Daisyworld & Feedback EffectsKump Chapter 2Tark Hamilton

Average Climate Response of the 5 Largest Volcanic Eruptions (1883-1991)

Krakatau (1883), Santa Maria (1902), Agung (1963), El Chichón (1982), Pinatubo (1991)

Mt. Pinatubo Luzon, Philippines

June 12, 1991-3days VEI=6 Event

10 km3 of tephra 20 Mtons of SO2

-0.5°C coolingO3 depletion

SO2 Aerosols block sunlight

Arc Volcanoes with subducted or sediment contamination are worst

Negative Feedback:

Equilibrium is Some Daisys &

Some Dirt!

Designing Graphs: Data Display (measurements points, details) versus

Concepts (general trends)(both are auto-scaled to show the range of variation)

Daily Temperature Variation

Systems Diagram

Graphic for how Surface Temperature Affects Daisy

Coverage

Two Forcing Functions: Surface

Temperature on Daisies (Curve) vs Daisys on Surface Temperature

(line)

& Equilibrium Diagram: P1 stable versus P2 unstable

Negative Feedback is Stable Equilibrium

Positive Feedback is unstable, runaway heating

Increased Solar

Luminosity increases

heat at constant

Daisy Coverage

Increasing Solar Luminosity Shifts Equilibria, while White Daisys still

reflect heat the same way: i.e. Just different stable %

coverage

Response of Daisyworld to Luminosity

ΔTeq = ΔT0 + ΔTf

Where: ΔT0 w/o feedback

ΔTeq < ΔT0

and ΔTf < 0

P1 shifts because of negative feedback

a) Daisyworld’s response to Increased

Luminosity (neg. feedback on T°C)

b) Lifeless Planet with fixed albedo

Captain Kirk

would never have

expected the blue curve!