milankovitch

Question 1

what are the three milankovitch cycles

Answer 1

eccentricity, obliquity, precession

Question 2

what is eccentricity

Answer 2

eccentricity cycles every 100,000 years
it is a change in the shape of earth’s orbit due to the gravity of other celestial bodies
goes from almost perfectly circular to more elliptical
highly variable compared to other cycles

Question 3

what is obliquity

Answer 3

obliquity cycles every 41,000 years
it is a change in the magnitude of earth’s tilt due to gravitational attraction from the moon
ranges from 22.1 to 24.5 degrees

Question 4

what is axial precession

Answer 4

axial precession cycles every 26,000 years
it is a change in the direction of earths tilt in a circular patter

Question 5

how does eccentricity affect climate

Answer 5

when it is more circular, heating is more even throughout the year. when it is more elliptical, heating varies based on months.
most heating at perihelion
least heating at aphelion

Question 6

how does obliquity affect climate

Answer 6

obliquity affects the intensity of seasons. when obliquity is higher, light is more/less dispersed during various seasons.

Question 7

how does precession affect climate

Answer 7

precession affects when seasons occur. when the axial tilt changes directions, seasons will occur at opposite times.
precession also affects how long seasons last since the rotation near perihelion is shorter than the rotation near aphelion

Question 8

what causes an ice age

Answer 8

interglacial periods start when the northern hemisphere experiences perihelion (eccentricity) while it is pointed towards the sun (precession) and has a higher axial tilt (obliquity).
glacial periods occur when the earth has a more circular orbit (eccentricity) and has a reduced axial tilt (obliquity)
it is influenced by the northern hemisphere because it has more land and therefore less specific heat, allowing temperature to change easier.
during interglacial periods, the summers are extreme enough to melt the ice from the previous winter. however it is unable to during glacial periods, leading to snow and ice to accumulate into ice sheets

Question 9

what are perihelion and aphelion

Answer 9

perihelion is when it is closest to the sun. aphelion is when it is farthest from the sun