Which of the following statements regarding the World Climate Types and their relation with Inter Tropical Convergence Zone (ITCZ) is/are correct? 1. Tropical Wet Climate is one of the world's rainiest due to the dominance of the ITCZ over it. 2. Tropical Savanna Climate experiences a distinctive alternation of wet and dry seasons, caused chiefly by the seasonal shift in latitude of the subtropical highs and ITCZ. 3. The Tropical Monsoonal Climate experiences heavy rainfall as a consequence of the nearness of the ITCZ for much of the year. Select the answer using the code given below:
- (a)1 only
- (b)1 and 2 only
- (c)2 and 3 only
- (d)1, 2 and 3
Correct — D, all three statements. The tropical wet (equatorial) climate lies where the Inter-Tropical Convergence Zone hovers for most of the year, producing convergence, rising air and near-daily convectional rain — among the wettest climates on Earth, so statement 1 is right. In the tropical savanna belt the ITCZ and the subtropical high-pressure cells swing north and south with the overhead sun, so the region has a rainy high-sun season when the ITCZ is overhead and a dry low-sun season when the dry subtropical high dominates — the alternation described in statement 2. The tropical monsoon climate also draws its heavy rain from the ITCZ staying close for much of the year, reinforcing the moist onshore monsoon flow, confirming statement 3. All three are correct.
- (a)1 only — Statements 2 and 3 are also correct — the savanna's wet-dry seasonality follows the migrating ITCZ and subtropical highs, and the monsoon's heavy rain comes from the nearby ITCZ; dropping them understates the answer.
- (b)1 and 2 only — Omits the true statement 3 — the tropical monsoon climate does receive heavy rainfall because the ITCZ lies near it for much of the year.
- (c)2 and 3 only — Drops the true statement 1 — the tropical wet climate is indeed one of the rainiest precisely because the ITCZ dominates it for most of the year.
The Inter-Tropical Convergence Zone is the low-pressure belt near the equator where the north-east and south-east trade winds meet, forcing air to rise and produce heavy rain. It migrates north and south through the year following the overhead sun, and its position governs the rainfall rhythm of the three great tropical climate types — wet (equatorial), savanna (wet-and-dry) and monsoon.
All three statements simply describe how the ITCZ controls tropical rainfall, so each is true. The exam is testing whether a student knows the ITCZ is not fixed at the equator but shifts seasonally, which is what creates the savanna's dry season and the monsoon's rainy season.
- The ITCZ is the equatorial low-pressure belt where the trade winds converge and air rises, giving heavy rainfall.
- It migrates north and south of the equator with the seasonal shift of the overhead sun.
- The tropical wet (equatorial) climate stays under the ITCZ most of the year, making it one of the rainiest.
- The tropical savanna's alternating wet and dry seasons follow the seasonal swing of the ITCZ and the subtropical highs.
All three describe the ITCZ correctly, so every statement is true — answer 1, 2 and 3.
- Assuming the ITCZ is fixed at the equator — it migrates north and south with the sun, which is what creates the savanna's dry season.
- Confusing the tropical monsoon (Am) with the tropical savanna (Aw) — both have a dry season, but the monsoon type is far wetter overall.
A statement-code question tying three tropical climate types to the ITCZ — recognise that all three descriptions are standard textbook truths.
Which one of the following is the characteristic climate of the Tropical Savannah Region?
- (a) Rainfall throughout the year
- (b) Rainfall in winter only
- (c) An extremely short dry season
- (d) A definite dry and wet season
Answer(d) A definite dry and wet season — the savanna (Aw) climate alternates a rainy high-sun season with a pronounced dry low-sun season.
Directly tests statement 2 of this NDA question — the tropical savanna's defining wet-and-dry seasonality driven by the migrating ITCZ.
The vegetation of savannah consists of grassland with scattered small trees, but extensive areas have no trees. The forest development in such areas is generally kept in check by one or more or a combination of some conditions. Which of the following are such conditions? 1. Burrowing animals and termites 2. Fire 3. Grazing herbivores 4. Seasonal rainfall 5. Soil properties Select the correct answer using the code given below.
- (a) 1 and 2
- (b) 4 and 5
- (c) 2, 3 and 4
- (d) 1, 3 and 5
Answer(c) 2, 3 and 4 — fire, grazing herbivores and the strongly seasonal rainfall keep the savanna open and grass-dominated.
Extends the savanna theme — the seasonal (ITCZ-driven) rainfall of statement 2 is one of the factors that keeps the savanna a grassland rather than a forest.
- practice — not a real PYQ
The alternation of a distinct wet season and dry season in the tropical savanna climate is caused chiefly by the
- (a)ocean currents offshore
- (b)seasonal migration of the ITCZ and subtropical high-pressure belts
- (c)El Nino events
- (d)polar jet stream
Answer(b) seasonal migration of the ITCZ and subtropical high-pressure belts — the rainy season comes when the ITCZ is overhead, the dry season when the subtropical high dominates.
- practice — not a real PYQ
The Inter-Tropical Convergence Zone (ITCZ) is also popularly known as the
- (a)horse latitudes
- (b)doldrums
- (c)roaring forties
- (d)polar front
Answer(b) doldrums — the equatorial low-pressure belt of light, calm winds where the trades converge.