Solutions: ps6_sol.pdf

Data: For this problem set, you'll look at annual averages of CO2 measured at Mauna Loa, Hawaii, originally by C. D. Keeling of Scripps. Here's the data file: keeling.mat

The file contains two variables:

keeling_year | indicates the year |

keeling_co2 | indicates CO2 concentration in ppm |

The full data record comes from http://cdiac.ornl.gov/ftp/trends/co2/maunaloa.co2. For more information see: http://cdiac.ornl.gov/trends/co2/sio-mlo.htm.

The annual averages have a statistical uncertainty of about 0.5 ppm.

Help with fminsearch: The Matlab function fminsearch requires an input function f(x) and an input guess at x. Matlab will minimize f(x) in the neighborhood of x. For the problem that we're solving, you can use my function expfit.m, which you will call using

x_out = fminsearch(@(x) expfit(x,concentration,year),x_in);

Of course you'll have to figure out how to define x_in, concentration, and year.