Weather And Climate Flashcards
What is weather
The state of the troposphere at a given place and time
What is climate
The expected pattern of weather in a region over an average year
What is a thermometer
The instrument used to measure temperature (C)
What is a barometer
The instrument used to measure air pressure (millibars)
What is an anemometer
The instrument used to measure wind speed (knots, km/h)
What is a wind vane
The instrument used to measure the wind direction (compass, degrees)
What is a rain gauge
The instrument used to measure precipitation (mm)
What is used to measure visibility
Visibility meter (km)
How far ahead we can see
What are some of the elements of weather
Temperature
Precipitation
Relative humidity
Cloud cover
Wind speed/ direction
Visibility
Pressure
Sunlight hours
Lightning
UV index
Pollution index
what is air pressure
the weight of the air
Why are there two containers in the rain gauge
To prevent evaporation in the inner container. The air space between the containers insulates
Which container has the scale to measure the rainfall
The inner container
Why is there a funnel in the rain gauge
It directs rain to the inner container and it reduces evaporation. The top or lip of the funnel should be a strong sharp edge, to have an exact collecting area at the top of the gauge.
why is cold air heavier
because the molecules are closer together therefore denser
what is specific heat capacity
the amount of energy required to raise one gram of a substance by 1C
what are the three types of rainfall
convectional rainfall
relief rainfall
frontal rainfall
describe convectional rainfall
- energy from the sun heats the ground
- the warm ground heats a shallow layer of the air above. moisture on the ground is evaporated
- warm, moist pockets of air (convection currents) rise rapidly
- raising air cools, condenses and forms clouds
- precipitation occurs
describe relief rainfall
- warm moist air from the Atlantic Ocean rises up over mountains
- warm air rises, it cools and condenses to form clouds
- precipitation occurs
- once the air has passed over the mountains, it descends and warms. This creates drier conditions known as a rain shadow
describe frontal rainfall
- cold air meets warm air in a ‘weather front’
- warm air rises, so when it bumps into the cold air, it rises above it
- it eventually cools and forms clouds
- precipitation occurs
what is windward side
the side of the mountain when the wind hits
what is leeward side
the side of the mountain away from the wind
what is a front
a boundary between warm and cold air
why are there sand dunes in hot deserts
A desert is a ‘‘deserted’’ place. A ‘‘hot’’ desert is a tropical desert. It is acid, which means it has a maximum of 250mm of precipitation per year. There are no clouds so it gets very hot during the day and very cold during the night. Rocks expand and contract every day causing gradual disintegration.
eg Sahara desert
why are deserts around the tropics
During the day the Equator absorbs a lot of heat and the air warms up. The hot air rises, containing the water vapour. As it rises, it cools and diverges as it drops on the side of the Tropics. This removes all the moisture in the air. Making the deserts hot.
what are the 4 layers of an ERF
at 40m height= emergents
at 30m height= canopy
at 15m height= under-canopy
at 0-5m height= shrub layer
characteristics of ERF
- over 2000mm of precipitation
- low range of temperature 26-28C
- no seasons, hot and wet year round
- high humidity, 75-80%
eg. amazon in south America, new guinea, south-east Asia, Zaire basin
reasons of deforestation
- land for industry
- government
- land for agriculture
- land for settlements
- hydroelectric power reservoirs
- timber
- kapok stuffing
- paper
- roads/ transport
deforestation leads to
- less O2 and more CO2
- global warming
- less translocation
- drought
- erosion
- fires
