Weather & Climate Flashcards
(13 cards)
Compare solar angles at higher/lower latitudes affecting temp
At HIGHER latitudes,
- SMALLER solar angle (acute)
- sun rays are spread over a WIDER area, leading to
- lower temperatures
At LOWER latitudes,
- LARGER solar angles (perpendicular)
- sun rays are spread over SMALLER area,
- higher temperatures
Describe altitude affecting temp
- Sun’s solar energy reaches the Earth’s surface in form of shortwave radiation
- Earth’s surface absorbs the shortwave radiation and in turn emits heat, in the form of longwave radiation
LOWER ALTITUDES
- At lower altitudes, air that is NEARER to the Earth’s surface absorbs MORE HEAT from longwave radiation, MORE HEAT TRAPPED by the greenhouse gases, HIGHER TEMP
HIGHER ALTITUDES
- At higher altitudes, air that is FURTHER from Earth’s surface, absorbs LESS HEAT from the longwave radiation, LESS HEAT TRAPPED by greenhouse gases, leading to LOWER TEMP
Describe cloud cover affecting temp
Presence of Clouds:
During the day:
- Reflects sun rays back to space,
- Preventing them from reaching earth’s surface and ABSORBS heat energy,
- Lowering surface temp
Night:
- Clouds absorb more heat radiated from Earth’s surface
- Preventing heat from ESCAPING into space,
- Lowering surface temperature
Absence of clouds:
During the day:
- Allow sun rays to reach Earth, earth’s surface HEATS UP QUICKLY, higher temperatures
Night:
- Allows heat radiated from Earth’s surface to ESCAPE, thus atmospheric air is cooler at night
Describe distance from sea affecting temp
Sea GAINS & LOSES heat SLOWER while land gains and loses heat FASTER
Maritime effect:
- Coastal areas experience COOLER SUMMERS and WARMER WINTERS due to moderation of temperatures by the sea (smaller annual temperature range)
- During Summer, sea gains heat slower than land, cooler air over the sea cools coastal areas (COOLER SUMMERS)
- During Winter, sea loses heat slower than land, warmer air over sea warms up coastal land, (WARMER SUMMERS)
Continental effect:
- Continental areas experience HOT SUMMERS and COLD WINTERS (large annual temperature range)
- During Summer, land gains heat faster than sea, higher temperatures in the summer
- During Winter, land loses heat faster than sea, lower temperatures in the winter
Describe convectional rainfall
- Occurs at tropical areas, and often associated with thunder & lightning while rain duration is short
Process:
- Earth’s surface is heated intensely, heats up surrounding air
- Air becomes unstable, expands then rises
- As air rises, it cools to DEW POINT TEMPERATURE, Condensation occurs, clouds are formed
- When water droplets in the clouds become too heavy, fall to the ground as rain
Describe relief rain
- Warm moist air passes over the sea and arrives at coasts
- Forced to rise over the windward side of mountain range
- As air cools until DEW POINT TEMPERATURE, condensation occurs and clouds are formed
- When water droplets in the clouds become too heavy, they fall to the ground as rain
- Leeward side of mountain is often dry as most rain is lost at the windward side
How does wind/ pressure affect temperature
- Temperature and air pressure have an inverse relationship
- Air moves from area of high pressure to area of lower pressure
SEA BREEZE (DAY)
- Air over land heated by sun causes warm heat to EXPAND and RISE, DECREASING air pressure on land
- At sea, air over sea COOLS and SINKS, (sea gains heat slower than land), INCREASING air pressure at sea
- Wind travels from an area of higher pressure (at sea) to an area of lower pressure (on land), forming sea breeze
LAND BREEZE (NIGHT)
- Air over land loses heat faster than sea, COOLS and SINKS, INCREASING air pressure on land
- At sea, air over sea is warmer as it loses heat slower than land, EXPANDS and RISES, (sea loses heat slower than land), DECREASING air pressure at sea
- Wind travels from an area of higher pressure (on land) to an area of lower pressure (at sea), forming land breeze
Describe Southwest monsoon (India Wet, Australia Dry)
(AIR CARRIES MOISTURE FROM SOUTH TO NORTH, DEFLECTS LEFT, southeast THEN deflects RIGHT, southwest after equator, MOISTURE FROM INDIAN OCEAN TO INDIA)
- From Jun to Sept, Northern Hemisphere experiences summer while Southern Hemisphere experiences winter
- In Northern hemisphere, high temperatures create area of lower pressure while in southern hemisphere, low temperatures create area of high pressure
- Air travels from an area of high pressure to an area of lower pressure
- When air moves in the southern hemisphere, it deflects to the LEFT via CORIOLIS EFFECT, wind travels from Southeast towards equator
- Once it passes equator into Northern hemisphere it deflects to the RIGHT via CORIOLSIS EFFECT moving from a Southwest direction
- Southwest monsoon passes the Indian Ocean, picking up alot of moisture, bringing heavy rain to South Asia, Central Asia is very dry
Describe Northeast monsoon (India Dry, Australia Wet)
(AIR CARRIES MOISTURE FROM NORTH TO SOUTH, DEFLECTS RIGHT, THEN LEFT MOISTURE FROM SOUTH CHINA SEA TO AUSTRALIA)
- From Oct to Jan, Northern hemisphere experiences winter while southern hemisphere experiences summer
- In northern hemisphere, low temperatures create high pressure while in southern hemisphere, high temperatures create area of low pressure
- Air travels from an area of high pressure to low pressure
- When air moves in the northern hemisphere, it deflects to the RIGHT by CORIOLIS EFFECT, winds travel from northeast towards equator
- Northeast monsoon monsoon blows over continental Asia, South Asia is very dry, However it blows over South China Sea, bringing heavy rain to Southeast Asia
- Once it passes the equator into southern hemisphere, deflects to the LEFT via CORIOLIS EFFECT moving from a northwest direction
- Northeast monsoon passes the Indian Ocean, picking up moisture, bringing heavy rain to Australia
Describe relative humidity affecting temperature
R.H. is the capacity of water vapour in the air
● Warm air can hold more water vapour as it expands ⇒ lower R.H.
● Cold air holds less water vapour as it is compressed ⇒ higher R.H.
➢ Influenced by temperature [recall 4 factors affecting temperature] - higher rate of evaporation of water, and presence of nearby water bodies
Describe equatorial climate
★ High temperatures:
➢ large solar angle ⇒ sun rays concentrated on
small area
➢ HIGHER mean annual temperature (abt 27C) AND
SMALLER annual temperature range
★ High amount of rainfall:
➢ Higher rate of evaporation of water vapour
➢ even rainfall pattern / high amount of rainfall
- Located between 10°N and 10°S, in the Tropics.
Describe Monsoon climate
★ High mean annual temperature, although lower than
that of equatorial climates, as they are further from the
equator
★ Small annual temperature range of 3C-4C
★ Uneven rainfall pattern:
➢ Distinct wet season in the summer and dry
season in the winter (give data for month with
lowest / highest amt of rainfall)
- Located between 5°N and 25°N, 5°S and 25°S
Describe cool temperate climate
★ Four distinct seasons
★ Cooler summers and mild winters
★ No distinct wet or dry season
★ Lower temperatures:
➢ Smaller solar angle ⇒ sun rays spread over wider
area
➢ LOWER mean annual temperature AND MODERATE
annual temperature range of 21C
★ Low amount of rainfall / Even rainfall pattern:
➢ Rainfall amount lower than monsoon / equatorial
climates
Located near coastal areas between 40°N and 60°N,40°S and 60°S
