## Saturday, June 9, 2012

### 5006.txt

cc: Eduardo.Zorita@gkss.de, hegerl@duke.edu, esper@wsl.ch, k.briffa@uea.ac.uk, m.allen1@physics.ox.ac.uk, weber@knmi.nl, t.osbornatXYZxyz.ac.uk
date: Mon, 04 Jun 2007 10:17:50 +0200
from: Anders Moberg <anders.mobergatXYZxyzgeo.su.se>
subject: Re: Fwd: cp-2006-0049 - Major Revision
to: Martin Juckes <m.n.juckesatXYZxyzac.uk>

Hi Martin and all others,

I have now had a look at our paper in relation to the three new reviews.
I have one major opinion: Move section 3 to a new appendix!

(However, I wasn't sure as to which file contained the revised version
on my PC, so I have instead read the CPD version. Hence, there may be
some inadequacies in my statements below)

If you read the paper without section 3, you will find that what remains
is a tightly focused paper which starts with a review of previous
reconstructions, followed by an investigation of the influence of
varying methods and data, which leads to an alternative reconstruction
that turns out to fit well with the instrumental record. This then leads
to some relevant conclusions.

Section 3 is not really needed for the rest of the paper. It is rather
an almost completely independent section, which is only in by-passing
referred to twice in section 4. Only one sentence in the conclusions
refer to section 3. It is not mentioned in the abstract.

So, given the fact that all three reviewers had concerns about section
3, I suggest you move it to an appendix. This would make the paper more
simple to read for most readers, while we still make it possible for
those who are interested to read our review of the hockey stick debate.
This is an easily made change. It would be sufficient with adding a
sentence or so in section 2.2, where we motivate an extended discussion
in an appendix (e.g. the political impact), and changing the very few
references to section 3 with references to an appendix.

1) Change my affiliation to be "Department of Physical Geography and
Quaternary Geology, and Department of Meteorology, Stockholm University,
Sweden"

2) sec 2, para 1. Change the mentioning of the scale factor (about
Esper) by 1.73, to specifying the time period and target region, which

3) We could omit the footnote abourt "underestimation"

4) sec 2.8. Rather than saying that "the debate is ongoing (several
refs)", we could mention some of the findings in these and other refs
(see below). For example, we could mention that results are dependent on
detrending/non-detrending, calibration period length, noise level, noise

@Article{sto06,
author = {von Storch, H. and Zorita, E. and Jones, J. M. and
Gonz\'alez-Rouco, J. F. and Tett, S. F. B },
title = {Response to comment on "{R}econstructing past climate from
noisy data"},
journal = {Science},
year = 2006,
volume = 312,
doi = {10.1126/science.1121571}
}

@Article{zor07,
author = {Zorita, E. and von Storch, H. and Gonz\'alez-Rouco, F.},
title = {Comment on "{T}esting the fidelity of methods used in
proxy-based reconstructions of past climate"},
journal = {Journal of Climate},
year = {2007, in print}
}

@Article{wah06,
author = {Wahl, E. R. and Ritson, D. M. and Ammann, C. M.},
title = {Comment on "{R}econstructing past climate from noisy data"},
journal = {Science},
year = 2006,
volume = 312,
DOI = {10.1126/science.1120866}
}

@Article{man07,
author = {Mann, M. E. and Rutherford, S. and Wahl, E. and Ammann, C.},
title = {Reply to comment by {Z}orita et al on {M}ann,
{R}utherford, {W}ahl, and {A}mmann '05},
journal = {Journal of Climate},
year = {2007, in print}
}

@Article{dmi06,
author = {Dmitriev, E. V. and Chavro, A. I.},
title = {Possible causes of the underestimation of paleoclimate
low-frequency variability by statistical methods},
journal = {Izvestiya, Atmospheric and Oceanic Physics},
year = 2006,
volume = {42},
number = {5},
pages = {586-597}
}

5) sec 4.2. The conclusion that "...the choice of proxy records is one
reason why different reconstructions show different ranges ..." is an
important one (even if it is not new). It should be mentioned both in
the abstract and the conclusions.

6) Remove the specific reference to the year AD 1091

7) At all relevant places, make it clear when we refer to the TAR and
when we refer to AR4 (if we do the latter at all)

8) Appendix A, INVR. Isn't there some mistakes in how the indices i and
k are used? As far as I can see, it should be:

Suppose $x_{ik}$, $i=1,N_{pr}$, $k=1,L$ is a set of $N_{pr}$
standardised proxy records of length $L$ and that we are trying
to obtain an estimate $\hat{y_k}$ of a quantity $y_k$ which is
known only in a calibration period ($k\in C$).

Suppose $x_{ik}$, $i=1,N_{pr}$, $k=1,L$ is a set of $N_{pr}$
standardised proxy records of length $L$ and that we are trying
to obtain an estimate $\hat{y_i}$ of a quantity $y_i$ which is
known only in a calibration period ($i\in C$).

cheers,
Anders