and physical properties.
Question
Term: Front
Answer
Definition: The boundary zone where a warm and a cold air mass confront each other.
Question
In a frontal system, why does the warmer air mass climb above the colder air mass?
Answer
The warmer air mass is lighter and less dense than the colder air mass.
Question
In which latitudes are depressions and cyclonic rainfall most common?
Answer
Temperate latitudes (Mid-latitudes)
Question
What is the typical duration of cyclonic rainfall in tropical cyclones?
Answer
Only a few hours.
Question
What form does cyclonic rainfall take in the temperate depressions of Western Europe?
Answer
A continuous drizzle lasting for several days.