This document discusses the key components of weather and climate. It describes the atmosphere as being made up of four layers - the troposphere, stratosphere, mesosphere, and thermosphere. The ozone layer, located in the stratosphere, protects the Earth from harmful ultraviolet radiation. Temperature varies based on factors like latitude, altitude, and distance from bodies of water. Humidity and precipitation are also influenced by temperature, with water vapor condensing into clouds and precipitating as rain, snow, or hail. Atmospheric pressure changes with temperature and altitude, and wind is caused by differences in air pressure.

1. UNIT 5
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Weather and Climates

2. 1º ESO
Social Sciences

3. Introduction

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 The weather and climate are affected by
atmospheric phenomena (temperature, humidity,
precipitation, atmospheric pressure and wind).
 Weather and climate are different:
 The weather describes the atmospheric conditions
in a particular time.
 Climate refers to atmospheric conditions that exist
in a region over a long period of time.

5. 1.
Atmosphere

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 The atmosphere is a
gaseous layer more than
1000 Km thick that
surrounds the Earth and
that serves to:
 Prevent the Sun’s rays from
directly reaching the Earth’s
surface.
 Protect the Earth against
falling meteorites.

7. Ozone layer
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 The atmosphere’s
function as a filter of
solar radiation is due to
the ozone layer:
 It is located at an
altitude of between 30
and 50 km.
 It prevents ultraviolet
radiation, which is very
harmful to living things,
from reaching the
Earth’s surface.

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 The atmosphere is made up of four layers:
 Troposphere: the closest layer to the Earth,
where meteorological phenomena happen.
 Stratosphere: this layer is made up of various
other layers, such as the ozone layer, and is very
stable.
 Mesosphere: in this layer, the air is very dense.
 Thermosphere: in this layer, temperatures are
very high.

9. Atomosphere
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10. 2.
Temperature

11. Atmospheric Temperature
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 Atmospheric
temperature represents
the degree to which
solar radiation warms
the air.
 The Sun’s rays are
transformed into heat
when they reach the
surface of the planet.

12. Thermometers and Isotherms
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 Temperature is
measured in
degrees centigrade
by
thermometers,
and it is
represented on
maps by imaginary
lines known as
isotherms.

13. Factors
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 Factors that cause a variation in temperature include:
 The latitude or distance from the equator.
 The altitude in relation to sea level.
 Distance from the sea.

14. Latitude
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 As the Sun’s rays fall
perpendicularly
on the equator,
the further from the
equator, the lower
the temperature
becomes.

15. Altitude
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 The higher the
altitude, the less
dense the air is
and the less
ability it has to
retain heat.
 Thus, the higher
we go, the colder
the temperature.

16. Distance from the sea
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 The sea regulates the
temperature because it
takes a long time to
warm up or to cool
down.

17. Distance from the sea
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18. 3.
Air Humidity and Precipitation

19. Humidity
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 Humidity is the amount
of water vapour in the
air from the Earth’s
waters and living things.
 Humidity is measured
using a hygrometer
and the result is
expressed as a
percentage.

20. Relative Humidity
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 The amount of water
vapour that the air can
absorb depends on its
temperature (warm air
absorbs more vapour than
cold air).

21. Precipitation
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 Water vapour causes
precipitation, which is
measured in L/m2 using a
rain gauge.

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 As air rises, water vapour
grows cold and
condenses into small
droplets that form
clouds.
 If the air continues to
rise, the water droplets
begin to stick to each
other, thus growing in
size, until they fall to
Earth in the form of rain.

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 If the air temperature
is very low, the
droplets are
transformed into
snowflakes.
 Hail forms when ice
crystals in the clouds
grow in size and fall to
Earth.

24. 4.
Atmospheric Pressure
and Wind

25. Atmospheric Pressure
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 Atmospheric
pressure is the
weight or force of
the air on the
Earth’s surface.
 It is measured in
hectopascals
using a
barometer.

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 Atmospheric pressure depends on:
a) Altitude: the higher the altitude, the lower the pressure.
b) Air temperature: when warm, air weighs less and rises,
producing low pressure areas and depressions. When cold,
air weighs more and falls, causing high pressure areas and
anticyclones.

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c) The wind: is a mass of moving air that is produced
between two areas of different atmospheric
pressure.
 There are different types of wind, depending on the
difference in atmospheric pressure that produces them.
 Some winds are constant, such as prevailing winds, and some
winds are seasonal.

28. Meteorological Station
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29. Instruments and units of measurement used to measure the
following atmospheric phenomena
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