Masses of air Movement of air Wind Earth Science II (Session 7)

Ciencias de la Tierra II What is a mass of air? It is the air that surrounds you, in your city, in your state … What is weather? The characteristics of the mass of air that surrounds you. Ciencias de la Tierra II

Ciencias de la Tierra II All the changes in weather occur in the troposphere. These changes happen when masses of air absorb heat and humidity from solid surfaces of the Earth and bodies of water. Ciencias de la Tierra II

Ciencias de la Tierra II The study of weather includes: Temperature of the air Formation of clouds Rain Humidity of the air Atmospheric pressure Speed of the air Ciencias de la Tierra II

Ciencias de la Tierra II Masses of air The diverse geography of the Earth provokes diverse conditions in the weather, due to the formation of different masses of air. Air masses are classified in 6 types: Polar continental Tropical continental Marine Polar Tropical marine Ecuatorial Artic Ciencias de la Tierra II

Ciencias de la Tierra II Tipos de masas de aire Air masses Description Symbol Artic (very cold very dry) It is formed over a very cold and dry surface. North Pole. Extremely cold. A Polar continental (very cold and dry) Formed over a very cold and dry surface. Canada. Pc Polar marine (cold and humid) Formed over cold and humid polar oceans, creating cold and humid weather when it moves toward the eath. Pm Tropical continental (hot and dry) Forms over hot and dry regions. Desertic regions. Tc Tropical marine (warm and humid) Forms over bodies of warm water. Generates rain y tornados. Mexico. Tm Ecuatorial (warm and humid) Forms over very warm and humid surface. The Ecuator. E DiSpezio, Michael , et al. (1999) Ciencias de la Tierra II

Ciencias de la Tierra II Polar marine Polar continental Artic Tropical marine Tropical continental Ecuatorial DiSpezio, Michael , et al. (1999) Diagram Ciencias de la Tierra II

Ciencias de la Tierra II Fronts Front: it is the transition zone between two different air masses. It’s the line where the masses are located. There are 4 types of fronts: Cold Warm Stationary Ocluded Ciencias de la Tierra II

Ciencias de la Tierra II Cold fronts occur when: A mass of cold air (heavy air) moves the hot air (light air), It starts low and moves upward. The result is cold air rising. A cold front advances quickly, producing a drastic change in weather. There is a formation of clouds and production of rain and wind. Ciencias de la Tierra II

Ciencias de la Tierra II Hot front It is a mass of hot air that comes from the ecuatorial zone, moving above and around the cold air on the bottom, because it is lighter. The humidity it contains cools and condenses forming clouds that produce rain. Ciencias de la Tierra II

Ciencias de la Tierra II Stationary front It is formed between two air masses that cannot move. Sometimes a layer of hot air is maintained over a layer of cold air. Ocluded Front When a hot and cold front crash they become an ocluded front. Ciencias de la Tierra II

Ciencias de la Tierra II Diagrama Ciencias de la Tierra II DiSpezio, Michael , et al. (1999)

Ciencias de la Tierra II Atmospheric pressure This is the air pressures at any part of the Earth’s surface. At sea level and 0° C, normal barometric pressure is 760 mm of Mercury (Hg) Ciencias de la Tierra II

Ciencias de la Tierra II Mercury barometer Random House, Inc. (2003) Random House, Inc. 2003 The atmospheric pressuer is measured with the mercury barometer. Virtual laboratory Ciencias de la Tierra II

Ciencias de la Tierra II Wind The constant movement of hot and cold masses of air produce great winds on the Earth. Winds are air masses in movement. Winds determine the major part of our atmospheric weather. Ciencias de la Tierra II

Ciencias de la Tierra II DiSpezio, Michael , et al. (1999) Diagrama Ciencias de la Tierra II

How is wind produced? When air masses with different characteristics collide: The difference of pressure between the air masses produces wind. The more the pressure the more the force of the wind. The difference of temperature in air masses also produces wind. The difference of the speeds of air masses can cause the wind to be higher. The rotation of the earth also produces winds, North and South winds. Ciencias de la Tierra II

How to use Aeolian energy?                                                                                    Desert Wind Power in Palm Springs Functioning of an air generator. Ciencias de la Tierra II

Ciencias de la Tierra II Wind Farm. Palm Springs California http://www.ronsaari.com/stockImages/windmills/WindFarmPalmSpringsCA.jpg Ciencias de la Tierra II

Ciencias de la Tierra II Class reading Textbookl… Science and Technology: Wind energy. Page 446 Ciencias de la Tierra II

Ciencias de la Tierra II Material webpage: Windpower Online webpage: Comisión Nacional para el Ahorro de Energía Ciencias de la Tierra II

Ciencias de la Tierra II Bibliograhy DiSpezio, M. et al. (1999). Science Insights: Exploring Earth and Space. first ed. USA: Prentice Hall. Random House, Inc (2003). Isaac´s Storm [Imagen]. Random House, Inc. Extraído el 24 de marzo de 2003 de la World Wide Web: http://www.randomhouse.com/features/isaacsstorm/science/glossary.html Ciencias de la Tierra II