Sunday, May 13, 2012

4178.txt

date: Wed Jul 27 16:38:28 2005
from: Phil Jones <p.jonesatXYZxyz.ac.uk>
subject: Re: Figure for AR4
to: Kevin Trenberth <trenbertatXYZxyzr.edu>

OK. Not sure where it could go then. Lisa's map is much more spotty
than a schematic.
Phil
At 16:23 27/07/2005, you wrote:

I put them all together: that schematic is from Groisman 2005.
Kevin
Phil Jones wrote:

Kevin,
My view here was that this could replace the schematic we have (3.8.2), unless
we now have one instead of that from the Groisman et al. (2005) paper.
Phil
At 15:02 27/07/2005, Kevin Trenberth wrote:

Hi all
At present we do not have the figure Lisa sent on precvipitation in our chapter. Should
we? If so should we replace one or add it?
Kevin
Lisa Alexander wrote:

All,

Oops - sorry I can't spell. Please find new graph attached.
I've
plotted anomalies as bars like in the temperature plots. Phil, you
were
right - zero line is 22.53%. Caption:-

Observed trends (%) per decade for 1951-2003 for the contribution to
total annual precipitation from very wet days i.e. (R95p/PRCPTOT)*100.
Trends were only calculated for grid boxes where both PRCPTOT and R95p
had at least 40 years of data during this period and had data until at
least 1999. Black lines enclose regions where trends are significant at
the 5% level. Below the map is the global annual time series
anomalies
(with respect to 1961-1990) defined as the percentage change from the
base period average (22.5%). The red line shows a 21-term binomial fit
to the data to show decadal variations.

Cheers.

Lisa.

-----Original Message-----
From: Phil Jones
[[1]mailto:p.jones@uea.ac.uk]
Sent: Tuesday, 26 July 2005 8:26 PM
To: Lisa Alexander; Kevin Trenberth; Klein Tank, Albert
Subject: RE: Figure for AR4


Lisa,
Thanks for all this. The temperature ones look
fine now.
For the precip plot, the title needs to say 'contribution', so add
the
't'.
As with the temperature, it would be best if the map and the
time
series
were in the same units, so can you plot the time series
as % anomaly rather than % of the total contribution.
The plot should be the same. Maybe you can add
to the caption that zero is 22.5% of the annual total. It looks
about this number for 1961-90. We can do this if you give us
the
number.

Cheers
Phil


Cheers
Phil


At 10:29 26/07/2005, Lisa Alexander wrote:


Hi All,

I have redone the PDF's with the new subset of stations (this makes


very


little difference). Phil, you wanted the number of stations
used in


the


graphs so I've included that too.

Cheers.

Lisa.

-----Original Message-----
From: Lisa Alexander
Sent: Tuesday, 26 July 2005 4:41 PM
To: 'Kevin Trenberth'; Phil Jones
Cc: Klein Tank, Albert; David Parker
Subject: RE: Figure for AR4

Hi all,

I have converted the temperature maps and timeseries to days and used
the same y-axis for each of the timeseries plots.

Revised caption should be:

Observed trends (days) per decade for 1951 to 2003 for the percentile
temperature indices (a) cold nights (TN10p), (b) warm nights (TN90p),
(c) cold days (TX10p), (d) warm days (TX90p). Trends were only
calculated for grid boxes that had at least 40 years of data during


this


period and had data until at least 1999. Black lines enclose
regions
where trends are significant at the 5% level. Below each map is the
global annual time series anomalies (with respect to 1961-1990). The


red


line shows a 21-term binomial fit to the data to show decadal
variations. Trends are significant at the 5% level for all the indices
shown using a modified Kendall tau test. From Alexander et al.


(2005a).


I have also created the updated R95pT map and timeseries plot. The
map
is not currently in the paper but I am going to add it into Fig 9.


Note


that R95pT is only defined where PRCPTOT and R95p both exist.
The


R95pT


map is as the temperature map but for decadal trends (%) of the
contribution to total annual precipitation from very wet days.
The
timeseries is shown as actual percentage contribution (as in the paper)
but could be changed to anomalies for consistency with the temperature
plots if required.

Finally, I will have to check the PDF's since a slightly different US
network has been used but I will send you an updated plot if necessary.

Cheers.

Lisa.


-----Original Message-----
From: Kevin Trenberth
[[2]mailto:trenbert@ucar.edu]
Sent: Tuesday, 26 July 2005 12:34 AM
To: Phil Jones
Cc: Klein Tank, Albert; Lisa Alexander; David Parker
Subject: Re: Figure for AR4

Hi all
Thanks for being so responsive, especially Lisa. Agree with
Phil's
assessment. I would point out that precip is in another category
and %
is much more appropriate there as it provides a normalization and makes
more physical sense. The latter comes from Clausius-Clapeyron
which
expresses change in saturation vapor pressure as function of
itself
plus T etc. Thus it is a logarithmic relation de/e = d
(ln e) or


de/e


is a fraction = percent.
Kevin

Phil Jones wrote:



Lisa, Albert,
Agree that the paper and the IPCC plots should
be in the same


units.


Also the maps and the time series plots should be in the
same


units,


and


agree that days/decade are the most easily understood. The 4
temperature-
related indices (warm/cold nights/days) can be in these units.

The precip plot (R95pT) currently isn't in, but should with
its


map


replace what is currently there for 3.8.2.

By the way Lisa, the plot you sent (once in consistent
units)


will


be


with common question 3.1 on changes in extremes. For the text
on
temperature-related indices we will be using two of the panels
(cold/warm
nights) - top two plots from Figure 3 of the paper. If these
plots
have been
altered by any of the updated data (it would seem not) then can
you


send


revised plots.

So, in summary, I think the consensus for the 4
temp indices
will be days/decade.

For David, the change in units should make no
difference to the
REML trends.

Cheers
Phil


At 08:44 25/07/2005, Klein Tank, Albert wrote:



Hi Lisa,

Thanks for the updates.

Yes, I would prefer IPCC (and the paper) to present all temperature
indices results (time series plots, maps, tables) in days/decade,


which


I think avoids confusion about the calculated trends. I have done


this


in the past for Europe and the Pune paper, but I am aware that


others


have also used %.

Albert.



-----Original Message-----
From: Lisa Alexander
[[3]mailto:L.Alexander@bom.gov.au]
Sent: maandag 25 juli 2005 07:56
To: Kevin Trenberth; Klein Tank, Albert
Cc: Phil Jones; David Parker
Subject: RE: Figure for AR4

Hi All,

OK there seems to be some confusion (I must confess I'm a bit


confused


myself!). Do you want me to put either or both the timeseries
and


maps


as % or days? I changed the timeseries plots into days as


requested


(hence why the y-axis was different) but I didn't change the


gridded


maps.

I have now redone the maps and timeseries using updated data. The


main


changes are that additional data have been added over Brazil and


Africa


(precip only) and a more homogeneous US station network has been


used.


For some of the indices this has reduced the decorrelation length


scales


but for others (particularly precip) the correlations have


improved.


Hence you might note some slight differences in coverage in the
new
plots. I have also recalculated the timeseries using the new


dataset.


The attached plot shows the trends on the maps as % (index
measure)


per


decade and the timeseries are shown as anomalies (as in the
paper).


I'm


also attaching the actual global timeseries (% temperature,


fraction


precip as before) for David to calculate the REML trends. I
can


see


that trends of days might be more understandable but all trends in


the


paper were calculated using the units pertaining to each
particular
index. Albert, as a co-author of the paper would you prefer to
see


the


trends of both the maps and timeseries as days per decade?

If we can come to a consensus, I would be willing to redo the


diagrams


if you thought this would make the results clearer (bearing in
mind


that


I haven't received both reviews back yet).

Cheers.

Lisa.




-----Original Message-----
From: Kevin Trenberth
[[4]mailto:trenbert@ucar.edu]
Sent: Saturday, 23 July 2005 6:29 AM
To: Albert Klein Tank; Lisa Alexander
Cc: Phil Jones; David Parker
Subject: Figure for AR4

Hi all, esp Lisa:
I was going thru stuff on the figure and I am not sure we have it


right.


Albert suggested that the change in units of the time series makes


it


days instead of %. I do notice some small discrepancies with
the
original if it is % in relative values rescaled .
[Is it that 10% is 10% of 365 so it scales to 36.5 days?]

The problem is the maps are in %. So shouldn't we do the time


series


in


% too? We can add explanation in terms of days in the
text or


cpation


perhaps? Lisa does this mean the panels for the time series
need


to


be


redone with % scaling? Hopefully all the same. Or can we
explain


what


the time series is and why the maps are %?
Thanks
Kevin

--
****************
Kevin E.
Trenberth
e-mail:
[5]trenbert@ucar.edu
Climate Analysis Section, NCAR


[6]www.cgd.ucar.edu/cas/


P. O. Box
3000,
(303) 497 1318
Boulder, CO
80307
(303) 497 1333


(fax)


Street address: 1850 Table Mesa Drive, Boulder, CO 80303


Prof. Phil Jones
Climatic Research Unit
Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603
507784
University of East Anglia
Norwich
Email
[7]p.jones@uea.ac.uk
NR4 7TJ
UK



-----------------------------------------------------------------------


-


----




--
****************
Kevin E.
Trenberth
e-mail:
[8]trenbert@ucar.edu
Climate Analysis Section,
NCAR
[9]www.cgd.ucar.edu/cas/
P. O. Box
3000,
(303) 497 1318
Boulder, CO
80307
(303) 497 1333 (fax)

Street address: 1850 Table Mesa Drive, Boulder, CO 80303




Prof. Phil Jones
Climatic Research Unit
Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603
507784
University of East Anglia
Norwich
Email
[10]p.jones@uea.ac.uk
NR4 7TJ
UK
------------------------------------------------------------------------
----



--
****************
Kevin E.
Trenberth
e-mail:
[11]trenbert@ucar.edu
Climate Analysis Section,
NCAR
[12]www.cgd.ucar.edu/cas/
P. O. Box
3000,
(303) 497 1318
Boulder, CO
80307
(303) 497 1333 (fax)

Street address: 1850 Table Mesa Drive, Boulder, CO 80303

Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email [13]p.jones@uea.ac.uk
NR4 7TJ
UK
----------------------------------------------------------------------------


--
****************
Kevin E. Trenberth e-mail: [14]trenbert@ucar.edu
Climate Analysis Section, NCAR [15]www.cgd.ucar.edu/cas/
P. O. Box 3000, (303) 497 1318
Boulder, CO 80307 (303) 497 1333 (fax)

Street address: 1850 Table Mesa Drive, Boulder, CO 80303

Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email p.jonesatXYZxyz.ac.uk
NR4 7TJ
UK
----------------------------------------------------------------------------

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