24 February 2025 : Daily Answer Writing

MAINS MODEL QUESTION: 24th FEBRUARY 2025

Q1) Discuss the unique geographical features of the Indian ocean and their  impact on global oceanic circulations patterns. How do these features influence the climate of the Indian subcontinent? (15 marks, 250 words)

• The Indian Ocean is considered to be the youngest of the three oceans, Atlantic, Pacific, and Indian oceans. 
• It is the only ocean with an asymmetric and, in the north, semiannually reversing surface circulation. It has no separate source of bottom water (i.e. the Indian Ocean’s bottom water originates outside its boundaries) and has two sources of highly saline water (the Persian Gulf and the Red Sea). 
• Due to the El-Nino effect in the Indian and Pacific Ocean temperatures were way beyond normal in the month of June.

FEATURES OF THE INDIAN OCEAN:

1. Physiography and geology:
2. Origin: The formation of the Indian Ocean is a consequence of the breakup of the southern supercontinent Gondwanaland; by the movement to the northeast of the Indian subcontinent, which began colliding with Eurasia; and by the western movement of Africa and separation of Australia from Antarctica.
3. Shape and Boundaries: The Indian Ocean is a relatively enclosed basin that has a distinct shape that influences water circulation and monsoonal patterns. It is bounded by Asia to the north, Africa to the west, Australia to the east, and the Southern Ocean to the south.
4. Submarine features: The Indian Ocean Houses all major Submarine features like Oceanic ridges (Carlsberg Ridge in the Arabian Sea), fracture zones (Diamantina Fracture Zone), Continental rise, slope, shelf, trenches (Java Trench) etc.
5. Coastal features: Several well-defined coastal configurations are found in the Indian Ocean: estuaries and deltas (Indus Delta)), salt marshes, mangrove swamps (Sunderbans), cliffs (Varkala beach), coral reefs (Great Barrier Reef), and complexes of barrier islands (Cocos Island), lagoons (Chilika lake), beaches (Maldives), and dunes (Chandipur).
6. Island features: The Maldives, Seychelles, Socotra, and Sri Lanka are continental fragments. The other islands—including Christmas, Cocos, Andaman and Nicobar, Chagos, and Comoros, Lakshadweep, Mauritius,  and Réunion—are of volcanic origin. The Andamans and Sundas are island arc–trench subduction systems, with the trench on the oceanic side of the arc.
7. Climate
8. Monsoon Zone and Trade Wind Zone: The Indian Ocean is the only ocean with a monsoon circulation pattern. The seasonal reversal of winds, driven by the differential heating of the landmass and the ocean, plays a  crucial role in the region’s climate.
9. Hydrology
10. Warm Pool and High Surface Temperature: The Indian Ocean hosts the world’s warmest pool of water, which significantly affects atmospheric circulation and climate patterns both locally and globally.
11. Subtropical Gyres: The Indian Ocean has a subtropical gyre in the southern part, which is less prominent compared to the Atlantic and Pacific Oceans due to the presence of the Indian subcontinent.
12. Thermohaline circulation: Below the influence of the surface currents, water movement is sluggish and irregular. Two sources of highly saline water enter the Indian Ocean from the Persian Gulf and the Red Sea and sink below the fresher surface water.
13. Major Currents: The Indian Ocean features prominent currents such as the Agulhas Current, which flows along the southeastern coast of Africa, and the Indian Monsoon Current, which reverses direction seasonally.

THE IMPACT OF UNIQUE GEOGRAPHICAL FEATURES OF INDIAN OCEAN ON

GLOBAL OCEANIC CIRCULATION PATTERN:

1. Regional Weather and Climate: Changes in the state of the Indian Ocean, particularly its sea surface temperature (SST), can trigger droughts, floods, and wildfires in the densely populated countries surrounding it. These regions, with their agrarian societies, are especially vulnerable to these climate fluctuations. For example, La-nina caused droughts in the West Australian Region.
2. Interocean Exchange: The Indian Ocean connects with the Atlantic through the Agulhas Current, which retroflects and leaks warm, salty water into the Atlantic, influencing the global thermohaline circulation.
3. Indian Ocean Dipole (IOD): The IOD is an irregular oscillation of sea surface temperatures in which the western Indian Ocean becomes alternately warmer and then colder than the eastern part. This affects rainfall patterns across the Indian Ocean region and beyond.
4. Global Teleconnections: The Indian Ocean isn’t an isolated system, although landlocked on the northern side. Atmospheric teleconnections  triggered by its conditions, can influence weather patterns in other major ocean basins and even affect higher latitudes in both hemispheres (North Atlantic Oscillation and Atlantic Meridional Overturning Circulation) For example, Pacific (El Niño-Southern Oscillation).
5. Impact of Climate Change: The Indian Ocean is particularly susceptible to the effects of human-induced climate change, exhibiting strong warming trends. This warming further affects how the Indian Ocean influences regional and global climate, potentially creating even more dramatic weather patterns.

UNIQUE FEATURES OF INDIAN OCEAN INFLUENCING THE CLIMATE OF

INDIAN SUB CONTINENT:

1. Indian Ocean Monsoon: Impacts the entire Indian subcontinent including countries which are predominantly agrarian in nature like Bhutan, Bangladesh, India, Nepal, Pakistan and Sri Lanka. For example, 51% of net sown area in India is rainfed.
2. Narrow continental shelf and submerged coasts: Due to its geological history, Indian ocean and surrounding land masses remain an exception. For example, Fewer Islands as compared to other oceans nearby.
3. Only ocean with high asymmetry and semi-annual reversing

surface circulations: As the Inter-tropical convergence belt of low pressure moves north and southward during summer and winter respectively, the surface currents of the Indian ocean change their direction. For example, Determining the weather of the continent for instance formation of low pressures even in winters.

4. No separate source of bottom water: The majority of its bottom water comes from outside of its boundaries and contains two of the most saline water sources Red Sea and the Persian Gulf. For example, Low oxygen levels in the middle layers of the ocean water.
5. Cyclones: The Indian Ocean is a breeding ground for annual tropical cyclones, which can bring extreme weather events to the Indian subcontinent, including heavy rains, strong winds, and storm surges like Cyclone Mocha (2023), Cyclone Fani (2019) etc
6. High Temperature: The warm waters of the Indian Ocean help regulate temperatures in the region. The warm pool in the Indian Ocean contributes to high humidity and temperatures, especially during the pre-monsoon period.

• Therefore, The Indian Ocean is equally crucial to India as it is to the rest of the world. The location of the waters allows for global trade and connects various international economies. 
• It is also a major hub for conducting commerce, and the water beds are rich in natural resources. The Indian Ocean not only impacts the immediate neighbourhood but also influences the world’s water currents and weather events, reminding us that the world at large is one big ecosystem constantly interacting.

Read more- MAINS MODEL QUESTION: 22th FEBRUARY 2025