Articles | Volume 16, issue 4
https://doi.org/10.5194/cp-16-1469-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-16-1469-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
11 Aug 2020
Research article |
| 11 Aug 2020
| 11 Aug 2020
A spectral approach to estimating the timescale-dependent uncertainty of paleoclimate records – Part 1: Theoretical concept
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Research Unit Potsdam, Telegrafenberg A45, Potsdam, 14473, Germany
Andrew M. Dolman
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Research Unit Potsdam, Telegrafenberg A45, Potsdam, 14473, Germany
Thomas Laepple
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Research Unit Potsdam, Telegrafenberg A45, Potsdam, 14473, Germany
MARUM – Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Bremen, 28334, Germany
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The Cryosphere, 18, 3685–3698, https://doi.org/10.5194/tc-18-3685-2024, https://doi.org/10.5194/tc-18-3685-2024, 2024
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Paleoclimate proxy records contain a combination of climate signals and non-climatic noise. This noise can affect year-to-year variations, or introduce uncertainty on medium and long timescales. Proxies contain different types, or "colors" of noise stemming from the diverse physical and biological processes that go into their creation. We show how non-climatic noise affects tree rings, corals and ice cores. We aim to improve representations of noise in paleoclimate research activities.
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Fast variability of water isotopes in ice cores is attenuated by diffusion but can be restored if the diffusion length is accurately estimated. Current estimation methods are inadequate for deep ice, mischaracterising millennial-scale climate variability. We address this using variability estimates from shallower ice. The estimated diffusion length of 31 cm for the bottom of the Dome C ice core is 20 cm less than the old method, enabling signal recovery on timescales previously considered lost.
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Stable water isotopes from firn cores provide valuable information on past climates, yet their utility is hampered by stratigraphic noise, i.e. the irregular deposition and wind-driven redistribution of snow. We found stratigraphic noise on the Antarctic Plateau to be related to the local accumulation rate, snow surface roughness and slope inclination, which can guide future decisions on sampling locations and thus increase the resolution of climate reconstructions from low-accumulation areas.
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Bryan C. Lougheed, Philippa Ascough, Andrew M. Dolman, Ludvig Löwemark, and Brett Metcalfe
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Clim. Past, 15, 521–537, https://doi.org/10.5194/cp-15-521-2019, https://doi.org/10.5194/cp-15-521-2019, 2019
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Thomas Münch and Thomas Laepple
Clim. Past, 14, 2053–2070, https://doi.org/10.5194/cp-14-2053-2018, https://doi.org/10.5194/cp-14-2053-2018, 2018
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Andrew M. Dolman and Thomas Laepple
Clim. Past, 14, 1851–1868, https://doi.org/10.5194/cp-14-1851-2018, https://doi.org/10.5194/cp-14-1851-2018, 2018
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Climate proxies from marine sediments provide an important record of past temperatures, but contain noise from many sources. These include mixing by burrowing organisms, seasonal and habitat biases, measurement error, and small sample size effects. We have created a forward model that simulates the creation of proxy records and provides it as a user-friendly R package. It allows multiple sources of uncertainty to be considered together when interpreting proxy climate records.
Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valerie Masson-Delmotte, and Jean Jouzel
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Ice core isotopic records rely on the knowledge of the processes involved in the archival processes of the snow. In the East Antarctic Plateau, post-deposition processes strongly affect the signal found in the surface and buried snow compared to the initial climatic signal. We evaluate the different contributions to the surface snow isotopic composition between the precipitation and the exchanges with the atmosphere and the variability of the isotopic signal found in profiles from snow pits.
Thomas Laepple, Thomas Münch, Mathieu Casado, Maria Hoerhold, Amaelle Landais, and Sepp Kipfstuhl
The Cryosphere, 12, 169–187, https://doi.org/10.5194/tc-12-169-2018, https://doi.org/10.5194/tc-12-169-2018, 2018
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We explain why snow pits across different sites in East Antarctica show visually similar isotopic variations. We argue that the similarity and the apparent cycles of around 20 cm in the δD and δ18O variations are the result of a seasonal cycle in isotopes, noise, for example from precipitation intermittency, and diffusion. The near constancy of the diffusion length across many ice-coring sites explains why the structure and cycle length is largely independent of the accumulation conditions.
Thomas Münch, Sepp Kipfstuhl, Johannes Freitag, Hanno Meyer, and Thomas Laepple
The Cryosphere, 11, 2175–2188, https://doi.org/10.5194/tc-11-2175-2017, https://doi.org/10.5194/tc-11-2175-2017, 2017
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The importance of post-depositional changes for the temperature interpretation of water isotopes is poorly constrained by observations. Here, for the first time, temporal isotope changes in the open-porous firn are directly analysed using a large array of shallow isotope profiles. By this, we can reject the possibility of post-depositional change beyond diffusion and densification as the cause of the discrepancy between isotope and local temperature variations at Kohnen Station, East Antarctica.
Kira Rehfeld, Mathias Trachsel, Richard J. Telford, and Thomas Laepple
Clim. Past, 12, 2255–2270, https://doi.org/10.5194/cp-12-2255-2016, https://doi.org/10.5194/cp-12-2255-2016, 2016
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Indirect evidence on past climate comes from the former composition of ecological communities such as plants, preserved as pollen grains in sediments of lakes. Transfer functions convert relative counts of species to a climatologically meaningful scale (e.g. annual mean temperature in degrees C). We show that the fundamental assumptions in the algorithms impact the reconstruction results in he idealized model world, in particular if the reconstructed variables were not ecologically relevant.
Mathieu Casado, Amaelle Landais, Ghislain Picard, Thomas Münch, Thomas Laepple, Barbara Stenni, Giuliano Dreossi, Alexey Ekaykin, Laurent Arnaud, Christophe Genthon, Alexandra Touzeau, Valérie Masson-Delmotte, and Jean Jouzel
The Cryosphere Discuss., https://doi.org/10.5194/tc-2016-263, https://doi.org/10.5194/tc-2016-263, 2016
Revised manuscript not accepted
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Ice core isotopic records rely on the knowledge of the processes involved in the archival of the snow. In the East Antarctic Plateau, post-deposition processes strongly affect the signal found in the surface and buried snow compared to the initial climatic signal. We evaluate the different contributions to the surface snow isotopic composition between the precipitation and the exchanges with the atmosphere and the variability of the isotopic signal found in profiles from snow pits.
Thomas Münch, Sepp Kipfstuhl, Johannes Freitag, Hanno Meyer, and Thomas Laepple
Clim. Past, 12, 1565–1581, https://doi.org/10.5194/cp-12-1565-2016, https://doi.org/10.5194/cp-12-1565-2016, 2016
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Ice-core oxygen isotope ratios are a key climate archive to infer past temperatures, an interpretation however complicated by non-climatic noise. Based on 50 m firn trenches, we present for the first time a two-dimensional view (vertical × horizontal) of how oxygen isotopes are stored in Antarctic firn. A statistical noise model allows inferences for the validity of ice coring efforts to reconstruct past temperatures, highlighting the need of replicate cores for Holocene climate reconstructions.
Related subject area
Subject: Proxy Use-Development-Validation | Archive: Marine Archives | Timescale: Holocene
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Holocene trends in the foraminifer record from the Norwegian Sea and the North Atlantic Ocean
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Katrin Hättig, Devika Varma, Stefan Schouten, and Marcel T. J. van der Meer
Clim. Past, 19, 1919–1930, https://doi.org/10.5194/cp-19-1919-2023, https://doi.org/10.5194/cp-19-1919-2023, 2023
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Julia Rieke Hagemann, Lester Lembke-Jene, Frank Lamy, Maria-Elena Vorrath, Jérôme Kaiser, Juliane Müller, Helge W. Arz, Jens Hefter, Andrea Jaeschke, Nicoletta Ruggieri, and Ralf Tiedemann
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Alkenones and glycerol dialkyl glycerol tetraether lipids (GDGTs) are common biomarkers for past water temperatures. In high latitudes, determining temperature reliably is challenging. We analyzed 33 Southern Ocean sediment surface samples and evaluated widely used global calibrations for both biomarkers. For GDGT-based temperatures, previously used calibrations best reflect temperatures >5° C; (sub)polar temperature bias necessitates a new calibration which better aligns with modern values.
Jaap S. Sinninghe Damsté, Lisa A. Warden, Carlo Berg, Klaus Jürgens, and Matthias Moros
Clim. Past, 18, 2271–2288, https://doi.org/10.5194/cp-18-2271-2022, https://doi.org/10.5194/cp-18-2271-2022, 2022
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Reconstruction of past climate conditions is important for understanding current climate change. These reconstructions are derived from proxies, enabling reconstructions of, e.g., past temperature, precipitation, vegetation, and sea surface temperature (SST). Here we investigate a recently developed SST proxy based on membrane lipids of ammonium-oxidizing archaea in the ocean. We show that low salinities substantially affect the proxy calibration by examining Holocene Baltic Sea sediments.
Darrell S. Kaufman and Nicholas P. McKay
Clim. Past, 18, 911–917, https://doi.org/10.5194/cp-18-911-2022, https://doi.org/10.5194/cp-18-911-2022, 2022
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Global mean surface temperatures are rising to levels unprecedented in over 100 000 years. This conclusion takes into account both recent global warming and likely future warming, which thereby enables a direct comparison with paleotemperature reconstructions on multi-century timescales.
Gabriella M. Weiss, Julie Lattaud, Marcel T. J. van der Meer, and Timothy I. Eglinton
Clim. Past, 18, 233–248, https://doi.org/10.5194/cp-18-233-2022, https://doi.org/10.5194/cp-18-233-2022, 2022
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Here we study the elemental signatures of plant wax compounds as well as molecules from algae and bacteria to understand how water sources changed over the last 11 000 years in the northeastern part of Europe surrounding the Baltic Sea. Our results show diversity in plant and aquatic microorganisms following the melting of the large ice sheet that covered northern Europe as the regional climate continued to warm. A shift in water source from ice melt to rain also occurred around the same time.
Teodora Pados-Dibattista, Christof Pearce, Henrieka Detlef, Jørgen Bendtsen, and Marit-Solveig Seidenkrantz
Clim. Past, 18, 103–127, https://doi.org/10.5194/cp-18-103-2022, https://doi.org/10.5194/cp-18-103-2022, 2022
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We carried out foraminiferal, stable isotope, and sedimentological analyses of a marine sediment core retrieved from the Northeast Greenland shelf. This region is highly sensitive to climate variability because it is swept by the East Greenland Current, which is the main pathway for sea ice and cold waters that exit the Arctic Ocean. The palaeoceanographic reconstruction reveals significant variations in the water masses and in the strength of the East Greenland Current over the last 9400 years.
Andrew M. Dolman, Torben Kunz, Jeroen Groeneveld, and Thomas Laepple
Clim. Past, 17, 825–841, https://doi.org/10.5194/cp-17-825-2021, https://doi.org/10.5194/cp-17-825-2021, 2021
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Uncertainties in climate proxy records are temporally autocorrelated. By deriving expressions for the power spectra of errors in proxy records, we can estimate appropriate uncertainties for any timescale, for example, for temporally smoothed records or for time slices. Here we outline and demonstrate this approach for climate proxies recovered from marine sediment cores.
Linda K. Dämmer, Lennart de Nooijer, Erik van Sebille, Jan G. Haak, and Gert-Jan Reichart
Clim. Past, 16, 2401–2414, https://doi.org/10.5194/cp-16-2401-2020, https://doi.org/10.5194/cp-16-2401-2020, 2020
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The compositions of foraminifera shells often vary with environmental parameters such as temperature or salinity; thus, they can be used as proxies for these environmental variables. Often a single proxy is influenced by more than one parameter. Here, we show that while salinity impacts shell Na / Ca, temperature has no effect. We also show that the combination of different proxies (Mg / Ca and δ18O) to reconstruct salinity does not seem to work as previously thought.
Giulia Faucher, Ulf Riebesell, and Lennart Thomas Bach
Clim. Past, 16, 1007–1025, https://doi.org/10.5194/cp-16-1007-2020, https://doi.org/10.5194/cp-16-1007-2020, 2020
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We designed five experiments choosing different coccolithophore species that have been evolutionarily distinct for millions of years. If all species showed the same morphological response to an environmental driver, this could be indicative of a response pattern that is conserved over geological timescales. We found an increase in the percentage of malformed coccoliths under altered CO2, providing evidence that this response could be used as paleo-proxy for episodes of acute CO2 perturbations.
Yue Hu, Xiaoming Sun, Hai Cheng, and Hong Yan
Clim. Past, 16, 597–610, https://doi.org/10.5194/cp-16-597-2020, https://doi.org/10.5194/cp-16-597-2020, 2020
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Tridacna, as the largest marine bivalves, can be used for high-resolution paleoclimate reconstruction in its carbonate skeleton. In this contribution, the modern δ18O shell is suggested to be a proxy for sea surface temperature in the Xisha Islands, South China Sea. Data from a fossil Tridacna (3673 ± 28 BP) indicate a warmer climate and intense ENSO-related variability but reduced ENSO frequency and more extreme El Niño winters compared to modern Tridacna.
Maria Reschke, Kira Rehfeld, and Thomas Laepple
Clim. Past, 15, 521–537, https://doi.org/10.5194/cp-15-521-2019, https://doi.org/10.5194/cp-15-521-2019, 2019
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We empirically estimate signal-to-noise ratios of temperature proxy records used in global compilations of the middle to late Holocene by comparing the spatial correlation structure of proxy records and climate model simulations accounting for noise and time uncertainty. We find that low signal contents of the proxy records or, alternatively, more localised climate variations recorded by proxies than suggested by current model simulations suggest caution when interpreting multi-proxy datasets.
Andrew M. Dolman and Thomas Laepple
Clim. Past, 14, 1851–1868, https://doi.org/10.5194/cp-14-1851-2018, https://doi.org/10.5194/cp-14-1851-2018, 2018
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Climate proxies from marine sediments provide an important record of past temperatures, but contain noise from many sources. These include mixing by burrowing organisms, seasonal and habitat biases, measurement error, and small sample size effects. We have created a forward model that simulates the creation of proxy records and provides it as a user-friendly R package. It allows multiple sources of uncertainty to be considered together when interpreting proxy climate records.
Irina Polovodova Asteman, Helena L. Filipsson, and Kjell Nordberg
Clim. Past, 14, 1097–1118, https://doi.org/10.5194/cp-14-1097-2018, https://doi.org/10.5194/cp-14-1097-2018, 2018
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We present 2500 years of winter temperatures, using a sediment record from Gullmar Fjord analyzed for stable oxygen isotopes in benthic foraminifera. Reconstructed temperatures are within the annual temperature variability recorded in the fjord since the 1890s. Results show the warm Roman and Medieval periods and the cold Little Ice Age. The record also shows the recent warming, which does not stand out in the 2500-year perspective and is comparable to the Roman and Medieval climate anomalies.
Christof Pearce, Aron Varhelyi, Stefan Wastegård, Francesco Muschitiello, Natalia Barrientos, Matt O'Regan, Thomas M. Cronin, Laura Gemery, Igor Semiletov, Jan Backman, and Martin Jakobsson
Clim. Past, 13, 303–316, https://doi.org/10.5194/cp-13-303-2017, https://doi.org/10.5194/cp-13-303-2017, 2017
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The eruption of the Alaskan Aniakchak volcano of 3.6 thousand years ago was one of the largest Holocene eruptions worldwide. The resulting ash is found in several Alaskan sites and as far as Newfoundland and Greenland. In this study, we found ash from the Aniakchak eruption in a marine sediment core from the western Chukchi Sea in the Arctic Ocean. Combined with radiocarbon dates on mollusks, the volcanic age marker is used to calculate the marine radiocarbon reservoir age at that time.
Anne-Sophie Fanget, Maria-Angela Bassetti, Christophe Fontanier, Alina Tudryn, and Serge Berné
Clim. Past, 12, 2161–2179, https://doi.org/10.5194/cp-12-2161-2016, https://doi.org/10.5194/cp-12-2161-2016, 2016
Maria-Angela Bassetti, Serge Berné, Marie-Alexandrine Sicre, Bernard Dennielou, Yoann Alonso, Roselyne Buscail, Bassem Jalali, Bertil Hebert, and Christophe Menniti
Clim. Past, 12, 1539–1553, https://doi.org/10.5194/cp-12-1539-2016, https://doi.org/10.5194/cp-12-1539-2016, 2016
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This work represents the first attempt to decipher the linkages between rapid climate changes and continental Holocene paleohydrology in the NW Mediterranean shallow marine setting. Between 11 and 4 ka cal BP, terrigenous input increased and reached a maximum at 7 ka cal BP, probably as a result of a humid phase. From ca. 4 ka cal BP to the present, enhanced variability in the land-derived material is possibly due to large-scale atmospheric circulation and rainfall patterns in western Europe.
Mathias Trachsel and Richard J. Telford
Clim. Past, 12, 1215–1223, https://doi.org/10.5194/cp-12-1215-2016, https://doi.org/10.5194/cp-12-1215-2016, 2016
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In spatially structured environments, conventional cross validation results in over-optimistic transfer function performance estimates. H-block cross validation, where all samples within h kilometres of the test samples are omitted is a method for obtaining unbiased transfer function performance estimates. We assess three methods for determining the optimal h using simulated data and published transfer functions. Some transfer functions perform notably worse when h-block cross validation is used.
B. Jalali, M.-A. Sicre, M.-A. Bassetti, and N. Kallel
Clim. Past, 12, 91–101, https://doi.org/10.5194/cp-12-91-2016, https://doi.org/10.5194/cp-12-91-2016, 2016
K. Tachikawa, L. Vidal, M. Cornuault, M. Garcia, A. Pothin, C. Sonzogni, E. Bard, G. Menot, and M. Revel
Clim. Past, 11, 855–867, https://doi.org/10.5194/cp-11-855-2015, https://doi.org/10.5194/cp-11-855-2015, 2015
M. Moreau, T. Corrège, E. P. Dassié, and F. Le Cornec
Clim. Past, 11, 523–532, https://doi.org/10.5194/cp-11-523-2015, https://doi.org/10.5194/cp-11-523-2015, 2015
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The influence of salinity on the Porites Sr/Ca palaeothermometer is still poorly documented. We test the salinity effect on Porites Sr/Ca-based SST reconstructions using a large spatial compilation of published Porites data from the Pacific, Indian Ocean, and the Red Sea. We find no evidence of a salinity bias in the Sr/Ca SST proxy at monthly and interannual timescales using two different salinity products. This result is in agreement with laboratory experiments on coral species.
S. M. P. Berben, K. Husum, P. Cabedo-Sanz, and S. T. Belt
Clim. Past, 10, 181–198, https://doi.org/10.5194/cp-10-181-2014, https://doi.org/10.5194/cp-10-181-2014, 2014
D. J. R. Thornalley, M. Blaschek, F. J. Davies, S. Praetorius, D. W. Oppo, J. F. McManus, I. R. Hall, H. Kleiven, H. Renssen, and I. N. McCave
Clim. Past, 9, 2073–2084, https://doi.org/10.5194/cp-9-2073-2013, https://doi.org/10.5194/cp-9-2073-2013, 2013
M.-A. Sicre, G. Siani, D. Genty, N. Kallel, and L. Essallami
Clim. Past, 9, 1375–1383, https://doi.org/10.5194/cp-9-1375-2013, https://doi.org/10.5194/cp-9-1375-2013, 2013
S. Alessio, G. Vivaldo, C. Taricco, and M. Ghil
Clim. Past, 8, 831–839, https://doi.org/10.5194/cp-8-831-2012, https://doi.org/10.5194/cp-8-831-2012, 2012
B. Christiansen and F. C. Ljungqvist
Clim. Past, 8, 765–786, https://doi.org/10.5194/cp-8-765-2012, https://doi.org/10.5194/cp-8-765-2012, 2012
V. Nieto-Moreno, F. Martínez-Ruiz, S. Giralt, F. Jiménez-Espejo, D. Gallego-Torres, M. Rodrigo-Gámiz, J. García-Orellana, M. Ortega-Huertas, and G. J. de Lange
Clim. Past, 7, 1395–1414, https://doi.org/10.5194/cp-7-1395-2011, https://doi.org/10.5194/cp-7-1395-2011, 2011
C. Martín-Puertas, F. Jiménez-Espejo, F. Martínez-Ruiz, V. Nieto-Moreno, M. Rodrigo, M. P. Mata, and B. L. Valero-Garcés
Clim. Past, 6, 807–816, https://doi.org/10.5194/cp-6-807-2010, https://doi.org/10.5194/cp-6-807-2010, 2010
C. Andersson, F. S. R. Pausata, E. Jansen, B. Risebrobakken, and R. J. Telford
Clim. Past, 6, 179–193, https://doi.org/10.5194/cp-6-179-2010, https://doi.org/10.5194/cp-6-179-2010, 2010
I. Dormoy, O. Peyron, N. Combourieu Nebout, S. Goring, U. Kotthoff, M. Magny, and J. Pross
Clim. Past, 5, 615–632, https://doi.org/10.5194/cp-5-615-2009, https://doi.org/10.5194/cp-5-615-2009, 2009
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Short summary
This paper introduces a method to estimate the uncertainty of climate reconstructions from single sediment proxy records. The method can compute uncertainties as a function of averaging timescale, thereby accounting for the fact that some components of the uncertainty are autocorrelated in time. This is achieved by treating the problem in the spectral domain. Fully analytic expressions are derived. A companion paper (Part 2) complements this with application-oriented examples of the method.
This paper introduces a method to estimate the uncertainty of climate reconstructions from...
