Download presentation
Presentation is loading. Please wait.
1
Uncontrolled copy not subject to amendment
Basic Navigation Using Map and Compass
2
Basic Navigation Using Map and Compass
Learning Outcome 5: Be able to recognise weather conditions that affect land navigation
3
Hot and Cold Air Masses BECAUSE OF THE RELATIONSHIP OF THE EARTH’S
UK SUMMER AUSTRALIA WINTER. AUSTRALIA SUMMER UK WINTER. BECAUSE OF THE RELATIONSHIP OF THE EARTH’S ORBIT AROUND THE SUN TO THE TIME OF YEAR, THE ANGLE THAT THE SUN’S RAYS HIT THE EARTH VARY WITH TIME.
4
MOISTURE IN THE AIR ALL AIR CONTAINS MOISTURE. IT IS ONLY THE AMOUNT THAT VARIES. HOW THE AIR ARRIVES AT OUR SHORES AFFECTS THE MOISTURE IN THE AIR. IF IT HAS TRAVELLED OVER LAND IT IS MOST LIKELY TO BE DRY. LITTLE MOISTURE. IF IT HAS TRAVELLED OVER THE SEA IT IS MOST LIKELY TO BE WET. LOTS OF MOISTURE.
5
MOISTURE IN THE AIR THE AMOUNT OF MOISTURE SUSPENDED IN THE AIR IS DEPENDENT ON THE AIR TEMPERATURE. THE WARMER THE AIR THE MORE MOISTURE IT WILL HOLD. THE MOISTURE CANNOT BE SEEN UNTIL THE AIR BECOMES SATURATED AND THE MOISTURE COMES OUT OF SUSPENSION AND FORMS CLOUDS. THE SATURATION POINT IS KNOWN AS THE ‘DEW POINT’. THE TYPE OF CLOUD FORMED IS DEPENDENT ON THE RATE OF TEMPERATURE CHANGE AND THE STRENGTH OF THE WIND.
6
Width of the arrows indicates the frequency of occurrence
Main Air Masses Width of the arrows indicates the frequency of occurrence
7
Main Air Masses ARCTIC MARITIME – VERY COLD AND WET/SNOW
POLAR MARITIME – COLD AND WET/SNOW RETURNING POLAR MARITIME – COOL AND WET TROPICAL MARITIME – WARM AND WET (GULF STREAM) TROPICAL CONTINENTAL - HOT AND DRY POLAR CONTINENTAL – COLD AND DRY IN WINTER WARM AND DRY IN SUMMER
8
ICAO STANDARD ATMOSPHERE
BASED ON SEA LEVEL ACCEPTED AROUND THE WORLD PRESSURE Mb TEMPERATURE 15º C LAPSE RATE OF -1.98ºC/1000Ft
9
Weather Map WIND CIRCULATES ANTI-CLOCKWISE AROUND A ‘LOW’.
AND CLOCKWISE AROUND A ‘HIGH’.
10
Fronts and Frontal Depressions
Numbers refer to pressure in millibars
11
Weather Map – Westerly Winds
12
Depression Chart
13
Depression
14
Fronts and Frontal Depressions
Section through a frontal system Cold front is steeper than the warm front
15
High and Low Pressure
16
High and Low Pressure
17
Upper Winds Weather map showing isobars for both upper
and lower winds. Lower winds affect the weather we get. Upper winds affect the speed the weather system moves.
18
SURFCE PRESSURE CHART – NORTH ATLANTIC & EUROPE
20
Names For Clouds The names for clouds are usually combinations of the
following prefixes or suffixes: Stratus/strato = flat/layered and smooth Cumulus/cumulo = heaped up/puffy, like cauliflower Cirrus/cirro = High up/wispy Alto = Medium level Nimbus/Nimbo = Rain-bearing cloud
21
CLOUD LEVELS HIGH CLOUDS BASE USUALLY 20,000ft OR ABOVE OVER UK.
TYPES – CIRRUS CIRROCUMULUS CIROSTRATUS MEDIUM CLOUDS BASE USUALLY BETWEEN 6,500ft AND 20,000ft OVER UK. TYPES – ALTO CUMULUS ALTO STRATUS NIMBOSTRATUS LOW CLOUDS BASE USUALLY BELOW 6,500ft OVER UK. TYPES – STRATO CUMULUS STRATUS CUMULUS CUMULONIMBUS
25
Approaching Rain
26
Warm Front
27
Cold Front
28
Occluded Front
29
Depression Cross Section Cloud Type
30
Depression Cross Section Air movement
31
TYPES OF CLOUD
32
TYPES OF CLOUD
33
TYPES OF CLOUD
34
TYPES OF CLOUD
35
TYPES OF CLOUD
36
CUMULONIMBUS CLOUD TYPICAL ANVIL HEAD TO THE CLOUD
AS THE RISING AIR COMES TO A STOP AND THE UPPER WINDS PULL THE TOP CLOUD OFF THE COLUMN.
37
Local Warming
38
Pockets of Air
39
Thermals above
40
Air rising over mountains
41
Rising Air Dewpoint
42
Cloudy foothills
43
Funnels and Eddies
44
Banner Clouds
45
Temperature Inversion
47
stratus cumulonimbus cumulus stratocumulus
55
Matches pressure chart
56
TYPES OF CLOUD
57
TYPES OF CLOUD
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.