160 likes | 333 Views
Chapter 3 Daisyworld. Objectives: Albedo Couplings between daisy coverage & T Equilibrium states in Daisyworld Response of Daisyworld to incr. solar output. A view of Daisyworld from outer space. Couplings between daisy coverage & T . T. Daisy coverage. Daisy Coverage. albedo. T.
E N D
Chapter 3 Daisyworld Objectives: Albedo Couplings between daisy coverage & T Equilibrium states in Daisyworld Response of Daisyworld to incr. solar output ENSC 425/625 Chapter 3UNBC
A view of Daisyworld from outer space ENSC 425/625 Chapter 3UNBC
Couplings between daisy coverage & T T Daisy coverage Daisy Coverage albedo T Daisy Coverage T • Incr. daisy coverage of planet => decr. T. ENSC 425/625 Chapter 3UNBC
daisy coverage daisy coverage T T optimum Daisy coverage T min. max. • Daisies can live between a min.T & a max. T ENSC 425/625 Chapter 3UNBC
Effects of daisy coverage on T daisy coverage daisy coverage T T P1 Effects of T on daisy coverage Daisy coverage P2 T • Intersection of 2 curves means the 2 effects are balanced => equilibrium points P1 & P2. ENSC 425/625 Chapter 3UNBC
Effects of daisy coverage on T P1 Effects of T on daisy coverage Daisy coverage P2 T Feedback loops ENSC 425/625 Chapter 3UNBC
P1 Daisy coverage P2 T • Perturb daisy coverage at P1 => sys. returns to P1 (stable equil. pt.) A large perturb. => daisies all die from extreme T ENSC 425/625 Chapter 3UNBC
Daisy coverage P1 P2 T • Large incr. in daisy cover => very low T => decr. in daisy cov. => very high T => lifeless. ENSC 425/625 Chapter 3UNBC
daisy coverage T Daisy coverage P1 P2 T • From P2, incr. daisy cov. => decr. T => further incr. in daisy cov. => converge to P1 unstable equilib. pt. ENSC 425/625 Chapter 3UNBC
Gradual incr. in solar luminosity P1 P1 P2 Daisy coverage To Tf Teq P2 T For any particular value of daisy cov., T incr. The effect of T on Daisy unchanged ENSC 425/625 Chapter 3UNBC
% daisy cov. T Solar luminosity • As solar lum. incr., T incr. => daisy cov. incr. • Eventually, daisies cannot expand, but T keeps incr. => daisies dying => decr. albedo => rapid T incr. (pos. feedback) => daisies extinct. Max. T for daisy survival Min. T for daisy survival ENSC 425/625 Chapter 3UNBC
Lessons from Daisyworld • Despite change in forcing, climate sys. can counter part of the change by negative feedback loops. • Non-intelligent life form can appear to be ‘intelligent’, i.e. they do the right thing to their environment. • Daisies do not optimize T: T at stable equil. pt. P1 < T for optimum daisy growth. ENSC 425/625 Chapter 3UNBC