VIDEO LESSON

LESSSON OBJECTIVES

At the end of this lesson, you will be able to:

• Describe the major world climate regions;
• Explain the features of each climatic region; and
• Compare and contrast the elements of weather in different regions

BRAINSTORMING QUESTIONS

What do you think about the major classification schemes used for the identification of the world climate region?

What do you think is the importance of the classification of our world into the different climatic regions?

Dear Online Learner! The world’s climatic zones have been divided into three broad climate groups based on the Köppen classification and seasonal dominance of air masses.

Low-latitude climate, mid-latitude climate, and high-latitude climate are the three types.

Keywords:

• Climatic regions
• Highlands
• High-latitude
• Low-latitude
• Mid-latitude
• Inter-Tropical Convergence Zone (ITCZ)

2.4.1. Low-latitude Climatic Regions

I. Tropical wet region

• Found along the equator between 6⁰N and 6⁰S.
• Dominate the region indicated by maritime tropical air masses the Köppen classification “Af.”
• The inter-tropical convergence zone and the equatorial westerlies have an impact on the region all year. It
• Has high daily temperatures ranging from 2⁰ to 30⁰C,
• Monthly temperatures ranging from 24 to 28⁰C,
•  Consistent precipitation throughout the year (over 80 inches of total rainfall).
• Dominate by rainforests, which are dense, tall, broad-leafed, and evergreen trees.
• Cumulus or cumulonimbus cloud forms and thunderstorms.
• The Amazon basin, Congo basin of equatorial Africa, East Indies, and the area from Sumatra to New Guinea fall under this region.

II. Tropical wet and dry region

• Found between 6⁰ and 15⁰ N and S latitude.
• Lies halfway between the wet tropics and the subtropical deserts.
• Maritime tropical air masses, high sun season, continental tropical air masses, and low sun season describe it.
• Influenced by the migration of the inter-tropical convergence zone.
• Dominated by savanna biomass in terms of vegetation cover.
• Found in India, Indochina, West Africa, southern Africa, South America, and Australia’s north coast.

Figure 2.5: World climate region
Source:https: sites.google.com

III. Dry desert (BWh) and steppe (BSh) region

• Lies between 15⁰ and 25⁰ North and South latitude.
• Continental tropical air masses dominate.
• The largest region of tropical desert climate is located near the tropics of Cancer and Capricorn, usually on the western side of the continents.
• Low relative humidity and amount of precipitation, high mean annual temperature, high monthly and daily temperatures, and strong wind velocity.
•  Characterized by the desert biome and steppe plains.
• Encompasses the southwestern United States, Northern Mexico, Argentina, North Africa, South Africa, and the central section of Australia

2.4.2. Mid-latitude Climatic Region

• Principally influenced by the continual fight between tropical air masses moving towards the poles and polar air masses moving towards the equator.

I. Mid-latitude desert (BWK) and Steppe (BSk)

• Located between 30⁰ and 55⁰ N and S latitude.
• Summer is dominated by continental tropical air masses, whereas winter is dominated by continental polar air masses.
• Low relative humidity and cloud cover, low frequency and volume of precipitation, and moderate to high average monthly temperature.
• The main source of precipitation is moisture from maritime sources.
• The east of the Caspian Sea, the north of the Himalayas, the western United States, and the east of the Andes are the key areas influenced by mid-latitude deserts.
• When compared to subtropical deserts, summer temperatures in mid-latitude deserts are not as high. There are exceptions, such as Death Valley, California, which is one of the world’s hottest locations.
• The winter months are usually fairly cold.
• Mid-latitude temperatures have a wider range of daily annual temperatures than their subtropical counterparts.
• Covers significant parts of western North America and central Asia.

II. Mid-latitude wet region

• In the winter, the polar climate is dominated by frontal weather linked with a mid-latitude cyclone. Abundant precipitation is evenly spread throughout the year, and total annual precipitation is very variable.
• During the summer, the equatorial borders experience convectional rainfall.
• Monthly average temperatures in the region range from 21 to 26⁰C.
• The deciduous forest biome is the most common in terms of vegetation.
• The climatic areas of northern America run from Canada’s Pacific coast at latitudes above 55⁰ eastward to the Atlantic coast.
• Extends to the southeastern tip of South America, New Zealand, and Australia’s southeast coast.

III. Mid-latitude winter dry (Cw and Dw)

• The temperature and precipitation patterns in this region have distinct seasonal patterns.
• Maritime tropical air masses with conditional tropical air masses from nearby deserts arrive in the summer.
• Summers are hot and humid, with plenty of traditional summer storms, showers, and thunderstorms.
• In the winter, continental polar air masses associated with dry and cold weather conditions predominate, with maritime polar air emerging on occasion.
• During the season, a little amount of precipitation was produced by the mid-latitude cyclone’s activities.
• The major vegetation type is grassland.
• Geographically limited to the interiors of North America and Eurasia

IV. Mid-latitude summer dry (Cs)

• Between 30⁰ and 50⁰ latitude.
•  Commonly referred to as a Mediterranean climate, with precipitation falling primarily in the winter due to a mid-latitude cyclone.
• The chaparral biome, Sclerophyll plants dominates the region.
• Central and Southern California, coastal zones bordering the Mediterranean Sea, coastal Western Australia and South Australia, the Chilean coast, and the Cape Town region of South Africa all have Mediterranean climates

2.4.3. High-latitude Climate

I. Polar Tundra (ET)

• Cold winters, cool summers, and a summer rainfall
• Arctic coasts of North America, Iceland, coastal Greenland, Europe, Asia’s Arctic coasts, and the Southern Hemisphere islands of Macquarie, Kerguelen, and South Georgia.
• During the summer, most places receive less than 10 inches of yearly precipitation.

II. Polar Ice Cap (EF)

• Encompasses a large portion of the globe, particularly the high latitudes and continental territories like Greenland and Antarctica.
• Receives no sun energy for half of the year.
• Because of the long days and relatively transparent atmosphere, available insolation is rather high throughout the summer months.
• The albedo of a snow-covered surface, on the other hand, reflects up to 90% of the insolation back to space.
• Monthly average temperatures are typically below 0 degrees Celsius.
• High-velocity, persistent winds occur in the region most of the time, resulting in blizzard conditions.

2.4.4. Highlands Climate

• Lower temperatures, but heavier precipitation owing to orographic lifting typical.
• Mostly found in mountains and high plateaus.