Weather & Climate Flashcards
What are cumulus clouds?
detached, individual clouds usually spotted at fair weather conditions
found low/mid altitudes
What are cumulonimbus clouds?
- more commonly known as thunderclouds
- associated with extreme weather conditions (e.g. heavy torrential downpours)
- only type of cloud that can produce hail, thunder & lightning
- vertical in shape due to very low pressure (rising air)
What are stratus clouds?
- low-level layers layers with fairly uniform grey or white colour
- lowest lying cloud type & sometimes appear at surface in form of mist or fog
- if these are thick enough they can cause light drizzle
What are cirrus clouds?
- short detached wispy clouds found at high altitudes
- don’t cause precipitation
- fast moving
- formed from ice crystals
What is weather?
short term variations (minutes to 15 days) in atmospheric conditions
What are the adaptations of a stevensons screen?
- double roof - heat not absorbed
- painted white - heat not absorbed
- slatted sides - allow air flow
- raised 1.2m above ground
What are stevensons screens for?
- standardising how weather temps are recorded around the world
- thermometers, hygrometers kept inside, sometimes barometers to shelter from rain
Where do you place stevensons screens?
away from buildings
What does a maximum-minimum thermometer show?
highest, lowest & current temp (C)
Why would a digital thermometer be better than a maximum-minimum thermometer?
more accurate, precise & easier to read
What maps are temps displayed on?
isoline map
What is a hygrometer for?
measuring relative humidity (%)
What does a dry bulb thermometer do?
used to record actual air temp & is just like a normal thermometer
What does a dry wet thermometer do?
has its bulb wrapped in saturated cloth, wet bulb temp is usually higher than dry bulb temp
How do you calculate humidity using a hygrometer?
- read off wet & dry bulb temps
- record dry bulb temp & difference between dry & wet bulb temps
- use relative humidity table
- find where dry bulb temp & difference between dry & wet bulb intersect
- table will tell you humidity as a % (e.g. 60% tells you the air is 60% saturated with water vapour)
What is a rain guage
measures amount of rainfall that falls over a given time (day/week/month) in mm
Where is a rain gauge placed?
- open space - no run off from trees/buildings can get into tunnel
- sunken into ground - prevent suns heat from evaporating any rain collected in collecting can inside
- sticking up at least 30cm from ground - ensures any rain that hits the ground doesn’t splash into funnel
What does a sunshine recorder measure?
hours of sunshine (hours)
How does a sunshine recorder work?
glass sphere partly surrounded by metal frame, suns rays burn a trace on cord, which is divided into hours & minutes, it should be replaced daily
What does a barometer measure?
atmospheric pressure (millibars - mb)
How does a barometer work?
inside is a small metal cylinder, which is a vacuum or spring inside that contracts/expands with changes in air pressure, which moves a pointer on the scale
What does an anemometer measure?
wind speed (km/h or m/s)
Where should an anemometer be placed?
outside away from obstacles which could block the wind
How does an anemometer work?
cups rotate as wind blows, stronger the wind, the faster the rotation, number of rotations are recorded on meter to give win speed
