Weather and Climate Flashcards
Describe how latitude affects temperature
Spherical shape of the earth –> unequal distribution of solar energy at different angles of incidence
At equator: vertical rays -> greater concentration of solar radiation
- passes through shorter distance through atmosphere so less energy lost by reflection, scattering and absorption
- more intense heating, higher temperatures
Higher latitudes (nearer to the poles):
- larger angle of incidence
- larger surface area
- sun’s rays passes through longer distance through atmosphere so more energy is lost by reflection scattering and absorption
- less intense heating, lower temperatures
How does distance from the sea affect temperature?
- sea has a greater heat capacity than land
- water is more transparent than land so heat is able to be transferred at a greater depth, larger area is being heated
Maritime effect:
- the effect that large bodies of water have on coastal climates
- due to higher heat capacity, seas can gain heat more slowly during summers and retain more during winters
- onshore winds blow from the sea to the land, lowering temperatures in the summer and raising winter temperature
- temperature range is smaller than inland regions
Continental effet:
- due to lower heat capacity, landmasses gain heat more quickly during summer and lose heat more quickly during winters
- hotter summers, colder winters
- temperature range is larger than coastal regions
How do ocean currents affect temperature of Earth?
- prevailing wind blows over the ocean surface -> streams of flowing water
- warm ocean currents:
- coastal lands in temperate regions are moderated by warming effect on ocean currents
- warm currents warm the air above them –> warm air blows onshore so temperatures are kept higher
Cold ocean currents:
-cold currents cool the air above them so cool air blows onshore, temperature kept lower for coastal lands
How does cloud cover affect temperature?
-Clouds reflect and absorb heat
In the day:
- reflects some of the Sun’es energy back to space
- Reflects some of earth’s radiation back to the surface
At night:
- reduce loss of heat to space
- absorb heat radiated from Earth’s surface and reflects back to surface, keeping the surface warmer
- increased cloud cover:
- cooler days, warmer nights, smaller diurnal temperature range
How does type of surface affect temperature?
Albedo: measure of how much light that hits a surface is reflected without being absorbed
- Darker surfaces have a lower albedo
- Affects the microclimate of an area
- E.g. Arctic regions
- high albedo
- smooth and shiny ice caps reflect most incoming insolaton, so little heat is absorbed
- daytime temperature kept low
How does altitude affect temperature?
Greater altitude: cooler air
Increasing heights:
- air becomes less dense, cannot retain much heat
- less dust and water vapour, less heat trapped
- heat from the Earth’s surface escapes more rapidly
- Normal lapse rate = 6 to 6.5 degrees celcius per 1000m
What is the difference between relative and absolute humidity?
Absolute:
- Measure of actual amount of water vapour in the air (kg^-3m)
- provides little idea about the state of saturation of the air
Relative:
-gives relationship between actual amounts of water vapour and the maximum amount of water vapour the air can hold
Formula: (amount of water vapour in air)/(maximum amount of water vapour the air can hold) *100%
Describe relief/orographic rain!!!!! :) sup akshath
- onshore winds are quite moist
- blocked by mountain ranges so air is forced to rise and expand due to lower pressure at higher altitudes
- Due to expansion, air cools down, increasing relative humidity
- Water vapour reaches dew point, which is the temperature at which air is saturated
- Water vapour condenses
- Tiny water droplets aggregate to form clouds
- Continual condensation leads to larger droplets more rain on windward slope
Describe convectional rain
- Commonly occurs in warm or heated areas
- Air layer near the surface is heated up excessively due ot intense insolation
- Warm air expands and rises
- Rising air cools due to higher altitudes, reaching dew point, so air is saturated
- Tiny water droplets to form aggregate to form clouds
- Continual condensation leads to larger droplets, leading to rain
Describe land and sea breeze
Land breeze:
at night: land cools down faster than the sea
-Air above the land is cooler and denser -> higher pressure zone
-Air above sea is warmer and lighter -> lower pressure zone
-Air moves from land to sea
Sea breeze:
In the day:
-sea gains heat less quickly than the land
-air above the sea is cooler and denser so there is a higher pressure zone
-Air above the land is warmer and lighter, lower pressure zone
-Air moves from the sea to the land
Define L neck
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