Principles of Astrophysics 342
Spring 2003

HOMEWORK ASSIGNMENT #2
Due Thursday Feb 6, 2003 4:30PM

Click here for a PDF version of this assignment.

C&O refers to the textbook An Introduction to Modern Astrophysics, by B.W. Carroll & D.A. Ostlie

For atmospheric CO concentrations not too different from the present value, the radiative forcing of CO can be expressed by the formula

$\begin{displaymath} \Delta F = -6.3\times 10^3 \ln \left({C\over C_0} \right), \end{displaymath}$

where ppm is the CO concentration near the turn of the 20th century, is the CO concentration at some other time, and $\Delta F$ is the change (in ergs s $^{-1}$ cm $^{-2}$ ) in the outgoing infrared flux caused by the change in CO concentration.

(a)
By how much would the outgoing infrared flux decrease if the atmospheric CO concentration were increased from 300 ppm to 600 ppm?
(b)
By how much would surface temperature have to increase in order to bring the radiation budget back into balance in part (a), assuming that the planetary albedo and the amount of water vapor in the atmosphere do not change?

C&O, page 779, problem 18.13
C&O, page 818, problem 19.9

The address of this page is http://www.physics.rutgers.edu/~jackph/2003s/hw2.html
Please send any comments to Jack Hughes, jph@physics.rutgers.edu.

Revised January 30, 2003