Transcript High pressure

Standard Grade Geography
Weather and Climate
What is the Standard Grade course?
The Standard Grade course is a two year
course over S3 + S4.
 It is split into different levels (Foundation,
General and Credit).
What do you know about the
 You will sit two final exams.
Standard
Grade
course?
 The exams are split into two sections
Knowledge and Understanding (KU) and
Enquiry Skills (ES)

KU and ES




KU:
Your knowledge of the topics that we
cover.
ES:
Your ability to gather knowledge from a
range of different sources.
What is expected of you?

You must take responsibility for your learning –
homework must be completed on time and you
must revise topics you find difficult.

Use the Geography department online blog to
find resources and revise.

Each topic will have an end of unit test. You will
also sit an S3 exam, an S4 prelim and the final
exam in two years.
If you need help.

You can ask any member of the
Geography department.

Come along to the Geography revision
club on a Monday at lunchtime.

Use the Geography department Blog.
Unit 1: Weather and Climate

This unit should be straight forward for
you as you covered it in S1.
Unit 1: Weather and Climate

Starter:
How many people know what the weather
is going to be the next three days?

How do you know?

Can you predict the weather?

Unit 1: Weather and Climate


Tip:
Start watching the weather reports in the
news, looking at the weather reports in
the paper and checking online.
Unit 1: Weather and Climate

Why is it important to study the weather?
Unit 1: Weather and Climate


Task 1:
What is the difference between weather
and climate? (2 minutes to discuss)
Unit 1: Weather and Climate




Weather:
The state of the atmosphere at any given
time. (Look out the window and view the
weather)
Climate:
The atmosphere of an area recorded
over a given time period (often 30 years)
Weather Elements:

Task 2:
Write down as many different weather
elements that you can remember.

Hint: temperature is one.

Weather Elements:
Precipitation
Temperature
Wind Speed
Wind Direction
Sunshine
Humidity
Cloud Cover
Air Pressure
Visibility
Task: Weather Elements

Look at page 42 of the Geography
SG book.

Take notes on all of the weather
elements you just copied down.
Starter:
Homework task

Find out the weather report for the weekend
and write it in your jotter under the title
“Weather report for the weekend”

Task, compare the weather reports that you
recorded. Are they the same?

If they are different why do you think this is?
Recording the weather

As well as knowing all of the
elements of the weather you must
also know how we record each one.

How do we record the weather?
Recording the weather
Using the handout you have been
given write down:
 The name of each weather
recording instrument.
 What the measure.
 The unit that they measure in.

Instrument:
Sunshine recorder
What does it measure:
Hours of Sunshine
What unit does it measure in:
Hours
Instrument:
Rain Gauge
What does it measure:
Precipitation
What unit does it measure in:
mm
Instrument:
Anemometer
What does it measure:
Wind speed
What unit does it measure in:
MPH
Instrument:
Wind vain
What does it measure:
Wind direction
What unit does it measure in:
Compass points (N,S,E,W)
This also measures humidity
Instrument:
Stevenson Screen
What does it measure:
It houses thermometers
to measure air temperature.
What unit does it measure in:
°C

Visibility is measured by the eye.

Cloud cover is measured in oktas.
Location of a weather station
For each of the following site
write down the positives
and negatives of each.
Exam question:

Which of the following sites would be the
best for a weather station. (5KU)

You must say the positives of 1 but also
mention the negatives of others to make
up full marks.
Fieldwork: Jordanhill weather station.









Things to remember.
The weather station must have:
A Stevenson screen
A Barometer
A Anemometer
A Wind vane
A Sunshine recorder
A Rain Gauge
You must think about all of these when
you are picking the site.
Factors that influence the weather.






Latitude
Altitude
Proximity to sea
Ocean currents
Rainshadow
Aspect


Latitude:
The suns rays are most concentrated at the
equator, and they have less of a distance to cover
here too. This means the closer to the equator you
are the hotter it will be. The further you are the
colder it will be.



Altitude:
The higher up you are the colder it is.
For every 100m you climb it goes down roughly
0. 6°C. This is called the lapse rate.
Very cold due to
massive height



Proximity to the sea
The sea cools down and warms up slower than the
land.
This means it helps keep places close to the sea
cool in the summer and warmer in the winter.
Stays cool
in the summer
and
warm in
the winter.
Land heats
and cools much
more
quickly than
the sea.


Ocean currents.
Ocean currents can cool or warm the land.
The UK is kept warm due to the North
Atlantic Drift (or Gulf Stream) coming from
S.American water.
Thermal
images show
the warm
current





Rainshadow
The Rainshadow is caused due to areas of high
land.
The moist air from the sea is blown over mountains
and therefore many clouds are formed, and there
is lots of rain.
This means that the area after the mountains will
have a dry period.
This is known as the rainshadow.
Copy this
diagram

Aspect – in the northern hemisphere south
facing slopes receive more sunshine than north
facing slopes. North facing slopes are in the
shade and so will be colder than south facing
slopes. Snow tends to last longer on north
facing slopes.
North:
This will be
cooler in the
northern
hemisphere
South
This will be
warmer in the
northern
hemisphere
Air masses
Arctic Maritime

Air masses also affect the weather
greatly.

The UK is affected by 5 main air
masses.
Air masses

This
may seem complicated
Polar
= coldbut it is
actually pretty easy.
Tropical
= hot
Maritime
= wet
Continental
= dry

You just have to know what each word
means, and it is easy to work out.
Air masses

Now just add them together.

Polar continental =
Cold and dry weather

Polar maritime =
Cold and wet weather

Tropical continental =

Tropical maritime =

Arctic =
Hot and dry weather
Hot and wet weather.
Extremely cold weather
Stevenson Screen:

You have been given a handout with a
diagram of a Stevenson Screen on it.

You must explain why it has each of it’s
features.
Inside the Stevenson screen

What is inside a Stevenson screen?

Maximum and minimum thermometer.

Wet and dry bulb thermometer.
(to measure humidity)
Sloped roof
Painted White
Slated sides
1m long legs
Placed on
grass
Stevenson Screen: homework






Features:
Why does it have
each of these
features?
1m long legs.
Placed on grass.
Slanted roof.
Slats in the side of the main box.
Painted white.
1m Long legs.


So that the ground temperature is not
measured.
This makes the reading of the air
temperature more accurate.
Placed on grass


Grass does not heat up as much as other
surfaces such as tarmac.
This means that the readings from the
thermometer are more accurate.
Slanted roof.


This is so rain and snow do not lie on top
of the Stevenson screen.
If they did they could lower the
temperature readings.
Slats on the sides.


This is so air can circulate through the
box without letting precipitation get in.
If it was enclosed the temperature would
increase a lot when hot.
Painted White


White reflects heat more than any other
colour.
This means that the readings are far
more accurate as the Stevenson Screen
does not heat up.
Weather forecasting.

We know that you can get information
from a weather station.

But one weather station is just a single
location.
Weather forecasting.

Sometimes we need to look at weather on
a bigger scale.

How does the MET office get their
information?


Satellite
Satellites around the
planet give detailed
information to
weather offices.

Weather Planes:

These planes are
fitted with devices
that help measure the
weather. They can
get readings from
high in the sky and
also over large
distances.



Radiosonde/
Weather balloon
These ballonons are
sent up in the
atmosphere and
collect data.

Weather ship.

These ships
have weather
stations on
them to collect
data at sea.
Aircraft or land
weather station
Radar
Weather ship
Satellite
The Met Office collects
Information to predict the
Future state of the weather.
THIS IS CALLED FORECASTING
Radiosonde/
balloon
Weather Symbols

Aims of this section:


To learn what different weather symbols
mean.
To be able to identify the weather from
looking at weather charts and maps.
Weather Symbols


Task:
Collect a whiteboard 1 between 2.

A number of different weather situations
will come up on the board.

You must draw what you think the symbol
could look like.
Weather Symbols
Sunny with
Snow
Rain
10mph
Heavy
Cloudy
Sunny
Cloud
winds
Heavy
Sleet
rain
Hail
Fog
showers
TYPICAL MEDIA WEATHER MAP
Look at the symbols.
What weather does
Eastern England have?
What is the weather
like in Northern
Scotland ?
MET office weather symbols.

See weathersymbols.pp

Lesson starter:

See whiteboard.
Pressure systems.

We are going to learn about two different
types of pressure systems:

Low pressure systems: A depression.

High pressure systems: An anti-cyclone.
But first……..

We have to know a few things
Things we need to know.

IsoIsobars
barsshow air pressure
on weather charts.
The level of pressure will
be shown by numbers.
Generally under 1000mb
is low pressure, and over
is high pressure
Isobars also tell us what the
wind will be like. If the isobars are
close together it will be very windy.
If they are far apart it will be calm.
Low pressure usually brings bad weather.
High pressure usually brings
calm nice weather.
Fronts


Fronts are VERY important too.
Important: Fronts of any sort ALWAYS
bring rain!
Fronts

Warm front: Warm air comes behind it.
Generally brings light steady rain.
Cold sector
Warm sector
Direction of front
Fronts

Cold front: Cold air comes behind it. This
front will cause very heavy rain and
thunderstorms on occasion.
Warm sector
Cold sector
Direction of front
Fronts

Occluded front: This will bring the worst
weather. Very wet, windy and usually
storms.
Direction of front
High pressure and low
pressure.

The amount of air pressure is how much the air
in the atmosphere is pushing down on the earth.
High pressure and low
pressure.

If the pressure is high that means that the air is
low and pushing down on the earths surface.
Air is low
=
Lots of pressure = high pressure
High pressure and low
pressure.

If the pressure is high that means that the air is
low and pushing down on the earths surface.
Air is low
=
Lots of pressure = high pressure
High pressure and low
pressure.

If the pressure is low it means
airhigh
is higher and
Air the
is up
therefore not putting as much pressure on the earth.
=
Low pressure
High pressure and low pressure.

QUESTION: If the air is close to the
ground (high pressure) what do you think
we will not get?
 Copy this:

In areas of
high pressure you do not get
Answer:
many clouds in the sky.
 Clouds. The air is close to the
ground and therefore too warm for
clouds to form.
High pressure and low pressure.

QUESTION: If you don’t get clouds in
areas of high pressure what happens in
areas of low pressure?
 Copy this:

In areas of
low pressure the air is high in
Answer:
the atmosphere and it is colder. This
 The air is higher up and therefore
means that it cools, condenses and forms
it cools, condenses and forms
clouds. (The 3 C’s)
clouds.
High pressure – what does it mean?


From what we know already about isobars, air
pressure and fronts what can we tell about this
pressure system. What will the weather be like?
Talk with each other come up with as many ideas as
you can.
High Pressure = an anticyclone
Isobars are far apart.
This means that the winds
will be calm.
Air pressure is getting
higher as it moves into the middle,
also over 1000mb = high pressure
Air pressure is high so
no cloud cover
One last thing you can
tell is wind direction.
In an anticyclone wind
blows clockwise.
(In the northern hemisphere)
High pressure/anticyclone weather
High pressure in
the summer:
• Calm
• Dry
• Sunny
• Warm weather
• Sometimes
thunder
and storms
High pressure in
the winter:
• Calm
• Dry
• Clear conditions
• Cold
• Frosty
• Fog
Low pressure systems = Depression
Again you can tell wind
direction. It travels anti
Isobars close together,
clockwise in a depression
this means strong winds.
Low pressure, this
means very cloudy
Pressure decreases
towards the centre.
This shows a depression
Weather during a depression

The weather during
a depression
depends a lot on the
fronts that come
with it.

Each stage of a
depression brings
very different
weather.
Cold sector
=
cold air
Cold sector
=
cold air
Warm sector
=
warm air
Depressions – how are they
formed?



Depressions form where warm air meets
cold air
The boundary between the two air
masses is called a front
Along a front there will usually be thick
cloud and heavy rain
A Depression
Warm Front
Cold Front
Depressions bring very
changeable weather.
The weather in Wick
would be very different to
Stornoway
Passage of a depression
Living graph of a depression.

Copy the diagram on the white board then place the
numbers on it:




1. Weather getting warmer with only a little drizzle.
2. Weather for T-shirt, shorts and sun glasses.
3. Warm clothes but you can leave the umbrella at
home.
4. Umbrella and wellies needed! Warm clothes too.

Q: Describe
the weather
in Wick over
the next 12
hours.




Lesson starter.
The direction of wind.
You would be right to think the wind was
blowing in an anticlockwise direction
here. But that’s not what you would say in
an exam.
You need to say the direction it is coming
from.
A
C
D
A
B
B
C
D
DECEMBER
IMPORTANT!

The difference between

DESCRIBE

and

EXPLAIN
IMPORTANT!

DESCRIBE: Say what you see, or what is
happening. You don’t have to say why!

EXPLAIN: Say why something is
happening or how you know something is
happening.

Q: Explain
the changes
in weather
in Wick over
the next 12
hours.
Explain the changes in weather.

The weather in wick will start off with
relatively clear sky's as the warm front is
yet to pass over it (1). There will be some
wind but it will not be too strong as the
isobars a spaced apart (1).

As the warm front comes in the warm air
will meet the cold air which will cause the
air to cool, condense and then form
clouds (1).This will produce light steady
rainfall (1).
Explain the changes in weather.



The temperature in wick will rise as the
warm front passes over it bringing
warmer air (1).
At this time wick will experience
relatively clear sky’s as no fronts will be
overhead (1).
As the cold front approaches the weather
will become far worse. The cold air will
force the warm air up quickly causing
very rapid condensation. This will bring
heavy rain, lots of cloud cover and
possible thunderstorms (2)
Explain the changes in weather.

Wick will experience higher winds as the
isobars are far closer together (1).

After the cold front has passed the
temperature will fall as the cold sector
passes over wick (1).

After the cold front there may be some
showers, but as the front is gone there
will not be heavy rain (1).
Weather and people
Weather and people

For Credit level questions you will often
be asked about how the weather can
affect people.
High pressure synoptic chart



The word high is written in the middle of the
high pressure area
The isobars are widely spaced
The value of the isobars get higher towards
the centre of the anticyclone
Anticyclone weather - Summer



Dry and hot days with little or no cloud.
Early morning dew and mist.
Nights are cool due to lack of cloud during
the day.
Anticyclone weather - Winter





Fog that may last all day.
Mostly clear skies.
Frost in the mornings.
Freezing nights.
Dry.