4/3/24 - Lecture 3: Climate and Biomes Flashcards
Climate
The average atmospheric conditions, and the extent of their variation, at a particular place over a long time
Biomes
The world’s major communities, classified according to the predominant vegetation and characterized by adaptations of organisms to a particular climate
Name some (seven) of the biomes
Tropical rainforest, desert, temperate grassland, temperate deciduous forest, boreal forest, temperate evergreen forest, and tundra
What determines climate?
Incident solar radiation
Air circulation driven by solar radiation and Earth’s rotation
Coriolis effect
The deflection of air or water due to different latitudes of Earth moving at different speeds.
This means air going north from the equator will appear to curve right because it is going faster than the air there.
In the tropics, wind blows from the east to the west (trade winds). From 30°-60° latitudes, it blows from west to east (westerlies). Above that (60°+), it also blows from east to west (easterlies)
Easterlies
Wind coming from the east to the west
Westerlies
Wind coming from the west to the east
How does solar energy input influence atmospheric circulation and precipitation?
The equator receives the most sun. Parcels of air are warmed by the sun and expand and rise, but cool as they get higher. Cool air can’t hold as much water as warm air, so it releases it in the form of precipitation. Eventually the rising air starts moving north or south instead. Once this cool, dry air reaches 30° N or S latitudes, it goes back down which makes climates at those latitudes dry.
Similar concepts apply to the rest of the latitudes
Rain shadow
When a mountain is adjacent to a ocean, one side of the mountain has a wet climate and the other side has a dry climate.
This is because winds deliver moist air evaporated from the ocean to one side of the mountain, and the air rises and cools as it travels up the mountain, releasing rain or snow. On the other side of the mountain, the dried air goes back down and warms up, resulting in arid conditions
What causes seasonal variation?
Earth is at a 23.5° angle, which results in seasonal variation because the amount of light an area receives will be more or less intense depending on the angle at which light hits it
Intertropical Convergence Zone (ITCZ)
The area of most intense rainfall where the northern and southern Hadley cells meet
Tropical rainforest
Climate diagram: precipitation always higher than temperature, both rain and temp high year-round
Species: very diverse, home to epiphytic species
Desert
Climate diagram: temperature always higher than precipitation
Species: plants adapted to conserve water
Temperate grassland
Climate diagram: precipitation always higher than temperature (peak around 120 mm), but temp sometimes goes below freezing
Species: perennial grasses and forbs (herbaceous plants) that are adapted to grazing and fire
Temperate deciduous forest
Climate diagram: precipitation always higher than temperature, but temp sometimes goes below freezing. Compared to temperate grassland, has less rainfall (peaks around 90 mm)
Species: deciduous trees that shed leaves during winter
