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PLAN
INTRODUCTION 2
1. CLOUDS AND TROPOPAUSE 3
1.1 CLASSIFICATION OF CLOUDS 3
1.2 THE HIGHT OF TROPOPAUSE 4
1.3 CLOUDS IN RELATION TO THE TROPOPAUSE 6
2. CUMULONIMBUS CLOUDS IN DIFFERENT SINOPYICAL SITUATIONS 8
2.1 CLOUDS OF VERTICAL DEVELOPMENT 8
2.2 THE NECESSARY INGREDIENTS FOR THUNDERSTORMS 10
2.3 LIFE CYCLE OF CB CLOUD 12
2.3.1 SINGLE CELL STORM. 13
2.3.1.1 DEVELOPING STAGE: 13
2.3.1.2 MATURE STAGE: 14
2.3.1.3 DISSIPATING STAGE: 14
2.4 THUNDERSTORM TYPES 14
2.4.1 MULTI CELLS STORM 14
2.4.2 SUPER CELL STORM 15
2.4.3 SQUALL LINES 16
2.4.4 WALL CLOUDS 17
2.4.5 TORNADOES AND FUNNEL CLOUD 17
3.CAUTIONS AND NOTIFICATIONS FOR AIRMAN 18
3.1 THE DANGERS OF FLYING IN OR CLOSE TO A THUNDERSTORM 18
3.2 THUNDERSTORM AVOIDANCE 24
3.3 INFORMATION FOR A PILOT 24
3.4 IN-FLIGHT ADVISORIES (WARNINGS) 25

INFERENCE 28
LITERATURE 29



INTRODUCTION

The atmosphere/flight environment is forever in a state of constant physical change, giving rise to weather conditions, which vary throughout the range of an extremely large scale. The airman not only lives at the base of this sea of air, but also navigates and flies through it. The weather, therefore, is a matter of vital concern to him, particularly conditions such as fog, ice formation, thunderstorms line squalls, all of which presents particularly unusual hazards to flying.
To a pilot knowledgeable in the science of meteorology, clouds are an indication of what is happening in the atmosphere. The location and type of cloud are evidence of such weather phenomena such as fronts, turbulence, thunderstorms, and tell the pilot what type of conditions may be expected during flight.




1. CLOUDS AND TROPOPAUSE

Clouds are continuously in a process of change and appear, therefore in an infinite variety of forms. It is possible, however, to define a limited number of characteristic forms, frequently observed all over the world, into which clouds can be broadly grouped. A classification of the characteristic forms of clouds, in terms of "genera," "species" and "verities" has been established.

1.1 CLASSIFICATION OF CLOUDS

GENERA SPECIES VARIETY
Cirrus fibratus, uncinus, spissatus, castellanus, floccus intortus, radiatus, vertebrates, duplicatus
Cirrocumulus stratiformis, lenticularis, castellanus, floccus Undulates, lacunosus
Cirrostratus Fibratus, nebulosus Duplicatus, undulatus
Altocumulus Stratiformis, lenticularis, castellanus, floccus translucidus, perlucidus, opacus, duplicatus, undulatus, radiatus, lacunosus
Altostratus translucidus, opacus, duplicatus, undulates, radiatus
Nimbostratus
Stratocumulus Stratiformis, lenticularis, castellanus Translucidus, perlucidus, opacus, duplicatus, undulates, radiatus, lacunosus
Stratus Nebulosus, fractus Opacus, translucidus, undulatus
Cumulus Humulis, mediocris, congestus, fractus radiatus
Cumulonimbus Calvus, capillatus
ETAGE CLOUD GENERA HIGHT
Tropical Region Temperate Region Polar Region
High CirrusCirrostratusCirrocumulus 20,000-60,000 ft 16,000-45,000ft 10,000-26,000ft
Middle AltostratusAltocumulus 6,500-26,000 ft 6,500-23,000 ft 6,500-13,000ft
Low StratusStratocumulusNimbostratusCumulusCumulonimbus 0-6,500 ft 0-6,500 ft

By convention, the part of the atmosphere in which clouds are usually present has been vertically divided into three "étages": high, middle and low. The base of the following cloud genera is normally found in the étage indicated:

Surface and aircraft observations have shown that clouds are generally encountered over a range of altitudes varying from sea level to the level of the tropopause, i.e. to 18 kilometers (60,000 feet) in the tropics, 13 kilometers (45,000 feet) in middle latitudes and 8 kilometers (26,000 feet) in polar regions.



1.2 THE HIGHT OF TROPOPAUSE

The height of the tropopause depends on the location, notably the latitude. It also depends on the season. Thus, it is about 16 km high over Australia at year-end, and between 12 - 16 km at midyear, being lower at the higher latitudes. At latitudes above 60, the tropopause is less than 9 -10 km above sea level; the lowest is less than 8 km high, above Antarctica and above Siberia and northern Canada in winter. The highest average tropopause is over the oceanic warm pool of the western equatorial Pacific; about 17.5 km high, and over Southeast Asia, during the summer monsoon, the tropopause occasionally peaks above 18 km. In other words, cold conditions lead to a lower tropopause, obviously because of less convection. Deep convection (thunderstorms) in the Intertropical Convergence Zone, or over mid-latitude continents in summer, continuously push the tropopause upwards and as such deepen the troposphere. This is because thunderstorms mix the tropospheric air at a moist adiabatic lapse rate.

In the upper troposphere, this lapse rate is essentially the same as the dry adiabatic rate of 10K/km. So a deepening by 1 km reduces the tropopause temperature by 10K. Therefore, in areas where (or at times when) the tropopause is exceptionally high, the tropopause temperature is also very low, sometimes below -80° C. Such low temperatures are not found anywhere else in the Earth's atmosphere, at any level, except in the winter stratosphere over Antarctica.
On the other hand, colder regions have a lower tropopause, obviously because convective overturning is limited there, due to the negative radiation balance at the