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Winds. By: Justin, James and Roger Submitted to: Mr. Halpin Snc 2D1. Definition. Wind is a natural movement of air. Katabatic (foehn) winds – The down slope flow of cold and dry air under the influence of gravity.
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Winds By: Justin, James and Roger Submitted to: Mr. Halpin Snc 2D1
Definition • Wind is a natural movement of air. • Katabatic (foehn) winds – The down slope flow of cold and dry air under the influence of gravity. • Chinook – A type of katabatic wind. Refers to the warm down slope wind in the Rocky Mountains and is also known as the Snow Eater. • Mistral - A cold dry wind blowing from the north over the northwest coast of the Mediterranean sea.
Definitions • Sirocco – A warm wind of the Mediterranean area, either a katabatic or a hot southerly wind in advance of a low pressure area moving to the sea from the Sahara or Arabian deserts. • Dust Storms – Strong winds moving over dry ground with little or no vegetation can lift particles of dust or sand into the air. These airborne particles can reduce visibility, cause respiratory problems and have an abrasive effect on machinery.
Chinook Winds • The process of the making Chinook winds starts in the pacific ocean. Westerly winds blow warm and moist air over the Pacific Ocean towards the west coast of B.C. As the moisture laden air reaches the coast it encounters a group of mountains before reaching the higher Rocky Mountains. As the air climbs the mountains it expands and cools. Some of the moisture condenses and falls to the ground.
Chinook Winds • The stored heat is released and the air that descends the other side of the mountain is drier and warmer. • These are examples of how this effect is created.
Chinook Winds • This air meets a second group of mountains and the process is repeated and the air is now a lot warmer and drier. Finally the air reaches the Rockies and process begins a third time and the compression of the air causes a rise in the temperature. • This wind happens 30 days each year during the winter.
Chinook Winds • They are most common in the mountainous regions of Western Canada and Chinook Winds are least likely to occur in the prairies or any other flatland regions. • There have not been any types of Chinook winds in Windsor because there are no mountains here.
Chinook Winds • Chinook winds have very low potential for destruction. • Chinook winds are viewed favourably by residents in Western Canada as they provide a break from harsh winter weather. Calgary residents have been known to break out the golf clubs in January when the Chinooks blow.
Katabatic Winds • Katabatic winds normally originate in highland areas with large snow-covered plateaus. • These types of winds begin as inversion winds and are driven down slope by gravity but the slopes are steeper. The wind is then channeled and builds pressure and increases in speed. • Katabatic winds are classified into two categories. There are ordinary katabatic winds and extraordinary katabatic winds.
Katabatic Winds • Ordinary Katabatic Winds have a constant direction and are very gusty. They form a cool inversion basin and the basin builds up and then it drains really quickly creating the wind. The cold air in the basin has to refill itself before the next katabatic wind can take off down slope. • Extraordinary Katabatic Winds rage for a long period of time. They tend to occur in Antarctica between Cape Denison and Port Martin or in any region with a large basin and a long term temperature inversion and a landscape that funnels escaping wind.
Katabatic Winds • Katabatic winds occur mostly in Antarctica and occur throughout the year. • They are least likely to occur in a flat region of land. • These winds have not occurred in Windsor because there are not enough big slopes. • The pressure that is built up in the basins creates a dangerous potential for devastating winds to occur.
Sirocco Winds • Sirocco winds occur as a result of surface and upper level depressions moving eastward over the southern Mediterranean Sea. • Sirocco winds happen all year round. • Sirocco winds are most common in the Mediterranean Sea or Northern Africa. It is least likely to occur in places that are cold.
Sirocco Winds • This type of wind has never occurred in our area because we don’t have very hot weather in Windsor. • A friend of mine visited his cousin in Italy last year and he said that once and a while there were very hot winds that would come. My friend asked his cousin why there are such hot winds and the cousin explained that these winds were Sirocco winds.
Sirocco Winds • Sirocco winds produce hot, dry and dusty conditions over the Northern African Coast bring clouds of sand which cause poor visibility and can lead to damage to plants, animals, instruments and equipment.
Sirocco Winds • The Sirocco winds have been implicated as the cause of “hot latin tempers”. • This wind affects residents of Spain, Italy, Sicily and Greece and the hot weather it produces along with oppressive humidity has been associated with raw nerves and flaring tempers.
Dust Storms • Dust storms form when high winds at the earth’s surface pick up dust and sand in dry environments. • Dust storms occur mainly during the late winter and early spring when pressure gradients are extreme. These conditions worsen during late morning and are most intense during late afternoon.
Dust Storms • Dust storms occur most frequently over deserts and regions of dry soil, where particles of dirt or sand are loosely settled to the surface. • Dust storms have not yet occurred in Windsor because Essex county has firm top soil.
Dust Storms • A dust storm which lasted for 5 hours near Jingchang, China caused 640 million yuan in economic damage over a wide area and injured and killed upwards of 300 people. As you can see they have potential for destruction. • The highest frequency of dust storms occurs in the area of Iran with over 30 per year. • Strong winds and dry air produce the dust storms.
Dust Storms • Fact- Dust from the Sahara Desert regularly crosses the Atlantic, causing bright red sun rises and sunsets in Miami and traveling as far as the Caribbean and the Amazon basin.
Mistral Wind • Mistral wind means masterful wind. • The mistral wind is a cold northerly katabatic wind that flows into the Gulf of Lion. • Because the mistral wind is a katabatic wind it needs a slope to flow along to pick up speed. • Mistral winds are unique to the Gulf of Lion.
Mistral Wind • Mistrals are most common during the winter and in the spring although gale-force events can occur year-round. • In the winter the wind speeds can reach hurricane levels of over 100 knots making the mistral wind one of the most dangerous of all the Mediterranean winds.
Winds • The difference between regions of high and low air pressure, impels air in the direction of lowest pressure creating wind. • The larger the air pressure gradient, the greater the wind speed and direction. The most important of these are the Coriolis effect and friction.
Winds • Coriolis Effect: The earth’s rotation creates a force (coriolis force) that deflects moving air to the right of its initial direction in the Northern Hemisphere and to the left of its initial direction in the Southern Hemisphere. • It’s effect is zero at the equator and increases to a maximun at the poles. • Coriolis force explains why winds circulate around high and low pressure systems.
Winds • Local winds result from thermal differences that generate a local pressure gradient. • Meteorologists report wind speed in meters per second. • Wind direction is always reported as the direction the wind is coming from.
