weather and climate

• Depressions: Isobars are close together showing strong winds

  Centre- Low pressure

  Fronts are present

  Winds moving in anticlockwise direction
• Anticyclone: air mass with high pressure at the centre

  consists of a single air mass so there are no fronts

  clear cloudless skies

  calm conditions

  dry weather
• Anticyclone weather: Summer - hot with lots of sunshine

  Winter - days are sunny, nights are cold and frosty

  Isobars are well spaced

  Winds blow in a clockwise direction

  Area of high pressure in centre

  No fronts meeting so weather is settled
• Campbell-Stokes Sunshine Recorder: Measures hours of sunshine per day

  Unit: Hours per day
• Rain gauge: measures rainfall

  Unit: millimetres (mm)
• Anemometer: Wind speed

  Unit: Kilometres per hour
• Wind vane: Wind direction

  unit: direction from where wind is blowing
• Thermometer: temperature

  unit: degrees celsius (isotherms)
• Barometer: atmospheric pressure

  unit: mill bars or hectopascals (isobars)
• Wet and dry bulb thermometers: relative humidity

  unit: percentage of air
• Stevenson screen: used to protect and store certain instruments

  painted white to reflect the sun
• Ireland's climate: cool temperature oceanic climate
• weather refers to the state of the atmosphere at a given time or place
• climate refers to the common/average weather conditions of a particular place over a long period of time
• met éireann - looks after weather in ireland
• information gathered is put into synoptic charts
• meteorologists study different things when studying the weather
• weather elements: humidity

  temperature

  atmospheric pressure

  wind force

  wind direction

  precipitation

  sunshine
• through regularities and patterns in weather conditions, forecasts can be made
• isoyets - lines on a map for rainfall
• a cloud is a collection of very tine and light droplets of water or ice crystals held in the atmosphere
• clouds form: warm air rises, it expands and cools. as it rises it cools and condenses to form tiny droplets. when billions of these droplets come together they form a cloud
• Cloud types: cirrus

  cumulus

  stratus
• cirrus = curl

  cumulus = heap

  stratus = layer
• cirrus clouds: looks like brush stroke

  high in the sky (above 8,000m)

  associated with fair weather
• Cumulus: looks like fluffy castles in the sky or cauliflower

  medium altitudes (below 5,000m)

  some large and dark cumulus clouds bring showers
• stratus: occur in thick layers

  are usually very low (below 2,000m)

  can bring long spells of precipitation
• types of rainfall: Relief rain

  Frontal rain

  Convectional Rain
• Relief rain: evaporation -> prevailing wind -> warm moist air rises over high ground -> air cools and condenses, forms clouds -> precipitation -> dry air descends and warm
• Convectional rain: sun heats the land and air above -> warm air rises, cools and condenses, forming clouds -> rain can then occur
• Factors that influence world climate: Latitude

  Prevailing winds and air masses

  Distance from sea/ocean
• Aspect: refers to the direction in which the slope is facing. For example, a slope can be facing north or south
• Aspect: In the northern hemisphere, the sun shines directly onto south facing slopes

  Warm southerly winds blow against south facing slopes

  They are protected from the cold northerly winds
• Altitude: Height above sea level

  In general, the higher you go, the colder it is

  The temperature drops 7 degrees for each 1000m you go

  This is because the air is thinner and it can hold less heat

  Upland areas are more exposed to the wind which also makes it colder. This is known as the Wind Chill Factor.
• Hot Climate

  Example: Hot deserts

  They are close to the equator

  1 Equatorial

  2 Savannah

  3 Hot Desert

  All 30degrees North and South of the equator
• Hot desert climate: Very dry - less than 250mm rain per year

  Hot - 30+ degrees

  Daily temperature range - 50degrees - 0degrees at night because of lack of clouds

  Natural vegetation: cactus

  Wildlife: Desert fox, Jackrabbit, Rattlesnake, Camel

  Lifestyle/human activity
• Tundra: 65-80 north of equator

  Alaska, north-west Canada, Northern Siberia

  Temperature: Winter: -25 Summer: 10-0

  Rainfall: Mainly snow, annual rainfall: Less than 250mm

  Fauna: Snowy owl, polar bear, arctic fox, reindeer, musk ox

  Flora: Severe cold limits growth - lichens and moss

  Human activity: Eskimo: base lives around fishing and hunting
• Boreal:

  Canada, Russia, Norway, Finland, Sweden

  Temperatures: Summer: Have long hours of daylight (due to the tilt of the earths axis), Temperatures are warm - average of 15 inland, Coastal areas are cooler

  Winter: Long hours without sunlight : -15

  Wildlife: Black bear, Lynx, Moose, Coyote, Timber wolf, Bison, Caribou (use forest for shelter in winter)