date: Thu, 15 Jul 2004 06:41:09 -0600
from: Tom Wigley
subject: next
to: Sarah Raper
Sarah,
I will cover the new points and add the refs. They are
important in case we get some of these authors as
reviewers. It is hard to add text specifically to knock
the TAR method. One problem is that it should be
a differential equation at the outset. My addition changes
it to a differential equation -- but in a rather roundabout
way. The reason that the TAR method is OK is that
if the time scale is >> 100 years (as it seems to be) then
the d/dt term drops out. Praps I can add a little bit about
this at the end.
What is annoying to me is that the TAR method is
conceptually flawed and it happens to work not becoz of
cleverness and forward thinking by Jonathan, but by a
fluke.
Oh well.
Jane Leggett, who is funding some of my MAGICC work,
wondered about sensitivity proportional to remaining
V instead of A. To test this I can use proporional to V**n
for different 'n'.. Then we could cite the J. Glac. paper too.
This is only one line of code.
What 'n' range?
Here is what I said to Jane .....
------------------
> The linear with volume vs linear with area is something I will look
> into. There
> is a paper that Sarah is first author on in J. Glaciology a few years
> back where
> we note that one can use A = V**n. I can put this in the code to see the
> sensitivity to 'n'. My intuition says it will be small. To 2100,
> volume has no
> effect, so 'n' cannot be important. For large times the paths must
> tend to the
> initial volume, so 'n' can have no effect there either. Still, it is
> easy to do the
> full sums to check this out. Good point.
----------------------------
Tom.