August 2009

Our new garden shed

new_shed.jpgMy summer project is pretty much done. I haven't done much carpentry in the past, and found the construction process surprisingly educational. Constructing the flooring, framing, siding, roof, and putting in the window and door all had their own unique challenges in measurement, cutting, joining, etc. I still have to build some shelving and bins and put up some hooks and other devices to hold our tools - can't do that yet though as the kids have installed a couch and turned it into a play house for now. Another couple of weeks though and our new shed should be fully operational!

Perturbative two-box: applying the constraints

Continuing from the previous post, suppose we want to look at solutions where the (s) box is close to the short-time-constant (τ-) solution, and the (o) box then close to the long-time-constant (τ+) solution. That suggests setting the corresponding inverse time constants perturbatively close to τ- and τ+, respectively. Define dimensionless small numbers εs and εo as follows:

Eq. 27: αs = (1 - εs)/τ-
Eq. 28: αo = (1 - εo)/τ+

Then from the definitions of ν+ and ν- (unnumbered equation between 22 and 23 in the previous post) we find:

Two-box continued: solution space

This is essentially a continuation of the math in the previous post. The same warnings apply!

The previous analysis indicated we have 3 free variables to play with. Let them be αs, αo and Cs (the initial inverse time constants of the two boxes, and the heat capacity of the "surface" box).

Equations 9 and 12 of the previous post show a relationship between w+s and w+o depending on the α's, γ's and τ+, and equations 10 and 13 show the same relationship for w-s and w-o with τ- instead of τ+.

More two-box model: some fun with math

This will probably be painful for anybody who hasn't already been following this (which I'm sure is all but 1 or 2 readers, if that many). So skip this post unless you're really into solving systems of equations...

Playing with R trying to fit the modern temperature record to forcings

Ok, this time I'm going to start with the graph, and explain what's going on after. Seems to work for other folks... :
Global mean temperature and a fit to forcings