weather Flashcards
What does a Stevenson screen look like
white wooden box standing on four legs at a height of 121cm to avoid heat radiating from the ground and to have the thermometer bulbs at a standard height of 125cm
Reading must be taken at the same time each day
what instruments are found inside a stevenson screen?
rain gauge
wind vane
anemometer
wind vane
- what does it look like and what does in measure
measures the direction of the wind
compass points fixed in the correct directions
top of the long pole 10 meters high or three metres above a building
arrow at the top points to the direction from which the wind has come
broad end of the shaft catches the wind and swings in line with it
anemometer
measures wind speed with the units of m/s or Km/hr
it consists of 3 to 4 cups fixed on metal arms that rotate freely on a 10cm vertical pole
the stronger the wind the faster the cups rotate - more rotations recorded
many anemometers are digital that transmit data directly to apps and computers to show readings
they are placed far away from buildings or trees that can interfere with air movement
rain gauge
used to measure precipitation - can be measured per day in mm
measuring cylinder has to be flat on a flat surface
a too small reading is recorded as a trace
six’s thermometer
measures the variation temperature in celsius or fahrenheit depending on where you are in the world
temp measured using a thermometer of thermograph
shows daily minimum and maximum temperature
hygrometer
collects water vapour and then tells you the humidity
wet and dry bulb thermometers are used to measure relative humidity and are called hygrometer
warm air can hold more water vapour than cold air
when air holds as much water as it can it is sturated
not sturated when vapour evaporates from the wet bulb
aneroid barometer
has a partly vacuumed, ridgid metal chamber inside
there is a strong metal spring within the chamber that prevents it from collapsing
the spring will expand and contract with changes in atmospheric pressure
name all the cloud types (10)
- cirrus
- cirrostratus
- cirrocumulus
- altostratus
- altocumulus
- stratus
- cumulus
- stratocumulus
- nimbostratus
- cumulonimbus
what does relative humidity mean?
it’s a measure of how much water vapour the air is holding in relation to the maximum amount it could hold at a specific temperature
how is the mean daily temperature calculated?
maximum temperature + minimum tempe
2
state the meaning of precipitation
any form of eater that falls to earth, rain, snow, hail
cirrus
level
description
weather
- high above 6 km
- narrow wisps, white and made of ice crystals
- fine
cirrostratus
level
description
weather
- high above 6km
- thin, white layers made of ice crystals with a wide horizontal spread often covers the whole sky
- fine
cirrocumulus
level
description
weather
- high above 6 km
- thin, white, cloud with ice crystals
- fine
altostatus
level
description
weather
- medium 2 - 6 km
- either thin and white or grey and thick with layer of water droplets
- fine
altocumulus
level
description
weather
- medium 2 - 6 km
- thick white or grey looking, filled with water droplets
- fine
stratus
level
description
weather
- low 0-2km
- thin, uniform grey sheet of small water droplets with a fairly flat base
- fine drizzle
cumulus
level
description
weather
- 0 - 2 km
- white with a darker flat base and a wavy upper surface made of water droplets and can be compact or have hieght
- sunny by day, fine weather
stratocumulus
level
description
weather
- low 0 - 2 km
- white and grwy partly filled cloud made of water droplets
- fine
nimbostratus
level
description
weather
- base can be low or above 2 km
- thick, dark layers of water droplets
- steady rain or drizzle
cumulonimbus
level
description
weather
- low base but cloud usually extends to high levels
- dense, dark grey with vertical height, storm clouds. form from cumulous clouds and have a wavy head.
- very heavy rain, snow showers or hail with thunder and lighting 2
- tropical storms is the name for…..
2.
- deep, low pressure systems with spirals of strong air
2.
