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- Quantifying and reducing researcher subjectivity in the generation of
climate indices from documentary sources
Abstract: Quantifying and reducing researcher subjectivity in the generation of climate indices from documentary sources
George C. D. Adamson, David J. Nash, and Stefan W. Grab
Clim. Past, 18, 1071–1081, https://doi.org/10.5194/cp-18-1071-2022, 2022
Descriptions of climate held in archives are a valuable source of past climate variability, but there is a large potential for error in assigning quantitative indices (e.g. −2, v. dry to +2, v. wet) to descriptive data. This is the first study to examine this uncertainty. We gave the same dataset to 71 postgraduate students and 6 professional scientists, findings that error can be minimized by taking an average of indices developed by eight postgraduates and only two professional climatologists.
PubDate: Tue, 17 May 2022 11:53:26 +020
DOI: 10.5194/cp-18-1071-2022 2022
- Non-spherical microparticle shape in Antarctica during the last glacial
period affects dust volume-related metrics
Abstract: Non-spherical microparticle shape in Antarctica during the last glacial period affects dust volume-related metrics
Aaron Chesler, Dominic Winski, Karl Kreutz, Bess Koffman, Erich Osterberg, David Ferris, Zayta Thundercloud, Joseph Mohan, Jihong Cole-Dai, Mark Wells, Michael Handley, Aaron Putnam, Katherine Anderson, and Natalie Harmon
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-36,2022
Preprint under review for CP (discussion: open, 0 comments)
Ice core microparticle data typically use geometry assumptions to calculate particle mass and flux. We use dynamic particle imaging, a novel technique for ice core dust analyses, combined with traditional laser particle counting and coulter counter techniques to assess particle shape in the South Pole Ice Core (SPC14) spanning 50 – 10 ka. Our results suggest that particles are dominantly ellipsoidal in shape and that spherical assumptions overestimate particle mass and flux.
PubDate: Tue, 17 May 2022 11:53:26 +020
DOI: 10.5194/cp-2022-362022
- Simulated range of mid-Holocene precipitation changes from extended lakes
and wetlands over North Africa
Abstract: Simulated range of mid-Holocene precipitation changes from extended lakes and wetlands over North Africa
Nora Farina Specht, Martin Claussen, and Thomas Kleinen
Clim. Past, 18, 1035–1046, https://doi.org/10.5194/cp-18-1035-2022, 2022
Palaeoenvironmental records only provide a fragmentary picture of the lake and wetland extent in North Africa during the mid-Holocene. Therefore, we investigate the possible range of mid-Holocene precipitation changes caused by an estimated small and maximum lake extent and a maximum wetland extent. Results show a particularly strong monsoon precipitation response to lakes and wetlands over the Western Sahara and an increased monsoon precipitation when replacing lakes with vegetated wetlands.
PubDate: Fri, 13 May 2022 11:53:26 +020
DOI: 10.5194/cp-18-1035-2022 2022
- Calendar effects on surface air temperature and precipitation based on
model-ensemble equilibrium and transient simulations from PMIP4 and
PACMEDY
Abstract: Calendar effects on surface air temperature and precipitation based on model-ensemble equilibrium and transient simulations from PMIP4 and PACMEDY
Xiaoxu Shi, Martin Werner, Carolin Krug, Chris M. Brierley, Anni Zhao, Endurance Igbinosa, Pascale Braconnot, Esther Brady, Jian Cao, Roberta D'Agostino, Johann Jungclaus, Xingxing Liu, Bette Otto-Bliesner, Dmitry Sidorenko, Robert Tomas, Evgeny M. Volodin, Hu Yang, Qiong Zhang, Weipeng Zheng, and Gerrit Lohmann
Clim. Past, 18, 1047–1070, https://doi.org/10.5194/cp-18-1047-2022, 2022
Since the orbital parameters of the past are different from today, applying the modern calendar to the past climate can lead to an artificial bias in seasonal cycles. With the use of multiple model outputs, we found that such a bias is non-ignorable and should be corrected to ensure an accurate comparison between modeled results and observational records, as well as between simulated past and modern climates, especially for the Last Interglacial.
PubDate: Fri, 13 May 2022 11:53:26 +020
DOI: 10.5194/cp-18-1047-2022 2022
- Response of terrigenous weathering to the African monsoon during the
penultimate deglaciation and the last interglacial period
Abstract: Response of terrigenous weathering to the African monsoon during the penultimate deglaciation and the last interglacial period
Christopher John Lepre, Clara Chang, and Owen Yazzie
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-40,2022
Preprint under review for CP (discussion: open, 0 comments)
Understanding African climate change necessitates the study of geological data, some of the best of which comes from the sedimentary sequences of the Atlantic Ocean that preserve long records of dust blown from the continent. We use such a record to demonstrate that, depending on latitude, the monsoon responds differently to climate perturbations. This has implications not only for future environmental change but also for interpreting archaeological patterns of Middle Stone Age human groups.
PubDate: Fri, 13 May 2022 11:53:26 +020
DOI: 10.5194/cp-2022-402022
- Melt in the Greenland EastGRIP ice core reveals Holocene warm events
Abstract: Melt in the Greenland EastGRIP ice core reveals Holocene warm events
Julien Westhoff, Giulia Sinnl, Anders Svensson, Johannes Freitag, Helle Astrid Kjær, Paul Vallelonga, Bo Vinther, Sepp Kipfstuhl, Dorthe Dahl-Jensen, and Ilka Weikusat
Clim. Past, 18, 1011–1034, https://doi.org/10.5194/cp-18-1011-2022, 2022
We present a melt event record from an ice core from central Greenland, which covers the past 10 000 years. Our record displays warm summer events, which can be used to enhance our understanding of the past climate. We compare our data to anomalies in tree ring width, which also represents summer temperatures, and find a good correlation. Furthermore, we investigate an outstandingly warm event in the year 986 AD or 991 AD, which has not been analyzed before.
PubDate: Tue, 10 May 2022 20:03:09 +020
DOI: 10.5194/cp-18-1011-2022 2022
- Unraveling the mechanisms and implications of a stronger mid-Pliocene AMOC
in PlioMIP2
Abstract: Unraveling the mechanisms and implications of a stronger mid-Pliocene AMOC in PlioMIP2
Julia E. Weiffenbach, Michiel L. J. Baatsen, Henk A. Dijkstra, Anna S. von der Heydt, Ayako Abe-Ouchi, Esther C. Brady, Wing-Le Chan, Deepak Chandan, Mark A. Chandler, Camille Contoux, Ran Feng, Chuncheng Guo, Zixuan Han, Alan M. Haywood, Qiang Li, Xiangyu Li, Gerrit Lohmann, Daniel J. Lunt, Kerim H. Nisancioglu, Bette L. Otto-Bliesner, W. Richard Peltier, Gilles Ramstein, Linda E. Sohl, Christian Stepanek, Ning Tan, Julia C. Tindall, Charles J. R. Williams, Qiong Zhang, and Zhongshi Zhang
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-35,2022
Preprint under review for CP (discussion: open, 0 comments)
We study the behavior of the Atlantic Meridional Overturning Circulation (AMOC) in the mid-Pliocene. The mid-Pliocene was about 3 million years ago and had a similar CO2 concentration to today. We show that the AMOC is stronger during this period due to changes in geography and that this has a significant influence on ocean temperatures and heat transported northwards by the Atlantic Ocean. Understanding the behavior of the mid-Pliocene AMOC can help us to learn more about our future climate.
PubDate: Tue, 10 May 2022 20:03:09 +020
DOI: 10.5194/cp-2022-352022
- Insolation evolution and ice volume legacies determine interglacial and
glacial intensity
Abstract: Insolation evolution and ice volume legacies determine interglacial and glacial intensity
Takahito Mitsui, Polychronis C. Tzedakis, and Eric W. Wolff
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-41,2022
Preprint under review for CP (discussion: open, 0 comments)
We provide simple quantitative models for the interglacial and glacial intensities over the last 800,000 years. Our results suggest that the memory of previous climate states and the time course of the insolation in both hemispheres are crucial for understanding interglacial and glacial intensities. In our model, the shift in interglacial intensities at the Mid-Brunhes Event (~430 ka) is ultimately attributed to the amplitude-modulation of obliquity.
PubDate: Tue, 10 May 2022 20:03:09 +020
DOI: 10.5194/cp-2022-412022
- Is it possible to estimate aerosol optical depth from historic colour
paintings'
Abstract: Is it possible to estimate aerosol optical depth from historic colour paintings'
Christian von Savigny, Anna Lange, Anne Hemkendreis, Christoph Hoffmann, and Alexei Rozanov
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-38,2022
Preprint under review for CP (discussion: open, 0 comments)
This study investigates the possibility to infer information on aerosol optical depth from photographs of historic paintings. The idea – which has been applied in previous studies – is very interesting, because it would provide an archive of the atmospheric aerosol loading covering many centuries. We show that twilight colours do not only depend on the aerosol optical thickness, but also on several other parameters, making a quantitative estimate of aerosol optical depth essentially impossible.
PubDate: Mon, 09 May 2022 20:03:09 +020
DOI: 10.5194/cp-2022-382022
- Reorganization of Atlantic Waters at sub-polar latitudes linked to
deep-water overflow in both glacial and interglacial climate states
Abstract: Reorganization of Atlantic Waters at sub-polar latitudes linked to deep-water overflow in both glacial and interglacial climate states
Dakota E. Holmes, Tali L. Babila, Ulysses Ninnemann, Gordon Bromley, Shane Tyrrell, Greig A. Paterson, Michelle J. Curran, and Audrey Morley
Clim. Past, 18, 989–1009, https://doi.org/10.5194/cp-18-989-2022, 2022
Our proxy-based observations of the glacial inception following MIS 11 advance our mechanistic understanding of (and elucidates antecedent conditions that can lead to) high-magnitude climate instability during low- and intermediate-ice boundary conditions. We find that irrespective of the magnitude of climate variability or boundary conditions, the reorganization between Polar Water and Atlantic Water at subpolar latitudes appears to influence deep-water flow in the Nordic Seas.
PubDate: Fri, 06 May 2022 13:32:53 +020
DOI: 10.5194/cp-18-989-2022 2022
- Humidity changes and possible forcing mechanisms over the last millennium
in arid Central Asia
Abstract: Humidity changes and possible forcing mechanisms over the last millennium in arid Central Asia
Shengnan Feng, Xingqi Liu, Feng Shi, Xin Mao, Yun Li, and Jiaping Wang
Clim. Past, 18, 975–988, https://doi.org/10.5194/cp-18-975-2022, 2022
We present a continuous humidity history in arid Central Asia over the past millennium based on the ~1.8-year high-resolution multiproxy record from Lake Dalongchi. Our findings emphasize that the Gleissberg solar cycle and quasi-regular period of ENSO amplitude play critical roles in controlling the effective humidity at century and multidecadal timescales, respectively. Our analysis provides new insights for hydroclimate predictions and climate simulations in arid Central Asia in the future.
PubDate: Fri, 06 May 2022 13:32:53 +020
DOI: 10.5194/cp-18-975-2022 2022
- Drought increased since the mid-20th century in the northern South
American Altiplano revealed by a 389-year precipitation record
Abstract: Drought increased since the mid-20th century in the northern South American Altiplano revealed by a 389-year precipitation record
Mariano S. Morales, Doris B. Crispín De La Cruz, Claudio Álvarez, Duncan A. Christie, Eugenia Ferrero, Laia Andreu-Hayles, Ricardo Villalba, Anthony Guerra, Ginette Ticse-Otarola, Ernesto Rodríguez-Ramírez, Rosmery LLocclla Martínez, Joali Sanchez-Ferrer, and Edilson J. Requena-Rojas
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-37,2022
Preprint under review for CP (discussion: open, 0 comments)
In this study, we develop the first tree-ring based precipitation reconstruction for the northern South American Altiplano back to 1625 CE. We established the significance of our reconstruction by using it to determine that the occurrence rate of extreme dry events together with a shift in mean dry conditions for the late 20th-beginning 21st century is unprecedented in the past 389 years. Our reconstruction provides also valuable information about the ENSO influences in the local precipitation.
PubDate: Fri, 06 May 2022 13:32:53 +020
DOI: 10.5194/cp-2022-372022
- Pliocene evolution of the tropical Atlantic thermocline depth
Abstract: Pliocene evolution of the tropical Atlantic thermocline depth
Carolien M. H. van der Weijst, Josse Winkelhorst, Wesley de Nooijer, Anna von der Heydt, Gert-Jan Reichart, Francesca Sangiorgi, and Appy Sluijs
Clim. Past, 18, 961–973, https://doi.org/10.5194/cp-18-961-2022, 2022
A hypothesized link between Pliocene (5.3–2.5 million years ago) global climate and tropical thermocline depth is currently only backed up by data from the Pacific Ocean. In our paper, we present temperature, salinity, and thermocline records from the tropical Atlantic Ocean. Surprisingly, the Pliocene thermocline evolution was remarkably different in the Atlantic and Pacific. We need to reevaluate the mechanisms that drive thermocline depth, and how these are tied to global climate change.
PubDate: Mon, 02 May 2022 12:59:07 +020
DOI: 10.5194/cp-18-961-2022 2022
- Documentary-based climate reconstructions in the Czech Lands
1501–2020 CE and their European context
Abstract: Documentary-based climate reconstructions in the Czech Lands 1501–2020 CE and their European context
Rudolf Brázdil, Petr Dobrovolný, Jiří Mikšovský, Petr Pišoft, Miroslav Trnka, Martin Možný, and Jan Balek
Clim. Past, 18, 935–959, https://doi.org/10.5194/cp-18-935-2022, 2022
The paper deals with 520-year series (1501–2020 CE) of temperature, precipitation, and four drought indices reconstructed from documentary evidence and instrumental observations for the Czech Lands. Basic features of their fluctuations, long-term trends, and periodicities as well as attribution to changes in external forcings and climate variability modes are analysed. Representativeness of Czech reconstructions at European scale is evaluated. The paper shows extreme character of past decades.
PubDate: Fri, 29 Apr 2022 12:59:07 +020
DOI: 10.5194/cp-18-935-2022 2022
- Influence of warming and atmospheric circulation changes on multidecadal
European flood variability
Abstract: Influence of warming and atmospheric circulation changes on multidecadal European flood variability
Stefan Brönnimann, Peter Stucki, Jörg Franke, Veronika Valler, Yuri Brugnara, Ralf Hand, Laura C. Slivinski, Gilbert P. Compo, Prashant D. Sardeshmukh, Michel Lang, and Bettina Schaefli
Clim. Past, 18, 919–933, https://doi.org/10.5194/cp-18-919-2022, 2022
Floods in Europe vary on time scales of several decades. Flood-rich and flood-poor periods alternate. Recently floods have again become more frequent. Long time series of peak stream flow, precipitation, and atmospheric variables reveal that until around 1980, these changes were mostly due to changes in atmospheric circulation. However, in recent decades the role of increasing atmospheric moisture due to climate warming has become more important and is now the main driver of flood changes.
PubDate: Thu, 28 Apr 2022 12:59:07 +020
DOI: 10.5194/cp-18-919-2022 2022
- Pre-industrial Temperature Variability on the Swiss Plateau Derived from
the Instrumental Daily Series of Bern and Zurich
Abstract: Pre-industrial Temperature Variability on the Swiss Plateau Derived from the Instrumental Daily Series of Bern and Zurich
Yuri Brugnara, Chantal Hari, Lucas Pfister, Veronika Valler, and Stefan Brönnimann
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-34,2022
Preprint under review for CP (discussion: open, 0 comments)
We digitized dozens of weather journals containing temperature measurements from in and around Bern and Zurich. They cover over a century before the creation of a national weather service in Switzerland. With these data we could create daily temperature series for the two cities that span the last 265 years. We found that pre-industrial climate on the Swiss Plateau was colder than suggested by most existing temperature reconstructions and almost 3 °C colder than present-day climate.
PubDate: Wed, 27 Apr 2022 17:36:02 +020
DOI: 10.5194/cp-2022-342022
- Technical Note: Past and future warming – direct comparison on
multi-century timescales
Abstract: Technical Note: Past and future warming – direct comparison on multi-century timescales
Darrell S. Kaufman and Nicholas P. McKay
Clim. Past, 18, 911–917, https://doi.org/10.5194/cp-18-911-2022, 2022
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.
PubDate: Tue, 26 Apr 2022 17:36:02 +020
DOI: 10.5194/cp-18-911-2022 2022
- A cosmogenic nuclide-derived chronology of pre-Last Glacial Cycle
glaciations during MIS 8 and MIS 6 in northern Patagonia
Abstract: A cosmogenic nuclide-derived chronology of pre-Last Glacial Cycle glaciations during MIS 8 and MIS 6 in northern Patagonia
Tancrède Pierre Marie Leger, Andrew Steven Hein, Ángel Rodés, Robert George Bingham, Irene Schimmelpfennig, Derek Fabel, Pablo Tapia Gonzalez, and the ASTER Team
Clim. Past Discuss., https//doi.org/10.5194/cp-2022-32,2022
Preprint under review for CP (discussion: open, 0 comments)
Understanding why the past 800 thousand years of Earth’s history has been paced by ~100 thousand-year cycles of alternating cold glacial and warm interglacial conditions remains a major scientific debate. To contribute knowledge to this question, we studied well-preserved glacial deposits in eastern Patagonia. Our work provides a new detailed glacier chronology that enables to establish the timing of multiple Patagonian ice-sheet expansion events over the last three hundred thousand years.
PubDate: Mon, 25 Apr 2022 17:36:02 +020
DOI: 10.5194/cp-2022-322022
- The long-standing dilemma of European summer temperatures at the
mid-Holocene and other considerations on learning from the past for the
future using a regional climate model
Abstract: The long-standing dilemma of European summer temperatures at the mid-Holocene and other considerations on learning from the past for the future using a regional climate model
Emmanuele Russo, Bijan Fallah, Patrick Ludwig, Melanie Karremann, and Christoph C. Raible
Clim. Past, 18, 895–909, https://doi.org/10.5194/cp-18-895-2022, 2022
In this study a set of simulations are performed with the regional climate model COSMO-CLM for Europe, for the mid-Holocene and pre-industrial periods. The main aim is to better understand the drivers of differences between models and pollen-based summer temperatures. Results show that a fundamental role is played by spring soil moisture availability. Additionally, results suggest that model bias is not stationary, and an optimal configuration could not be the best under different forcing.
PubDate: Fri, 22 Apr 2022 17:36:02 +020
DOI: 10.5194/cp-18-895-2022 2022
- Orbital insolation variations, intrinsic climate variability, and
Quaternary glaciations
Abstract: Orbital insolation variations, intrinsic climate variability, and Quaternary glaciations
Keno Riechers, Takahito Mitsui, Niklas Boers, and Michael Ghil
Clim. Past, 18, 863–893, https://doi.org/10.5194/cp-18-863-2022, 2022
Building upon Milancovic's theory of orbital forcing, this paper reviews the interplay between intrinsic variability and external forcing in the emergence of glacial interglacial cycles. It provides the reader with historical background information and with basic theoretical concepts used in recent paleoclimate research. Moreover, it presents new results which confirm the reduced stability of glacial-cycle dynamics after the mid-Pleistocene transition.
PubDate: Thu, 21 Apr 2022 22:15:47 +020
DOI: 10.5194/cp-18-863-2022 2022
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