Relevance for UPSC: GS-I (Physical Geography – Oceans) | GS-III (Climate Change)
Source: Recent climate science studies; global carbon cycle research

Context and Importance

Recent studies point to a Southern Ocean carbon anomaly, where climate models may be underestimating future carbon dioxide release from the ocean under global warming. 

This is significant because the Southern Ocean is a major regulator of Earth’s climate system.

Encircling Antarctica, it absorbs nearly 40% of excess ocean heat and about 25–30% of human-induced carbon dioxide, acting as the world’s largest oceanic carbon sink.

What Is the Anomaly and Why Models Miss It

Climate change is intensifying westerly winds over the Southern Ocean. Stronger winds enhance upwelling, which brings deep, cold, carbon-rich waters to the surface. 

Once near the surface, this stored carbon can escape back into the atmosphere, reducing the ocean’s ability to absorb carbon dioxide.

Key Concepts

• Upwelling: Vertical movement of deep, carbon-rich water towards the surface.
• Ocean stratification: Layering of water by temperature and salinity; melting ice can trap carbon below, but strong winds can break this barrier.
• Carbon sink vs carbon source: A sink absorbs more carbon than it releases; the Southern Ocean risks shifting partly towards a carbon source.

Why This Matters

• Faster accumulation of atmospheric carbon dioxide
• Reduced carbon budget for meeting 1.5°C and 2°C targets
• Creation of a positive climate feedback loop: warming → carbon release → more warming
• Highlights limits of relying on natural sinks to offset emissions

UPSC Prelims Value Box Southern Ocean: Largest oceanic carbon sink Key process: Wind-driven upwelling of carbon-rich deep waters Concern: Climate models may underestimate future carbon release

Superkilonova: A Rare ‘Double-Explosion’ Cosmic Event

Relevance for UPSC: GS-III (Science & Technology – Space)
Source: Recent astrophysics research; international observational studies

What is a Superkilonova?

A superkilonova is a rare astronomical event that combines a supernova (explosion of a massive star) with a kilonova (merger of two neutron stars). It is called a “double-whammy” explosion because energy is released in two stages.

How It Occurs 

• A massive star explodes as a supernova, forming two neutron stars.
• These neutron stars spiral inward due to gravitational wave emission.
• Their merger triggers a kilonova, ejecting heavy elements.
• Some ejected matter falls back, making the event brighter and longer-lasting than a normal kilonova.

Why It Matters

• Explains the origin of heavy elements like gold and platinum .
• Important for multi-messenger astronomy (light + gravitational waves).
• Challenges existing models of stellar evolution.

UPSC Prelims Value Box Supernova: Explosion of a massive star Kilonova: Neutron-star merger Superkilonova: Combination of both; brighter and longer Linked to gravitational waves

Q. With reference to a Superkilonova, consider the following statements:

1. It involves both a supernova explosion and a neutron star merger.
   
2. It is associated with the production of heavy elements like gold and platinum.
   
3. It is detected only through gravitational waves and does not emit light.
   

Which of the statements given above are correct?

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3