Articles | Volume 28, issue 3
https://doi.org/10.5194/npg-28-311-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/npg-28-311-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
29 Jul 2021
Research article |
| 29 Jul 2021
| 29 Jul 2021
Comparing estimation techniques for temporal scaling in palaeoclimate time series
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Telegrafenberg A45, 14473 Potsdam, Germany
Institute of Geosciences, University of Potsdam, Karl-Liebknecht-Str. 24–25, 14476 Potsdam, Germany
Kira Rehfeld
Institut für Umweltphysik, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany
Thomas Laepple
Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Telegrafenberg A45, 14473 Potsdam, Germany
MARUM – Center for Marine Environmental Sciences and Faculty
of Geosciences, University of Bremen, 28334 Bremen, Germany
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Ulrike Herzschuh, Thomas Böhmer, Manuel Chevalier, Raphaël Hébert, Anne Dallmeyer, Chenzhi Li, Xianyong Cao, Odile Peyron, Larisa Nazarova, Elena Y. Novenko, Jungjae Park, Natalia A. Rudaya, Frank Schlütz, Lyudmila S. Shumilovskikh, Pavel E. Tarasov, Yongbo Wang, Ruilin Wen, Qinghai Xu, and Zhuo Zheng
Clim. Past, 19, 1481–1506, https://doi.org/10.5194/cp-19-1481-2023, https://doi.org/10.5194/cp-19-1481-2023, 2023
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Ulrike Herzschuh, Thomas Böhmer, Chenzhi Li, Manuel Chevalier, Raphaël Hébert, Anne Dallmeyer, Xianyong Cao, Nancy H. Bigelow, Larisa Nazarova, Elena Y. Novenko, Jungjae Park, Odile Peyron, Natalia A. Rudaya, Frank Schlütz, Lyudmila S. Shumilovskikh, Pavel E. Tarasov, Yongbo Wang, Ruilin Wen, Qinghai Xu, and Zhuo Zheng
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Antoine Grisart, Mathieu Casado, Vasileios Gkinis, Bo Vinther, Philippe Naveau, Mathieu Vrac, Thomas Laepple, Bénédicte Minster, Frederic Prié, Barbara Stenni, Elise Fourré, Hans Christian Steen-Larsen, Jean Jouzel, Martin Werner, Katy Pol, Valérie Masson-Delmotte, Maria Hoerhold, Trevor Popp, and Amaelle Landais
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Janica C. Bühler, Josefine Axelsson, Franziska A. Lechleitner, Jens Fohlmeister, Allegra N. LeGrande, Madhavan Midhun, Jesper Sjolte, Martin Werner, Kei Yoshimura, and Kira Rehfeld
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Roman Procyk, Shaun Lovejoy, and Raphael Hébert
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Elisa Ziegler and Kira Rehfeld
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Past climate changes are the only record of how the climate responds to changes in conditions on Earth, but simulations with complex climate models are challenging. We extended a simple climate model such that it simulates the development of temperatures over time. In the model, changes in carbon dioxide and ice distribution affect the simulated temperatures the most. The model is very efficient and can therefore be used to examine past climate changes happening over long periods of time.
Janica C. Bühler, Carla Roesch, Moritz Kirschner, Louise Sime, Max D. Holloway, and Kira Rehfeld
Clim. Past, 17, 985–1004, https://doi.org/10.5194/cp-17-985-2021, https://doi.org/10.5194/cp-17-985-2021, 2021
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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.
Laia Comas-Bru, Kira Rehfeld, Carla Roesch, Sahar Amirnezhad-Mozhdehi, Sandy P. Harrison, Kamolphat Atsawawaranunt, Syed Masood Ahmad, Yassine Ait Brahim, Andy Baker, Matthew Bosomworth, Sebastian F. M. Breitenbach, Yuval Burstyn, Andrea Columbu, Michael Deininger, Attila Demény, Bronwyn Dixon, Jens Fohlmeister, István Gábor Hatvani, Jun Hu, Nikita Kaushal, Zoltán Kern, Inga Labuhn, Franziska A. Lechleitner, Andrew Lorrey, Belen Martrat, Valdir Felipe Novello, Jessica Oster, Carlos Pérez-Mejías, Denis Scholz, Nick Scroxton, Nitesh Sinha, Brittany Marie Ward, Sophie Warken, Haiwei Zhang, and SISAL Working Group members
Earth Syst. Sci. Data, 12, 2579–2606, https://doi.org/10.5194/essd-12-2579-2020, https://doi.org/10.5194/essd-12-2579-2020, 2020
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This paper presents an updated version of the SISAL (Speleothem Isotope Synthesis and Analysis) database. This new version contains isotopic data from 691 speleothem records from 294 cave sites and new age–depth models, including their uncertainties, for 512 speleothems.
Mathieu Casado, Thomas Münch, and Thomas Laepple
Clim. Past, 16, 1581–1598, https://doi.org/10.5194/cp-16-1581-2020, https://doi.org/10.5194/cp-16-1581-2020, 2020
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The isotopic composition in ice cores from Antarctica is usually interpreted as a temperature proxy. Using a forward model, we show how different the signal in ice cores and the actual climatic signal are. Precipitation intermittency and diffusion do indeed affect the archived signal, leading to the reshuffling of the signal which limits the ability to reconstruct high-resolution climatic variations with ice cores.
Torben Kunz, Andrew M. Dolman, and Thomas Laepple
Clim. Past, 16, 1469–1492, https://doi.org/10.5194/cp-16-1469-2020, https://doi.org/10.5194/cp-16-1469-2020, 2020
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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.
Kira Rehfeld, Raphaël Hébert, Juan M. Lora, Marcus Lofverstrom, and Chris M. Brierley
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Under continued anthropogenic greenhouse gas emissions, it is likely that global mean surface temperature will continue to increase. Little is known about changes in climate variability. We analyze surface climate variability and compare it to mean change in colder- and warmer-than-present climate model simulations. In most locations, but not on subtropical land, simulated temperature variability up to decadal timescales decreases with mean temperature, and precipitation variability increases.
Laia Comas-Bru, Sandy P. Harrison, Martin Werner, Kira Rehfeld, Nick Scroxton, Cristina Veiga-Pires, and SISAL working group members
Clim. Past, 15, 1557–1579, https://doi.org/10.5194/cp-15-1557-2019, https://doi.org/10.5194/cp-15-1557-2019, 2019
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We use an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled climate model to provide a protocol for using speleothem isotopic data for model evaluation, including screening the observations and the optimum period for the modern observational baseline. We also illustrate techniques through which the absolute isotopic values during any time period could be used for model evaluation.
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.
Matthias M. May and Kira Rehfeld
Earth Syst. Dynam., 10, 1–7, https://doi.org/10.5194/esd-10-1-2019, https://doi.org/10.5194/esd-10-1-2019, 2019
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Current CO2 emission rates are incompatible with the 2 °C target for global warming. Negative emission technologies are therefore an important basis for climate policy scenarios. We show that photoelectrochemical CO2 reduction might be a viable, high-efficiency alternative to biomass-based approaches, which reduce competition for arable land. To develop them, chemical reactions have to be optimized for CO2 removal, which deviates from energetic efficiency optimization in solar fuel applications.
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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Proxy data on climate variations contain noise from many sources and, for reliable estimates, we need to determine those temporal scales at which the climate signal in the proxy record dominates the noise. We developed a method to derive timescale-dependent estimates of temperature proxy signal-to-noise ratios, which we apply and discuss in the context of Antarctic ice-core records but which in general are applicable to a large set of palaeoclimate records.
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
The Cryosphere, 12, 1745–1766, https://doi.org/10.5194/tc-12-1745-2018, https://doi.org/10.5194/tc-12-1745-2018, 2018
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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
Short summary
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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.
S. Lovejoy, L. del Rio Amador, and R. Hébert
Earth Syst. Dynam., 6, 637–658, https://doi.org/10.5194/esd-6-637-2015, https://doi.org/10.5194/esd-6-637-2015, 2015
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Numerical climate models forecast the weather well beyond the deterministic limit. In this “macroweather” regime, they are random number generators. Stochastic models can have more realistic noises and can be forced to converge to the real-world climate. Existing stochastic models do not exploit the very long atmospheric and oceanic memories. With skill up to decades, our new ScaLIng Macroweather Model (SLIMM) exploits this to make forecasts more accurate than GCMs.
K. Rehfeld, N. Molkenthin, and J. Kurths
Nonlin. Processes Geophys., 21, 691–703, https://doi.org/10.5194/npg-21-691-2014, https://doi.org/10.5194/npg-21-691-2014, 2014
L. Tupikina, K. Rehfeld, N. Molkenthin, V. Stolbova, N. Marwan, and J. Kurths
Nonlin. Processes Geophys., 21, 705–711, https://doi.org/10.5194/npg-21-705-2014, https://doi.org/10.5194/npg-21-705-2014, 2014
N. Molkenthin, K. Rehfeld, V. Stolbova, L. Tupikina, and J. Kurths
Nonlin. Processes Geophys., 21, 651–657, https://doi.org/10.5194/npg-21-651-2014, https://doi.org/10.5194/npg-21-651-2014, 2014
K. Rehfeld and J. Kurths
Clim. Past, 10, 107–122, https://doi.org/10.5194/cp-10-107-2014, https://doi.org/10.5194/cp-10-107-2014, 2014
Related subject area
Subject: Scaling, multifractals, turbulence, complex systems, self-organized criticality | Topic: Climate, atmosphere, ocean, hydrology, cryosphere, biosphere | Techniques: Simulation
On dissipation timescales of the basic second-order moments: the effect on the energy and flux budget (EFB) turbulence closure for stably stratified turbulence
Clustering of settling microswimmers in turbulence
Phytoplankton retention mechanisms in estuaries: a case study of the Elbe estuary
Fractional relaxation noises, motions and the fractional energy balance equation
Evgeny Kadantsev, Evgeny Mortikov, Andrey Glazunov, Nathan Kleeorin, and Igor Rogachevskii
Nonlin. Processes Geophys., 31, 395–408, https://doi.org/10.5194/npg-31-395-2024, https://doi.org/10.5194/npg-31-395-2024, 2024
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Our study investigates how turbulence behaves in stable conditions using direct numerical simulations. We found that rethinking how energy dissipates in these situations is crucial. By revising existing models, we uncovered limitations in understanding how temperature is transported vertically in very stable conditions. We focus on how turbulence works in extreme stability and offer new insights that could improve our understanding of natural phenomena affected by stable atmospheric conditions.
Jingran Qiu, Zhiwen Cui, Eric Climent, and Lihao Zhao
Nonlin. Processes Geophys., 31, 229–236, https://doi.org/10.5194/npg-31-229-2024, https://doi.org/10.5194/npg-31-229-2024, 2024
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The swimming of settling microswimmers in a fluid flow is found to induce a gyrotactic torque, causing them to swim against gravity. A Lagrangian model of the swimmer under this effect is used in the analysis of small-scale clustering in turbulence. The intensity and location of clustering under this swimming-induced gyrotactic torque are found to depend on not only the swimming velocity but also the settling speed, indicating the importance of the settling effect on gyrotaxis.
Laurin Steidle and Ross Vennell
Nonlin. Processes Geophys., 31, 151–164, https://doi.org/10.5194/npg-31-151-2024, https://doi.org/10.5194/npg-31-151-2024, 2024
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Phytoplankton are key in estuaries, as they form the ecosystem's base. Despite being washed out by river flow and facing a large range of different salinities, they persist. Our Lagrangian simulation of the Elbe estuary shows that buoyancy helps them to be retained. Riverbanks and tidal flats offer refuges from strong currents. Our findings emphasize the need for careful ecosystem management in estuaries.
Shaun Lovejoy
Nonlin. Processes Geophys., 29, 93–121, https://doi.org/10.5194/npg-29-93-2022, https://doi.org/10.5194/npg-29-93-2022, 2022
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The difference between the energy that the Earth receives from the Sun and the energy it emits as black-body radiation is stored in a scaling hierarchy of structures in the ocean, soil and hydrosphere. The simplest scaling storage model leads to the fractional energy balance equation (FEBE). We examine the statistical properties of FEBE when it is driven by random fluctuations. In this paper, we explore the statistical properties of this mathematically simple yet neglected equation.
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Short summary
Paleoclimate proxy data are essential for broadening our understanding of climate variability. There remain, however, challenges for traditional methods of variability analysis to be applied to such data, which are usually irregular. We perform a comparative analysis of different methods of scaling analysis, which provide variability estimates as a function of timescales, applied to irregular paleoclimate proxy data.
Paleoclimate proxy data are essential for broadening our understanding of climate variability....
