climate topic 1 Flashcards
(32 cards)
what is weather?
state of the atmosphere at a particular place and time. (short period of time)
what is climate?
average state of the atmosphere at a particular place over a long period of time
describe tropical equatorial climate in terms of temperature
- small temperature range
- high temperatures all year round
describe tropical equatorial climate in terms of precipitation
- high annual precip.
- precip. falls evenly throughout the year
describe tropical monsoon climate in terms of temperature
- high temp all year round
- small annual temp range
describe tropical monsoon climate in terms of precipitation
- high annual precip.
- distinct wet and dry seasons
describe cool temperate climate in terms of temperature
- 4 distinct seasons
- large annual temp range
describe cool temperate climate in terms of precipitation
- low annual precip.
- precip. fall evenly throughout the year
what are climatic hazards?
- extreme weather events that which impact natural and human systems
why do different countries experience different temperatures at the same time?
when the northern hemisphere leans towards the sun, it receives more direct solar radiation and experiences higher temperatures.
when the southern hemisphere leans away from the sun, it receives less direct solar radiation and experiences lower temperatures.
which time of day is the hottest and why?
midday.
- sun is directly overhead
- solar radiation is spread over a smaller area
- solar radiation is more conc
- highest temp
describe how the earth experiences day and night.
due to the earth’s rotation on its own axis, the side of the earth facing the sun experiences day and receives solar radiation. as the earth continues rotating, this side will eventually face away from the sun and experience night time where it does not receive solar radiation. 1 complete rotation takes 24 hours.
what are the 4 factors affecting temperature?
latitude, altitude, type of surface, dist. from sea
describe how latitude affects temperature
temp. are lower at higher latitudes. the higher the latitude, the smaller the solar angle so solar radiation is less direct as it is spread over a larger area and is less concentrated. thus they experience low temp. the lower the latitude, the bigger the solar angle so solar radiation is more direct as it is spread over a smaller area and is more conc. thus they experience higher temp.
e.g. sg 1 degree north of equator-> 29 degress celcius
beijing 40 degrees north of equator-> 12 degrees celcius
describe how altitude affects temperature
- temp is lower at higher alt.
- air is less dense at high alt, air is more dense at low alt.
- denser air absorb and radiate more heat. -> high temp
e.g. genting highlands:
alt of 1700m above sea level -> 21 degrees celcius. surronding areas at sea level are about 32 degrees celcius
describe how the type of surface affects temperature
- dark surfaces absorb more solar radiation and radiate more heat -> high temp.
- light-coloured surfaces reflect more solar radiation and radiate less heat -> low temp.
- urban areas with dark surfaces like roads have high temp. as the roads absorb and radiate more solar radiation
- rural areas with have more vegetation -> low temp
e.g. sg CBD is 2 degrees celcius warmer at night than in Macritchie reservoir which has dense vegetation
describe how distance from sea affects temperature
maritime effect:
- cooler summers
- warmer winters
- low temp. range
- air above sea heats up and cools down slower than land
continental effect:
- hotter summers
- colder winters
- higher temp. range
- air above sea heats up and cools down faster than sea
e.g. anchorage, a coastal city has a lower annual temp range of 23 degrees celcius
fairbanks, an inland city has a higher annual temp. range of 40 degrees celcius
describe the water cycle
- when the sun rays reach the earth, the air above the sea is heated up
- the warm water gains heat and evaporates into water vapour
- when water vapour rises, it cools and condenses into water droplets at dew point temp.
- when the water droplets in the clouds become big and heavy enough, they fall to the ground as precipitation
what is relative humidity?
the ratio of the amount of water vapour in the air to the max amount of water vapour the air can hold at a given temp.
what happens to relative humidity when temperature increases?
the amount of water vapour that air can hold increases
-> RH decreases
capacity of the atmosphere to hold the water vapour or moisture increases, thus decreasing the relative humidity
what happens when relative humidity exceeds 100%?
condensation occurs when more water vapour is added to the air or when air temp. drops
how is rain formed?
water droplets in the clouds collide and coalesce, becoming bigger and heavier. once water droplets are large enough , they fall to the ground as raindrops
describe the formation of convectional rain
- heat from the sun is absorbed by the land and the air above it gains heat
- warm air rises and cools and condenses on condensation nuclei at dew point temp. clouds are formed
- water droplets in the clouds collide and coalesce, and once water droplets are large enough, they fall to the earth as rain
e.g. thunderstorms in sg
describe the formation of relief rain
- prevailing winds pick up moisture over the sea and push it up the windward side of a mountain
- the rising moist air cools and condenses on condensation nuclei at dew point temp and clouds form
- water droplets in the clouds collide and coalesce, and once water droplets are large enough , they fall to the ground as rain on the windward side.
e.g. the windward side of sierra nevada mountain ranges receives higher rainfall and has lush forests. the leeward side is hot and dry creating the death valley desert.
