Chapter 6 - Atmospheric Conditions Flashcards
What are high pressure systems called?
Anticyclones
Weather forecasts
Global patterns of weather
What are the three kinds of barometer?
Mercury
Aneroid
Barograph
How does a maximum thermometer work?
○Measures highest temperature for the day
○Contains mercury which rises up the tube as the temperature increases
○Pushes pin in tube upwards
○Pin stays at highest point reached that day
__% of solar radiation directly heats the earth
50% of solar radiation directly heats the earth
Isotherm
Line on a weather map joining places of equal temperature
How does a Campbell-Stokes sunshine recorder work?
►Glass sphere
►Focuses sun’s rays onto a sensitive strip of paper slotted into a semi-circular frame behind the ball
►Sun’s rays scorch the paper
►As the earth spins, the position of the sun changes -> burn mark moves along the paper
►Scorch indicates duration and times of sunshine for day
How does a thermometer work?
►Glass rod with thin tube
►Liquid supplied from bulb - mercury or alcohol
►Temperature of liquid in bulb increases and it expands
►Rises up tube
►Fall in temperature causes liquid to contract and fall
►Tube marked with a scale in ºC
How does a wind vane work?
►Horizontal arm at one end and a tail at the other -> tail larger than arrow
►Wind blows tail around and points arrow to the direction from which the wind id blowing
How is a warm front formed? What weather occurs because of it?
○When a warm air mass moves into a cold air mass
○Because the warm air is less dense,it slides up over the colder air
○First cumulus clouds may appear; characterised by several days of rain
○May be followed by stratus clouds and some precipitation
What are the weather characteristics?
Temperature Humidity Atmospheric pressure Precipitation Wind direction and speed Sunshine Cloud amounts
Weather
The day-to-day condition of the atmosphere
Describe the characteristics of tropical continental air masses
○From Sahara
○Bring dry, sunny weather
Describe winter in terms of its relation to the tilt of the earth’s axis
○Northern hemisphere tilts away
○Days are short and temperatures are low as it receives the less solar radiation
○Sun located over Tropic of Capricorn
Describe summer in terms of its relation to the tilt of the earth’s axis
○Northern hemisphere tilted towards the sun
○Long days, receive the most solar radiation
○Sun located over the Tropic of Cancer
Solar radiation is transmitted in…
…rays, waves or particles
What is the Beaufort scale?
○Measures wind force
○Shows force of wind and resulting damage caused
○Recorded on a scale of 0-12
Describe the characteristics of polar maritime air masses
○From northeast Atlantic
○Bring cold, wet air and showers
What weather is associated with anticyclones?
○Clear cloudless skies
○Calm
○Dry
○Summer: Good weather. Hot with lots of sunshine
○Winter: Days sunny nights very cold and frosty. Clear skies allow heat to escape at night
Stevenson Screen
Meteorological screen used to shield instruments from wind, precipitation and direct heat from the sun
What weather occurs after a warm front passes?
○Sky clears, air pressure rises
○Temperatures also increase as the warm air replaces to cold air
○Air becomes warmer and more humid
Weather maps/synoptic charts
Summarise weather over a wide area using lines and symbols
Saturated
When air has absorbed as much moisture as it can
Describe how occluded fronts form and what weather is associated with them
○When cold front catches up with a warm front○Warm air is completely lifted off the ground by cold air in front and behind
○Changeable weather