![]() Radiation fog or ground fog is produced when stagnant moist air is in contact with ground that has become progressively cooler during the night because of an excessive outgoing radiation. It can also be produced, if the cold air mass moves across warm sea surface. Steam fog is found in the middle latitudes in the vicinity of lakes and rivers in autumn when water surfaces are still warm and air is cold.Īdvection fog is produced by the transport of warm moist air over a colder surface, resulting in the cooling of the surface layers below their dew points, with condensation taking place in the form of fog. It is an unstable type of fog produced by intense evaporation from water surface into relatively cold air. When warm rain falls through cold air, fog or stratus clouds form at the frontal surface due to super saturation caused by evaporation from warm rain into cold air. amount of cooling and relative humidity in the air. Generally its value remains around 5☌/km, however, its value varies from about 4☌/km for very humid air in the equatorial regions to about 9☌/km for cold air in the polar regions.Ĭondensation, therefore, depends upon two variables, i.e. The lower cooling rate is called saturated adiabatic lapse rate (SALR). The latent heat of condensation mixes with the moving air mass.Īs a result, the parcel of air mass cools more slowly than dry adiabatic lapse rate. During condensation, water vapours are converted into liquid releasing latent heat of condensation. Further cooling of the air mass results in condensation. The temperature of the rising air mass continues to decrease till it becomes saturated. ![]() It is also called environmental lapse rate, which is recorded by the thermometer carried through the atmosphere by a rising balloon. It is different from the normal lapse rate. ![]() If the air mass remains dry, the rate of decrease of temperature is called dry adiabatic lapse rate (DALR). Here, we say there is saturation, and the water/ice crystals are ready to come down in the form of precipitation.The rate of decrease of temperature of the moving air mass with height is called adiabatic lapse rate (ALR). Soon, there is so much moisture in the atmosphere, far more than the air in that region can take. Cloud droplets can range from sizes between 10 microns to about 1 millimeter. As more and more water particles and aerosols stick together, clouds are formed. The water particles bump into the aerosols and stick together. As the surrounding temperatures fall, the water vapor turns into very tiny particles of water and ice crystals. This is what happens in cloud formation in the atmosphere.Īs water vapor rises into the atmosphere, they mix up with very tiny particles of dust, soot, and salt, which are all particulate matter in the atmosphere. When vapor comes into contact with lower (cooler) temperatures, the vapor is forced to change from gas state to liquid state. For condensation to happen, there must be water vapor (higher temperature). Diagram showing water vapor Why does condensation occur?Ĭondensation occurs because of temperature differences. Cooler temperatures are essential for condensation to happen because as long as the temperature in the atmosphere is high, it can hold the water vapor and delay condensation. This stage is vital because it is the cloud formation stage. That is what happens during condensation.Ĭondensation is the process by which water vapor (gas) in the atmosphere turns into water (liquid state). What happens? Water droplets run down the lid and fall into the pot. ![]() Take a dry lid and cover it for a minute, and lift the lid. Put a pot of water on the stove and bring it to a boil. Here is a scenario of how condensation works:
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |