Thursday, May 10, 2012


cc: Keith Briffa <>, Simon Tett <>,
date: Tue, 25 Jul 2000 15:28:56 -0600 (Mountain Daylight Time)
from: "Tom M.L. Wigley" <>
to: Lesley Aspinall <>


Minor comments on Science Plan below:
(1) Para 1, last line: "The" to "the"; Hadley Ctr name in full (?)

(2) Para 2, line 3: "communities" should be "community's"

(3) Para 2, line 4: Check consistency of "Met" vs "Met." vs
"Meteorological" -- as in ditto Office.

(4) Para 2, line 8: redundant "with" at end of sentence.

(5) Para 2, line 12: insert "also" before "enable" in the second use of
the latter word.

(6) Para 2, last line: delete "during this period" -- sounds very odd.

(7) Para 3, line 2: delete comma before "or prediction".

(8) Para 3, line 4: delete comma before "or their".

(9) Para 3, lines 9, 10: should "jointly formulated...scientists" be
italicized? This is a really crucial point! (Check italicizing idea with
Keith and Simon.) There may be other phrases that could be emphasized in
this way.

(10) Research Prog., Para. 1, lines 5,6: "major
emphasis...millennia" could be italicized (see (9)).

(11) Items 1, 2, 3, 4: title phrases could be italicized.

(12) Item 1, line 3: "It includes" to "This includes".

(13) Item 1, line 7: For better flow, change "This encompasses" to
"Investigations in this area may encompass"

(14) Item 1, line 8: Inconsistency -- decadal to century earlier, annual
to multidecadal here. Change required. (Check with Keith and Simon.)

(15) Item 2, line 5: Should be a comma after "i.e."

(16) Item 2, line 10: "at the last" to "around the time of and subsequent
to the last". The key issue here is really the changes around the time of
the Younger Dryas and early Holocene -- the present wording doesn't cover
this period and must be changed.

(17) Item 4, line 1: "global-mean" should be hyphenated when used as an

(18) Item 4, lines 4,5: "models responses" to "model responses". Also,
put "such as vegetation" in parentheses (i.e., "(...)").

(19) Item 4, line 7: "and irreversible" to "and/or irreversible". These
things don't have to go together!

(20) Item 4, line 9: "to provide" to "may provide".

(21) Item 4, line 10: comma after "studies"

(22) Item 4, last sentence: I strongly recommend deleting this
sentence. It is unnecessarily constraining; and the relevant timescales
have already been covered.

(23) Bullet 2, line 2: "can" to "may"

(24) Bullet 3, line 1: delete comma before "sets".

(25) Bullet 4, end: Period at end seems misplaced.

Apart from these details, the text now reads extremely well -- clear,
informative and eschewing sesquipedalianisitic verbosity.

Best wishes,


On Thu, 20 Jul 2000, Lesley Aspinall wrote:

> Dear Tom and John In case there is any problem opening the attachment
> to my previous e-mail, here is the cut and pasted version: Best wishes
> Lesley
> Palaeo-climatic Research and Earth System Modelling for Enhanced
> ClImatic and ENvironmental PredicTion (PRESCIENT)
> Draft Science Plan
> PRESCIENT is a five-year thematic program that will fund co-operative
> research between scientists creating palaeo-climatic reconstructions
> and those developing and using models of the Earth System. It aims to
> improve our understanding of, and prediction of changes in, the
> climate and biological system by rigorously testing the capabilities
> and reliability of Earth System models using palaeo-data. Its specific
> focus will be on increasing the sophistication and versatility of
> Earth System models with particular emphasis on that being developed
> at The UK Met. Office's Hadley Centre.
> The programme aims to assemble palaeo-data and to develop a
> methodological framework for its use in validating Earth System
> Models. It will combine the palaeo-climatic communities work in
> reconstructing past climatic changes with the modelling work of the
> Met Office and the UK academic community. Both communities will gain
> from this partnership with the palaeo-community having a better
> understanding of the modes and mechanisms of the global climate system
> and the modelling community obtaining palaeo-datasets with which to
> test Earth System models with. Therefore, both the Hadley Centre and
> the University Global Atmospheric Modelling Programme will be closely
> involved in the research programme. The partnership that will be
> fostered within PRESCIENT will enable the latest experimental model
> runs to be made available to the wider palaeo-climate community. It
> will enable a thorough testing of the natural variability of Earth
> System Models. Additional sensitivity experiments, using forcings
> provided by appropriate research communities, will evaluate specific
> sub-components of the model. This work will greatly enhance the
> validation and development of Earth System models far beyond what
> would be achieved by modellers alone during this period.
> We welcome proposals that are concerned with a mode of climatic or
> environmental variability of immediate relevance to the detection, or
> prediction of anthropogenic change, or have a focus on regions of
> major relevance to important climatic and biological processes, or
> their sensitivity to climate change. Joint studies between modellers
> and palaeo-scientists are encouraged. Proposals that aim to collect,
> analyse or interpret palaeo-climate archives and which aim to produce
> new simulations will also be considered providing they are clearly
> formulated to challenge important model assumptions or results. In
> other words, each proposal should test a hypothesis jointly formulated
> by modellers and palaeo-scientists. Given this, the timeframes of
> likely relevance to PRESCIENT are the late Holocene, the late
> glacial-Holocene transition, the last glacial maximum and the last
> interglacial. Proposals that lie outside these timeframes but which
> are relevant to Earth System modelling will also be considered.
> Research Programme General Scientific Aims � The overall aim is to
> quantitatively test and improve the individual and linked processes
> that make up Climate and Earth System models with particular emphasis
> on Hadley Centre models. This will be done by comparing
> palaeo-climate-related data with the results of existing and new model
> simulations. The major emphasis will be on decadal to century
> variability during the past few millennia. Hence, we aim to provide a
> much-improved understanding of the models' ability to simulate natural
> climate variability; provide insight into the reliability of its
> natural and anthropogenically-perturbed simulations; and suggest where
> future model development might be best concentrated. This will give
> greater confidence in predictions of 21st century climate change and
> improve our ability to quantify the contribution to historical climate
> change from 'natural' and 'anthropogenic' causes. The programme also
> aims to produce a more co-ordinated and interactive body of earth and
> climate model scientists and an increased number of interdisciplinary
> researchers with experience of assessing and using palaeo-data in a
> climate and Earth System modelling context.
> The programme will emphasise investigations into four aspects of the
> analysis of palaeo (observed) and simulated data. This could be done
> by collecting new paleo-data, interpreting existing data, developing
> models and carrying out new simulations. The four aspects are:
> 1. Climate system variability: The nature, range and mechanisms of
> climate variability in the current and pre-industrial periods (late
> Holocene) will be investigated. It includes the statistical variations
> of weather that go to make up a climate regime (e.g. characteristics
> of extreme events), coherent climate variability (e.g. El
> Ni�o/Southern Oscillation and the North Atlantic Oscillation) and
> variability due to changes in forcing (e.g. from volcanic eruptions,
> changes in solar output and land-surface changes). This encompasses
> timescales from annual to multidecadal, with an emphasis on
> characterisation of the last 2000 years. Consequently, there will be a
> requirement for firm dating control and an emphasis on high temporal
> resolution, ideally seasonal or annual though decadal resolution will
> also be welcome. Currently detection and attribution studies use
> model simulations to estimate natural climatic variability.
> Palaeo-data would allow comparison of these estimates with the real
> variability of the natural system to assist in validating the
> simulated estimates. There is also the exciting possibility of using
> palaeo-data directly in detection and attribution studies. This
> aspect corresponds directly with IGCP PAGES Stream 1 research and
> represents a major contribution to the GOALS, DECCEN and ACC
> components of the World Climate Research CLIVAR program as well as
> making an important contribution to the research activities at the
> Hadley Centre.
> 2. Climate system sensitivity: Climate sensitivity is usually defined
> as the equilibrium global-mean change in temperature per unit of
> radiative forcing. Palaeo-studies can help understand the processes
> that influence climate sensitivity. They can be used to quantify more
> general aspects of the Earth system's "sensitivity" (i.e. response) to
> external forcings. Appropriate paleo-studies might be those that
> quantify the local or large-scale vegetation patterns, or cryospheric
> responses to changes in appropriate external forcings. This is likely
> to be most appropriate to studies of specified longer-period regimes,
> e.g. the vegetation changes in the mid-Holocene or the cryospheric and
> ocean circulation changes at the last glacial maximum. However, data
> must be in a suitable form for comparison with model simulations and
> thus should be representative of large spatial scales, include some
> error estimates and be accurately dated.
> 3. Carbon cycle: The key periods for testing and validation of the carbon cycle component of Earth system models, such as the one developed at the Hadley Centre, will be the Last Glacial Maximum (LGM), and the glacial-interglacial transition. The LGM represents climate and carbon cycle states that are distinctly different from the present day. The transition between the late glacial periods and the Holocene provides information on Earth System dynamics and rates of change. Validation of models in these periods requires high quality palaeo-reconstructions of the forcing factors (e.g. from aerosols) and of the climate (primarily temperature and precipitation). Validation of the carbon cycle simulation itself can be based on the atmospheric CO2 concentrations recorded in ice cores. Such validation needs palaeo-reconstructions of carbon sources and sinks (e.g. ocean versus land uptake, or changes in the frequency of forest fires), and the tightly coupled cycles of other biogeochemical elements (e.g. nitrogen, sulphur and phosphorous).
> 4. Rapid and "non-linear" climate change: Models predict rapid changes
> in global mean temperature during the 21st century. The effects of
> rapid climate change in past climates could act as a surrogate for
> what may happen during the next century and help to validate some
> aspects of models responses such as changes in vegetation. In
> addition, some models predict, as a response to global warming, large
> changes in the North Atlantic Thermohaline Circulation and changes in
> El-Ni�o. Some of these changes may occur as sudden and irreversible
> transitions to a new state once a certain climate change has occurred.
> Use of palaeo-data to provide evidence for the nature and climatic
> context of any such previous behaviour. In conjunction with modelling
> studies such evidence will improve our understanding of mechanisms and
> has the potential to increase our ability to assess the probability of
> future "surprises". The minimum temporal resolution of such
> reconstructions will be decadal-to-century.
> Within the above themes, it may be necessary for the scientific
> steering committee to co-ordinate and amalgamate proposed research
> projects. Several examples where this might be profitable include:
> � The production of high-resolution records and contemporaneous and
> correlatable records for different environments and geographical
> areas. These might, for example, include biological and physical
> evidence that may be interpreted in terms of: climate forcings,
> climate change and variability, or important associated physical or
> biological processes, such as evidence of carbon budget changes or
> biogeochemical processes. � The construction of palaeo-data fields,
> uncertainties therein, and transects for chosen time periods so that
> they can be immediately used for comparison with simulations. � The
> assembly of different contemporaneous, sets of model boundary
> condition data to facilitate setting up model simulations, including
> experiments with isolated sub-model processes and interactions. � The
> simulation of modelled data that is directly equivalent to specific
> palaeo-data (e.g. isotopic data, vegetation patterns) . � Model
> experiments with specified boundary conditions and forcings to explore
> the realism, roles, and interactions of important regional climate
> systems (e.g. El-Ni�o, NAO, thermohaline circulation) or sub-model
> processes (e.g. climate variability influences on the cryosphere;
> climate and vegetation interactions; etc.) in past climates.
> Lesley Aspinall
> Programme Administrator
> Science Programmes Directorate
> Natural Environment Research Council
> Polaris House
> North Star Avenue
> Swindon
> SN2 1EU
> Tel No: 01793 411536
> Fax No: 01793 411502
> E-mail

Tom M.L. Wigley
Senior Scientist
ACACIA Program Director
National Center for Atmospheric Research
P.O. Box 3000
Boulder, CO 80307-3000
Phone: 303-497-2690
Fax: 303-497-2699

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