PRESENTED BY: “ SHEIKH MARYAM ” SS15-10

DEPARTMENT OF SPACE SCIENCE UNIVERSITY OF PUNJAB

MAIN CONTENTSTYPES OF ATMOSPHERIC CLOUDSPROCESSES OF PRECIPITATION

WHAT IS A CLOUD???

STATEMENT:“Cloud is the accumulation of tiny water

droplets and ice, suspended in air.”

TYPES OF CLOUDS

HIGH CLOUDSMIDDLE CLOUDS

LOW CLOUDSCLOUDS WITH VERTICAL DEVELOPMENT

“HIGH CLOUDS”

CIRRUS CLOUDS (Ci)Cirrus clouds are most common type of

clouds.They are:• White clouds• Detached clouds

• Having narrow bands between a cloud.• Delicate filaments and • Having a fibrous look

FIGURE DESCRIPTS: CIRRUS CLOUDS

CIRROCUMULUS CLOUDS (Cc)They are less commonly seen as compared

to cirrus clouds.They are:• usually thin, white clouds• Composed of small elements like grains or ripples.• These grains have a width less than one degree.• Also have a fibrous look but do not constitute its greater

part.

• FIGURE DESCRIPTS: CIRROCUMULUS CLOUDS

CIRROSTRATUS CLOUDS (Cs)These clouds are:• White and sheet like• So thin that sun and moon can be clearly seen from

them.• Produces a HALO.• Cirrostratus clouds having elements smaller than

cirrocumulus that distinguishes it from cirrostratus.

• FIGURE DESCRIPTS: CIRROSTRATUS CLOUDS PRODUCING HALO

“MIDDLE CLOUDS”

ALTOCUMULUS CLOUDS (Ac)

These clouds consists of water vapors.They are:• Hardly thicker than 1 km.• Grayish in color.• Having puffy mases.• May appear as parallel bands or round masses.

UPPER FIGURE DESCRIPTS PARALLEL BANDS AND LOWER DESCRIPTS ROUND MASSES

ALTOSTRATUS CLOUDS (AS)

They consists of water vapors and sometimes ice crystal.

They are:• Grayish and bluish in color.• They covers entire sky across an area that

extends over hundreds of sq. meter.

• FIGURE DESCRIPTS: ALTOSTRATUS CLOUDS

“LOW CLOUDS”

STRATOCUMULUS CLOUDS (Sc)

They are :• Low and dark or light clouds.• Having round masses with blue sky visible

between them.• Mostly form after sunsets.• Produces crepuscular rays.

• FIGURE DESCRIPTS: STRATOCUMULUS CLOUDS

STRATUS CLOUDS (St)

Stratus clouds are : Greyish in color

Usually no precipitation forms but sometimes it makes mist or drizzle.

FIGURE DESCRIPTS: STRATUS CLOUDS

NIMBOSTRATUS CLOUDS (Nb)They are: Greyish and Wet looking Intensity of precipitation is usually moderate Contains more or less continuously rain or

snow falling.

• FIGURE DESCRIPTS: NMIBOSTRATUS CLOUDS

“CLOUDS WITH VERTICAL DEVELOPMENT”

CUMULUS CLOUDS (Cu)

• The cumulus clouds that shows slightly vertical development termed as CUMULUS HUMILIS CLOUDS.

• The cumulus clouds that scattered across entire sky are termed as CUMILIS FRACTUS CLOUDS.

CUMULUS CONGESTUS (Cc)• When the growing cumulus resembles like a cauliflower

then it is called CUMULUS CONGESTUS or TOWERING CUMULUS.

• FIGURE DESCRIPTS: CUMULUS CONGESTUS

CUMULONIMBUS (Cb)• If the cumulus cloud continues to grow

vertically then it forms a large vertical cloud called CUMULONIMBUS CLOUD.• It is a thunderstorm cloud.

• FIGURE DESCRIPTS: CUMULONIMBUS CLOUD

“PRECIPITATION IN A CLOUD”

BERGERON FINDEISEN PROCESS (ICE FORMATION PROCESS)Bergeron Findeisen process is the process of

growing an ice crystal in mixed phase clouds (containing a mixture of super cooled water and ice)

-15 degree Celsius to -40 degree Celsius a water droplet remains in a state of liquid in a cloud.

Requirement of the presence of a mineral dust to use as a nucleus.

Super Power Attraction (towards water droplets)

COLLISION COALESCENCE PROCESS (RAIN FORMATION PROCESS)

The collision coalescence process is the process of cloud droplets increasing in size by colliding and coalescing. When droplets bump into each other, it is called collision and when they stick together, it is called coalescence.