Global Systems Flashcards
(29 cards)
Define lithosphere
Land
Define hydrosphere
Water
Define atmosphere
Air / gas
Define carbon cycle
The process by which carbon is recycled through soil, water, living things and the atmosphere
Sources in the carbon cycle
PRODUCES Respiration Oil Gas Fossil fuel combustion Coal Burning - woods & organic remains
Sinks in carbon cycle
CONSUME Tissue - plant & animal Trees Soils Oceans
Why is nitrogen essential for life
Nitrogen is an important element in proteins
- plants use nitrates from the soil
- animals consume nitrogen by eating plants & other animals
Define nitrifying bacteria
Absorbs nitrogen from the air trapped in the soil and convert it to nitrates that are useable for plants
Define denitrifying bacteria
Get their energy from the nitrates and convert them back into gaseous nitrogen, which is then released back into the atmosphere
What are leguminous plants
Plants that can take nitrogen from the air and fix it in their tissues
What are the effects of global warming on the water cycle
- energy from the sun drives the water cycle
- energy from the sun causes water to evaporated from moist surfaces (liquid ➡️ gas)
THIS CAUSES THE WORLD TO BE HOTTER
Difference between weather and climate
WEATHER
The state of the atmosphere over a short period of time
CLIMATE
The long-term averages of weather conditions
Natural influences on climate
SURFACE OF THE EARTH
- ice reflects 84% sun rays
- forest reflects 15% sun rays
GASES IN ATMOSPHERE
- nitrogen & oxygen allow heat waves in and out
ORIENTATION OF THE EARTH
- tilt of Earth affects how much sunlight hits it
- as Earth rotates, the atmosphere and waters of the ocean are dragged with it
Main causes of ocean currents
Wind Temperature Variations in salt levels Rotation of Earth on its own axis Gravitational pull of sun & moon
Thermohaline circulation
- surface currents and deeper currents interact
- water cycles from deep currents to surface currents then back to the deep again
THIS CIRCULATION IS VERY SLOW - takes 1600 years to complete one cycle
How the Global Conveyor Belt affects climate
- it distributes heat around the Earth
- as the global conveyor belt slows down the temperature difference is less between the poles and the equator
What is southern oscillation
- a sequence of changes to the atmosphere and ocean circulation across the Pacific Ocean and Indian Islands
- normally a cold current flows north along the coast of South America, then west along equator (it’s then warmed by the sun)
Factors used to calculate the southern oscillation index
The difference in air pressure between Tahiti and Darwin
El Niño
Drought
- QLD n NSW
La Niña
Significant rainfall
What is the Indian Dipole
A cycle of change in temperature between the Easter and western areas of Indian oceans, near equator
Evidence of climate change
GLACIERS
as glaciers move they grind against rocks on the sides of the valley through which they flow, the rock becomes deeply scored and when the glacier retreats this becomes visible
ICE CORES
on some glaciers and ice sheets enough snow falls each year to form layers
POLLEN ANALYSIS
pollen often becomes fossilised, which indicates changes in vegetation and climate
SEA LEVEL CHANGE
rocks and types of fossils can indicate changes in sea level
Difference between greenhouse effect and enhanced greenhouse effect
Greenhouse➡️ natural
Enhanced➡️ human impacts
Major gases that contribute to greenhouse effect
CARBON DIOXIDE
come from atmosphere
METHANE
produced in stomachs of cows and sheep and released when they fart
NITROUS OXIDE
produced in car exhausts, burning of forests and use of nitrous fertilisers
