date: Tue, 8 Oct 2002 15:45:46 +0100 from: "Sturt Manning" subject: Fw: Research grant proposal - NER/T/S/2002/00444 to: , , Dear Jo, Mike, Keith, You will have seen the referee comment below. I assume we should expect another one or more, much though the timetable is now getting rather tight. The tone is at least positive. The key things to respond about are clearly: (i) The TSI calculation point - converting 14C record into a real solar proxy. Yes, was left vague in application. Jo, do you have some thoughts on what we might say? Or slant to adopt. Do we take up a current model, or do we say will consider range of possibilities. (I will talk with the Heidelberg group re this also.) (ii) The dendroclimatic information able to be extracted from the Turkish wood. Clearly here we simply do not really know, yet. That is part of the point of the work. But we did indicate we were looking at precipitation and there is reason to believe this will work, and maybe more, and we need to clarify existing work (I actually cut a para and refs on this early on as space ran out for the 8 pages). I will be talking with the Cornell dendro people about this too, but would welcome your thoughts Keith and Mike. (iii) Finally, Jo, what do you suggest with regard to the last paragraph, wondering if apart from UV we will also consider effect of cosmic ray flux on cloud cover? There is clearly a limit to what we can do in the one project, but perhaps we could recognise issue, cite a few refs, and say we will review and consider other possible machanisms, such as ... also? There are 6 days to have response written and in. If you could send me any thoughts/comments, and any suggested text and references, I will aim to have a draft response ready by Friday/weekend for circulation, and submission on Monday 14th. Thank you very much, Sturt. ----- Original Message ----- From: "Rapid Rapid" To: Cc: ; ; Sent: Tuesday, October 08, 2002 3:08 PM Subject: Research grant proposal - NER/T/S/2002/00444 Dear Dr Manning Your application for a Research Grant will be considered at the November meeting of the Rapid Climate Change (RCC) Steering Committee. Referee comments have now been obtained on the application and it is now NERC policy to send all these comments (except those provided confidentially to the Committee) to the applicants. These comments are presented to you for clarification and do not represent any pre-judgement of the outcome of your application. You are advised to address any critical comments that the referees have raised in their report. Please ensure that your response, preferably by e-mail, to the points raised reaches me before 15th October so that it can be included in the papers for the PRC meeting. The NERC Steering Committee will then assess the application, taking into consideration all the referees' comments and your response to these comments. If any late comments from referees are received, these will also be forwarded to you for a response. This may require you to respond at short notice and I apologise for this in advance. Yours sincerely Miss Lauren Rowland REFEREE A: This is a timely proposal. In recent years the evidence for solar forcing of climate on a centennial time-scale has increased substantially. Yet, no satisfactory explanation for all observed climatic changes is available. In the latest assessment report of the Intergovernmental Panel on Climate Change, it is acknowledged that solar irradiance variations could have played an important role in forcing the climate during the last few centuries, but the level of scientific understanding is still considered to be "very low". It is essential for the improvement of this scientific understanding to start up multi-disciplinary research projects focussed at this issue that involve both palaeodata and climate modelling experts. In my opinion, this proposal has the potential to provide a major breakthrough in this respect. The idea to use same-age tree-rings from different latitudinal zones to study both the variations in solar activity and climate is highly original and should provide exciting results. Moreover, the two time-periods considered here, the Little Ice Age and the 9-8th century BC, are very suitable for this study, as evidence for changes in solar activity and climate exist for both periods. It will be interesting to compare the two periods in detail, for instance to see if the spatial patterns of climate change are comparable. The data set provided by this project is a good opportunity to test the mechanism proposed by Haigh, as the climate model output may be directly compared to the palaeoclimate reconstructions. It is a good idea to use a combination of low- and high-resolution climate models. FAMOUS can be used to carry out 1000-year ensemble simulations that are necessary to account for the full range of variability of climate. Subsequently, the results of FAMOUS could be evaluated by comparing them with selected simulations with the HadCM3 model, which has a more comprehensive representation of the physics. In addition, a Limited Area Model could be used to look at detailed spatial variations in climate (for instance, differences in climate response between Northern Europe and the Mediterranean region). The research group consists of leading experts in the field (on both the data and modelling sides), giving confidence that this project will be carried out successfully. One of the results of this project should be a high-resolution reconstruction of total solar irradiance (TSI), as this is required as input for the GCM simulations. The applications propose to use 14C to reconstruct temporal variations of solar activity. However, it is not clear to me how the applicants intend to translate solar activity into solar irradiance. This translation is problematic, as is evident from differences between TSI reconstructions for the last four hundred years (see e.g., IPCC 2001 report). For example, for the 17th century (i.e. within the Little Ice Age), these reconstructions differ by as much as 7 Wm-2. One of the major problems is that we have only detailed TSI measurements (using satellites) since the late 1970s, and even these give quite different results. This makes the calibration of proxies for solar irradiance very difficult. A key point in the proposal is to derive information on both solar activity and climate variability from the same tree rings. One could be concerned about the possibility to reconstruct temperatures from tree-ring records obtained from lower latitudes, as it could be expected that trees at these latitudes are primarily sensitive to changes in humidity rather than temperature variations. Have the applicants tested the values of low-latitude tree-ring records as proxies for temperature? In the proposed project, climate model experiments are used to address the mechanism for the amplification of solar forcing proposed by Haigh, involving a key role for variations in solar UV. However, in addition to the latter mechanism, other positive feedback mechanisms have been proposed in the literature, for instance the effect of cosmic-ray flux on cloud cover. It would be very useful to analyse the effect of both mechanisms. It is not clear from the proposal if the applicants are planning to make this comparison. Rapid Climate Change Research Grants Team Operations Group Science Programmes Directorate NERC Polaris House Swindon SN2 1EU Tel: 01793 411663 Fax: 01793 411655 http://www.nerc.ac.uk/funding