lec 9 Flashcards
sunspots
magnetic storms on the sun the result in a very high energy output
cycles of every 11 years (flare-ups that result in elevated radiation lvls)
Milankovitch theory
the relationship between the sun and earth is constantly changing over time, due to shift in the geometry of the earth relative to the sun.
eccentricity
refers to the shape of the Earth’s orbit
shift between a circular and slightly oblong (ovular) shape
90,000-100,000 yer cycle
orbital precession
refers to the wobble of the earth’s axis
11,000-year cycle
where the tilt changes in orientation (maintaining the 23.5 degree tilt)
obliquity
the variation in earths tilit.
will change between 22 and 24.5 degrees
cycle of 40,000 years
how will changes in obliquity affect climate?
there will be less seasonal differences between the equator and higher latitudes at a lesser angle. this is because the subsolar spot will remain closer to a fixed point when compared to a larger axial tilt.
at a more extreme tilt, the higher latitudes will experience hotter summers and cooler winters
which hemisphere has a greater temperature buffer?
the south. This is becuase there is less land mass (more water). Water has a greater specific heat capacity than land
what is the potential effect of all the factors of the milankoitch cycles working at the same time?
they can either amplify situations or cannel the effect(s) of one another
ex large obliquity and an oblong eccentricity hold the potential to cancel each other it amplify depending on the season (fine summer but really cold winter)
energy surface balance
the average energy on the entire earth at a given moment
if the total surface enery is set to 100, what do we multiply by to get the actual W/m2?
3.41 W/m2
albedo
the fraction of inoming shrot wave radiation from the sun and is returned to space
where are short waves predominately ABSORBED in the atmosphere?
in the stratosphere by ozone
19% is absorbed by atmos and clouds
contributed to increasing earhts energy
how much energy is absorbed by the surface
51%
how much energy is reflected and scattered?
30%
done by
reflection off the surface (4%)
reelection off clouds (20%)
scattering via atmos (6%)
which heat type is most important to earth
latent heat