Unit 3: Weather Dynamics

Chapter 1: Inquiring About Weather

Science 10

Mrs. Purba

UNIT 3 Chapter 1: Inquiring about Weather

Chapter 1: Inquiring about Weather

Is it important to study weather?

Why or why not?

UNIT 3 Chapter 1: Inquiring about Weather

Severe weather comes to Nova Scotia in the form of snow, fog,

freezing rain, hail, heavy rain, or strong winds. These weather events

can trigger flooding and storm surges that affect the whole province.

Meteorology

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

• Is the study of the Earth’s

atmosphere and weather

systems

How do meteorologists

use balloons?

Weather

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

• The physical conditions of the atmosphere at a specific time and

place.

• Changes constantly (hour to hour, day to day, and season to

season

• Varies from place to place

• Is closely monitored.

How are daily weather

forecasts beneficial?

1.1 The Atmosphere: Energy Transfer and Properties

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

Each of these weather

components can affect

activities or situations.

Climate

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

• The average weather conditions in a particular location or region

at a particular time of the year.

• Climate is usually measured over a period of 30 years or more.

• For example, the climate in Musquidoboit is cold and snowy in the

winter, while Hawaii’s climate is hot and humid.

• The climate in one area, like the Eastern Shore or Hawaii, is called

a regional climate.

• The average climate around the world is called global climate.

The Biosphere

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

• When energy from the Sun reaches Earth, the energy interacts

with just a thin layer of air, land, and water on or near Earth’s

surface.

• This layer is called the biosphere because all life on Earth exists

within it.it.

Three Parts of the Biosphere

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

1. The atmosphere (air) is a

mixture of nitrogen,

oxygen, and other

gases that extends more

than 700 km above

Earth’s surface. The first

12 km of the

atmosphere, called the

troposphere, is the

region in which all

weather takes place.

Three Parts of the Biosphere

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

2. The lithosphere (land) is made up of land-forming continental

crust above sea level and oceanic crust at the ocean bottom

Three Parts of the Biosphere

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

3. The hydrosphere (water) is

water on or near Earth’s

surface. It includes liquid

water and solid water in

oceans, rivers, lakes, and

streams, as well as gaseous

water vapour in the

atmosphere.

The Biosphere

• If all the Sun’s energy were

absorbed by the biosphere

without losing any of it, the

temperature on Earth would

continue to rise. Life would not

exist.

• However, conditions in the

biosphere are well-suited for

life.

• How can Earth’s average

temperature stay constant?

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

UNIT 3 Chapter 1: Inquiring about Weather Section 1.1

All weather takes place in the atmosphere. Nearly all of it in the lower atmosphere. Weather refers to the conditions of the atmosphere at a given time and place. Climate is the average of weather over a long time.

Imagine your grandmother who lives in a distant place calls you up. She asks what your weather is like today. What would you say? Is it warm or cold? Sunny or cloudy? Calm or windy? Clear or rainy? What features of weather are important to mention?

A location’s weather depends on:

air temperature.

air pressure.

fog.

humidity.

cloud cover.

precipitation.

wind speed and direction.

All of these characteristics are directly related to the amount of energy that is in the system, and where that energy is. The ultimate source of this energy is the Sun.

Weather is what we experience from day to day, or minute to minute. Weather can change rapidly.

What Causes Weather?

Weather occurs because of unequal heating of the atmosphere. The source of

heat is the sun. The general principles behind weather can be stated simply:

The sun heats Earth’s surface more in some places than in others.

Where it is warm, heat from the sun warms the air close to the surface. If there

is water at the surface, it may cause some of the water to evaporate.

Warm air is less dense, so it rises. When this happens, more dense air flows in

to take its place. The flowing surface air is wind.

The rising air cools as it goes higher in the atmosphere. If it is moist, the water

vapor may condense. Clouds may form, and precipitation may fall.

Summary

A region's weather depends on its air temperature, air pressure,

humidity, precipitation, wind speed and direction, and other

factors.

Climate is the long-term average of weather.

Weather can change in minutes, but climate changes very slowly.

Practice

Use the resource below to answer the questions that follow.

Climate and Weather at http://video.nationalgeographic.com/video/science/earth-sci/climate-weather-sci/

What is climate?

How many climate zones are there? List examples.

What did climate determine in the past?

Why doesn't climate have as much influence today?

What is weather?

What problems can severe weather cause?

Why is an accurate weather forecast important?

What tools do meteorologists use?