date: Mon Oct  7 12:49:12 2002
from: Keith Briffa <k.briffa@uea.ac.uk>
subject: Re: NER/T/S/2002/00440
to: "Rapid Rapid" <RAPID@wpo.nerc.ac.uk>

   Dear Lauren
   thanks for these comments . Clearly they are extremely positive but it is
   worth responding to some of the specific points where some clarification or comment is
   relevant . So here goes , in order...
   REFEREE C:
   1. There is possible overlap with other researchers such as Ed Cook,and
   Stahle. But if the stated collaboration with  these and other colleagues
   who produce the primary data is firm, this may not be a problem.
   There is no conflict in the overlap with other researchers. On the contrary, we emphasize
   the fact that these researchers (and others named) have agreed to collaborate actively in
   the provision of data and  in their interpretaion.
   2.  The last 1000 years are important. But several paleo records show the
   period ~1000-1500 years ago encompasses the very warm earliest part of the
   Medieval Warm period. This period is critical in assessing 20th century
   warming but prior widely cited studies (Mann et al, Crowley) are limited to
   the last 1000 years yet form the basis for statements about the causes of
   relative warmth in the 20th century.  Effort should be made to include even
   the few proxy record going back 1500-2000 years before present.
   We agree entirely with this referee that the period just prior to the last 1000 years has
   relevance to the issue of  climate change detection. Yes, we will make efforts to collect
   and amalgamate data prior to AD 1000, but this will not be a priority in the final analysis
   because the synergy in the work we propose lies in analyzing the overlap between empirical
   data and model-derived (principally GCM) data and this is clearly limited to the more
   recent period by the availability of appropriate simulations. We do note, however, the
   potential to use the earlier data in combination with simpler model (e.g. EBM ) output and
   we further note that a volcanic forcing series has been recently extended (Crowley,
   personal communication) and could be used to force the simpler models.
   3.  The most recent proxy records are nicely cited but given the
   investigation is seeking to examine links between NAO variability to
   deep-water processes (convection etc), it is unfortunate there are few
   marine paleo-records cited.  Some exist or are about to be published on the
   ocean and NAO and should be sought out, EVEN IF TEMPORAL RESOLUTION DOES
   NOT MATCH THAT OF TREE RINGS.
   We would accept the advice of the referee here. If the project is funded we commit to
   seeking advice from palaeo-ocean specialists about which series to use and how to
   quantitatively interpret them.
   4.  The use of model output for "synthetic" proxy records worries me.  More
   strategically placed high resolution proxy record, including more in
   oceans, are needed and let the models do their own thing.
   One of the key elements of our proposed project is to quantify the (potential) utility of
   various sets of proxy records - with differing individual "reliability" and geographic and
   seasonal coverage. For this element to be comprehensive, we wish to explore beyond the
   constraints of available records - thus allowing us to anticipate the benefit obtained from
   possible future enhancements of the climate proxy data base. Generating "synthetic" records
   from model output will allow us to do this - and even perhaps identify which "strategically
   placed high resolution" records offer most benefit for the various problems we will
   address. The referee should be reassured, however, that we will not use the model-derived
   synthetic records to tell us the past climate history - for that we will use real proxy
   records (including suitable oceanic ones).
   REFEREE D:
   Of course, there are limitations to the data * especially in reconstruction of external
   forcings *
   We thank this referee for their positive comments. Our only response is to agree that the
   data uncertainty (related to climate forcing histories and palaeoclimate interpretation)
   should be explicit in the consideration of covariance between empirical and model-based
   time series and fields.
   Thank you for the opportunity to respond to these and the earlier comments forwarded.
   Best wishes
   Keith
   At 11:25 AM 10/4/02 +0100, you wrote:

     Dear Professor Briffa
     Please find below, further referee comments on your research grant proposal.
     Regards
     Lauren
     REFEREE C:
     This is an excellent, ambitious proposal to conduct research extremely
     important to understanding climate variability and its causes in the North
     Atlantic region.  Investigators are the best, budget is reasonable, and the
     integrated nature of the work (atmosphere/ocean, proxy data modeling etc)
     is sorely needed.
     My only possible concerns are:
     1. There is possible overlap with other researchers such as Ed Cook,and
     Stahle. But if the stated collaboration with  these and other colleagues
     who produce the primary data is firm, this may not be a problem.
     2.  The last 1000 years are important. But several paleo records show the
     period ~1000-1500 years ago encompasses the very warm earliest part of the
     Medieval Warm period. This period is critical in assessing 20th century
     warming but prior widely cited studies (Mann et al, Crowley) are limited to
     the last 1000 years yet form the basis for statements about the causes of
     relative warmth in the 20th century.  Effort should be made to include even
     the few proxy record going back 1500-2000 years before present.
     3.  The most recent proxy records are nicely cited but given the
     investigation is seeking to examine links between NAO variability to
     deep-water processes (convection etc), it is unfortunate there are few
     marine paleo-records cited.  Some exist or are about to be published on the
     ocean and NAO and should be sought out, EVEN IF TEMPORAL RESOLUTION DOES
     NOT MATCH THAT OF TREE RINGS.
     4.  The use of model output for "synthetic" proxy records worries me.  More
     strategically placed high resolution proxy record, including more in
     oceans, are needed and let the models do their own thing.
     REFEREE D:
     The proposal outlines an interesting strategy to use models and palaeoclimatic data in a
     synergistic way, to evaluate the role of Atlantic variability in past climate changes
     affecting Europe.  The authors have articulated the main issues that need to be
     addressed, and are clearly aware of the data limitations.  Bringing together the talents
     of Briffa, Jones in empirical data analysis, with Osborn & Tett in theory and modelling
     should produce first rate research results.
     Weaknesses:
     I see no fundamental problems with their approach.  Of course, there are limitations to
     the data * especially in reconstruction of external forcings * but the authors are
     undoubtedly aware of these issues and will no doubt proceed with caution, as
     appropriate.
     Rapid Climate Change Research Grants Team
     Operations Group
     Science Programmes Directorate
     NERC
     Polaris House
     Swindon
     SN2 1EU
     Tel: 01793 411663
     Fax: 01793 411655
     [1]http://www.nerc.ac.uk/funding

   --
   Professor Keith Briffa,
   Climatic Research Unit
   University of East Anglia
   Norwich, NR4 7TJ, U.K.

   Phone: +44-1603-593909
   Fax: +44-1603-507784
   [2]http://www.cru.uea.ac.uk/cru/people/briffa[3]/

