Exp) All the statements are incorrect. Carbon dioxide is meteorologically a very important gas as it is transparent to the incoming solar radiation but opaque to the outgoing terrestrial radiation. It absorbs a part of terrestrial radiation and reflects back some part of it towards the earth’s surface. It is largely responsible for the green house effect.

The volume of other gases is constant but the volume of carbon dioxide has been rising in the past few decades mainly because of the burning of fossil fuels. This has also increased the temperature of the air.

Carbon dioxide has a higher density than the other gases found in air, which makes CO2 heavier than the air.

Source)

FUNDAMENTALS OF PHYSICAL GEOGRAPHY; Chapter 8; page number 77

Exp) Statement 1 is correct. Dust and salt particles act as hygroscopic nuclei around which water vapour condenses to produce clouds.

Statement 2 is incorrect. Dust particles are generally concentrated in the lower layers of the atmosphere; yet, convectional air currents may transport them to great heights. The higher concentration of dust particles is found in subtropical and temperate regions due to dry winds in comparison to equatorial and polar regions.

Source)

FUNDAMENTALS OF PHYSICAL GEOGRAPHY; Chapter 8; page number 78

Exp) The amount and the intensity of insolation vary during a day, in a season and in a year. The factors that cause these variations in insolation are:

(i) the rotation of the earth on its axis; 

(ii) the angle of inclination of the sun’s rays;

(iii) the length of the day;

(iv) the transparency of the atmosphere;

(v) the configuration of land in terms of its aspect.

The last two however, have less influence.

Source) FUNDAMENTALS OF PHYSICAL GEOGRAPHY; Chapter 9; page number 80

Exp) The transfer of heat through horizontal movement of air is called advection. In middle latitudes, most of dirunal (day and night) variation in daily weather are caused by advection alone. In tropical regions particularly in northern India during summer season local winds called ‘loo’ is the outcome of advection process.

Source) FUNDAMENTALS OF PHYSICAL GEOGRAPHY; Chapter 9; page number 81

Exp) Pair 1 is correctly matched. The troposphere is the lowest layer of the atmosphere. It extends from the earth's surface for a height of 6 miles. Within it, the temperature normally falls with increasing altitude.  All the climatic elements i.e. temperature, precipitation, clouds, pressure and humidity etc. found in this layer of atmosphere.  

Pair 2 is correctly matched. The Ionosphere has electrically conducting layers which make short-wave radio transmission possible over long distances. 

Pair 3 is incorrectly matched. The stratosphere lies above the troposphere. It is very cold and cloudless. It has extremely thin air and without dust, smoke or water vapour. There are marked seasonal temperature changes in this layer of atmosphere.

Source) G.C. Leong; Chapter 14; page number 105

Exp) Both the statements are correct. When the land warms up, it heats the air above it. This causes the air to expand and rise. As the air rises it cools and condenses into cumulonimbus clouds with great vertical extent. If this process continues then rain will fall. This type of rainfall does not last long. 

Conventional rainfall is common in the summer or in the hotter part of the day. It is very common in the tropical regions and interior parts of the continents, particularly in the northern hemisphere. The tropics are a region of the Earth surrounding the Equator.

Source) G.C. Leong; Chapter 14; page number 108

Exp) Statement 1 is correct. Frontal rain is caused by the cyclonic activity in the temperate regions (depressions) and tropical regions (cyclones). This type of rain occurs due to the convergence (meeting) of two different air masses with different temperatures. The colder air mass is heavier than the warmer air mass, therefore the lighter, warmer air rises over the top of the heavier, colder air. As the warm air is forced to rise it cools. Also, the warm air is in contact with the cold air along the fronts, and this also cools. Thus, condensation occurs and clouds are formed. This process causes rain along the front.

Statement 2 is incorrect. Orographic or relief rainfall is best developed on the windward slopes of mountains where the prevailing moisture-laden winds come from the sea.  When the saturated air mass comes across the mountain, it is forced to ascend and as it rises, it expands (because of fall in pressure); the temperature falls, and the moisture is condensed. Thus, the windward slopes receive greater rainfall. 

After giving rain on the windward side, when these winds reach the other slope, they descend, and their temperature rises. Then their capacity to take in moisture increases and hence, these leeward slopes remain rainless and dry. The area situated on the leeward side, which gets less rainfall is known as the rain-shadow area. Example: Eastern slopes of Western Ghats.

Source) G.C. Leong; Chapter 14; page number 109

Exp) Both the Fohn and Chinook winds are dry winds experienced on the leeward side of mountains when descending air becomes compressed with increased pressure. 

The Fohn wind is experienced in the valleys of the northern Alps, particularly in Switzerland in spring. 

Chinook winds are experienced on the eastern slopes of the Rockies in U.S.A. and Canada in winter.

Source) G.C. Leong; Chapter 14; page number 111

• Option D is the Correct Answer: The atmosphere can be divided into five layers according to the diversity of temperature and density. They are:

1. Troposphere
2. Stratosphere
3. Mesosphere
4. Thermosphere (Ionosphere)
5. Exosphere

• Option B is the Correct Answer:
  • Nitrogen-78.08%
  • Oxygen- 20.95%
  • Argon- 0.93%
  • Carbon Dioxide- 0.036%
  • Neon- 0.002%

• Option A is the Correct Answer: Aurora is natural phenomena observed when the magnetosphere is ionized and excited by the solar winds. These solar winds destabilizes the earth's magnetosphere which causes ionisation. It is generally observed in higher altitudes.

• Option D is the Correct Answer: Temperature of air decline steadily in Troposphere, which is the lowermost layer of the atmosphere. After this, temperature remains constant for some height and then increases in the stratosphere. Height of the troposphere is more over the equator due to strong convection currents. It is minimum at the poles. Ionosphere contains electrically charged particles called ions which reflect radio waves and thus makes radio transmission possible on the earth.

• Option A is the Correct Answer: Temperature inversion is a condition when temperature increases going upwards in atmosphere rather than usual decreasing. Long winter nights with clear skies may lead to Temperature inversion. In cloudy conditions, heat from terrestrial radiation will not be able to escape from the lower layer of air and thus inversion would not occur. In mountainous regions, cold air produced at hills at night becomes dense and flows under gravity and pile up in the valleys. This is called air drainage and results into inversion of temperature. Climate change and Greenhouse gases has nothing to do with inversion of temperature which is usually a local phenomenon.

Option A is the Correct Answer: Inversion of temperature takes place only in the troposphere, where majority of atmospheric phenomena takes place related to weather

• Option D is the Correct Answer: Latitude affects insolation at a point which affects temperature at any place. As earth get heated by terrestrial radiation so the temperature of the atmosphere in the troposphere goes on decreasing with rise in altitude. Due to higher specific heat of water and moderating influence of sea breeze, places near the sea always have moderate temperatures. Warm ocean currents increases the temperature and cold currents cools the place.