Weather Flashcards
Why is the equator warmer
The Earth is divided into the northern hemisphere in the southern hemisphere. The line dividing these two is called the equator. Because of the earths spherical shape the equator is close to the Sun. This means that area is close to the equator are warmer area is close to the poles. The suns rays have a short distance to travel to the equator so the heat more intense here than at higher latitudes.
Why do we experience seasons
The Earth spins and every 24 hours and orbit the Sun every 364 1/4 days. During this time different parts of the Earth surface tilted towards the sun. This influenced the seasons and the length of the day and night. The northern hemisphere is tilted towards the Sun. Days are long and we receive more solar radiation. During the winter, the northern hemisphere is tilted away from the Sun days are short and temperatures are low because there’s little so solar radiation.
How do winds happen
The unequal heating of the atmosphere and earth surface leads to movements of air. Wind is the movement of air over the surface of the Earth. Winds blow from areas of high pressure to areas of low pressure.
What is the most common wind in Ireland?
Prevailing Westerlies
Tell me about the prevailing westerlies
Between 30° and 60° latitude the winds that move towards poles appear to curve east. Because winds are named after the direction which they come from these wins are called westerlies. Prevailing westerlies in the northern hemisphere are responsible for many of the weather movements across Europe and especially in Ireland.
What are air masses?
Air masses are large moving pocket to air that are distinct from surrounding atmosphere warm air masses carrying more moisture or water vapour than cold air masses
What are isobars?
Isobars are launched on the weather map which joined together places of equal atmospheric pressure
Tell me about warm air fronts
Warm fronts are formed when warm air rises over a mass of cold air. As warm air rises into areas of lower pressure, it expands cools and condenses the water vapour as wide flat sheets of cloud which bring gentle rain.
Tell me about cold fronts
A cold front occurs where a cold air mass of warmer air mass. The cold air follows warm air and gradually moves underneath it pushing the warm air upward. When the warm air is pushed upwards it will heavily rain. As the cold front passes, the clouds rolled by and the air temperature is cooler.
Tell me about a occulted fronts
Occulted fronts occur out of the point where front takes over a warmer front or the other way around. They bring changeable weather conditions.
Tell me about anticyclones
Descending air and temperature rise, high atmospheric pressure, winds blow in a clockwise direction, isobars are well spaced indicating light winds, clear skies and cold nights in winter and dry weather
Tell me about depressions
Ascending air and temperatures fall, low atmospheric pressure, winds blow in a anticlockwise direction,isobars are closely together indicating strong winds, cloudy skies and wet weather
Tell me about stratus clouds
Stratus clouds occur below 2000 meters. They look like floss sheets of clouds and indicate an overcast and rainy day. These clouds are usually a uniform grey colour and cover most of the sky.
Tell me about cumulus clouds
Cumulus clouds occur below 5000 meters. They look like big fluffy balls of cotton wool. They usually mean that the weather will be nice. Sometimes they can look very woolly and bring heavy showers, especially in warm weather.
Tell me about Circus cloud
Circus clouds cover from above 8000 meters. They are wispy clouds because there is very little water vapour at this height. Circus clouds are created water vapour forms ice crystals which are very thin because of the height at which they form.
Tell me about relief rainfall
Prevailing winds pick up moisture from the sea as they travel across it making the air moist. When this moist air reaches the coast, it is forced to rise up over the coastal mountains and hills. This forces the air to cool and condense forming clouds. As air continues to be forced over the mountain, it drops its moisture as relief rainfall. Once over the mountain, the air will usually drop down the other side warming as it does. This means it can hold more moisture and so there is a little rain on the far side of the mountain. This area is called the rain shadow. It is very common in Ireland.
Tell me about atmospheric pressure and how you measure it
Atmospheric pressure is the weight of the atmosphere pressing down the Earth. The instrument used to measure atmospheric pressure is called a barograph. A barograph consist of a small container with a movable top. As the atmospheric pressure rises, the top is pushed inwards. As the pressure decreases the top pushes back up again. The unit of measurement of atmospheric pressure is millibars. The lines on the weather map that show areas of equal atmospheric pressure are called isobars.
Tell me about sunshine and how you record it
Sunshine is when the suns race reached the surface of the earth. Sunshine is measured using a Cambell-Strokes sunshine recorder. A glass sphere focuses the suns raise onto a spot of sensitive strip paper into the semicircle frame surrounding the ball. The suns rays burn a mark on the paper. Sunshine is measured in hours per day. The lines on the weather map showing areas of equal sunshine are called isohels
