All questions of Climatology for UPSC CSE Exam

Both options are correct The organic compounds are the amino acids, nucleic acids, proteins, vitamins and pigments.Generally, nitrogen is usable only after it is fixed. 90% of fixed nitrogen is biological.Only a few types of organisms like certain species of soil bacteria and blue-green algae are capable of utilising it directly in its gaseous form.

All statements are correct; hence answer is (d). There are six major controls of the climate of any place. They are latitude, altitude, pressure and wind system, distance from the sea (continentality), ocean currents and relief features.

All the given definitions are right.

Understanding the Correctness of the Statements
The question assesses three statements related to meteorology and atmospheric science. Let's analyze each statement to confirm their accuracy.
Statement 1: Air's Capacity to Hold Moisture
- As the temperature of air increases, its ability to hold moisture indeed rises. This principle is grounded in the fact that warmer air can accommodate more water vapor, significantly impacting weather patterns and humidity levels. Thus, this statement is correct.
Statement 2: White Trails from Jets
- The white trails, known as contrails, produced by jets are a result of the condensation of water vapor in the exhaust from aircraft engines. When the hot, moist air from the engines mixes with the colder upper atmosphere, it cools rapidly, leading to condensation. Therefore, this statement is also correct.
Statement 3: Cyclonic Rainfall Formation
- Cyclonic rainfall occurs at the convergence of warm and cold air masses. This interaction leads to the rising of warm air over cold air, causing cooling and condensation, which results in precipitation. This statement is correct as well.
Conclusion
All three statements are accurate and reflect fundamental principles of meteorology. Therefore, the correct answer to the question is indeed option 'A': All of the above. Understanding these concepts is crucial for analyzing weather patterns and conditions.

Understanding the Assertion and Reason
The statements provided relate to atmospheric science, specifically regarding air temperature and moisture capacity.
Analysis of Assertion (A)
- Assertion (A): "Warmer air will always have more moisture than cooler air."
- This statement is misleading. While warmer air can hold more moisture due to its higher capacity, it does not necessarily mean that it always contains more moisture. For instance, a cooler air mass can be saturated with moisture (like in fog) while warmer air may be dry.
Analysis of Reason (R)
- Reason (R): "The capacity of air to hold moisture in the form of water vapour is related to air temperature."
- This statement is accurate. The capacity of air to hold water vapor increases with temperature. Warmer air can hold more moisture than cooler air, which is a fundamental principle in meteorology.
Conclusion
- Based on the analyses:
- Assertion (A) is incorrect because it implies a definitive relationship that does not account for varying humidity levels.
- Reason (R) is correct as it accurately describes how temperature influences moisture capacity.
Thus, the correct answer is option D: "A is incorrect, but R is correct." This highlights the distinction between air's moisture capacity and its actual moisture content.

Dew point, the temperature at which the atmosphere is saturated with water vapour when it is cooled without changing its pressure or vapour content. A given volume of air containing much water vapour has a higher dew point than the same volume of drier air; thus, the dew point indicates the humidity. In meteorology, the dew point is applied, for example, in predicting the height of the base of certain types of clouds. A higher dew point means there will be more moisture in the air.

The troposphere is thicker at the equator than at the poles because the equator is warmer. The convection currents of air expand the thickness of the troposphere (atmosphere) at poles. Thus, the simple reason is thermal expansion of the atmosphere at the equator and thermal contraction near the poles.

Tyndall effect can be observed when sunlight passes through the canopy of a dense forest. In the forest, mist contains tiny droplets of water, which act as particles of colloid dispersed in the air.

The concept of albedo refers to the ability of a surface to reflect sunlight back into space. The higher the albedo of a surface, the more sunlight it reflects, resulting in less absorption and less warming of the atmosphere. Conversely, a lower albedo means that a surface absorbs more sunlight, leading to more warming.

Lowest albedo: Moist ploughed soil

Moist ploughed soil is likely to have the lowest albedo among the given options. This is because soil is generally dark in color, which means that it absorbs more sunlight. Additionally, moist soil tends to be more reflective than dry soil, but still absorbs more sunlight than other materials like snow and clouds.

Other options and their albedo

- Thick cloud: Clouds have a high albedo, as they reflect a significant amount of sunlight back into space. Therefore, thick cloud is unlikely to have the lowest albedo.
- Fresh snow in Antarctica: Snow has a high albedo, as it reflects sunlight very effectively. Therefore, fresh snow in Antarctica is also unlikely to have the lowest albedo.
- Mirror: Mirrors have a very high albedo, as they reflect almost all of the sunlight that falls on them. Therefore, a mirror is also unlikely to have the lowest albedo.

Conclusion

In conclusion, moist ploughed soil is likely to have the lowest albedo among the given options. This means that it absorbs more sunlight, leading to more warming of the atmosphere. It is important to understand the concept of albedo in order to better understand the impact of different surfaces and materials on the Earth's climate.

The general distribution of winds throughout the lower atmosphere is known as planetary winds. Confined within some latitudinal belts, these winds blow rather regularly throughout the year and are basically controlled by the latitudinal pressure belts.

The main planetary winds are (i) the North-east and the South-east Trade winds, (ii) the Temperate Westerlies and (iii) the Polar Easterlies, which blow from the polar high-pressure area to the temperate low-. Pressure area.

All of them are affected by Coriolis force (Earth's rotation on its axis), and migration of pressure belts apart from how heat patterns vary across the Earth (creating pressure difference).

The westerly winds develop within the equatorial trough when the Intertropical Convergence Zone is well north or south of the Equator. The northeasterly or southeasterly trade winds cross the Equator and, because of the reversal of the Coriolis effect, acquire a westerly component. The term is also applied to the westerlies that arc present throughout most of the year in the eastern Indian Ocean.

More than 200cm per annum

Explanation:

Statement 1: Warm air can hold more water vapour than cold air.
This statement is correct. Warm air has a higher capacity to hold water vapor compared to cold air. As the temperature increases, the air molecules move faster and have more energy. This increased energy allows the air to hold more water vapor. Conversely, cold air has less energy and thus a lower capacity to hold water vapor. This is why warm air can feel more humid than cold air.

Statement 2: A weathercock is used for measuring wind direction.
This statement is correct. A weathercock, also known as a weather vane, is a device used to determine the direction of the wind. It typically consists of a rotating arrow or figure mounted on a pole or rooftop. The arrow or figure is designed to align itself with the direction of the wind, allowing observers to easily determine the wind direction.

Statement 3: The cirrus clouds are high clouds which indicate fair weather.
This statement is correct. Cirrus clouds are generally high-level clouds found at altitudes above 20,000 feet (6,000 meters). They are composed of ice crystals and appear thin, wispy, and feathery. Cirrus clouds are often associated with fair weather conditions because they indicate stable atmospheric conditions. Their presence indicates that the air is dry and stable, which is not conducive to the formation of precipitation or storms. However, it is important to note that cirrus clouds can also precede the arrival of a warm front or a tropical cyclone, which may eventually lead to changes in weather conditions.

Conclusion:
All three statements are correct. Warm air can hold more water vapor, a weathercock is used for measuring wind direction, and cirrus clouds are high clouds that indicate fair weather.

As the evaporation is high and moisture content is lesser in the subtropical and temperate areas compared to equatorial and polar regions, winds are dry; and dust particles are more. Where the moisture is high they fall back to the ground.

Albedo:
Albedo refers to the measure of the reflectivity of a surface. It quantifies how much sunlight is reflected back into space compared to how much is absorbed. The albedo value ranges from 0 to 1, where 0 indicates complete absorption and 1 indicates complete reflection.

Lithosphere:
The lithosphere refers to the rigid outer layer of the Earth, including the crust and uppermost part of the mantle. It consists of various materials such as rocks, soil, and minerals. The albedo of the lithosphere varies depending on the type of surface. For example, the albedo of rocks can range from 0.05 to 0.40, while the albedo of soil can range from 0.10 to 0.30.

Atmosphere:
The atmosphere is the layer of gases surrounding the Earth. It consists of various components such as nitrogen, oxygen, carbon dioxide, and water vapor. The albedo of the atmosphere is primarily influenced by the presence of clouds and aerosols. Clouds have a relatively high albedo, ranging from 0.30 to 0.90, depending on their thickness and composition. Aerosols, which include particles like dust and pollution, can also affect the albedo of the atmosphere.

Cryosphere:
The cryosphere refers to the frozen parts of the Earth's surface, including glaciers, ice caps, and sea ice. The albedo of the cryosphere is generally high due to its reflective nature. Fresh snow has one of the highest albedo values, ranging from 0.80 to 0.90, meaning that it reflects 80-90% of the incoming sunlight. Ice also has a high albedo, ranging from 0.40 to 0.70.

Hydrosphere:
The hydrosphere includes all forms of water on Earth, such as oceans, lakes, rivers, and groundwater. The albedo of the hydrosphere varies depending on the angle of the Sun, the presence of waves, and the amount of dissolved and suspended materials in the water. Generally, the albedo of water ranges from 0.05 to 0.10, meaning that it reflects only 5-10% of the incoming sunlight.

Conclusion:
Among the given options, the cryosphere has the highest albedo. This is because the frozen surfaces of the cryosphere, such as snow and ice, have a high reflectivity, leading to a higher percentage of sunlight being reflected back into space. This high albedo of the cryosphere plays a significant role in regulating the Earth's climate by reducing the amount of solar energy absorbed at the surface.

Explanation:
The thermal equator is an imaginary circle around the Earth that connects the points where the highest mean annual temperature is recorded at each longitude. The following points explain why the thermal equator is slightly north of the geographical equator:

- Solar insolation is comparatively much higher in the Northern Hemisphere than in the Southern Hemisphere. This is due to the fact that the Earth's orbit is not circular but slightly elliptical. As a result, the Earth is closer to the Sun during the Northern Hemisphere summer than during the Southern Hemisphere summer. This means that there is more solar radiation falling on the Northern Hemisphere, leading to higher temperatures.

- The Northern Hemisphere is dominated by land, which heats up faster than water. Land has a lower heat capacity than water, which means that it takes less energy to raise its temperature. This is why temperatures in the interior of continents can be much higher than temperatures on the coasts. In contrast, the Southern Hemisphere is dominated by ocean waters, which have a higher heat capacity and take longer to warm up. This leads to lower temperatures in the Southern Hemisphere.

Therefore, both factors contribute to the fact that the thermal equator is slightly north of the geographical equator. Option B is the correct answer.

Not Related to Formation or Modification of Present Atmosphere

Differentiation is not related to the formation or modification of the present atmosphere.

Explanation:

Formation and modification of the present atmosphere involve various processes that have occurred over millions of years. Some of the significant processes that have led to the formation or modification of the atmosphere are:

1. Solar winds: Solar winds are streams of charged particles that originate from the sun. These solar winds have contributed to the formation of the atmosphere by stripping away the outer layer of the early atmosphere.

2. Degassing: Degassing refers to the release of gases from the Earth's interior. Volcanic eruptions and other tectonic activities have contributed to the release of gases such as carbon dioxide, nitrogen, and water vapor.

3. Photosynthesis: Photosynthesis is the process by which plants convert carbon dioxide and water into oxygen and organic compounds. This process has led to the increase in the concentration of oxygen in the atmosphere.

However, differentiation is not related to the formation or modification of the present atmosphere. Differentiation refers to the process by which the Earth's interior became separated into distinct layers, with the heaviest materials sinking to the core and the lighter materials rising to the surface. This process occurred early in the Earth's history, and it did not have a significant impact on the formation or modification of the atmosphere.

Explanation:

Capacity of air to hold moisture is measured in terms of relative humidity. Relative humidity is the percentage of moisture present in the air compared to the maximum amount of moisture that the air can hold at a particular temperature. The higher the temperature, the more moisture air can hold.

Hot subtropical deserts have high capacity of air to hold moisture because of the following reasons:

1. High temperatures: Subtropical deserts are characterized by hot and dry climate. The temperature in these regions can reach up to 50°C during the day and drop to near freezing at night. The high temperature increases the capacity of air to hold moisture.

2. Low humidity: Subtropical deserts have low humidity because of the scarcity of water. The dry air has more capacity to hold moisture.

3. High pressure: High pressure systems dominate in subtropical deserts. High pressure causes the air to sink and warm, increasing the capacity of air to hold moisture.

Coastal regions and tropical rainforests have high humidity, which means that the air is already saturated with moisture. Therefore, the capacity of air to hold moisture is lower in these regions. Cold Tundra regions have low temperatures, which means that the capacity of air to hold moisture is also low.

In conclusion, hot subtropical deserts have the highest capacity of air to hold moisture because of the high temperatures, low humidity, and high pressure systems.

Assertion (A): The eastern coasts of continents within the tropics have much heavier rainfall than the interiors of the west coasts.
Reason (R): All western coasts fall in the rain shadow zone.

The correct answer is option 'C', which states that Assertion (A) is correct, but Reason (R) is incorrect.

Explanation:

Eastern Coasts of Continents within the Tropics have Heavier Rainfall:
- The eastern coasts of continents within the tropics, such as the eastern coast of India or the eastern coast of Africa, receive heavier rainfall compared to the interiors of the west coasts.
- This is due to the prevailing wind patterns in the tropics, specifically the trade winds.
- The trade winds blow from east to west in the tropics, carrying moist air from the oceans towards the western coasts of continents.
- As the moist air encounters the landmass, it is forced to rise, leading to the formation of clouds and subsequent rainfall along the western coasts.
- This phenomenon is known as orographic rainfall, where the moist air is lifted over a mountain or elevated terrain, resulting in enhanced precipitation.
- As a result, the western coasts of continents within the tropics receive significant rainfall.

Rain Shadow Zone:
- The rain shadow zone refers to the area that lies on the leeward side of a mountain range or elevated terrain.
- When moist air is lifted over a mountain range, it cools and condenses, leading to rainfall on the windward side of the mountain.
- However, as the air descends on the leeward side, it warms and dries up, resulting in reduced rainfall and arid conditions.
- This creates a rain shadow zone, which is characterized by low precipitation and dry climate.
- The rain shadow effect is prominent on the leeward side of mountain ranges, where the prevailing winds are blocked by the mountains, preventing the moist air from reaching the area.

Reason (R) is Incorrect:
- While it is true that western coasts often experience the rain shadow effect, it is not true that all western coasts fall in the rain shadow zone.
- There are several factors that determine the occurrence of the rain shadow effect, including the direction of prevailing winds, the height and orientation of the mountain range, and the distance from the coast.
- In some cases, the western coasts may not be affected by the rain shadow effect and may receive significant rainfall due to other atmospheric factors or geographical features.

Conclusion:
- The assertion that the eastern coasts of continents within the tropics have heavier rainfall than the interiors of the west coasts is correct.
- However, the reason that all western coasts fall in the rain shadow zone is incorrect, as it does not consider the various factors that determine the occurrence of the rain shadow effect.

Explanation:

Statement 1: Wind will strike your back and continue to the sea if you are sitting on the beach facing the sea on a sunny afternoon.

This statement is incorrect. On a sunny afternoon, the land heats up faster than the sea due to the differential heating of land and water. The warm air rises over the land and creates a low-pressure area. The cool air from the sea rushes towards the land to fill this low-pressure area, creating a sea breeze. Therefore, if you are sitting on the beach facing the sea, the wind will strike your face and continue towards the land.

Statement 2: Wind will strike your face and continue to the sea if you are sitting on the beach with your back facing the sea on a cold night.

This statement is correct. During a cold night, the land cools down faster than the sea. The cool air over the land becomes denser and sinks, creating a high-pressure area. The relatively warmer air over the sea rises, creating a low-pressure area. The wind flows from the land towards the sea to fill this pressure gradient, resulting in a land breeze. Therefore, if you are sitting on the beach with your back facing the sea, the wind will strike your face and continue towards the sea.

Conclusion:

Based on the explanations above, we can conclude that Statement 2 is correct, while Statement 1 is incorrect. Therefore, the correct answer is option 'B' - 2 only.

Explanation:
The westerlies are prevailing winds that blow from west to east in the mid-latitudes. They originate from the subtropical high-pressure belts known as the horse latitudes and move towards the poles. In the Northern Hemisphere, the westerlies are strong due to the presence of large land masses, while in the Southern Hemisphere, they are weaker due to the dominance of oceans.

Therefore, the correct statements are:

1. Westerlies originate in the horse latitudes and move towards the poles.
2. Westerlies move from west to east.

Hence, the correct answer is option A (1 and 2 only).

Meteorological drought:
Meteorological drought refers to a prolonged period of significantly below-average precipitation. It is characterized by a lack of rainfall or snowfall, which leads to a deficit in water supply. However, meteorological drought alone does not necessarily indicate a depletion of water resources, as it focuses solely on the lack of precipitation.

Hydrological drought:
Hydrological drought occurs when the availability of water in different storages and reservoirs, such as aquifers, lakes, and reservoirs, falls below what the precipitation can replenish. It considers the overall water balance, taking into account both inflows and outflows of water sources. Hydrological drought reflects the impact of meteorological drought on water resources and can have severe consequences on water availability for human and environmental needs.

Agricultural drought:
Agricultural drought specifically relates to the impact of water scarcity on agricultural activities. It occurs when the water deficit affects crop growth and production, leading to reduced yields and potential agricultural losses. Agricultural drought is closely linked to hydrological drought, as it depends on the availability of water for irrigation and other agricultural purposes.

Ecological drought:
Ecological drought refers to the impact of water scarcity on ecosystems and the natural environment. It occurs when the water deficit affects the health and functioning of ecosystems, including vegetation, wildlife, and aquatic habitats. Ecological drought can result in habitat degradation, loss of biodiversity, and disruptions in ecosystem services.

Explanation of the correct answer:
The correct answer is option 'B', which is hydrological drought. This is because hydrological drought considers the availability of water in different storage and reservoirs, taking into account both inflows and outflows, which directly relates to the depletion of water resources. When the availability of water falls below what the precipitation can replenish, it indicates a deficit in water supply and reflects the impact of meteorological drought on water resources. Therefore, hydrological drought is the appropriate term to describe the situation described in the question.