Thursday, June 14, 2012

5142.txt

date: Thu, 16 Apr 2009 17:13:36 +0100
from: Thomas Crowley <thomas.crowleyatXYZxyzac.uk>
subject: Re: trends for n. land (summer) vs globe
to: Phil Jones <p.jonesatXYZxyz.ac.uk>

<x-flowed>
Phil

its hard to believe the nh land record is off - so the 1.5 C warming is
still significant - and the global temp. record is being cited a zillion
times - so as long as I keep it at that level, I don't understand why
there should be a problem - especially if I cut out or minimize any
discussion about offsets in the latter part of the record - doesn't that
seem a little worthwhile, given the fixation on global temps. rather
than land temps? tom
>
> Tom,
> I wouldn't bother posting this on Real Climate.
> Cheers
> Phil
>
>
> At 21:15 15/04/2009, you wrote:
>> Quoting Phil Jones <p.jones@uea.ac.uk>:
>>
>>
>> I don't want to be posting something on RealClimate.org that is going
>> to create confusion rather than clarification.
>>
>> should I just not submit the piece after all?
>>
>> tom
>>
>>
>>>
>>> John,
>>> Another possible issue is the 61-90 ship based SST normals
>>> for the SH oceans in the range 40-60S. I presume you're working on
>>> improving these for the next version.
>>>
>>> Cheers
>>> Phil
>>>
>>>
>>> At 12:10 15/04/2009, John Kennedy wrote:
>>>> The ARGO data don't go into SST analyses at the moment. They do make
>>>> measurements at depths that overlap with the deeper ship-based
>>>> measurements, so there's no reason why they couldn't be included in
>>>> the
>>>> future or used as an independent validation of the SST data once
>>>> the QC
>>>> issues are sorted out.
>>>>
>>>> Drifting buoys measure SSTs about 0.15C cooler than ships (with some
>>>> geographic variation) probably due to predominantly warm biases in the
>>>> ship data. They are included in SST analyses - more than 85% of all
>>>> SST
>>>> observations now come from buoys - and have probably led to a slight
>>>> underestimate in the rate of warming since the late 1970s when they
>>>> were
>>>> first introduced.
>>>>
>>>> John
>>>>
>>>> On Fri, 2009-04-10 at 22:29 +0100, Simon Tett wrote:
>>>>> I don't think ARGO goes into the SST dataset though there are a
>>>>> lot more
>>>>> buoys in it. When I was at the Hadley Centre we wondered if buoys
>>>>> were
>>>>> causing a slight cooling trend. [John Kennedy CCed might have some
>>>>> more
>>>>> thoughts on that.]
>>>>>
>>>>> Simon
>>>>>
>>>>> Susan.SolomonatXYZxyza.gov wrote:
>>>>> > Tom
>>>>> > The fact that land could be shown to be warming more than ocean
>>>>> was a
>>>>> > major conclusion of the AR4.
>>>>> >
>>>>> > It's good to see the update to 2008. Quite striking.
>>>>> >
>>>>> > I hate to say this, but I wonder if some of the recent behavior is
>>>>> > spurious - the Argo floats just don't seem very consistent with
>>>>> earlier
>>>>> > records not only for surface temperature but also for sea level (ie
>>>>> > subsurface). What do you think?
>>>>> > Susan
>>>>> >
>>>>> >
>>>>> > ----- Original Message -----
>>>>> > From: Thomas Crowley <thomas.crowleyatXYZxyzac.uk>
>>>>> > Date: Friday, April 10, 2009 6:10 am
>>>>> > Subject: trends for n. land (summer) vs globe
>>>>> >
>>>>> >> Hi,
>>>>> >>
>>>>> >> I am in the process of producing a new, long (733-1960) paleo
>>>>> >> reconstruction at annual resolution for purposes of better
>>>>> >> validation
>>>>> >> against models. since tree rings are most sensitive to summer
>>>>> half-
>>>>> >> year
>>>>> >> temperatures, and trees usually grow on land, I am calibrating
>>>>> >> against
>>>>> >> 30-90N summer (land), using HadCRU data updated through 2008,
>>>>> >> kindly
>>>>> >> provided by Phil.
>>>>> >>
>>>>> >> some interesting items jump out from just comparing (attached) the
>>>>> >> instrumental reconstructions for 30-90N land, summer vs global
>>>>> >> temps
>>>>> >> (anomalies based on 1960-1990 mean for each data set):
>>>>> >>
>>>>> >> 1) the n summer land changes are almost twice as large (1.5 vs.
>>>>> >> 0.8�C)
>>>>> >> as the global - this is not surprising because we know that land
>>>>> >> heats
>>>>> >> up faster than ocean, but the magnitude is quite striking.
>>>>> >>
>>>>> >> 2) since most people still live on land, this means the human
>>>>> >> impact
>>>>> >> factor has been twice as large as normally assumed for close to 3
>>>>> >> billion people
>>>>> >>
>>>>> >> 3) the divergence between northern land and global temps seems to
>>>>> >> be
>>>>> >> increasing - both record show the recent decrease in temperatures,
>>>>> >> but
>>>>> >> on land it only started last year (2008)
>>>>> >>
>>>>> >> 4) seven large volcanic eruptions can easily be identified in the
>>>>> >> northern land record - this again makes sense from an energy
>>>>> >> balance
>>>>> >> viewpoint, as summer temperatures are more driven by
>>>>> thermodynamics
>>>>> >> than
>>>>> >> dynamics, so the signal is more easily detectable, especially
>>>>> given
>>>>> >> the
>>>>> >> added impact of maximized reflection of insolation due to high sun
>>>>> >> angle.
>>>>> >> 5) this suggests that northern hemisphere land (summer) might be
>>>>> >> the
>>>>> >> most logical data set to look at for detection of volcanic
>>>>> signals.
>>>>> >> as
>>>>> >> I have nearly finalized the new paleo reconstruction of volcanos,
>>>>> >> it
>>>>> >> might be interesting to re-apply detection and attribution to the
>>>>> >> new,
>>>>> >> longer, and (hopefully improved) data sets.
>>>>> >>
>>>>> >> fyi, Tom
>>>>> >>
>>>>> >> --
>>>>> >> The University of Edinburgh is a charitable body, registered in
>>>>> >> Scotland, with registration number SC005336.
>>>>> >>
>>>>> >>
>>>>> >
>>>> --
>>>> John Kennedy Climate Monitoring and Research Scientist
>>>> Met Office Hadley Centre FitzRoy Road Exeter EX1 3PB
>>>> Tel: +44 (0)1392 885105 Fax: +44 (0)1392 885681
>>>> E-mail: john.kennedyatXYZxyzoffice.gov.uk http://www.metoffice.gov.uk
>>>> Global climate data sets are available from http://www.hadobs.org
>>>
>>> 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
>>> ----------------------------------------------------------------------------
>>>
>>
>>
>>
>> --
>> The University of Edinburgh is a charitable body, registered in
>> Scotland, with registration number SC005336.
>>
>
> 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
> ----------------------------------------------------------------------------
>
>


--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.

</x-flowed>

No comments:

Post a Comment