Transcript Mapping, Climate and Weather Weather, mapping and

Mapping, Climate
and Weather
Weather, mapping and our atmosphere
What is the difference between weather and climate?
Weather, mapping and our atmosphere
Weather is the combination of atmospheric
elements, such as temperature, precipitation and
humidity, that occur at a specific time and place.
Weather, mapping and our atmosphere
Climate describes the same atmospheric
conditions that have been averaged over
a long period – often 30 years or more.
Weather, mapping and our atmosphere
Around the planet, a wide range of weather
occurs at any given time.
Our weather is caused by different conditions
in the Earth’s atmosphere.
Weather, mapping and our atmosphere
The Earth’s atmosphere extends to around 1200 km
above the surface. It is the first 50 km of the
atmosphere that most affects our weather.
Weather, mapping and our atmosphere
There are five layers to Earth’s atmosphere.
Weather, mapping and our atmosphere
There are five layers to Earth’s atmosphere.
Troposphere
Closest to Earth’s surface where things live. It contains
about 50% of the air we breathe, and contains all the
clouds we see and the weather we experience.
From sea level up to about 16 km.
Weather, mapping and our atmosphere
There are five layers to Earth’s atmosphere.
Stratosphere
The air is thinner, because there are fewer gas particles
than in the troposphere. Contains a further 40% of our air.
No clouds, contains the ozone layer. From above 16 km
to about 50 km.
Weather, mapping and our atmosphere
There are five layers to Earth’s atmosphere.
Mesosphere
Gas particles become thinner and thinner in this layer.
Shooting stars burn up here.
From above 50 km to about 80 km.
Weather, mapping and our atmosphere
There are five layers to Earth’s atmosphere.
Thermosphere
Fewer gas particles and very little effect on Earth’s air.
From above 80 km to about 600 km.
Weather, mapping and our atmosphere
There are five layers to Earth’s atmosphere.
Exosphere
The very outer layer, with only a sprinkling of gas particles,
many of which escape to outer space.
Above 600 km to just over 1200 km.
Heating places on Earth
Solar radiation from the Sun is the main source of
Earth’s energy. Without solar radiation, there would
be no plant growth and no weather systems.
Heating places on Earth
Different places on Earth receive different amounts
of solar radiation – because of Earth’s tilt.
Heating places on Earth
Fill in the gaps.
more
different Equator
poles less
An area on Earth at low latitudes (closer to the
Equator receives more heat than the same area
_________)
poles
at high latitudes (closer to the _______).
This is because the Sun’s rays hit places on Earth at
different angles.
_________
The more direct the Sun’s rays, the less
____ distance they
travel through the atmosphere to hit the Earth, and the
more heat is transmitted.
_____
Heating places on Earth
Where on Earth do the Sun’s
rays hit most directly?
Least directly?
What happens to solar radiation?
What happens to solar radiation?
Heat is reflected from Earth’s surface,
and some is trapped by greenhouse gases
in the lower layers of the atmosphere.
The main greenhouse gases are:
• water vapour
• carbon dioxide
• methane
• nitrous oxide
• ozone.
What happens to solar radiation?
While these gases occur naturally, their levels have
been increased by human activities.
Which human activities are thought to contribute
most to raising the levels of greenhouse gases
in the atmosphere?
Does this
situation
need to be
remedied?
Why?
What happens to solar radiation?
This is how a greenhouse works for growing plants.
What happens to solar radiation?
This is a simplified diagram of the
Greenhouse Effect on Earth.
What happens to solar radiation?
How do these diagrams explain the link between
the Greenhouse Effect and Global Warming?
What happens to solar radiation?
Global Warming refers to climate change –
what does this mean?
What happens to solar radiation?
What are the likely impacts of Global Warming
on the natural environment, and on human
activities like agriculture?
Climate graphs and maps
Temperature and rainfall are the
two most common measurements
of weather conditions.
Records are kept of these and other
measurements, and they provide
climatic data.
Weather records and climatic data
are kept on all continents, in many
different places.
Climate graphs and maps
This is climatic data for Cairns,
in northern Queensland.
Source: Bureau of Meteorology
Climate graphs and maps
Mean is the average of a set of measurements.
How is the mean daily temperature calculated?
Answer – Calculate the half-way point between the
mean maximum and minimum temperatures.
How is mean monthly
rainfall calculated?
Answer – Take an
average of the total
rainfall received each
month of the year, over
an extended period of
time (e.g. 30 years).
Climate graphs and maps
Does Cairns have a smaller or larger range
of temperatures over a year than cities in the
southern states of Australia?
Answer – Smaller
Climate graphs and maps
Cairns has a tropical climate. Does this mean its
temperatures are generally warm or cool?
Answer – Warm
Climate graphs and maps
Is its rainfall evenly spread or seasonal?
Answer – Seasonal
Rainfall maps
Rainfall maps use isohyet lines and colours
to show the ranges of average precipitation
in different areas.
An isohyet is a line
on a map that
connects places with
equal precipitation.
Source: Bureau of Meteorology
Rainfall maps
Name as many forms of precipitation as you can.
Answer – Rain,
hail, snow,
sleet, mist
Source: Bureau of Meteorology
Rainfall maps
Why aren’t things such as dew, frost and fog
classified as forms of precipitation?
Source: Bureau of Meteorology
Rainfall maps
What are the average rainfall ranges used on this map?
Source: Bureau of Meteorology
Rainfall maps
Which parts of Australia receive the most rain?
Source: Bureau of Meteorology
Rainfall maps
Which parts of Australia receive the least rain?
Source: Bureau of Meteorology
Rainfall maps
Describe the pattern of annual rainfall in Australia.
Source: Bureau of Meteorology
Temperature maps
Temperature maps use isotherm lines and colours
to show the ranges of average temperature in
different areas.
Source: Bureau of Meteorology
Temperature maps
An isotherm is a line on a map that connects
places of equal temperature.
It can be indicated by a change in colour.
Source: Bureau of Meteorology
Temperature maps
Why is it informative to have two temperature maps
for Australia – one showing January temperatures
and one showing July temperatures?
Source: Bureau of Meteorology
Temperature maps
Which parts of Australia are hottest in January?
Source: Bureau of Meteorology
Temperature maps
Suggest reasons for this spread of temperatures.
Source: Bureau of Meteorology
Temperature maps
Which parts of Australia have the highest
temperatures in July?
Source: Bureau of Meteorology
Temperature maps
Describe the pattern of temperatures in July,
from northern Australia to southern Australia.
Source: Bureau of Meteorology
Weather forecasting
Maps of expected weather conditions appear daily
on TV, in newspapers and on the Internet.
This is one type of weather forecasting map:
It summarises
expected weather
conditions –
temperature and
rainfall.
Weather forecasting
There are two figures shown for each city and town
on the map – what do these mean?
Answer – They
show the minimum
and maximum
temperatures for
each city or town.
Weather forecasting
Which areas have the highest probability of rain?
Answer – The areas
shaded the darkest
green
Weather forecasting
What does a lack of shading mean, regarding the
probability of rain?
Answer – That there is
little or no possibility
of rain (less than 10%)
Weather forecasting
Which three cities or towns are expected to have
the lowest minimum temperatures?
Answer – Canberra,
Hobart, Adelaide
Weather forecasting
Which four cities or towns are expected to have the
highest minimum temperatures?
Answer – Broome,
Darwin, Mt Isa,
Rockhampton
Synoptic weather maps
A synoptic chart shows the main elements of the
weather system at a particular time, such as highs,
lows and cold fronts.
Readings of
atmospheric
measurements
are taken at
ground level.
Synoptic weather maps
High is a short way of describing a high pressure
cell, where the air pressure increases towards
the centre.
Low is a short way of describing a low
pressure cell, where the air pressure
decreases towards the centre.
Cold front is the boundary where a mass
of cold air is replacing warm air, causing
a sharp change in temperature.
Isobars are lines on a synoptic weather
map that join places of equal air pressure.
Synoptic weather maps
Can you see different high and low pressure systems
on this synoptic chart?
Where are they?
What other
information is
shown by the
symbols on this
synoptic chart?
Climate change
Many scientists believe that
global warming is Earth’s
greatest environmental threat.
The global trend shows increasing
temperatures, which could be
caused by the Greenhouse Effect.
Climate change
What does this graph show?
Answer – The relationship
between temperatures and
concentrations of carbon
dioxide in the atmosphere
over an extended period
Source: World Data Center for Paleoclimatology
Climate change
Fill in the gaps.
400 000 carbon dioxide
temperature
temperature
This graph shows that variations in ____________
have occurred consistently over the past
400 000 years.
__________
There is a distinct relationship between temperature
carbon dioxide gas in the
and levels of _______________
atmosphere.
Climate change
Fill in the gaps.
fossil human
atmosphere
Over the past couple of centuries, carbon dioxide
atmosphere have been greater
levels in the ____________
than ever before.
human activity
This is because in that time __________
fossil fuels) has
(particularly the use of ________
resulted in many more emissions.
Climate change
Fill in the gaps.
increased globally
carbon dioxide
Source: World Data Center for Paleoclimatology
globally averaged
This graph shows that the __________
surface temperature has steadily ___________
increased since
carbon dioxide levels
1900. In that time, _______________
have also increased.
Climate change discussion
In what ways are these
three groups responsible
for climate change?
• individuals
• governments
• business and industry
In what ways could the three groups above contribute
to resolving the issues of climate change?
Do people in third-world countries have the
same responsibilities for climate change as
those in first-world countries? Why?