The horizontal movement or transfer of heat by convection.

A thick and extensive portion of the troposphere having uniform temperature and humidity characteristics derived from its source region.

The reflectivity of a surface.

The way in which a slope faces towards or away from the sun and only has a noticeable affect in mid-high latitudes.

The average state of the atmosphere

Water vapour changes (condenses) to droplets of water creating condensation forms like clouds, fog and dew.

The level In the atmosphere at which condensation takes place.

For condensation to occur, the temperature in the atmosphere or on the land surface must be reduced. As the temperature decreases, the relative humidity in the air increases. If the relative humidity reaches 100%, condensation occurs as the air becomes saturated with moisture.

A form of energy that can be transferred by passing of heat by contact.

The transfer of heat by air currents or movements.

When moist air passes over land surfaces that have been strongly heated, the air is forced to rise and the condensation process begins.

When two large air masses come together or converge, the air is forced to rise and the condensation process commences.

Dew is formed m calm and settled conditions generally associated with anti-cyclonic weather. During the night, the temperature falls and the air is unable to hold as much water vapour. The cooling which causes dew is the result of radiation during the night. The air-cools from the ground upwards, and if dew point is reached, condensation will occur.

The temperature at which condensation takes place.

The daily range of temperature or other weather elements.

The average number of months where the average precipitation is greater than evapo-transpiration.

A name given to the occasional development of a warm ocean current along the coast of Peru as a temporary replacement of the cold Humboldt current which normally operates. El Nino is an extension of the Equatorial current and leads to an increase in surface water temperature of ten degrees and a decrease in plankton, which thrive in the colder current As a result of this reduction in their food supply the fish population is seriously depleted. It recurs every seven to fourteen years and results from a weakening of the SE Trades in the Pacific.

Increased gas (greenhouse) carbon dioxide, methane, and nitrous oxide, CFC.

Liquid water changes to invisible water vapour.

Evaporation from all terrestrial bodies.

Fog occurs when a whole layer of air is cooled below its dew point and moisture is condensed around tiny particles of dust. Depending on the temperature, it may be in the form of droplets of water, or ice atmosphere. Fogs are usually the result of air cooling by atmosphere. Fogs are usually the result of air cooling by contact with a cold surface atmosphere. Fogs are usually the result of air cooling by contact with a cold surface.contact with a cold surface crystals, both of which are heavier than air, but they are kept suspended by the slightest movements of the atmosphere. Fogs are usually the result of air cooling by contact with a cold surface.

Rainfall that is associated with the passage of a front over a location.

The boundary zones between two air masses.

This is a natural warming process of the earth where the earth’s atmosphere has always retained heat from the sun by a process similar to that which takes place in a greenhouse. This works by the glass trapping the incoming short wave solar energy and preventing it from re-entering back into space as it has changed to long wave radiation. The temperature rises as more heat enters the greenhouse than escapes. In the case of the atmosphere it is not glass but a blanket of carbon dioxide, water vapour and other greenhouse gases. such as methane, which refract and reflect the heat energy and so prevent its outflow. When the sun’s energy reaches the earth, some of it is reflected back to space and the rest is absorbed. The absorbed energy . warms the earth’s surface, which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases such as carbon dioxide, methane and water vapour, which then radiate the energy in all directions, warming the earth’s surface and atmosphere.

Humidity refers to the amount of water vapour present within the atmosphere. The actual amount of water vapour per unit volume is called absolute humidity. Relative humidity is the amount of water vapour in a given volume of air.

Some water falling on the earth's surface soaks into the ground,. and joins the underground aquifers.

The suns energy transmitted in the form of short wave radiation.

Lines drawn on a weather map to show places of equal barometric pressure.

Lines drawn on a map to show places of equal average annual rainfall (millimeters)

Lines drawn on a map to show places of equal average temperature.

Heat transfer which occurs during evaporation, condensation, freezing and melting.

Outgoing radiation from the earth's surface - sometimes referred to as terrestrial radiation.

The angle the sun makes with the earth’s surface at midday. Albedo The reflectivity of a surface.

This is the difference between the incoming and outgoing energy.

Are large continuous movements of seawater which circulate in the oceans and are caused by the rotation of the earth.

When moist air is forced to rise up over a mountain range in its path.

Water falling from the clouds as rain, hail, snow or sleet.

Heat in wave form sent out by the sun or earth.

Evaporation and transpiration from a land or plant source. Water changes from a liquid to a gas through heating of the water surface. Heat is trapped within the vapour (latent heat). Vapour rises in the air. Temperature decreases, condensation begins to occur, relative humidity starts to increase (if the relative humidity reaches 100% condensation occurs as the . air becomes saturated with moisture). Condensation takes place in the atmosphere- at a level called condensation level. The temp at which condensation occurs is called the dew point Water droplets become to heavy to be suspended in the cloud–they hen fall out of the cloud as rain.

The water, which does not soak into the ground or is used by plants, animals and people, runs off the surface into streams, river and lakes.

Incoming radiation from the sun.

A weather map.

This is a feature occuring in the early morning after a clear night, when terrestrial radiation is lost to space and the air near the ground has become cooler than the air above.

An envelope of air composed mainly of nitrogen and oxygen, which stretches from the earth's surface to about l00km above our planet.

The interaction of the atmosphere, hydrosphere, lithosphere and biosphere.

The system of living things and non-living environment with which they interact.

This is a natural warming process of the earth where the earth's atmosphere has always retained heat from the sun by a process similar to that which takes place in a greenhouse. This works by the glass trapping the incoming short wave solar energy and preventing it from re-entering back into space as it has changed to long wave radiation. The temperature rises as more heat enters the greenhouse than escapes. In the case of the atmosphere it is not glass but a blanket of carbon dioxide, water vapour and other greenhouse gases. such as methane, which refract and reflect the heat energy and so prevent its outflow. When the sun's energy reaches the earth, some of it is reflected back to space and the rest is absorbed. The absorbed energy . warms the earth's surface, which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases such as carbon dioxide, methane and water vapour, which then radiate the energy in all directions, warming the earth's surface and atmosphere.

The layer of water that cover the earth from a maximum depth of more then 11km in the oceans to shallower and less extensive bodies of water in lakes and river.

The sphere of rocks or upper layer of the mantle, which lies above the hot, semi molten and deformed rock of the deeper earth's mantle.

This is a comparison of the energy gained and lo t (inputs and outputs of energy).

The layer from about 12,000 meters to about 50kms above the surface–this is where the sky is always clear, there is no water vapour and no changes in the weather.

A belt of heat about ten degrees either side of the equator.

The lowest layer nearest the surface i.e. where all our weather patterns develop (12,000m above the surface).

The movement of water from the sea to clouds: to rain or snow: to rivers or underground and back to the sea.

The day to day description and measurement of the weather elements (temperature, moisture, cloud and wind)