FYUG Even Semester Exam, 2024 Understanding the Climate (PHYIDC-151T)

SECTION-A (1 Mark Each)

Attempting all questions as per instructions.

Questions 1-10

• 1. Elementary idea of atmosphere: The atmosphere is a layer of gases surrounding the Earth, held in place by gravity, providing life-sustaining oxygen and protection from solar radiation.
• 2. Dynamic atmosphere: Refers to the continuous movement and physical processes of the atmosphere, such as wind patterns and heat exchange.
• 3. Ionosphere: A region of the upper atmosphere (part of the thermosphere) that contains a high concentration of ions and free electrons, reflecting radio waves.
• 4. Atmospheric pressure: The force exerted by the weight of the air above a given point on the Earth's surface.
• 5. Meteorology: The scientific study of the atmosphere and its phenomena, especially weather and weather forecasting.
• 6. Climate change: A long-term shift in global or regional climate patterns, often attributed to human activities like greenhouse gas emissions.
• 7. Deforestation: The permanent removal of trees to make room for something besides forest (e.g., agriculture or urban use).
• 8. Industrialization: The process by which an economy is transformed from primarily agricultural to one based on the manufacturing of goods.
• 9. Cloud seeding: A weather modification technique that involves dispersing substances into the air to serve as cloud condensation nuclei.
• 10. Lightning: A high-voltage electrostatic discharge occurring within a cloud or between a cloud and the ground.

Questions 11-20

• 11. Long-term climate changes: Variations in Earth's climate occurring over decades to millions of years, such as ice ages.
• 12. Global warming: The long-term heating of Earth's climate system due to human activities, primarily fossil fuel burning.
• 13. Variation of monsoon: Fluctuations in the timing, duration, and intensity of seasonal wind patterns and rainfall.
• 14. Intensity of cyclones: A measure of the maximum sustained wind speed and lowest central pressure of a tropical storm.
• 15. Heat waves: Prolonged periods of excessively hot weather, often accompanied by high humidity.
• 16. Humidity instrument: A hygrometer.
• 17. Radiation clouds: Clouds that form when the Earth's surface cools the air above it via long-wave radiation emission at night.
• 18. SI unit of pressure: Pascal (Pa).
• 19. Radar: Radio Detection and Ranging; a system for detecting the presence, direction, distance, and speed of objects.
• 20. SONAR: Sound Navigation and Ranging.

Questions 21-25

• 21. Atmospheric pollution: The presence of harmful or excessive quantities of substances (pollutants) in the atmosphere.
• 22. Types of pollutant: Primary pollutants (direct) and secondary pollutants (formed in air).
• 23. Trace gases: Gases that make up less than 1% of the atmosphere, such as argon, carbon dioxide, and methane.
• 24. Tropospheric zone: The lowest layer of the atmosphere where weather occurs, extending from the surface to about 8-15 km.
• 25. Geo-engineering: Large-scale manipulation of environmental processes to counteract the effects of global warming.

SECTION-B (2 Marks Each)

Question 26

2

How does temperature and pressure vary in earth's atmosphere?

Pressure decreases exponentially with altitude. Temperature decreases in the troposphere, increases in the stratosphere, decreases in the mesosphere, and increases in the thermosphere.

Question 27

2

What are meteorological processes? Write down different scales.

Processes like evaporation, condensation, and heat transfer that drive weather. Scales include Microscale (meters), Mesoscale (kilometers), and Synoptic scale (thousands of kilometers).

Question 28

2

Difference between weather and climate?

Weather refers to short-term atmospheric conditions (minutes to days), while climate is the average of weather patterns over a long period (usually 30 years).

Question 29

2

Products formed during combustion of fossil fuel.

Primary products include Carbon dioxide (CO2), Water vapor (H2O), Carbon monoxide (CO), Sulfur dioxide (SO2), and Nitrogen oxides (NOx).

Question 30

2

What are greenhouse gases?

Gases that trap heat in the atmosphere, such as CO2, Methane (CH4), Nitrous Oxide (N2O), and Water vapor.

Question 31

2

What are the different causes of climate change?

Natural causes include solar variations and volcanic eruptions. Anthropogenic causes include burning fossil fuels, deforestation, and industrial processes.

Question 32

2

Measurement of wind? Relationship between humidity and wind.

Wind is measured using an anemometer (speed) and wind vane (direction). High wind speeds typically increase evaporation, which can initially raise humidity but eventually disperse moist air.

Question 33

2

Applications of radars in atmospheric phenomenon.

Radars are used to track precipitation, monitor storm movement (cyclones/tornadoes), and measure wind profiles in the upper atmosphere.

Question 34

2

What is the Kyoto protocol?

An international treaty (1997) that committed industrialized nations to reduce greenhouse gas emissions based on the scientific consensus on global warming.

Question 35

2

Difference between climate change mitigation and adaptation?

Mitigation involves reducing or preventing emissions (e.g., solar energy), while adaptation involves adjusting to the actual or expected future climate (e.g., building sea walls).

SECTION-C (8 Marks Each)

Question 36

5+3=8

(a) Layers of the atmosphere.

The atmosphere consists of: 1. Troposphere (weather zone), 2. Stratosphere (ozone layer), 3. Mesosphere (coldest layer), 4. Thermosphere (ionosphere included), and 5. Exosphere (outer edge).

(b) Basic conservation laws in atmospheric dynamics.

1. Conservation of Mass (Continuity Equation).
2. Conservation of Momentum (Newton's 2nd Law).
3. Conservation of Energy (First Law of Thermodynamics).

Question 38

6+2=8

(a) Thunderstorm formation and causes.

Thunderstorms require moisture, unstable air (rising air), and a lift mechanism (like heat or cold fronts). They form when warm, moist air rises rapidly (updraft), cools, and condenses into cumulonimbus clouds. Precipitation then creates downdrafts, leading to the storm's peak and eventual dissipation.

(b) Difference between cyclones and anticyclones.

Feature	Cyclone	Anticyclone
Pressure	Low center	High center
Wind Direction (NH)	Counter-clockwise	Clockwise
Weather	Stormy/Rainy	Clear/Fair

Question 39

3+5=8

(a) Droplet growth and formation.

Droplets form around cloud condensation nuclei (CCN) when air cools to its dew point. They grow via condensation and collision-coalescence (droplets bumping into each other).

(b) Humidity: Relative vs. Absolute. High humidity effects.

Absolute humidity is the total mass of water vapor per volume of air. Relative humidity is the percentage of moisture air holds compared to its maximum capacity at that temperature. High humidity hinders sweat evaporation, making it feel hotter (heat index) and encouraging mold growth.

Question 40

5+3=8

(a) Effects of global warming and sea level rise causes.

Effects include frequent heat waves, melting polar ice, and biodiversity loss. Sea level rise is caused by thermal expansion of seawater as it warms and the melting of land-based ice (glaciers/ice sheets).

(b) How melting glaciers contribute to sea level rise.

When glaciers melt, water that was previously stored as ice on land flows into the ocean, increasing its total volume.

Question 41

5+3=8

(a) Climate change and cyclone frequency.

Warmer sea surface temperatures provide more energy for cyclones, potentially increasing their intensity and frequency. Types include Tropical, Extratropical, and Mesocyclones.

(b) Tornado vs. Hurricane. El Niño.

Tornadoes are small-scale, intense wind funnels over land, while hurricanes are large-scale tropical systems over oceans. El Niño is a climate pattern involving the warming of surface waters in the eastern Pacific Ocean.

Question 44

5+3=8

(a) Adaptation planning and four strategies.

Adaptation planning is the process of preparing for climate impacts. Strategies: 1. Protection (e.g., dikes), 2. Accommodation (e.g., salt-tolerant crops), 3. Retreat (moving inland), 4. Ecosystem-based adaptation.

(b) Ways to mitigate climate change.

Transitioning to renewable energy, improving energy efficiency, reforestation, and implementing carbon capture technologies.

Exam Focus Enhancements

• Exam Tips: Draw the atmospheric layer diagram for Q36(a) to secure full marks.
• Common Mistakes: Do not confuse "Relative Humidity" with "Absolute Humidity" – examiners look specifically for the temperature dependence in the definition of Relative Humidity.
• Important Formulas:
  • P = F/A (Pressure)
  • RH = (Actual VP / Saturated VP) x 100%

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