Changes in Solar radiation and volcanic activity Flashcards
What causes changes in the Global Energy Budget over time?
Changes in solar output and the chemical composition of the atmosphere due to volcanic activity
The Global Energy Budget is not static and fluctuates significantly.
What are sunspots?
Temporary phenomena on the Sun’s photosphere that appear as darker spots due to reduced surface temperature
Sunspots are caused by concentrations of magnetic field flux.
How often do sunspots increase and decrease?
Through an average cycle of 11 years.
What historical period is linked to minimum sunspot activity?
The Maunder Minimum, associated with ‘The Little Ice’ between 1645 - 1715.
What climate phenomenon marked the Maunder Minimum?
Significantly colder winters with lakes and rivers freezing.
What are the Milankovitch Cycles?
Three cyclical variations in the orbit of the Earth around the Sun: eccentricity, obliquity, and precession.
What does eccentricity refer to?
The variation of Earth’s orbit from nearly circular to slightly elliptical.
What is the cycle duration of eccentricity changes?
100,000 years.
Define obliquity in the context of Earth’s climate.
The angle of Earth’s axis of rotation, affecting the severity of seasons.
What is the current tilt of Earth’s axis?
23.4 degrees.
How long is the cycle of obliquity?
41,000 years.
What is precession?
The rotation of the Earth on its axis affecting seasonal contrasts.
What is the average cycle duration of axial and apsidal precession?
About 23,000 years.
What effect do volcanic eruptions have on climate?
They eject ash and sulphur into the atmosphere affecting radiative balance.
How long can sulphate aerosols linger in the stratosphere after an eruption?
Three to four years.
What is radiative forcing?
The alteration of Earth’s radiative balance due to volcanic aerosols.
What is a positive feedback loop?
A process that amplifies changes, leading to more rapid impacts.
Give an example of a negative feedback loop.
Increased evaporation leading to more precipitation, which can slow down warming.
What role does carbon dioxide play in climate change?
It is a greenhouse gas that amplifies the greenhouse effect.
What is the lapse rate?
The rate at which air temperature falls with height above sea level.
How does warming affect the lapse rate?
It causes a reduction in the lapse rate, leading to more outgoing longwave radiation.
What happens during periods of high eccentricity?
Approximately 23% more incoming solar radiation reaches the atmosphere.
