Weather Elements
- Atmospheric pressure. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/ article/atmospheric-pressure/10121
Atmospheric pressure, also called barometric pressure, force per unit area exerted by an atmospheric column (that is, the entire body of air above the specified area). Atmospheric pressure can be measured with a mercury barometer (hence the commonly used synonym barometric pressure), which indicates the height of a column of mercury that exactly balances the weight of the column of atmosphere over the barometer. - BBC Bitesize. (2014). Isobars and fronts. Retrieved from http://www.bbc.co.uk/schools/gcsebitesize/geography/weather_climate/weather_ systems_rev2.shtml
Fronts occur where two different air masses meet. This BBC Bitesize website explains how cold fronts, warm fronts and occluded fronts occur. - Britt, R.(2005, October 13). Wind and rain. Retrieved from http://www.livescience.com/407-weather-101-wind-rain.htmlThe root of all weather is the Sun, which heats the Earth. The heating is uneven, because of night and day, because different surfaces (such as rocks and trees) absorb and reflect sunlight in different amounts, and because sunlight hits the equator more directly than the poles. Uneven heat creates pressure differences, and wind flows between areas of high and low pressure.
- Cloud. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/ article/cloud/24441Clouds are formed when relatively moist air rises. As a mass of air ascends, the lower pressures prevailing at higher levels allow it to expand. In expanding, the air cools adiabatically (i.e., without heat exchange with the surrounding air) until its temperature falls below the dew point, upon which the air becomes supersaturated such that water vapour condenses onto cloud condensation nuclei or tiny water droplets (or deposits onto ice nuclei or tiny ice crystals).
- Main, D. (2013, May 9). How cirrus clouds form and why it matters. Retrieved from http://www.livescience.com/29472-how-cirrus-clouds-form.htmlIt has long been a mystery exactly what causes the formation of cirrus clouds, the wispy billows of ice that can be seen high in the sky. But new research, detailed in the May 9 issue of the journal Science, finds that the clouds condense and freeze, or nucleate, on very specific mineral and metal particles high in the atmosphere. That makes cirrus clouds unique: Most other clouds form primarily by condensing onto organic particles, said study author Dan Cziczo, an atmospheric chemist at the Massachusetts Institute of Technology.
- Cyclone. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/ article/cyclone/28378Cyclone, any large system of winds that circulates about a centre of low atmospheric pressure in a counterclockwise direction north of the Equator and in a clockwise direction to the south. Cyclonic winds move across nearly all regions of the Earth except the equatorial belt and are generally associated with rain or snow.
- Front. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/ article/front/35494Front, in meteorology, interface or transition zone between two air masses of different density and temperature; the sporadic flareups of weather along this zone, with occasional thunderstorms and electrical activity, was, to the Norwegian meteorologists who gave it its name during World War I, analogous to the fighting along the battle line in Europe. Frontal zones are frequently accompanied by low barometric pressure (a pressure trough), marked changes in wind direction and relative humidity, and considerable cloudiness and precipitation.
- Rain. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/ article/rain/62486Rain, precipitation of liquid water drops with diameters greater than 0.5 mm (0.02 inch). When the drops are smaller, the precipitation is usually called drizzle. Concentrations of raindrops typically range from 100 to 1,000 per cubic m (3 to 30 per cubic foot); drizzle droplets usually are more numerous. Raindrops seldom have diameters larger than 4 mm, because as they increase in size they break up. The concentration generally decreases as diameters increase. Except when the rain is heavy, it does not reduce visibility as much as does drizzle. Meteorologists classify rain according to its rate of fall. The hourly rates relating to light, moderate, and heavy rain are, respectively, less than 2.5 mm, 2.8 to 7.6 mm, and more than 7.6 mm.
- Storm. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/article/ storm/69834Storm, violent atmospheric disturbance, characterized by low barometric pressure, cloud cover, precipitation, strong winds, and possibly lightning and thunder.
- Temperature inversion. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/ article/temperature-inversion/71634Temperature inversion, a reversal of the normal behaviour of temperature in the troposphere (the region of the atmosphere nearest the Earth’s surface), in which a layer of cool air at the surface is overlain by a layer of warmer air. (Under normal conditions air temperature usually decreases with height.)
- Wave. (2017). In Encyclopædia Britannica. Retrieved from http://school.eb.com.au.db.plcscotch.wa.edu.au/levels/high/ article/wave/76315Wind waves are the wind-generated gravity waves. After the wind has abated or shifted or the waves have migrated away from the wind field, such waves continue to propagate as swell.
Tuvalu
TWIG. (n.d.). Tuvalu the threat of rising seas. [Video file]. Retrieved from https://www-twig-world-com.db.plcscotch.wa.edu.au/film/tuvalu-the-threat-of-rising-seas-1628/
The Tuvala island group includes both atolls and reef islands. The atolls—Nanumea, Nui, Nukufetau, Funafuti, and Nukulaelae—have islets encircling a shallow lagoon; the reef islands—Nanumanga, Niutao, Vaitupu, and Niulakita—are compact with a fringing reef. The islands are low-lying, most being 13 to 16 feet (4 to 5 metres) above sea level. (Encyclopedia Britannica, 2017)
Bozeman Science
Anderson, P. (2013, June 9). Weather and climate.[Video File]. Retrieved from https://www.youtube.com/watch?v=gLT1J8je5lo
In this video Paul Andersen describes both weather and climate. Weather is the day-to-day conditions on the Earth's surface, including temperature, wind, humidity, air pressure, and precipitation. Climate are the long term conditions on the Earth's surface. Both climate and weather are determined by sunlight, water, landforms and life forms.
Coriolis Effect
TWIG. (n.d.). Coriolis effect [Video file]. Retrieved from https://www-twig-world-com.db.plcscotch.wa.edu.au/film/ coriolis-effect-1156/
The Coriolis force is evident in the behaviour of ocean currents. For Earth, horizontal deflections due to the rotational induced Coriolis force act on particles moving in any horizontal direction. Because Earth rotates from west to east about its axis, an observer in the Northern Hemisphere would notice a deflection of a moving body toward the right. In the Southern Hemisphere, this deflection would be toward the left. As a result, ocean currents move clockwise (anticyclonically) in the Northern Hemisphere and counterclockwise (cyclonically) in the Southern Hemisphere; Coriolis force deflects them about 45° from the wind direction, and at the Equator there would be no apparent horizontal deflection. (Encyclopedia Britannica, 2017)
Cloud Spotting
Chubb, J. (2011, November 11). Trainspotting [Video File]. Retrieved from https://www.youtube.com/watch?v=QWeorlkJ39M
How do clouds form? How can you tell one cloud from another? In this video, James Chubb explains how clouds form and how to tell one cloud from another.
How Do Tides Work?
BrainStuff (2014, March 17). How do tides work [Video File]. Retrieved from https://www.youtube.com/watch?v=5ohDG7RqQ9I
Most people are already familiar with the idea of high and low tides, but where do they come from? What causes this movement and why does it occur with such regularity? Tune in as Josh demystifies the rise and fall of the sea.
CNN Explains Tropical Cyclones
CNN. (2012, May 25). Tropical cyclones. [Video File]. Retrieved from https://www.youtube.com/watch?v=oO-U4nEqL08
CNN Meteorologist Ivan Cabrera explains what a tropical cyclone is and why they are a necessary evil.