weather and climate Flashcards
Air pressure
The weight of air on the Earth’s surface measured by a barometer in Millibars
Air Temperature
The degree or intensity of heat present in the atmosphere, measured by dry and wet thermometer and places in a Stevenson Screen
Cloud cover
The amount of clouds in a sky measured by observation in Oktas
Precipitation
Water falling from the sky in different forms, snow, sleet, hail, fog. Measured by a rain gauge in mm
Relative Humidity
The quantity of water vapor in parcel of air, measured by a hygrometer in grams of water vapor per kilogram of dry air
Wind speed
The velocity of moving air in the atmosphere, measured by an anemometer, usually in knots(nautical mile per hour
Wind direction
Measured from the direction wind comes from, measured by a wind vane
Isobars
lines on a weather map joining together places of equalatmospheric pressure
weather in low pressures
wet and windyweather
weather in high pressures
dry, sunny weather
Air pressure range
from900 mb(a hurricane) to1100 mb(an anticyclone).
isohyet
A line on a map that joins up places of equal rainfall
isotherm
A line on a map that joins up places of equal temperature
equatorial climate
Equatorial –heavy rainfall all year
Temperature - 25-30 all year, cold winters, mild summers
Annual rainfall – less than 250mm.
types of deserts
Extremely arid areas
Arid areas ( hot deserts)
Semi - arid areas
Cold deserts
extremely arid areas
have at least 12 consecutive months without rainfall e.g. Atacama desert.
Arid areas ( hot deserts)
less than 250mm of annual rainfall e.g. Namib desert.
Semi - arid areas
Less than 500mm of annual rainfall e.g. Mali
Cold deserts
Less than 250mm of rainfall. Located in interior of a continent or high latitude. Lower temperatures, often minus degrees in winter months.
where are deserts located
near the Tropics of Cancer and Capricorn
equatorial climate
home to TRF, heavy rainfall all year & temp 25-30 all year.
arid climate
( tropical zone) – deserts, clear skies, cool night, day time temp can exceed 45. Low annual rainfall – less than 250mm.
polar climate
cold ( below zero temp)and dry all year
tundra climate ( sub polar)
located 60-70 degrees North, cold and dry, slow growing plants
grasslands (subtropical zone)
Distinct wet & dry seasons – located 15-30 N/S.
relief rainfall
- occurs when warm, moist air from the Atlantic Ocean rises up over mountains.
- When the warm air rises, it cools and condenses to form clouds, which brings rain.
- Once the air has passed over the mountains, it descends and warms.
- This creates drier conditions known as arain shadow
conventional rainfall
- usually occurs during the summer in the UK, when the sun heats the land.
- This creates rising pockets of warm air, known as convection currents.
- Warm air rises rapidly, where it starts to cool and condenses to form clouds.
- These clouds can be largecumulonimbusclouds.
- The clouds can produce heavy rainfall and thunderstorms.
latitude
- distance from the equator
- Temperatures drop the further an area is from the equator due to the curvature of the earth
altitude
- height above sea level
- Locations at a higher altitude have colder temperatures. Temperature usually decreases by 1°C for every 100 metres in altitude.
distance from sea
Oceans heat up and cool down much more slowly than land. This means that coastal locations tend to be cooler in summer and warmer in winter than places inland at the same latitude and altitude
prevailing wind
The prevailing wind is the most frequent wind direction a location experiences
climate in tropical rainforests (TRF)
- Low pressure all year on the Equator.
- Midday sun almost vertical, giving maximum isolation.
- Average temperature all year round 26 degrees Celsius.
- Heavy convection rainfall and thunderstorms in the afternoon, as the sun has warmed the ground, causing the air to rise.
- Average annual rainfall 1750 - 2500mm
- High relative humidity 75%.
soil in TRF
- Most of the soil is not veryfertile.
- A thin layer of fertile soil is found at the surface where the dead leaves decompose.
- It is red in colour because it is rich in iron.
- Due to heavy rainfall the nutrients are quickly washed out of the soil.
lianas
these are woody vines that have roots in the ground but climb up the trees to reach the sunlight. Their leaves and flowers grow in thecanopy.
tree trunks
these are tall and thin to allow trees to reach the sunlight. The bark on these trees is smooth to allow water to flow down to the roots easily
drip tips
plants have leaves with pointy tips. This allows water to run off the leaves quickly without damaging or breaking them.
epiphytes
these are plants which live on the branches of trees high up in thecanopy. They get their nutrients from the air and water, not from the soil.
buttress roots
large roots have ridges which create a large surface area that help to support large trees.
animal adaptations in TRF
- Theslothusescamouflageand moves very slowly to make it difficult forpredatorsto spot.
- Thespider monkeyhas long, strong limbs to help it to climb through the rainforest trees.
- Theflying froghas fully webbed hands and feet, and a flap of loose skin that stretches between its limbs, which allows it to glide from plant to plant.
characteristics of hot deserts
- Hot seasons for most of the year
- Average monthly temperature of 29 degrees Celsius.
- Average annual rainfall of less then 250mm
- Temperature range of 5-50 degrees Celsius.
- Low humidity 25-30%
- Clear skies all day and night
- Coarse sandy soils with good drainage, little sub-surface water, low in nutrients and organic matter.
causes of hot deserts
- hight pressure
- cold ocean currents
- rainshadow effect
- continentality
high pressure
- sinking air warms and dries by compression
- no clouds = no rain
low pressure
deep rain cloud
cold ocean currents
ensures that there is little moisture available to cool and form clouds
rainshadow and continentality
Air descending from mountainous areas warms and dries by compression, little rainfall forms and aridity is the result.
