milankovitch cycle

Question 1

eccecnticity cycle

Answer 1

• over time, the shape of the earths orbit changes from being circlular to more eliptical. this changes the amount of solar radiation the earth recieves.
• the earth is reletivley further from the sun when the orbit is more circular recieviing less solar radiation causing a glacial period to occur

the shape of the orbit changes every 100,000 years which closely match to the glacial- interglacial cycle

Question 2

obliquity cycle

Answer 2

• the tilt of the earths axis changes between 21.1° and 24.5° , the current tilt is 23.4°
• the smaller the climatic defference between summer and winter when the tillt is 21.1°, meaning snow and ice is more likely to last the summer season, leading to a build up over time
• at 24.5° the temperature range between the seasons will be greater

Question 3

axil precession

Answer 3

• the earth goes through long cycles of ‘wobbles’ on its axis, meaning different parts of the earth go through phases of facing towards or away from the sun
• this causes the seasons to last different lengths in time. the longer the winter lasts, the more snow and ice remain on the earths surface

these cycles las 26,000 years

Question 4

long term

Answer 4

milankovitch cycles are the main driver of long term climate change. some scientisits believe that the milankovitch cycle and the interaction berween them are a way of kickstarting feedbacks which lead to further climate change
* the albedo effect
* during glacial periods cloud cover is greater due to increased evapouration. clouds reflect solar radiation back into space, cooling the earth down

Question 5

albedo effect

Answer 5

• where land and sea ice reflect solar radiation back into the atmostphere, creating cooler conditions which allow more ice to form