As per the 'Dynamic Concept' of origin of India monsoon, at summer solistice the NITCZ is extended up to:

Question

Accepted Answer

As per the 'Dynamic Concept' of origin of India monsoon, at summer solstice the NITCZ is extended up to:

**Option 1: 30° N Latitudes - Correct**

**Explanation:**

The 'Dynamic Concept' of the Indian monsoon emphasizes the role of shifting pressure belts and the Intertropical Convergence Zone (ITCZ). During the summer solstice (around June 21st), the sun is directly overhead the Tropic of Cancer (approximately 23.5° N). This intense heating causes a low-pressure zone to develop over the Indian subcontinent and the surrounding landmasses. Consequently, the ITCZ, which is a zone of low pressure and converging winds, shifts northward following the apparent movement of the sun.

The northward shift of the ITCZ is crucial for the onset of the Indian monsoon. The ITCZ's extension up to approximately 30° N latitude during the summer solstice is a key factor in drawing in moisture-laden winds from the Indian Ocean, which then bring rainfall to the Indian subcontinent. The intense heating over the landmass creates a strong pressure gradient, further strengthening the monsoon circulation. Therefore, the extension of the NITCZ (Northern Intertropical Convergence Zone) up to 30° N latitudes is a direct consequence of the summer solstice and the associated thermal low pressure development, making Option 1 the correct answer.

**Why the other options are incorrect:**

*   **Option 2: 45° N Latitudes:** The ITCZ does not extend as far north as 45° N latitude during the summer solstice. While it shifts northward, its typical maximum extent is around 30° N. Extending to 45° N would imply a much more extreme northward shift than what is observed in reality.

*   **Option 3: 15° N Latitudes:** 15° N latitude is too far south. While the ITCZ is present around this latitude during other times of the year, it shifts significantly northward during the summer solstice due to the intense heating over the Indian subcontinent. Therefore, 15° N is not the correct extent during the summer solstice.

*   **Option 4: 30° S Latitudes:** 30° S latitude is in the Southern Hemisphere. During the summer solstice in the Northern Hemisphere, the Southern Hemisphere is experiencing winter. The ITCZ shifts *towards* the hemisphere experiencing summer, not away from it. Therefore, the ITCZ would not be located at 30° S latitude during the Northern Hemisphere's summer solstice.