- Humidity –
- Humidity capacity.
- Capacity of air of certain volume at certain temperature to retain maximum amount of moisture content.
- Absolute humidity.
- Total weight of moisture content per unit volume of air at definite temperature.
- Specific humidity.
- Mass of the water vapors (grams) contained in a kg of air.
- It represents the actual quantity of moisture present in a definite volume.
- Relative humidity.
- (Absolute humidity * 100 )/ Humidity capacity
- Humidity capacity.
- Dew point – When relative humidity reaches 100%, the air is completely saturated. That air temperature is said to be the Dew point.
- Fog –
- Made from the droplets of water suspended in the lower of the atmosphere.
- It is not considered as the form of precipitation.
- Visibility of less than 1 km.
- Smog – Smoke +Fog.
- Haze –
- Formed by the water particles that have condensed in the atmosphere.
- Visibility lies between 1 km – 2 km.
- Frost – Is the moisture on the ground that condenses directly into ice. (condensation below freezing point)
- Clouds –
- Mass of small water droplets or tiny ice crystals.
| Latin names | There meaning |
| Cirrus | Like feather, Very high clouds |
| Cumulus | Like heap, Flat base and rounded top |
| Stratus | Lying in level sheets, Layer type |
| Alto | High |
| Nimbus | Rain clouds |
- Classified according to their appearance, form and height:
- High clouds. (6000 m to 12000 m)
- Cirrus.
- Contains small ice crystals.
- White wispy and fibrous appearance.
- Cirro Cumulus.
- Contains ice crystals.
- Rippled in appearance.
- Cirro Stratus.
- Appears like a thin white almost transparent sheet.
- Cirrus.
- Middle clouds. (2100 m to 6000 m)
- Alto Cumulus.
- Contains droplets in layers and patches.
- Alto Stratus.
- Contains droplets forming sheets of grey or watering looking clouds.
- Alto Cumulus.
- Low clouds. (below 2100 m)
- Strato Cumulus.
- Large globular masses.
- Bumpy looking.
- Soft and grey in appearance.
- And regular or wavy pattern.
- Nimbo Stratus.
- Dark grey and rainy looking.
- Dense and shape less.
- Often gives continuous rain.
- Stratus.
- Are low grey and layered.
- Fog like in appearance.
- Brings dull weather accompanied by drizzle.
- Strato Cumulus.
- Clouds with great vertical extent. (1500 m to 9000 m)
- Cumulus.
- Round top flat base.
- A whitish grey globular mass.
- Consists of individual cloud units.
- Cumulo Nimbus.
- Great vertical extent.
- White or black globular masses.
- Brings conventional rain and thunder.
- Cumulus.
- High clouds. (6000 m to 12000 m)
- Precipitation –
- Classified on the basis of its origin.
- Conventional rainfall.
- Occurs due to thermal conventional currents caused due to insolational heating of ground surface.
- Example: Congo basin, Amazon basin, South-east Asia etc.
- Orographic rainfall.
- Caused due to ascent of air forced by mountain barrier.
- Example: Mahabaleshwar, Western Ghats (600 cm rainfall) etc.
- Frontal rainfall.
- Due to upward movement of air caused by convergence of cold air masses against warm air masses.
- Example: North-west Europe (due to convergence of cold continental and warm oceanic air) etc.
- Conventional rainfall.
- Classified on the basis of its origin.