FORMS OF CONDENSATION

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. When air ascends, clouds are formed. The cloud is having very low temperature , called cold cloud. In these clouds ice particles as well as water drops are formed due to very low temp. (-15 to -25 ). These ice particles are grow readily by deposition of water vapour ( Sublimation) developing into hexagonal shaped ice crystals. 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)

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

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

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

33. 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)

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

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

36. 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

37. Cirrocumulus (Cc)

38. Composition - Ice Crystal Possible weather change- storm Description and appearance – Whitish veil, produce halo. 3) Cirrostratus ( Cs)

39. cirrostratus

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

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

42. ALTOCUMULUS(Ac)

43. 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.

44. ALTOSTRATUS (As)

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

46. 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.

47. STRATOCUMULUS (Sc)

48. 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.

49. STRATUS (St)

50. 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.

51. NIMBOSTRATUS (Ns)

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

53. 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.

54. CUMULUS (Cu)

55. 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.

56. CUMULONIMBUS ( Cb )

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