SAJC Cluster 2 Lecture 1 Notes (Climate Zones in The Tropics)

St Andrew’s Junior College H2 Cluster 2: Tropical Environments H2_Cluster 2 Lecture 1_2024/pg1 Lecture 1 Tropical Climates (I): Climatic Zones in the Tropics KEY QUESTION: What are the similarities and differences in the temperature and rainfall patterns in the tropics? With the completion of this lecture, attached readings and tutorial, you should be able to understand that: • Locations in the tropics are classified into climatic zones according to their temperature and rainfall characteristics. • High temperatures are the key distinguishing characteristics of the tropics. • There are variations in the amount of rainfall between the humid and arid tropics. • There are seasonal variations in rainfall patterns in parts of the tropics. Lecture Outline 1.1 Introduction: Where is “the Tropics”? 1.2 The Tropics and the Köppen-Geiger Climate Classification System 1.3 Humid Tropical Climates (A Climates) 1.3.1 Tropical Rainforest Climate (Af) 1.3.2 Tropical Monsoon Climate (Am) 1.3.3 Tropical Savanna Climate (Aw) 1.4 Arid Tropical Climates (B Climates) 1.4.1 Tropical Desert Climate (BWh) 1.4.2 Subtropical Steppe Climate (BSh) 1.5 Summary Box 1: The Shifting Location of the Overhead Sun Relative to the Earth’s Surface Box 2: Reading climographs The Tropics: A climatic region of radiation surplus delimited by boundaries fluctuating between 30° and 35° latitude, north and south of the equator.

St Andrew’s Junior College H2 Cluster 2: Tropical Environments H2_Cluster 2 Lecture 1_2024/pg2 1.1 Introduction: Where is “the Tropics”? • The Tropics may be described as… A climatic region of solar radiation surplus delimited by boundaries fluctuating between 30 ˚ and 35˚ north and south latitudes. Common to all areas in this region (at sea level) is high temperature. Significant variations in the amount and pattern of rainfall differentiate these areas into different tropical climate zones, primarily the humid tropics and the arid tropics. 1.2 The Tropics and the Köppen-Geiger Climate Classification System • A climatic zone is an area designated by broadly similar weather statistics, especially temperature and precipitation. For our purpose, the Köppen-Geiger climate classification system will serve as our reference. • The Köppen-Geiger system is by far the most widely used climatic classification system. It uses a numerical basis of classification (either average temperatures or average amounts of precipitation), and zone boundaries are determined by vegetation patterns. • As Fig. 1 shows, the world’s climate can be broadly classified into are five major climatic zones (A through E) plus a sixth zone (H) called highland climates. Tropical Climates • Tropical clim