Definition of Condensation, Dew, Fog & Clouds
Condensation-
The formation of Dew and Frost
Dew is formed when the air has high relative humidity and the
temperature of the air near the earth’s surface becomes very low. This
causes condensation of water vapour into water droplets.
The condensation of water vapour in dew does not take place around the
nuclei in the atmosphere, but it takes place on the cold surface on the
ground. These cold surfaces can be grass, metal, or any other object.
Frost is just a type of dew which is formed when the dew point
temperature of the air near the earth’s surface is below its freezing point
of water. This causes the water vapour to convert into ice crystals or frost.
If the dew point temperature of air is above freezing point of water, it will
form dew.
But if the dew point temperature of air is below the freezing point of
water, it will form frost.
Condensation Nuclei
The truth is, cloud formation isn't as simple as it first appears because to
understand clouds you must first understand something called condensation nuclei.
Condensation nuclei are tiny particles in the air on which water vapor condenses
and they are the key to making clouds, fog, haze, rain, and other forms of
precipitation.
Condensation nuclei come in many forms. They can form from dust, soot from fires
and vehicle exhaust, sea salts from waves crashing onto shore, volcanic eruptions,
or any other way small particles enter the atmosphere. Make no mistake, these
particles are very small and you likely don't even notice them. The average
condensation nuclei is only about 1/100th the size of a cloud droplet. Because nuclei
are made from different materials, they also differ in terms of their ability to form
clouds (or fog). For example, something like sea salt can absorb water very well,
thus forming droplets easily. However materials like soot from a coal fired stove or
dust from the highway don't absorb water well and would have more difficulty
producing a cloud droplet.
Haze
Haze is a suspension in the air of extremely small, dry particles invisible to the
naked eye and sufficiently numerous to give the air an opalescent appearance
(WMO, 2017).
Slide 1: Title Slide
Title: Condensation: Dew, Fog, and Clouds
Subtitle: Understanding the Formation and Types of Condensation
Your Name
Date
Slide 2: Introduction to Condensation
Definition of Condensation
o Process where water vapor cools and changes to liquid.
Importance in Weather and Climate
Slide 3: Overview of Condensation Types
Main Types:
o Dew
o Frost
o Fog
o Clouds
Slide 4: Formation of Dew
Definition of Dew
o Water droplets that form on surfaces during cool nights.
How Dew Forms:
o Cooling of surfaces leads to condensation of moisture from the air.
Conditions Favoring Dew Formation:
o Clear skies, calm winds, and high humidity.
Slide 5: Formation of Frost
Definition of Frost
o Ice crystals that form when the temperature drops below freezing.
How Frost Forms:
o Similar to dew but occurs when temperatures are at or below 0°C
(32°F).
Conditions Favoring Frost Formation:
o Clear, calm nights with high humidity.
Slide 6: Condensation Nuclei
Definition:
o Small particles in the atmosphere that provide a surface for water
vapor to condense upon.
Types of Condensation Nuclei:
o Dust, pollen, smoke, salt particles.
Role in Weather Phenomena:
o Essential for cloud formation and precipitation.
Slide 7: Haze
Definition of Haze
o Suspension of fine particles in the air that reduces visibility.
Causes of Haze:
o Pollution, dust, smoke, and moisture.
Impact on Weather and Health
Slide 8: Fog & Foggy Weather
Definition of Fog
o A thick cloud of tiny water droplets suspended in the air at or near the
Earth's surface.
Types of Fog:
o Radiation Fog
o Advection Fog
o Upslope Fog
o Valley Fog
Conditions Favoring Fog Formation:
o Temperature inversions, high humidity, and calm winds.
Slide 9: Clouds
Definition of Clouds
o Visible mass of condensed water vapor in the atmosphere.
Types of Clouds:
o Cirrus, Cumulus, Stratus, Nimbus.
Role of Clouds in Weather:
o Indicate weather patterns and precipitation potential.
Slide 10: Summary of Key Concepts
Dew and Frost Formation
Importance of Condensation Nuclei
Understanding Haze and Fog
Types of Clouds and Their Impact on Weather
Slide 11: Conclusion
Importance of Understanding Condensation
o Its role in the water cycle and climate.
Future Implications:
o Effects on agriculture, ecosystems, and climate change.
Slide 12: Questions & Discussion
Open the floor for questions.
Encourage discussion on personal experiences with fog, dew, and clouds.
Slide 13: References
List of sources used for information and images.
