Latitude

Low latitudes: 0-30˚N or 0-30˚S of the equator

Sun's rays are direct, concentrated on a small section

of the Earth and travel through a shallower depth

of atmosphere

High latitudes: 60-90˚N or 60-90˚S of the equator

Sun's rays are slanted, spread over a large section of the earth and travel through a large depth of atmosphere

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Equator

Poles

Earth

The Earth orbits the sun, the revolution takes 365 days (1 Year).

The Earth also rotates on it's axis, it spins fully once every 24 hours. It rotates from west to east. Weeeeeeeee!

The tilt of the Earth's axis makes some of the earth lean closer to the sun at different times of the year. This creates seasons.

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The Coriolis effect

Wind moves from high to low pressure in a slanted direction because of the west to east rotation of the earth on its axis.

In the Northern hemisphere winds are deflected to the right.

In the Southern hemisphere winds are deflected to the left.

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Ireland is located at 53˚N.

It has south westerly prevailing winds.

It is in a temperate climate zone.

Wind

Wind is moving air.

Warm wind expands, it becomes lighter and rises. This is an area of low pressure.

Cold wind is dense, it is heavier and sinks. This is an area of high pressure.

Wind moves from areas of high pressure to low pressure. Winds are named after where they come from. This is called PREVAILLING WIND. Ireland’s prevailing

Air mass

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An air mass is a body of air with similar characteristics, such as temperature, humidity and pressure.

Examples

Polar Tropical Maritime Continental

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Fronts

Warm and cold fronts do not like to meet. When they do an invisible boundary forms. This boundary line is called a FRONT.

When cold air pushes into warm air it is

called a COLD FRONT.

When warm air pushes into cold air it is

called a WARM FRONT.

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Associated with heavy cloud and rain.

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Brings dark clouds and periods of rain.

Ocean Currents

Cold currents are ones which originate in cooler waters and flow into warmer waters.

Warm currents are ones which originate in warmer waters and flow into cooler waters.

Cold water is heavier and it sinks, warm water is lighter and rises. This creates convection currents in the seas.

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Prevailing winds blow over the surface of the water dragging it along in a current.

Effects of warm currents

They warm the water into which they flow, this keeps ports ice free and increases the temperature of the air blowing onto the land (onshore breezes).

As the air is warmed it can hold onto more water, this brings moist air onshore.

Example: North Atlantic drift. Originates in the Gulf of Mexico, begins as the warm Gulf Stream and flows past Western Europe bringing warm water to our shores.

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The south westerlies also blow in the same direction.

This brings warm moist air to Ireland.

Effects of cold currents

They cool the water into which they flow, this decreases the temperature of the water into which they flow and blow cool air onto the land (onshore breezes). Ports often freeze over.

As the air is cooled it holds less water, this brings dry air onshore.

Example: Labrador current - originates in the arctic brings cold water along the East coast of America.

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Canaries current - originates below Spain and flows along the West coast of Africa.

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Air pressure

Low pressureDepression / cyclone

When moist warm air meets cold dry air forming a front.The cold air moves in an anticlockwise direction.Centre of depression is in the 900's.Happen often in Ireland.

Weather conditions in a depression

1. Cloud forms as the warm air rises and condenses.2. Precipitation: Cloud becomes heavier, they fall as rain, hail, sleet or snow.3. Strong winds blow towards the centre of a depression.

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Brings wet, wind, unsettled weather to Ireland

The isobars close together indicates strong winds.

High pressureAnticyclone

A single air mass with a high pressure in the centre. Air gets warmer as it descends so clouds don't form.Air moves from high to low, so the winds travel in a clockwise direction.

Weather conditions in an anticyclone

1. Cloudless skies. Descending air, warms and doesn't condense.2. Hot & sunny weather in Summer and cold and frosty in winter.3. Dry as clouds don't form.4. Light winds as they blow out

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Centre of an anticyclone is over 1,000

from the centre of the anticyclone.

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The water cycle / hydrological cycle

Clouds

Three main types21

High: Wispy, good weather ,cirrus.

Low: Fluffy, cotton wool, light coloured = good weather. Dark = Rain Cumulus

Low: Layers, block out the sun and sky, bring wet weather or fog. Stratus.

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Precipitation

There are three main types of rainfall

Relief: Moist air meets a mountain, it rises, cools and condenses and falls as precipitation.

Cyclonic: The sun heats the earth, the warm land heats the air above it. The warm air rises, cools and condenses and falls as rain.

Convectional: Warm and cold air meet and form a front. Warm air rises, cools and condenses and falls as rainfall.

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Relief Cyclonic Convectional

Weather forecasting

Weather stations measure the following elements

1. Temperature 5. Wind direction

2. Precipitation (rain etc) 6. Atmospheric pressure

3. Sunshine 7. Humidity

4. Wind speed

All of these different aspects of the weather can be measured.

There are different weather instruments to measure each thing. 26

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