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The Millennium project: latest news and events from the consortium

 

www.millenniumproject.net

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Nordic partners of the Millennium project at Stockholm Univeristy, The Norwegian Polar Institute and The University of Oulu receive funding from Mestä Tissue AB.

Congratulations to three Nordic partners of the Millennium project, Gunhild Rosqvist, Sheila Hicks and Elisabeth Isaksson, who have received a donation (of €100,000) from Metsä Tissue AB for palaeoclimate related research in northern Scandinavia.

The funding will be used to further explore ice, lake and peat archives for black carbon and monitoring of present deposition of black carbon in
the north.

Black carbon is the residue of burned organic matter. When fossil fuels and biomass are burned for energy tiny particles of fly ash and soot are released into the atmosphere. These black carbon particles are not only air pollutants but also a climate forcing agent that warms the planet by absorbing heat in the atmosphere and by reducing albedo.

You can read more about the team's work on black carbon in lake sediments in Finland, and Sweden and in ice cores in Norway.

You can also blog with Elisabeth Isaksson, Senior scientist at  Norwegian Polar Institute, The Polar Environmental Centre, Tromsø, with Gunhild Roqvist at Stockholm University and with Sheila Hicks at The Univeristy of Oulu, if you have questions about their project.

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Article: Moberg et al (2008) Analysis of the Moberg et al. (2005) hemispheric temperature reconstruction.

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Anders Moberg, Rezwan Mohammad, Thorsten Mauritsen 

 
Abstract
The Moberg et al. (Nature 433(7026):613–617, 2005 . doi:10.1038/nature03265 ; M05) reconstruction of northern hemisphere temperature variations from proxy data has been criticised; the M05 method may artificially inflate low-frequency variance relative to reality. We test this assertion by undertaking several pseudoproxy experiments in three climate model simulations—one control run and two forced simulations that include several time-varying radiative forcings. The pseudoproxy series are designed to have the same variance spectra as the real M05 proxies, primarily to mimic the low-resolution character of several series. A simple composite-plus-scale (CPS) method is also analysed. In the CPS case all input data behave like annually resolved proxies. The spectral domain performance of both M05 and CPS is found to be dependent on the noise type and noise level in pseudoproxies, on the variance spectrum of the climate model simulation, and on the degree of data smoothing. CPS performs better than M05 in most investigated cases with the control run, but leads to deflated low frequency variance in some cases. With M05, low-frequency variance tend to be inflated for the control run but not for one
of the forced runs and only very slightly with the other forced simulation. Hence, the M05 approach does not routinely inflate low-frequency variance. In our experiment, the M05 approach performs better in the spectral domain than CPS when applied to forced climate model simulations. The results underscore the importance of evaluating the variance spectrum of climate reconstructions.

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Moberg, A., Mohammad, R., Mauritsen, T. 2008. Analysis of the Moberg et al. (2005) hemispheric temperature reconstruction, Climate Dynamics, 31, 957-971, doi 10.1007/s00382-008-0392-8. You can download a summary of the paper mobergetal08 .

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‘Tree rings’ of the sea

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Millennium SG4  team members from Bangor University’s School of Ocean Sciences have continued their research on Arctica islandica: the ‘tree rings of the sea’, with an In Press article in Radiocarbon as well as keen media interest in ‘Ming The Mollusc’; a 405 year old Arctica specimen which is part of their chronology. The team at Bangor have used the Arctica growth ring time series to reconstruct past climate in the north Atlantic. . Online articles are available here and here.

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In Press Article:

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Very Long-Lived Molluscs Confirm 17th Century AD Tephra-Based Radiocarbon Reservoir Ages for North Icelandic Shelf Waters.

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Alan D. Wanamaker Jr, Jan Heinemeier, James D. Scourse, Christopher A. Richardson, Paul G. Butler, Jón Eiríksson, and Karen Luise Knudsen

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Abstract
Marine sediment records from the north Icelandic shelf, which rely on tephrochronological age models, reveal an average deltaR (regional deviation from the modelled global surface ocean reservoir age) of approximately 150 years for the last millennium. These tephra-based age models have not hitherto been independently verified. Here, we provide data which corroborate deltaR values derived from these sediment archives. We sampled the youngest portion (ontogenetic age) of a bivalve shell, Arctica islandica (L.), for radiocarbon analysis, which was collected alive in 2006 from the north Icelandic shelf in ~80 m water depth. Annual band counting from the sectioned shell revealed that this clam lived for more than 405 years, making it the longest-lived mollusc and possibly the oldest non-colonial animal yet documented. The 14C age derived from the umbo region of the shell is 951 ± 27 yr BP. Assuming that the bivalve settled onto the seabed at AD 1600, the corresponding local value of deltaR is found to be 237 ± 35 years by comparison of the 14C age with the Marine04 calibration curve at this time. Furthermore, we cross-matched a 287-year-old, dead-collected, A. islandica shell from AD 1601 to 1656 from the same site with the live-caught individual. Radiocarbon analysis from the ventral margin of this shell revealed a deltaR of 186 ± 50 years at AD 1650. These values compare favourably with each other and with the tephra-based deltaR values during this period, illustrating that radiocarbon from A. islandica can effectively record radiocarbon reservoir changes in the shelf seas.

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You can download a summary of the article here: wanamakeretal08

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In press article: Isotopic composition (delta13C, delta18O) in wood and cellulose of Siberian larch trees for early Medieval and recent periods.

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Olga V. Sidorova1,2, Rolf T. W. Siegwolf2, Matthias Saurer2, Mukhtar M. Naurzbaev1,
Eugene A. Vaganov1,3

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1V.N. Sukachev Institute of Forest SB RAS, 660036 Akademgorodok, Krasnoyarsk, Russia;
2 Paul Scherrer Institute, 5232 Villigen, Switzerland;
3Siberian Federal University, 660041 Svobodniy av, 79

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Abstract:
We related tree ring width (TRW) and isotopic composition (delta13C, delta18O) of wood and cellulose from four larch trees (Larix cajanderi Mayr.) to climate parameters. The material was sampled in northeastern Yakutia [70°N-148°E] for the recent (AD 1880-2004) and early Medieval (AD 900-1000) periods. During the recent period June, July, and August air temperatures were positively correlated with delta13C and delta18O of wood and cellulose, while July precipitation was negatively correlated. Furthermore, the vapor pressure deficit (VPD) of July and August was significantly correlated with delta13C of wood and cellulose, but VPD had almost no influence on delta18O. Comparative analyses between mean isotope values for the (AD 900-1000) and (AD 1880-2004) periods indicate similar ranges of climatic conditions, with the exception of the period AD 1950-2004. Whilst isotopic ratios in cellulose are reliably related to climatic variables, during the some periods those in whole wood showed even stronger relationships. Strong positive correlations between delta18O of cellulose and Greenland ice-core (GISP2) data were detected for the beginning of the Medieval period (r=0.86; p<0.05), indicating the reliability of isotope signals in tree rings for large-scale reconstructions.

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Citation: Sidorova OV, Siegwolf RTW, Saurer MM, Naurzbaev MM, Vaganov EA (2008) Isotopic composition (d13C, d18O) in Siberian tree-ring chronology. J. Geophys. Res. Biogeoscinces: 113, G02019, doi:10.1029/2007JG000473. Sidorovaetal08

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SG1 special issue of the journal Climatic Change.

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The SG1 (Documentary and Instrumental Records) team have negotiated a special edition of the journal Climatic Change in which they are offering a series of papers on the theme of European climate change in the past 500 years. The papers (see below) embrace many of the areas in which they have worked over the past two years and are based on the results from Work Packages 1 and 6. The author teams include not only members of SG1 but also experts in the various themes that are introduced and discussed. The volume is under the general editorship of Christian Pfister, Rudolof Brazdil and Dennis Wheeler. The papers are currently under external peer-review and publication is planned for the second half of 2009. Climatic Change is a well-respected journal and will act as an excellent vehicle with which the Millennium project can disseminate this part of its developing activities.

The papers included in the Climatic Change special publication are as follows but will include also an overview paper being prepared by the general editors: 

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R. Böhm, P. D. Jones, J.  Hiebl, M. Brunetti, D. Frank, M. Maugeri: The early instrumental warm-bias: A solution for long Central European temperature series 1760-2007

P. Dobrovolný, A. Moberg, R. Brázdil, C. Pfister, R. Glaser, R. Wilson, A. van Engelen, D. Limanówka, A. Kiss, M. Halícková, J. Macková, D. Riemann, J. Luterbacher, R. Böhm: Monthly and seasonal temperature reconstructions for Central Europe derived from documentary evidence and instrumental records since AD 1500

D. Camuffo, C. Bertolin, M. Barriendos, F. Dominguez, C. Cocheo, S. Enzi, M. Sghedoni, A. della Valle, E. Garnier, M.-J. Alcoforado, E. Xoplaki, J. Luterbacher, N. Diodato, M. Maugeri, M.F. Nunes, R. Rodriguez: 500-year temperature and precipitation reconstruction in the Mediterranean Basin

L. Leijonhufvud, R. Wilson, A. Moberg, J. Söderberg, D. Retsö, U. Söderlind: Five centuries of winter/spring temperatures in Stockholm reconstructed from documentary evidence and instrumental observations

D. Wheeler, R. Garcia-Herrera, C. W. Wilkinson, C. Ward: Air circulation and storminess in the Atlantic-European region derived from logbooks: 1685 to 1750

R. Glaser, D. Riemann, J. Schönbein, M. Barriendos, R. Brázdil, C. Bertolin, D. Camuffo, M. Deutsch, P. Dobrovolný, A. van Engelen, S. Enzi, M. Halícková, S. Koenig, O. Kotyza, D.  Limanowka, J. Macková, M. Sghedoni: 500 years variability of European floods

E. Zorita, A. Moberg, L. Leijonhufvud, R. Wilson, R. Brázdil, P. Dobrovolný, J. Luterbacher, R. Böhm, C. Pfister, R. Glaser, J. Söderberg, F. Gonzáles-Rouco: European temperature records of the past five centuries based on documentary information compared to climate simulations

C. Pfister, E. Garnier, M.-J. Alcoforado, D. Wheeler, J. Luterbacher, F. Nunes, J. P. Taborda: The impact of devastating winter-storms in early eighteenth-century Europe against the background of different political systems and cultural milieus

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