What are air masses classify the air masses on the basis of temperature?
Air masses are commonly classified according to four basic source regions with respect to latitude. These are Polar (cold), Arctic (very cold), Equatorial (warm and very moist), and Tropical (warm).
What two weather conditions determine an air mass?
Air Mass is an extremely large body of air whose properties of temperature and moisture content (humidity), at any given altitude, are fairly similar in any horizontal direction.
Where do air masses get their characteristic temperature and humidity from?
source region
Temperatures and humidities vary gradually with latitude, longitude, and altitude throughout the air mass. The air masses obtain their characteristic temperature and humidity by sitting at a location on earth for a period of time. This location is the source region.
Does air mass have the same temperature and humidity?
An air mass has roughly the same temperature and humidity. Air masses form over regions where the air is stable for a long enough time. The air takes on the characteristics of the region. Air masses move when they are pushed by high level winds.
What is an air mass What governs the temperature and humidity of an air mass?
What governs the temperature and humidity of an air mass? An air mass is a huge volume of air with uniform temperature and humidity properties that are often indicative of where it was formed. For example, an air mass that develops over a warm ocean surface becomes warm and humid.
What type of air mass is cold and humid?
Maritime air masses form over water and are humid. Continental air masses form over land and are dry. Therefore, an air mass that develops over northern Canada is called a continental polar air mass and is cold and dry. One that forms over the Indian Ocean is called a maritime tropical air mass and is warm and humid.
How is the temperature of an air mass determined?
Air masses are formed when air stagnates for long periods of time over a uniform surface. The characteristic temperature and moisture of air masses are determined by the surface over which they form. Warm air masses usually form in tropical or subtropical regions and are called tropical air masses.
How is the density of moist air determined?
When the temperature increases a higher molecular motion results in expansion of volume and a decrease of density. The density of a gas, dry air, water vapor – or a mixture of dry air and water vapor like moist or humid air – can be calculated with the Ideal Gas Law. The amount of water vapor in air influence density.
How is humidity measured in the upper atmosphere?
The greatest use of the condensation hygrometer has been to measure humidity in the upper atmosphere, where a vapour pressure of less than a thousandth millibar makes other means impractical. Another index of humidity, the saturation deficit, can also be understood by considering air with a vapour pressure of 17 mb.
How is humidity of the air at saturation expressed?
Humidity of the air at saturation is expressed more commonly, however, as vapour pressure. Thus, it is necessary to understand vapour pressure and in particular the gaseous nature of water vapour.