L10 - The Water Cycle Flashcards
(24 cards)
What are the three natural forms of water?
Liquid water, water vapour, and ice.
How is hydrogen involved in the biosphere?
Incorporated into biomass via photosynthesis.
Released during respiration or combustion as water.
Why does water have a high boiling point?
Due to its strong electric dipole and hydrogen bonding between molecules.
Name four key properties of water
Large heat capacity
High latent heat of evaporation
Large surface tension
Effective heat transporter
Which reservoir holds the most water?
The oceans (1.338 × 10⁹ km³).
How fast does water turnover in the atmosphere compared to the ocean?
Atmosphere: ~8 days
Ocean: ~2600 years
What is the role of the oceans in the carbon and heat cycles?
Absorb CO₂
Act as the largest heat reservoirs
Transfer heat from tropics to poles with the atmosphere
What is the cryosphere’s effect on climate?
Influences planetary albedo and atmospheric circulation.
What is evapotranspiration?
The combination of evaporation from land and transpiration from plants.
What is the Bowen Ratio?
The ratio of sensible heat flux to latent heat flux at the Earth’s surface.
How does cloud formation begin?
Moist air rises and cools
Reaches dew point
Condensation onto cloud condensation nuclei (CCN)
What is the role of latent heat in cloud formation?
Released during condensation, promoting further convection and cloud growth.
What are cloud condensation nuclei (CCN)?
Aerosol particles that water condenses onto to form clouds.
What is glaciation in clouds?
The conversion of supercooled water droplets into ice crystals.
How does snow form?
Ice crystals coagulate and fall under gravity.
What is graupel?
Large ice pellets formed when supercooled water freezes onto falling ice particles.
What human activities alter the water cycle?
Aquifer mining
Surface water diversion
Desertification
Wetland drainage
Deforestation
Dam building
Why is water considered a climate feedback rather than a forcing?
Because atmospheric water increases in response to warming but is not directly controlled by human emissions.
How do aerosols influence clouds and climate?
More CCN → More, smaller cloud droplets
Increases cloud albedo
Net cooling effect (but complex and uncertain)
How does melting sea ice affect climate?
Reduces surface albedo
Alters atmospheric circulation
Potentially weakens the polar vortex
Why is the Greenland and Antarctic ice sheet melt concerning?
Could raise sea levels by ~70 meters
Disrupt thermohaline circulation
Lead to abrupt climate changes
What is snow-ice albedo feedback?
Melting snow/ice lowers albedo, leading to more solar absorption and further warming.
What happens if the Amazon rainforest is lost?
It may permanently transition to savannah, disrupting regional hydrology.
