Unit 4: The Atmosphere and Earth's Climates

The Earth's Climates

Climatologists divide the Earth into different climate zones. This division is based on similar temperatures and precipitation across large areas. We can identify five major climate zones. These lie between the different latitudes on Earth's surfaces.

• There are two cold climate zones located within the polar circles. In these zones, the angle of the Sun's rays is very oblique and annual temperatures are below 0ºC.
• There is a single hot climate zone known as the intertropical zone. It is situated between the two tropics, the temperatures are very high, with an annual average above 18 ℃. This is because the Sun's rays fall at a perpendicular angle most of the year.
• There are two temperate climate zones which are located between the tropics and the polar circles. In these zones, the angle of the Sun's rays is larger than in the hot zone. Annual temperatures are lower, between 0 ℃ and 18 ℃.Seasons in different hemispheres

Arctic Circle Tropic of Cancer Equator Tropic of Capricorn hot zone Antarctic Circle temperate zones cold zones

The Earth's Climate Types

By analysing temperatures, we can classify the climate in every region on the planet. However, there can be different climates in regions within the same thermal zone. There are eight main climate types:

Cold Climates

Polar climate: Very low temperatures, below 0 ℃, and very little precipitation.

• Alpine climate: Very cold winters and cool summers, precipitation (snow) is abundant.

Hot Climates

Equatorial climate: Very hot temperatures, abundant precipitation and regular throughout the year.

• Tropical climate: High temperatures, abundant precipitation and irregular throughout the year. There is a rainy and a dry season.
• Desert climate: Very high temperatures and low precipitation throughout the whole year.

Temperate Climates

• Mediterranean climate: Has a hot, dry season in the summer, low precipitation and mainly occurs in autumn and spring.
• Oceanic climate: Mild temperatures all year round, abundant and regular precipitation. This climate has some very cold winter months, summers are very hot and it rains a lot.

Mediterranean Climate (Alicante/Alacant)

average yearly temperature: 17,8 ℃ average yearly precipitation: 336 l/m2 50 + + 100 45 90 40 80 35 + + 70 30 60 25 50 20 40 15 30 10 20 5 10 0 0 J £ F M A M J J A S ON D J F M A M J J A S 0 N D annual figures T ºC 11.5 12.4 13.7 15.5 18.4 22.2 24.9 25.5 23.1 19.1 15.2 12.5 17.8 P 1/m2 22 27 26 30 33 17 6 8 47 52 42 26 336

The Climograph

We can represent a climate's temperatures and precipitation on a climograph. This graph lets us observe the annual evolution of temperatures and precipitation in a certain place. + precipitation (1/m2) temperature (C)

Beijing (China) Climograph Analysis

average yearly temperature: 11.8 ℃ average yearly precipitation: 578 1/m2 100 200 90 180 80 160 70 140 temperature (C) 60 120 50 100 40 80 30 60 20 40 10 20 0 0 -10 -20 J F M A M J J A S O N D Now you try!

• TEMPERATURE: We observe the average annual temperature. It's important to look at the variations between seasons. To do this, we calculate the temperature variation (difference between hottest and coldest months). The annual average is 11.8 ℃. This indicates a temperate climate. There are variations between summer and winter. The temperature variation is 30.2 ℃. precipitation (1/m2)
• PRECIPITATION: We look at the total volume of precipitation. We analyse whether it is regular during the year, or if there is a dry season. The total annual precipitation is almost 600 l / m2. It is concentrated in one season. IDENTIFY THE TYPE OF CLIMATE: We can identify the type of climate shown on the graph analysing the data represented. This climograph corresponds to a temperate continental climate.

Climates in Europe

Oceanic Climate in Europe

OCEANIC CLIMATE: Found to the west of the European Atlantic coasts. It has very moderate temperatures, with cool summers and mild winters. Precipitation is abundant, it falls regularly the whole year. average yearly temperature: 12.7 ℃ average yearly precipitation: 931 1/m2 55 110 50 100 45 90 40 80 35 70 temperature (ºC) 30 60 25 50 20 40 15 30 10 20 5 10 0 0 J F MA M J J A ASOND precipitation (I/m2)

Mediterranean Climate in Europe

average yearly precipitation: 397 l/m2 MEDITERRANEAN CLIMATE: This climate is found in the south of the continent, near the Mediterranean Sea. It has moderate temperatures in winter and hot summers. Precipitation is low and distributed irregularly throughout the year. average yearly temperature: 18.1 ºC 50 100 45 90 40 80 35 70 @ 30 60 .25 50 120 40 15 30 10 20 5 10 0 0 J F M A M J J A S O N D

Continental Climate in Europe

CONTINENTAL CLIMATE: This climate is found in central and eastern areas of the continent, far from the thermoregulatory action of the sea. Its characteristic is strong temperature contrasts: it has very hot summers and very cold winters. Precipitation is not abundant, it mainly falls in summer. average yearly precipitation: 486 1/m2 50 100 45 90 40 80 temperature (C) 35 70 30 60 25 50 20 40 precipitation (1/m2) 15 30 10 20 5 10 0 0 -5 -10 J F M A M J - A S O N D temperature (C) precipitation (l/m2) average yearly temperature: 9 ºC

Polar Climate in Europe

average yearly temperature: - 5.8 ℃ average yearly precipitation: 213 1/m2 30 60 25 50 20 40 15 30 temperature (ºC) 10 20 5 10 0 0 -5 J F M A A S N D -10 -10 -20 -15 -30 -20 -40 POLAR CLIMATE: This climate is found in the north of Europe, has very low temperatures. Precipitation is very low and falls as snow.

Alpine Climate in Europe

average yearly temperature: 3.8 ℃ average yearly precipitation: 1,072 1/m2 100 200 90 180 80 160 70 140 60 120 50 100 40 80 30 60 20 40 10 20 0 0 -10 -20 J F M A M JJ ASO N D precipitation (I /m2) temperature (℃) precipitation (1/m2) ALPINE CLIMATE: This climate is found in the highest mountains. Annual temperatures can fall below 0 ℃, with cold winters and cool summers. Precipitation is abundant, distributed throughout all months of the year and almost always falls as snow.

European Climate Map

ARCTIC OCEAN Scale: 1:29,500,000 0 400 800 1,200 km ATLANTIC OCEAN Climates oceanic climate Mediterranean climate continental climate polar climate Alpine climate Mediterranean Sea

Exercises

The Earth's climates exercises 13, 14, 15, 17, 19, 20, 21 and 22 The climograph exercise 23 Climates in Europe and Spain exercise 25