Equatorial & Hot Desert Climates

Equatorial and Hot Desert Climates

Lesson Objectives

• Describe the main characteristics of equatorial and hot desert climates.

• Explain the factors that influence equatorial and desert climates.

Equatorial Climate Characteristics

Equatorial regions are found on or near the equator

Open Ended

Using the map, name a country in the Equatorial region.

Main Characteristics: Equatorial

Generally above 26 degrees Celsius throughout the year.

Hot Conditions

Often over 2000 mm.

High levels of Rainfall

The temperatures are high throughout the year.

A lack of seasons

Known as diurnal range -- higher than the seasonal differences in temperature.

Daytime / Nighttime Temperatures

May fall on as many as 250 days each year.

Convectional Rainfall

May be limited in the morning, by the afternoon, towering cumulonimbus clouds mark the start of the convectional rains.

Variable Cloud Cover

The diurnal range is less than in hot desert areas.

Reduced Heat Loss due to Cloud Cover

Moisture in the atmosphere -- relative humidities of 100 % are often reached in the late afternoon.

High Humidity

Reduced wind speeds within the rainforest due to the large numbers of trees present.

Reduced Wind Speeds

Multiple Choice

What are the warmest months in Manaus, Brazil?

• October and November

• September and October

• January and February

• May and September

Multiple Choice

What are the coolest months in Manaus, Brazil?

• June and November

• September and December

• April and February

• May and September

Multiple Choice

Which months is Manaus wet season?

• November to May

• September to December

• April and November

• June to December

Multiple Choice

Which months is Manaus dry season?

• June to October

• September to December

• February and November

• June to December

Main Characteristics: Hot Desert

The diurnal range is less than in hot desert areas.

Hot days and Cold nights

Moisture in the atmosphere -- relative humidities of 100 % are often reached in the late afternoon.

Low/Irregular Rainfall

Reduced wind speeds within the rainforest due to the large numbers of trees present.

Reduced Wind Speeds

caused by the lack of cloud cover

Hot days, Cold nights

lacking any seasonal pattern

Low and Irregular rainfalls

throughout the year

Low Humidity

which sometimes caus sandstorms

Warm, dry winds

Multiple Choice

What are the warmest months in Cairo, Egypt?

• October to November

• June and August

• January to March

• June to October

Multiple Choice

What is the coolest month in Cairo, Egypt?

• May

• January

• June

• December

Open Ended

Suggest reasons why Cairo receives more annual sunshine hours (9.5) than Manaus (5.7)

• Factors:

  • The angle of the overhead sun

  • The thickness of the atmosphere

Latitude

Water properties:

• Water absorbs and loses heat slowly, compared with land.

Proximity to Sea

Warm currents from the equatorial regions raise the temperature of polar areas.

Ocean Currents

Air temperature decreases with increasing altitude, around 10 degrees per kilometer.

Altitude

Prevailing or dominant winds from land lower the winter temperatures (opposite in summer). While prevailing winds from the sea lower the summer temperatures and raise them in winter.

Winds

Decreases the amount of insolation reaching the surface by reflecting some of it.

Cloud Cover

In low-pressure systems, the air is rising -- producing rain -- found in equatorial areas.

In high-pressure areas, are is sinking, and rain formation is prevented.

Pressure