Consider the following statements:
- 1.Jet streams occur in the Northern Hemisphere only.
- 2.Only some cyclones develop an eye.
- 3.The temperature inside the eye of a cyclone is nearly 10°C lesser than that of the surroundings.
Which of the statements given above is/are correct?
Answer & explanation
Answer: (c) 2 only
Only statement 2 is correct. Jet streams blow in both hemispheres, and the eye of a tropical cyclone is warmer, not colder, than its surroundings; but an eye forms only once a cyclone has organised and intensified.
- ✗ 1. Jet streams exist in both hemispheres. The polar jet lies between about 50° and 60° latitude in the northern and the southern hemispheres alike.
- ✓ 2. An eye develops only when the inner spiral bands close into an eyewall, which usually happens around the time winds reach hurricane force. Weak tropical systems and temperate (extra-tropical) cyclones generally have no eye.
- ✗ 3. The eye is the region of lowest surface pressure and, aloft, the warmest air; a tropical cyclone has a warm core, so the eye is warmer than its surroundings, not cooler.
Remember · Jet streams occur in both hemispheres. A cyclone's eye forms only in mature tropical cyclones, and it is a calm, warm-cored centre.
Sources
- US National Weather Service / NOAA JetStream: The Jet Stream ↗ “The polar jet is located between the 50°-60° latitude lines in both the northern and southern hemispheres.”
- NOAA Hurricane Research Division FAQ: life cycle of a hurricane ↗ “the inner bands will close off into an eyewall, surrounding a central calm area known as the eye. This usually happens around the time wind speeds reach hurricane force. … The eye is the region of the lowest pressure at the surface and the warmest temperatures at the top.”
Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·