Variable Weather & Changing Climate Flashcards
define weather
condition of atmosphere at particular place & time
define climate
avg condition of atmosphere of specific place over long period of time
difference between weather & climate
climate is long term
weather is short term
4 elements of weather
- temperature
- relative humidity & clouds
- rainfall
- air pressure
4 Factors affecting the temperature of a place
- latitude
- altitude
- distance from sea
- cloud cover
what is a small vs large temperature range?
small: <10
large: >15 celsius
define latitude
distance of any point on the earth measuring from the north or south of the equator
How does latitude affect temp.?
sun rays strike at different angles at places with different latitude
Why at places with higher latitudes, there is lower temp.?
sun rays strike earth at smaller angles of incidence
more heat is lost b/c of longer distance travel
Why is the Equator high in temperature?
sun rays strike earth at right angle
larger incidence cause heat to be more intense, concentrated
less heat is lost to atmosphere b/c shorter distance travel
define altitude
the height of a place in relation to sea level
when altitude increase…
temperature decreases
Why temp decrease when altitude increase?
earth surface absorbs shortwave radiation
greenhouse gas absorb longwave radiation
atmosphere is mainly heated by earth surface
denser air absorbs more heat, but less dense air is found at high altitude
2 effects caused by distance from sea
- Maritime effect
- Continental effect
How does dist from sea affect temp.?
sea heats & cools faster than land
describe maritime effect briefly
cooler summer: cooler air by sea, lowers temp at coastal area b/c sea heats up slower
warmer winter: warmer air by sea, increase temp at coastal area b/c sea cools down slower
describe continental effect briefly
inland areas have no sea,
land heats and cools faster
warmer summer, cooler winter
describe how cloud cover affect temperature of a place
day: reflect large amount of sun energy back to space, reduce amount of sun energy from reaching earth surface
what is relative humidity?
ratio btwn actual amt of water vapour present in mass of air & maximum amt that air can hold at given temp
what is saturation
situation when relative humidity is 100%
how does saturation occur?
when max amt of water vapour that air can hold is reached
how are clouds formed
- water evaporates into vapour
- vapour rises, cooling starts
- vapour cools to dew point temp, condense and collide with each other to form large water droplets clouds
what is precipitation?
water in any form that fall from atmosphere to earth surface
ex of precipitation
snow, hail, rain
2 types of rain are
- convectional
- relief
describe convectional rain process
- earth surface heated excessively
- air becomes unstable as it expand & rise
- as air rise, temp decrease
- condensation occurs & formation of clouds
- heavy droplets rain down
describe process of relief rain
air passes over sea, picks up moisture before reaching coast, when moist air rise up windward side, it cools and rain by relief rain, most relief rain moisture falls on windward side
what is air pressure?
force exerted on unit area of earth surface by weight of column of air above it
whats the relationship between air pressure and altitude?
air pressure increase when alt decrease
air pressure decrease when alt increase
what are winds?
movement of air from area of high pressure to area of low pressure
what are monsoon winds?
regional wind patterns that reverse direction seasonally
describe formation of land breeze
land lose heat faster than sea, land has lower temp, air pressure higher, so air moves from land to sea
coriolis effect is a force produced by earth rotation. winds are deflected in which direction, in which part of the hemisphere
northern hemisphere: wind deflect right
southern hemisphere: wind deflect left
when does southwest monsoon occur
between june & september
when does northeast monsoon occur
between october & feb
for southwest monsoon, where does the monsoon come from and go to?
australia -> central asia
how does northeast monsoon occur
air over australia heats up, expand, rise, causes area of low pressure. since northern hemisphere experiences winter, air from asia moves to australia
3 types of climate
monsoon, equatorial, cool temperate
characteristics of equatorial climate
10 degrees N/S of equator
high temp & mean annual temp, small annual temperature range of 2 C, convectional rain
characteristics of monsoon climate
5 & 25 degrees N/S of equator
high annual mean temp
concentrated rainfall between june and sept
distinct wet & dry seasons
characteristics of cool temperate climate
40-60 degrees N/S of equator
4 distinct season, large annual temp range
mild winter cool summer
no distinct wet/dry seasons
what is global warming
increase in global temp over a long period of time
what 2 main causes lead to global climate change
natural & human activities
examples of natural causes that cause global warming
variations in solar output
volcanic eruptions
examples of human activities that cause global warming
burning of fossil fuels
deforestation
changing land use
how does variations in solar output affect global climate change?
when no. of sunspot increase, solar radiation become higher, areas surrounding sunspot release more energy, thus creating high & low cycle of temp
sunspot is what?
appear as dark spots & are the cooler regions on sun’s surface
how does volcanic eruptions affect global climate change?
eruption materials such as sulfur based particles, ash & dust can reflect solar energy back into space & causes cooling influence
what is greenhouse effect?
gases in atmosphere trap longwave radiation from earth surface & warm atmosphere
list some greenhouse gases
CO2, CH4,O3, NO2, CFCs, water vapour
what is shortwave radiation
electromagnetic radiation w shorter wavelengths & easily absorbed by hard surfaces
what is longwave radiation
electromagnetic radiation w longer wavelengths & easily absorbed by greenhouse gases
describe the PROCESS of greenhouse effect
shortwave radiation emitted by sun in visible light
some shortwave radiation reflected back into space, mostly absorbed
earth surface emit longwave radiation in atmosphere
