Weather Gateway 1 Flashcards
What is weather of a place?
Weather is the condition of atmosphere at a particular place and time.
What is climate of a place?
Climate is the average condition of the atmosphere of a specific place over a long period of time, usually over 30 years.
What are the factors influencing the temperature of locations? (4 factors)
Latitude (most important factor; solar angle)
Altitude (longwave & shortwave radiation)
Distance from the sea (maritime and continental effect)
Cloud cover (presence vs absence of clouds)
How does latitude influence the temperature of a location? (solar angle)
- temp is lower at higher latitude because
- solar angle is lower, sun rays strike at a lower angle, solar energy and heat is spread out over wider area.
- temp is higher at lower latitude between tropic of cancer and capricorn
- solar angle is higher, sun rays strike at a higher angle, solar energy and heat is more concentrated on a small area, higher temp
*this is the most important factor affecting temp of place
How does altitude influence the temperature of a location? (shortwave&longwave radiation; greenhouse gases; density of air)
- Higher the altitude, lower the temp (6.5°C decrease for every 1000m increase)
- About 45 percent of shortwave radiation from sun’s solar energy entering atmosphere is directly absorbed by the earth’s surface, heating it up.
- The warm surface emits heat in the form of longwave radiation. The higher the altitude, the further from the surface of the earth, air is heated less/cooler
- Longwave radiation that is emitted by the earth is absorbed by greenhouse gases like carbon dioxide in the atmosphere, causing sun’s solar energy to be trapped and warm the earth.
- Air that is nearer to the earth’s surface absorbs more heat from longwave radiation than air at higher altitudes.
- Air is denser at lower altitudes, dense air can absorb more heat from longwave radiation, higher temp at low altitudes (reverse is also true)
How does the distace from the sea influence the temperature of a location? (maritime and continental effect)
Maritime effect:
○The effect that lage ocean bodies have on climate of coastal areas → smaller annual temperature range
○Summer → air over the sea is cooler than air over land → land heats up quicker than sea → cooler air over sea cools coastal areas.
○Winter → air over sea warmer than air over land → sea cools more slowly than the land → warmer air over sea inceases the temp of coastal areas
Continental effect
○The effect that continental surfaces have on the climate of inland areas → larger annual temperature range
○inland areas are far away from the sea thus the temperatures are not influenced by sea
How does cloud cover influence the temperature of a location?
Presence of clouds:
○Day → large portion of the sun’s energy reflected back into space → earth’s surface remains cool → absorbs heat radiated from the earth’s surface
○Night → clouds absorb more of the heat that is radiated from the earth’s surface → prevents it from escaping into space → air near the earth’s surface kept warm at night
○Dunural temperature range is smaller
Absence of clouds:
○Day → allows large amounts of the sun’s energy to reach te earth. → the earth’s surface heats up quiickly → air near the earth’s surface is warmer
○NIght → allows more of the heat radiated from the earth’s surface to escape into space → air near the surface is cooler at night
○Dunural temperature range is larger
Relative humidity ( definiton, eqn, trend, saturation)
The ratio between the actual amount of water vapour present in a mass of air and the maximum amount of water vapour the air could hold at a given temoerature
relative humidity = amt of water vapour/max amt of water vapour the air can hold x 100%
warm air can hold more water than cold air
Saturation → when relative humidity is 100%
Air pressure
Air pressure: The force exerted on a unit area of the earth’s surface by the weight of a column of air above it
altitude increase → air pressure decrease → more compressed at lower elevations → larger overlying mass exerts a larger gravitational force
Wind
Air moves from an area of high pressure to an area of low pressure, known as wind
Pressure gradient is the difference in air pressure between two locations → ↑ in difference → ↑ air pressure
Land and sea breeze
Land breeze is wind that blows from the land to the sea
Night → land: lower temp, high pressure → sea: higher temp, low pressure → air looses heat to the land → air moves from an area of high pressure (land) to an area of low pressure (sea) as a land breeze. →air gains heat from the sea → warm air expands and rises, lowering the air pressure over the sea.
Sea breeze is wind that blows form the sea to the land
Day → land: high temp, low pressure → sea: low temp, high pressure → air looses heat to the sea→ air moves from an area of high pressure (sea) to an area of low pressure (low) as a sea breeze. →air gains heat from the land→ warm air expands and rises, lowering the air pressure over the land.
Southwest monsoon
Takes place between June and September → summer in the northern hemisphere → air over central Asia heats up → expands and rises → forming a region of low pressure over the area → Northern hemisphere is experiencing winter → low temperature causes air to be cold and dense → exerting a greater force on the earth’s surface → high pressure over Australia → pressure diff between central Asia and Australia → air moves from Australia to the Indian sub-continent and central Asia as southeast monsoon winds
As winds cross the equator, the coriollis
