Weather
The day to day changeable state of the atmosphere.
Climate
Average conditions of a large area over the period of 30 years.
Weather
Sunny, rainy, cloudy, windy, snowy, stormy, foggy, sleet, hail stones
Climate
Oceanic, tropical, desertic, polar, mediterranean, taïga, mild
Temperate zones
Means the mild/Mediterranean areas not too hot or cold we live here in Europe
2 types
1)cold temperate
Northern
2) warm temperate
Mediterranean - south
Factors that can change climate
-Latitude: The suns energy is directly focused on the equator the further north/south you
go that same energy is spread out.
-Distance from water: water absorbs the most energy from the sun. The closer the milder
the climate water heats up slowly in summer and cools down slowly in winter. Creating
small temperature ranges further from water. Land heats up fast in summer and cools
down fast in winter. Creating large temperature ranges.
-Ocean currents
Circular movement of water caused by temperature change water heating up sinks down
and cools.
Warm: originates from the equator heat up and move north/south. Cools downs becomes
dense and returns back to the equator.
Cool: originates from the pole cools up and moves north/south. Heats down becomes
dense and returns back to the pole.
-Elevation: the higher the colder it gets air is thin at high elevation every 1000 meters the
temperature drops 6,5°C
-Prevailling winds: depends on where the wind originates from and what it travels over.
If wind comes from the equator then it will bring warmer conditions and cooler from North/
South.
If it travels over water it will bring wet conditions or humid over land is generally dry.
If it comes from west or east it’s generally mild.
Topography = shape of the landscape
Mountains - height = colder
- block wind / sun (aspect)
Flat land - desert / plain huge amont of wind
Rain types
- Air is forced to rise over land ( relief rain )
- Air rising due to heat of the land ( convectional rain )
- Air is rising because of a weather front ( frontal rain )
Relief rain see topographic diagram
,Explain convectional rain
- what
- explain how
- characteristics
- location/when (equator)
Convectional rain is when the intense heat from the sun heats up the land then the air
above rises and cools down rapidly. The air then condenses rapidly which then leads to
thunderstorms and heavy warm rain these usually happen in warm areas or the equator
and when the lands heats up.
Frontal rain
Cold air & warm air masses do not mix well due to differences in temperature and density
creating frontal rain
-cold air advancing into warm air cold front is present
- warm air advancing warn front exists
Cold fronts creates cumulonimbus clouds
Warm air creates stratus clouds
Air movement
- wind is the movement of air from high pressure to low pressure
- the greater the difference, the faster the wind moves
Air pressure
- difference in air pressure and caused by the uneven heating of earth
Earth atmosphere and surface are heated unequally
- air is heated at the equator and rises
- 30 degree north and south of the equator air begins to cool and sinks creates high
pressure
-between 30 degree and the equator cooling air moves back to the equator rest of air
flows towards poles.
Coriolis effect
Global winds
- the combination of pressure belts and the Coriolis effect cause global winds
Horse latitudes
-Warm air rises at equator and flows both north and south
Doldrums (area of no wind)
- located along the equator where no winds blow because the warm rising air creates an
area of low pressure
Synoptic chart
Isobars
- lines on a weather map
- join in places equal atmosphere pressure
On weather map:
- millibars - measure atmospheric pressure
- closer together - stronger wind
, Fronts
- occur where two air masses meet
3 types:
- cold front
- warm front
- occluded front
Anticyclones - high pressure systems
- dry sunny weather
- air descends and gets warmer
- able to hold more water
- highest number on the map
Depressions - low pressure systems
- lowest number on map
- low atmospheric pressure
- cloud, precipitation, wind
- air ascends and cools
- cannot hold moisture
- strong winds
- isobars close together
1- in the south of France we have mild weather with lighter wind the air is descending and cooling
down. Weather is good and clear with little clouds
2- in Norway we have occluded fronts with low pressure, there are strong winds because the isobars
are close together and we have an unsettled weather which causes rain.
3- In the east side of the Atlantic lower pressure so hotter weather compared to the west side which has
colder weather with low atmospheric numbers on the map and strong winds next to Greenland.
4- will bring dry weather fronts will also approach and bring frontal rains
Hot desert
Close to the equator around 20-30 degrees latitude
Latitude- intense heat of sun
Located in areas of high pressure - air descends and expands
Climate characteristics
- very hot during the day
- very cold at night
- precipitation varies throughout the climate type but overall little precipitation
Drought = a month with less than 10mm of rain