lesson 8 atmosphere - composition + Evaluation + Insolation + Cycling of Energy + Climate Change Flashcards
Interactions between the Geosphere, Atmosphere, Hydrosphere and Celestial Sphere
Ultimately driven by uneven solar input of energy –> transfer of energy between spheres to reach equilibrium
What causes transfer of energy and matter between atmosphere and hydrosphere, evident in the ocean, the troposphere adn groundwater
Differential solar heating (insolation of different locations) –> differences in energy (heat energy or gravitational potentional energy due to altitude) –> action caused to reach equilibrium
The atmosphere consist of four distinct layers that are defined by the reversal of temperature gradient
The atmosphere layers get thinner and higher altitudes
e.g 99% of the mass of atmosphere is in the lowest 80km
The earth’s atmosphere is composed of which three most common elment and their percentage:
Nitrogen with 78%, Oxygen with 21%, Argon with 1%
What are the four atmosphere layers and what are their temperature vs altitude relationships?
(hint: vertical zigzag)
Troposphere, Stratosphere, Mesosphere and Thermosphere
Troposphere and Mesosphere are relative: with increasing altitude their temperature decreases gradually
Stratosphere and Thermosphere are relative: with increasing altitude their temperature increases gradually
Water vapour in the atmosphere is mostly from the evaporation of bodies of water, thus will vary due to location.
Hence define humidity
The amount of water vapour that can be held in the atmosphere is humidity.
This is dependent on the temperature of the air with hotter air allowing MORE water vapour to be suspended.
Evolution
There are four major stages of evolution in Earth’s atmosphere`
What happened in the Hadean stage?
4.56-4 billion
Planetary accretion (accumulation of materials), early formation period of Earth, H and He lost due to lack of magnetic field
What happened during Archean?
4 - 2.5 billion years ago
Outgassing and cooling of the planet, first photosynthetic organisms appeared in 3.5 Ga and use CO2 makes stromatolites
Relates to the consuming of iron ions to form banded iron formations, keeping O2 levels in the atmosphere relatively low
What happened during 2.5-0.5Ga
Photosynthesis continued, life began to evolve, oceans became saturated with oxygen. Available oxygen forming ozone (O3), blocking UV penetration
What happened during 0.5 billion years ago until now?
Cambrian explosion of complex life, O2 levels rose even further when iron ions depleted, –> 30% with large insects and first coal deposists in swamps. Mass extinctions followed and then
O2, Co2 reach equilibrium at modern levles, causing ice ages
Insolation definition
The amount of solar energy received by a particular areaij
