Chapter 15 Flashcards
solar forcing
the cyclical variation in the input of solar energy
climate system
all the components of the earth system and all the interactions among those components
troposphere
the layer closest to Earth’s surface
what is the troposphere’s average thickness?
11 km
stratoshpere
above the trposhpere
how high does the stratoshpere extend?
50 km
what is the cause of Earth’s uneven heating?
the sun warms the air which expands and rises, causing the cool air to fall
that combined with the earth’s rotation causes uneven heating
thermohaline circulation
a global three-dimensional oceanic circulation pattern driven by differences in the temperature and the salinity of ocean waters
cryosphere
the ice component of the climate system
how much of the world’s fresh water is stored in the cryosphere?
75%
what part of the lithosphere is the most important to the climate system and why?
the land surface because it’s composition affects the way it absorbs solar energy. As it heats up, more energy radiates into the atmosphere causing more water to evaporate and the land surface to cool
biosphere
comprises of all living organisms on and beneath earth;s surface, in its atmosphere and in its waters
albedo
the fraction of the solar energy reflected by earth’s surface
greenhouse gases
water vapor
carbon dioxide
methane
ozon
greenhouse effect
the trapping of heat, which increases the temperature at the surface relative to higher in the atmosphere
positive feedback
the change in one component is ENHANCED by the changes it induces in other components
negative feedback
the change in one component is REDUCED by the changes it induces on other components
types of feedback
water vapor feedback
albedo feedback
radiative damping
plant growth feedback
water vapor feedback
a rise in temperature increase the amount of water vapor which enhances the greenhouse effect by raising the temperature - positive feedback
albedo feedback
a rice in temperature reduces the amount of ice and snow in the cryosphere which increases the energy the surface absorbs, causing the temperature to rise - positive feedback
radiative damping
a rise in atmospheric temperature increases the amount of energy radiated back into space which moderates temperature rise - negative feedback
plant growth feedback
increasing carbon dioxide stimulates plant growth which removes more carbon dioxide from the atmosphere, reducing the greenhouse effect - negative feedback
Milankovitch cycles
periodic variations in Earth’s movement around the sun
three types of Milankovitch cycles
eccentricity
tilt
precession
eccentricity
the degree ellipticity (how circular or elliptical the orbit is)
does a circular orbit have low or high eccentricity?
low
tilt
the angle of the Earth’s axis of rotation
precession
the wobble of Earth’s axis of rotation
atmoshpere-ocean gas exchange (carbon cycle)
the echange of CO2 across the interface between the ocean and the atmosphere
atmosphere-biosphere gas exchange
- greatest carbon flux
- exchange of CO2 between the terrestrial biosphere and the atmosphere by photosynthesis, respiration and decomposition
lithosphere-atmosphere gas exchange
CO2 dissolved in rainwater forms carbonic acid which reacts with carbonates in the rock, releasing carbonate ions that are transported by rivers and oceans
global dimming
the gradual reduction in the amount of global direct irradiance at the Earth’s surface
residence time
the amount of time a molecule spends in a resivior
geochemical resivoirs
atmosphere, hydrosphere, cryosphere, lithosphere and biosphere
flux
flow of chemicals from one component of Earth’s system to another
