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Chapter 1
Physical Meteorology
Introduction

We all have some skills when it comes to the
weather

What will be lacking is both scope and depth

This chapter looks at what you probably know about
the weather
Class Exercise 1.1

Conduct a class discussion about the sources of
weather information and the types of information that
we receive

Complete the important terms list found on Page 12
of these notes
Meteorology vs Climatology

What is meteorology?
 Meteorology

is the study of the weather
What is climatology?
 Climatology
is the study of weather averages
The concept of scales

There are three common scales used in
meteorology;
 Global
(macro)
 Synoptic
 Local

(meso)
(micro)
There are many more scales used in meteorology
The scales of the weather
Meteorology & Society

The history
 First written discussion by Greeks
 Bloomed during Industrial Revolution
 Great advances were made during the
wars of the 20th
Century due to wars
 After WW2, computers changed the volume of data
processed
 This led to the Numerical Weather Prediction methods
used today
Meteorology in the news

We have all watched TV and seen the following;
 Storms
and hail damage
 Flood
 Cyclones,
tornadoes and hurricanes
 Drought
 Snow
and blizzards
Class Exercise 1.2
Weather phenomena
Country/Landmass or Region
Monsoon
East asia/Asutralasia
Doldrums
Equatorial regions
Roaring forties
South Western Australia
Southerly buster
South Eastern Australia
Cyclones
Tornadoes
Trade winds
Typhoons
Hurricanes
Northern Australia
Mainly Northern USA
30° Latitude
North Eastern Pacific
Southern USA, Mexico area
The social importance of weather

It really isn’t difficult to see why meteorology is
socially important.
 If
you are a surfer for example, then you will know what
weather brings good surf, and bad.
 The
same applies if you are a farmer, or even an office
worker, but for different reasons.
The social importance of weather

Government based meteorological, hydrological and
related information and services make important
contributions for achieving an increased social
awareness of the importance of meteorology
The social importance of weather

Weather and climate information and forecasts contribute to
the development of well managed and less vulnerable






agriculture,
combating droughts (and subsequent drought proofing),
desertification,
better air quality,
reduced health problems and
better quality of everyday life,
Exercise 1.3
Occupation
Farmer
Surfer
Salesperson
Sewer worker
Environmental technician
Meteorologist
Politician
Pilot
Ecologist
Reason for observation
Why do you need to know about meteorology?

This is the age of environmental legislation and
regulation (i.e. laws).

To monitor air pollution properly,
 we
need to now about where that pollution came from,
 and
where that pollution is going (amongst many other
things),

RESULT? We need to know about meteorology!
Meteorology and Climatology in Australia

So who runs meteorology and climatology in
Australia?
 The
Bureau of Meteorology (BoM, or ‘the Bureau’).
 Although
legislated in 1906, the Bureau started operation
in 1908, and has grown in conjunction with other national
meteorological institutions overseas into a world leader in
meteorological services.
Meteorology and Climatology in Australia

The BoM is a member of the World Meteorological
Organisation (WMO).

The WMO started operations in 1950, with the BoM
being a foundation member.
 The
WMO has allowed for otherwise impossible work to be
done.
 The
WMO cornerstone is the Global Weather Experiment
in 1979, which is the largest single scientific experiment
ever undertaken.
Meteorology and Climatology in Australia

The BoM, and the WMO are only two of a plethora of
international organisations that work with weather
and weather related information (such as
geographers and oceanographers) to provide the
world with meteorological information and data.
The Australian Climate

It is impossible to ‘average’ Australia’s climate

There are many different climate ‘zones’, and each
has its own average climate.

Over the years there have been numerous attempts
to define different climate zones, globally, and in
Australia.
The Australian Climate

The BoM currently (2005) use the Koppen (Koeppen)
system of classification, of which there are six
climate zones;
 Equatorial
 Tropical
 Subtropical
 Desert
 Grassland
 Temperate
The Australian Climate

The north of Australia lies close to the equator,

It also lies in the equatorial monsoonal region
(monsoon is rain that accompanies biannual wind
changes in the South-East Asia region)

So this area exhibits hot dry winters with hot wet
summers.
The Australian Climate

Australia's southern coastline is what makes the
southern Australian climate.

The other southern hemisphere continents do not
have long coastlines parallel to Antarctica.

The southern African coastline is more rounded, and
is further north.

While the tip of South America comes to within
1000km of the Palmer Peninsula on Antarctica, the
long spine of the Andes means that there is no
contrasting hot interior.
The Australian Climate

To the south of the Australian coast, the Southern
Ocean extends 3000km to the Antarctic continent.

From there, outbreaks of very cold polar air move
northwards, warming somewhat as they pass over
the ocean which results in the ‘cold fronts’ you see
on the TV weather segments.
The Australian Climate

Inland from the southern coast, a large proportion of
the country is arid or semi-arid, with low rainfall and
very hot summers.

This is due to a process called mid latitude
desertification, and air that travels from the hot
interior to the coast meets the cold air from
Antarctica, giving southern Australia highly variable
weather.
Exercise 1.4

Go to
http://www.bom.gov.au/climate/environ/other/kpn_gro
up.shtml
and print the map. On the map, indicate the reasons
why you think the climate zones exist where they do.
Physical Meteorology

Physically, we feel the weather.
 We
use all of our senses to gauge what the day will bring,
and what we should do about it.
 Our
senses are (and were) the first meteorological
instruments that we had, as we could see and hear a
storm coming, and we could taste and smell the rain or
dust, and we could feel wet or dry, or simply
uncomfortable.
 Emotionally
the weather makes us happy or sad, anything
else is up to you
Physical Meteorology

Of all the senses, it is sight that has given us the science.

We have found ways of taking visual information and using
that information to provide us with clues as to what the
weather will be like tomorrow, i.e. the weather forecast – the
holy grail of meteorology!

And the information we collect, we put onto a visual device
called a weather map.

If we look at maps over time, we start to see trends in the
weather, which gives us confidence to say what definitely will,
and definitely will not happen tomorrow
The Weather Map

The weather map would probably be the most looked
upon, and the most misunderstood map in the world.
A weather map has a enormous amount of
information on it, with most of this information being
symbolic in nature, which of course, needs to be
explained (in full, later in these notes).
Class Exercise 1.5

Look at the weather map below, and hold a class
discussion describing as many of the features on the
map as possible.

This is designed to test what you already know - you
are yet to be taught how to read a weather map
properly.
Class Exercise 1.5
Exercise 1.5

You may have been able to describe the following;
 Isobars
 Pressure
values
 High
(H) and low (L) pressure systems
 Wind
direction and speed
 Rainfall
 At
least that the country is Australia!
The Weather Map

Hopefully, by the end of this course, you will have the
skills to not only read a weather map, but you will be
able to predict from the information on the map what
is going to happen over the next few days.
Physical components of the atmosphere

Dusts, particulates and pollution
 Is
dust a nuisance or essential to weather?
 Without
solid material, (termed particulate), precipitation
would not form as the water (or ice) needs something to
‘stick’ onto (termed a nucleus).
 Dust
can be natural or pollution from human activites
Physical components of the atmosphere

Two very important terms arise from a discussion of
dusts and the like
 Aerosol
refers only to those liquid and solid particles that
are suspended in the air such as acid, dust, and smoke
particles
 Pollutant
refers to any substance (solid, liquid, or gas) that
contaminates the atmosphere and can potentially cause
adverse effects to our health and environment
Physical components of the atmosphere

Clouds

Clouds are classified according to their height in the
sky
 low
(from the earth's surface to 2.5 km)
 middle
 high

(2.5 to 6 km)
(above 6 km), and
According to their shape, colour and the weather
they bring.
Physical components of the atmosphere

In Australia (and generally worldwide), there are ten major
cloud types

Cirrus

Cirrocumulus

Cirrostratus

Altocumulus

Altostratus

Nimbostratus

Stratocumulus

Stratus

Cumulus

Cumulonimbus
Exercise 1.6

Go to http://www.bom.gov.au/info/clouds

For each of the clouds mentioned above, state
whether they are low medium or high

Provide a description of the weather they bring (if
any)
Physical components of the atmosphere

Fog
 What
exactly is fog?
 Simply
put, fog is a special type of stratus cloud, of which
there are two main types;


Radiation fog

Advection fog
Other types of fog include;

Steam fog

Maritime fog

Hill fog
Physical components of the atmosphere
fog – occurs when moist air above the ground
cools faster than air higher above
 Radiation
 Steam
fog – occurs when cold air moves over warm water
fog – is special as it can occur when air moisture
is very low due to slat particles in the air
 Maritime
fog – occurs when warm humid air travels over a
colder land
 Advection
 Hill
fog – occurs is actually a low lying cloud on a hill
Physical components of the atmosphere

Haze
 Remember
the concept of aerosols we mentioned earlier?
 Well
some aerosols, such as salt and certain dust particles,
have an attraction to water (termed hydrophilic).
 For
this reason, the relative humidity does not have to
reach 100% before water vapour condenses onto them.
 At
a relative humidity of about 70%, these aerosols start to
attract water vapour and dissolve, forming a tiny solution
droplet much smaller than a cloud droplet.
Physical components of the atmosphere

High concentrations of these solution particles in the
air form what we call haze.

Haze does not qualify as either a cloud or fog, but
greatly reduces visibility in the air both near the
ground and aloft.

Decreasing visual air quality as a result of haze is an
indicator of the increasing concentrations of
pollutants in our air
Physical components of the atmosphere

Precipitation
 Rather
than insult you, we shall just remind you that the
term precipitation covers rain, hail, snow, and sleet
 Lastly,
it is this (and temperature and wind) that we look
out for most in the weather segment on the news.
Physical components of the atmosphere

Wind
 Wind
is mentioned here due to its obvious importance and
effects.
 Firstly,
it is one mechanism by which all of the other
physical components of the atmosphere are transported
(such as clouds, fog and dusts),
 To
plant the seed for you that wind measurements are
crucial for environmental technicians due to its direct
influence on noise and air pollution analysis