The correct option is 1 and 3 only.
Explanation
The Tropical Wet and Dry Climate, designated as Aw in the Köppen classification, is also known as the Savanna or Sudan type climate. It represents a transitional zone between the wet Equatorial rainforests and the dry Hot Deserts, characterized by distinct wet and dry seasons.
Statement-wise Analysis:
- Statement 1 is Correct: The Amazon basin experiences an Equatorial climate (Af). The Tropical Wet and Dry climate borders this region to the north and south. In South America, these regions include the Llanos of the Orinoco basin (north of the Amazon) and the Campos of the Brazilian Highlands (south of the Amazon).
- Statement 2 is Incorrect: A defining characteristic of the Savanna climate is a distinct and prolonged dry season. Unlike the Equatorial climate where moisture is available year-round, the Savanna climate has a dry season that can last for several months. As the distance from the equator increases, the duration of the rainy season decreases while the dry season becomes longer. It is incorrect to state that the wet season is significantly longer; in many Savanna regions, the dry season is the dominant feature that prevents the growth of dense forests.
- Statement 3 is Correct: The diurnal range of temperature (the difference between the maximum and minimum temperature in a day) is greatest during the dry season. During this period, the skies are clear and humidity is low. This allows for intense solar heating during the day and rapid loss of heat through terrestrial radiation at night. In contrast, the wet season brings cloud cover and humidity, which moderates the temperature range.
Key Takeaway:
The Tropical Wet and Dry (Savanna) climate is characterized by alternating wet summers and distinct dry winters, with the diurnal temperature range being highest during the clear-skied dry season.