Educational information

1. CONDENSATION
Presented by
Dr. Dhaigude G.S

2. FORMS OF
CONDENSATION

3. CONDITIONS OF CONDENSATION
A) Presence of sufficient water vapour
B) Presence of condensation nuclei:
microscopic or sub microscopic particles ( size 0.1 to 1.0 micron )
like salt particles, Some combustion products released from
industries like sulfuric acid, nitric acid, dust etc. are present
atmosphere and hygroscopic in nature with water affinity and
water vapour can only deposit and condense them.
C) Cooling of air : Cooling upto dew point is necessary.

4.  DEW
 FROST
 FOG
 MIST
 SMOG
 RIME
 CLOUD
 RAIN
 SNOW
 SLEET
 HAIL
 DRIZZLE
 SHOWER
FROMS OF
CONDESATION

5. DEW
The deposition of water vapour in the form of tiny droplets
on the colder bodies by condensation.

6. FROST
When the temperature of air falls below 0 C before the dew point . Water vapour
directly converted into ice crystals and deposit on surface. When the temp. of air
falls below 0oc before the dew point reached

7. FOG
Temp. of air decreases to such extent that water droplets
remain suspended in air and not deposited on surface

8. MIST
Less dense fog. Disappear with rising sun

9. SMOG
Smoke+Fog+Dust

10. RIME
It is formed when wet fog having super cooled droplets
immediately freeze on striking objects like telegraph post having
temp. below freezing point. While ice is formed on winward side

11. CLOUD
The temperature of the air cooled sufficiently to cause
condensation of the surplus moisture into cloud.

12. LIQUID FORM -
i) RAIN
ii) DRIZZLE
iii) SHOWER
 SOILD FORM –
i) SNOW
ii) HAIL
 MIXED FORM –
i) SLEET
ii) HAILSTORM
FROMS OF
PRECIPITATION

13. Precipitation
Earthward falling of water droplets or ice particles that have
formed by rapid condensation in the atmosphere and are
too large to remain suspended in the atmosphere.

14. MECHANISM OR PROCESSES OF RAIN FORMATION OR
PRECIPITATION PROCESS
Raindrop have diameter extending from 0.5
to 4.0 mm. To form one raindrop, about one
million cloud particles must unite together .

15. Bergeron mechanism
Sweedish meteorologist Bergeron, 1933.
1. When air ascends, clouds are formed. The cloud is
having very low temperature , called cold cloud.
2. In these clouds ice particles as well as water drops
are formed due to very low temp. (-15 to -25 ).
3. These ice particles are grow readily by deposition
of water vapour ( Sublimation) developing into
hexagonal shaped ice crystals.
4. These ice crystals n collision form snow pellets and
melt into water droplets, when falling on ground
through a warm atmosphere.

16. Collision and Coalescence mechanism
• The cloud is having slightly higher temperature, hence
called hot cloud.
• In these clouds water droplets exists instead of ice
particles.
• These droplets colliode, combines and grow into the
larger size and fall on earth as rain drop.

17. RAINfall
It is predominant form of precipitation in which water
droplets of size grater than 0.5 mm fall on earth surface

18. Types of rainfall
• 1. Conventional rains :
 Due to heating of air near the ground beomes hot and light
and starts move in upward direction. These known as
convection.
 As it moves upward, it cools at the dry adiabatic lapse rate
( DALR 9.8 0 c/ km ) and becomes saturated and relative
humidity increases to 100 % and dew point is reached where
the condensation begins
 Above condensation air cools at SALR ( 4 0c/km)
 First cloud is formed and then results into precipation and
known as conventional rains , mostly observed in tropics.

19. Orographic or relief rains
• When moist air coming form sea or ocean
encounters mountains or relief barrier, it can
not move horizontally and move in upward
direction.
• When this air rises upwards ,cools down, cloud
is formed and condensation starts giving
precipitation.
• Thus high rain possible at windward side.

20. Cyclonic and frontal rains
• A) Frontal – When two opposing air currents with
different temperature meets, vertical lifting takes
place.
• When moist and cold air mixture with cold mass,
temperature of the warms air falls down saturation
takes place and may give precipitation.
• This mechanism is responsible for cyclones
formation between 55 o to 60 o latitude in both the
hemispheres.
• The rains received from the cyclones are called as
cyclonic rains.

21. DRIZZLE
IT IS MORE OR LESS UNIFORM PRECIPITATION OF
VERY SMALL RAIN DROPS SIZE 0.5 MM

22. Shower
• Precipitation lasting for a short time with
relatively clear intervals is called Shower.

23. Sleet-
precipitation+ snow

24. Snow
Precipitation of water in the solid form of small or large ice
crystal

25. HAIL-
Hail is precipitation of solid ice . In warm sunny day

26. HAILSTORM
Rainfall + Hailstones

27. CLOUD AND ITS CLASSIFICATION
• CLOUD –
Cloud is defined as a mass of tiny
droplets or ice crystals or both condensed on
hygroscopic nuclei and suspending in
atmosphere.

28. TYPES OF CLOUD
CIRRUS
 CUMULUS
 STRATUS
 NIMBUS

29. CIRRUS (Ci)- (High Cloud)
• Curl – Veil like fibrous or feathery form.
highest cloud – 20,000 to 35,000 feet ( 7- 12 km)

31. CUMULUS (Cu)-
• Heap- wooly, bunchy cloud with rounded top
and flat base
Summer season and high temperature.
Height is variable and depends on RH

33. STRATUS (St)-
• Sheet – without any form, lower than cumulus
cloud

34. NIMBUS (Nb) -
• Any dark and ragged cloud and form which
precipitation occurs.

35. CLASSIFICATION OF CLOUD
• WMO- Height and Appearance into 10
categories.
Family A – Height- 7-12 km (20000-35000 ft)
 Family B – Height – 3-7 km (6500-20000 ft)
 Family C – Height from ground to 3 km(upto
6500 ft)
 Family D – cloud with vertical development
from 0.5 to 16 km.(1600-60000 ft)

36. FAMILY A – 7-12 KM (20000-35000 Ft)
High cloud
 1) Cirrus (Ci)
 2) Cirrocumulus (Cc)
 3) Cirrostratus (Cs)

37. 1) CIRRUS (Ci)
Composition- Ice Crystal
Possible weather change- storm, showery
Description and appearance-
Wispy and feathery, Sunshine without
shadow, does not produce ppt.

39. 2) CIRROCUMULUS (Cc)
• Composition- Ice Crystal
• Possible weather change- possible storm
• Description and appearance – Mackerel sky ,
often fore runners of cyclones, look like
rippled sand

41. • Composition- Ice Crystal
• Possible weather change- storm
• Description and appearance – Whitish veil,
produce halo.

43. FAMILY B ( MIDDLE CLOUD ) 3-7 km
(6500-20000 Ft)
 Altocumulus (Ac)
 Altostratus ( As)

44. 4) ALTOCUMULUS(Ac)
• Composition- Ice water
• Possible weather change- Steady rain or
snow
• Description and appearance – Separate
wool pack, sheep back clouds.

45. ALTOCUMULUS(Ac)

46. 5) ALTOSTRATUS (As)
• Composition- Water and Ice Crystal
• Possible weather change- Impending rain or snow
• Description and appearance – Fibrous veil or
sheet , gray or bluish, produce coronas,
usually cast shadow.

47. ALTOSTRATUS (As)

48. FAMILY – C (LOW CLOUD)
GROUND TO -3 KM (0 TO 6500 FT)
 STRATOCUMULUS (Sc)
 STRATUS ( St)
 NIMBOSTRATUS ( Ns)

49. 6 ) STRATOCUMULUS (Sc)
Composition- Water
Possible weather change- Rain possible
Description and appearance-
Long parallel rolls, pushed together or broken
masses which look soft and gray but with darker
parts, air is smooth above but strong updrafts
occurs below.

50. STRATOCUMULUS (Sc)

51. 7) STRATUS (St)
Composition- Water
Possible weather change- May produce drizzle
Description and appearance-
A low uniform layers, resembling fog, but not
resting on the ground, chief winter cloud.

52. STRATUS (St)

53. 8) NIMBOSTRATUS (Ns)
Composition- water or Ice Crystal
Possible weather change- continuous rain or snow
Description and appearance-
Low stratus, chief precipitationmaker, look
dark grey, uniform layer.

54. NIMBOSTRATUS (Ns)

55. FAMILY- D (VERTICAL DEVELOPMENT)
0.5 TO 16 KM (1600-60000 FT)
 CUMULUS (Cu)
 CUMULONIMBUS (Cb)

56. 9) CUMULUS (Cu)
Composition- Water
Possible weather change- Fair weather
Description and appearance-
Looks like wool pack, dark below due to
shadow, may develop into cumulonimbus flat
base.

57. CUMULUS (Cu)

58. 10 )CUMULONIMBUS (Cb)
Composition- Ice in upper levels and water in lower
levels
Possible weather change- Violent winds rain or all
possible thunder storm, hail lightening possible
Description and appearance-
Thunder head, towering anvil top, violent up and
down drafts , chief precipitation makers.

59. CUMULONIMBUS (Cb)