Tuesday, May 8, 2012

4001.txt

cc: rbattarb@geography.ucl.ac.uk, k.briffa@uea.ac.uk, rbradley <rbradleyatXYZxyzmate1.geo.umass.edu>
date: Mon, 19 May 1997 15:24:28 +0100
from: oldfieldatXYZxyzeigbp.unibe.ch (Frank Oldfield)
subject: PEP III in the Implementation Plan
to: gasseatXYZxyzphy.geol.u-psud.fr

Dear friends,

It is my prilvilege and delight on this sunny Whit Monday afternoon to be
finalising the text of our dear and much anticipated Implementation Plan.
As one of the books I was obliged to learn my terrible french from in the
1940's said (for reasons I have never fully understood...it was sometimes
hard to work out what Michel and Denise were getting up to... but the
phrase sticks in the numbed and crumbling mind)... "Oh joie! Oh paresse!"

There was a plan to put some stuff on Stream I into the Plan from the
Beirville Meeting - it is even minuted in the Stellenbosch SSC notes. All I
have is a Working Group report from Keith. I have created a new sub-heading
( STREAM I PRIORITIES) and used his text to put together a draft entry. In
so doing I have deleted some bits that seem to be said elsewhere in the PEP
III part of the Plan and I have changed odd bits where they need to be
rephrased. Please can I have reactions from you all as soon as possible.
Rick and Keith - does this still say what you mean and would you like to
see it included? Francoise - est-ce que tu pense que ca sera bon de
l'ajouter a ce qui est deje la? Y-a-t-il des idees dedans qui ne sont pas
essentielles ou avec lesquelles tu n'est pas contente? (Et j'espere que ca
va mieux pour toi).

Please let me have your responses as soon as ever possible. I really must
try to get this finalized before, like the Forth Bridge, the whole damn lot
needs another coat of paint.

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

STREAM I PRIORITIES

Arisng from discussions at the September 1996 Bierville Meeting, the
following priorities were identified:-

* A major focus of PEP III Stream I research should be on establishing the
degree to which 20th century climates are unprecedented. This must involve
quantitative reconstruction of past mean climates on multi-decadal and
century timescales as well as inter-annual variability and the frequency of
extremes.

* There remains a widespread preconception that the Little Ice Age and
Medieval Warm Epoch were ubiquitous features of the climate history of the
last two millennia. There is still a need to further clarify the
definition of these concepts in terms of their character, extent and
precise timing, even within Europe. More research is required to establish
the extent to which the concepts of the Little Ice Age and Medieval Warm
Epoch are valid or relevant in other areas of the transect. Future
research must attempt to clarify whether, if real, these phenomena
represent unique events within the last 2000 years, and, if possible, in
the context of the Holocene as a whole.

* Traditionally, high-resolution studies within the Stream I timeframe have
been very much concentrated in the mid-to-high latitudes of the northern
part of the PEP III transect. In part, this reflects genuine difficulty in
locating datable, high-resolution records in low latitudes and in the
African part of the transect.The existence of numerous, long tree-ring
chronologies in Morocco is an important exception. Some potential for
other dendroclimatological studies in north and east Africa has been
clearly demonstrated and the future development of this potential should be
explored.

* Given the problems of identifying annually resolved palaeosources in
Africa, there is a need to explore other less-well-resolved sources,
particularly where they might be represented across wide areas of the
transect. The concept of a specific research initiative aimed at exploring
climate proxies in the sediments of a series of African crater lakes along
the East African section of the transect is considered worthy of
prioritisation and a Workshop in Ethiopia in November 1997 has been
provisionally planned.

* Even in Europe, there is important potential for identifying and
processing historical and early meteorological records. Some
palaeo-series, produced perhaps decades ago, now require updating.

* More research is required in order to identify and gauge the significance
of anthropogenic environmental disturbance and the implications for
palaeoclimate estimates calibrated against modern climate data.

* Archaeological data have been underutilised in a palaeoclimate context.
Collaboration between archaeologists and palaeoclimatologists, especially
in areas with a tradition of detailed high-resolution archaeological work
and historical and palaeoclimate proxies, should be promoted. Several
regions, such as in the Mediterranean and in monsoon areas (particularly in
Egypt) and in the south of Africa, are potential foci for such efforts.

* Intense attention to accurate chronology is encouraged in situations
where absolute dating is not feasible. This might involve multiple dating
proxies.

* Work to establish a detailed network of tephra histories in the circum
North Atlantic Region and the possibility of developing a widely applicable
tephra chronology to provide fixed dating points for many
less-well-resolved data sources is noted.

* Studies within Time Stream I should not be constrained by the 2000 year
limit if longer timescales within the Holocene can be embraced with
equivalent precision and accuracy.

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

Over to you,

Frank


No comments:

Post a Comment