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2. SISALv2: a comprehensive speleothem isotope database with multiple age–depth models

Author

Comas-Bru, Laia, Rehfeld, Kira, Roesch, Carla, Amirnezhad-Mozhdehi, Sahar, Harrison, Sandy P, Atsawawaranunt, Kamolphat, Ahmad, Syed Masood, Brahim, Yassine Ait, Baker, Andy, Bosomworth, Matthew, Breitenbach, Sebastian FM, Burstyn, Yuval, Columbu, Andrea, Deininger, Michael, Demény, Attila, Dixon, Bronwyn, Fohlmeister, Jens, Hatvani, István Gábor, Hu, Jun, Kaushal, Nikita, Kern, Zoltán, Labuhn, Inga, Lechleitner, Franziska A, Lorrey, Andrew, Martrat, Belen, Novello, Valdir Felipe, Oster, Jessica, Pérez-Mejías, Carlos, Scholz, Denis, Scroxton, Nick, Sinha, Nitesh, Ward, Brittany Marie, Warken, Sophie, Zhang, Haiwei, and members, SISAL Working Group

Subjects
Climate Action, Atmospheric Sciences, Geochemistry, Physical Geography and Environmental Geoscience
Abstract

Characterizing the temporal uncertainty in palaeoclimate records is crucial for analysing past climate change, correlating climate events between records, assessing climate periodicities, identifying potential triggers and evaluating climate model simulations. The first global compilation of speleothem isotope records by the SISAL (Speleothem Isotope Synthesis and Analysis) working group showed that age model uncertainties are not systematically reported in the published literature, and these are only available for a limited number of records (ca. 15 %, n = 107/691). To improve the usefulness of the SISAL database, we have (i) improved the database's spatio-temporal coverage and (ii) created new chronologies using seven different approaches for age- depth modelling. We have applied these alternative chronologies to the records from the first version of the SISAL database (SISALv1) and to new records compiled since the release of SISALv1. This paper documents the necessary changes in the structure of the SISAL database to accommodate the inclusion of the new age models and their uncertainties as well as the expansion of the database to include new records and the qualitycontrol measures applied. This paper also documents the age-depth model approaches used to calculate the new chronologies. The updated version of the SISAL database (SISALv2) contains isotopic data from 691 speleothem records from 294 cave sites and new age-depth models, including age-depth temporal uncertainties for 512 speleothems.

Published
2020

6. High resolution paleo-monsoon records from peninsular Indian speleothems

Author

Kaushal, Nikita, Henderson, Gideon, and Rickaby, Ros

Subjects
551.44
Abstract

The Indian Summer Monsoon is a major component of the global climatic system. Stalagmites have a proven ability to provide information of such monsoon systems. In this thesis, examination of cave records and field work provides a framework of the spatial and temporal distribution of stalagmites in peninsular India. Stable oxygen isotope records from stalagmites are supported by trace element records. An aragonite stalagmite from the west coast of India suggests that changes in growth surface can effect precipitation through time available for dissolved inorganic carbon removal. Calculation of empirical partition coefficients from the aragonite stalagmite indicates that U/Ca, Sr/Ca and P/Ca ratios may be paleo-aridity indicators through the process of Prior Aragonite Precipitation. There may also be source and/or temperature control on the partitioning of Sr/Ca into the aragonite stalagmite. These are the first trace element measurements for stalagmites from peninsular India and some of the few available from aragonite stalagmites. The δ18O composition of a calcite stalagmite from central India that grew from 3130 to 2100 years BP is consistent with the hypothesis that δ18O is controlled by air parcel trajectory and amount of rainout between source and cave site. P/Ca and U/Ca records from this stalagmite provide information on past rainfall conditions. Correlation analysis of δ18O, P/Ca and U/Ca indicates that rainfall amount was not the dominant control on δ18O composition at this cave site. Examination of a stalagmite that has diagenetically altered from aragonite to calcite shows that the δ18O system is extremely susceptible to diagenesis. Sr/Ca and U/Ca of the primary aragonite are retained in secondary calcite. Higher Mg/Ca ratios in secondary calcite compared to primary aragonite indicates that diagenetic fluid adds material to the primary carbonate. The variation in U-Th ages are caused by differential addition and losses of U and Th isotopes.

Published
2017

7. SISALv3: A global speleothem stable isotope and trace element database

Author

0000-0002-2220-9046, 0000-0002-1697-0429, 0000-0002-5022-3195, 0000-0002-5100-4226, 0000-0002-1552-6166, 0000-0002-4238-1230, 0000-0003-0398-9005, 0000-0001-5687-1903, 0000-0002-9262-7315, 0000-0002-9442-5362, 0000-0002-0496-120X, 0000-0002-2953-7835, 0000-0002-1969-8555, 0000-0002-7070-7365, 0000-0003-3858-4462, 0000-0003-0527-9381, 0000-0001-5410-062X, 0000-0002-5013-4811, 0000-0002-0458-5996, 0000-0003-4900-2587, 0000-0002-4458-2204, 0000-0001-9904-9178, 0000-0003-0004-0910, 0000-0002-0120-3745, 0000-0002-8370-9271, 0000-0003-4733-1125, 0000-0003-0767-5783, 0000-0002-8410-9569, 0000-0002-3339-1488, 0000-0002-0855-1283, Kaushal, Nikita, Lechleitner, Franziska A., Wilhelm, Micah, Azennoud, Khalil, Bühler, Janica C., Braun, Kerstin, Ait Brahim, Yassine, Baker, Andy, Burstyn, Yuval, Comas-Bru, Laia, Fohlmeister, Jens, Goldsmith, Yonaton, Harrison, Sandy P., Hatvani, István G., Rehfeld, Kira, Ritzau, Magdalena, Skiba, Vanessa, Stoll, Heather M., Szűcs, József G., Tanos, Péter, Treble, Pauline C., Azevedo, Vitor, Baker, Jonathan L., Borsato, Andrea, Chawchai, Sakonvan, Columbu, Andrea, Endres, Laura, Hu, Jun, Kern, Zoltán, Kimbrough, Alena, Koç, Koray, Markowska, Monika, Martrat, Belen, Masood Ahmad, Syed, Nehme, Carole, Novello, Valdir Felipe, Pérez-Mejías, Carlos, Ruan, Jiaoyang, Sekhon, Natasha, Sinha, Nitesh, Tadros, Carol V., Tiger, Benjamin H., Warken, Sophie, Wolf, Annabel, Zhang, Haiwei, 0000-0002-2220-9046, 0000-0002-1697-0429, 0000-0002-5022-3195, 0000-0002-5100-4226, 0000-0002-1552-6166, 0000-0002-4238-1230, 0000-0003-0398-9005, 0000-0001-5687-1903, 0000-0002-9262-7315, 0000-0002-9442-5362, 0000-0002-0496-120X, 0000-0002-2953-7835, 0000-0002-1969-8555, 0000-0002-7070-7365, 0000-0003-3858-4462, 0000-0003-0527-9381, 0000-0001-5410-062X, 0000-0002-5013-4811, 0000-0002-0458-5996, 0000-0003-4900-2587, 0000-0002-4458-2204, 0000-0001-9904-9178, 0000-0003-0004-0910, 0000-0002-0120-3745, 0000-0002-8370-9271, 0000-0003-4733-1125, 0000-0003-0767-5783, 0000-0002-8410-9569, 0000-0002-3339-1488, 0000-0002-0855-1283, Kaushal, Nikita, Lechleitner, Franziska A., Wilhelm, Micah, Azennoud, Khalil, Bühler, Janica C., Braun, Kerstin, Ait Brahim, Yassine, Baker, Andy, Burstyn, Yuval, Comas-Bru, Laia, Fohlmeister, Jens, Goldsmith, Yonaton, Harrison, Sandy P., Hatvani, István G., Rehfeld, Kira, Ritzau, Magdalena, Skiba, Vanessa, Stoll, Heather M., Szűcs, József G., Tanos, Péter, Treble, Pauline C., Azevedo, Vitor, Baker, Jonathan L., Borsato, Andrea, Chawchai, Sakonvan, Columbu, Andrea, Endres, Laura, Hu, Jun, Kern, Zoltán, Kimbrough, Alena, Koç, Koray, Markowska, Monika, Martrat, Belen, Masood Ahmad, Syed, Nehme, Carole, Novello, Valdir Felipe, Pérez-Mejías, Carlos, Ruan, Jiaoyang, Sekhon, Natasha, Sinha, Nitesh, Tadros, Carol V., Tiger, Benjamin H., Warken, Sophie, Wolf, Annabel, and Zhang, Haiwei

Abstract

Palaeoclimate information on multiple climate variables at different spatiotemporal scales is becoming increasingly important to understand environmental and societal responses to climate change. A lack of high-quality reconstructions of past hydroclimate has recently been identified as a critical research gap. Speleothems, with their precise chronologies, widespread distribution, and ability to record changes in local to regional hydroclimate variability, are an ideal source of such information. Here, we present a new version of the Speleothem Isotopes Synthesis and AnaLysis database (SISALv3), which has been expanded to include trace element ratios and Sr isotopes as additional, hydroclimate-sensitive geochemical proxies. The oxygen and carbon isotope data included in previous versions of the database have been substantially expanded. SISALv3 contains speleothem data from 365 sites from across the globe, including 95 Mg/Ca, 85 Sr/Ca, 52 Ba/Ca, 25 U/Ca, 29 P/Ca, and 14 Sr-isotope records. The database also has increased spatiotemporal coverage for stable oxygen (892) and carbon (620) isotope records compared with SISALv2 (which consists of 673 and 430 stable oxygen and carbon records, respectively). Additional meta information has been added to improve the machine-readability and filtering of data. Standardized chronologies are included for all new entities along with the originally published chronologies. Thus, the SISALv3 database constitutes a unique resource of speleothem palaeoclimate information that allows regional to global palaeoclimate analyses based on multiple geochemical proxies, permitting more robust interpretations of past hydroclimate and comparisons with isotope-enabled climate models and other Earth system and hydrological models. The database can be accessed at 10.5287/ora-2nanwp4rk (Kaushal et al., 2024).

Published
2024

9. SISALv3: a global speleothem stable isotope and trace element database.

Author

Kaushal, Nikita, Lechleitner, Franziska A., Wilhelm, Micah, Azennoud, Khalil, Bühler, Janica C., Braun, Kerstin, Ait Brahim, Yassine, Baker, Andy, Burstyn, Yuval, Comas-Bru, Laia, Fohlmeister, Jens, Goldsmith, Yonaton, Harrison, Sandy P., Hatvani, István G., Rehfeld, Kira, Ritzau, Magdalena, Skiba, Vanessa, Stoll, Heather M., Szűcs, József G., and Tanos, Péter

Subjects
*DATABASES, *STABLE isotopes, *TRACE elements, *STRONTIUM isotopes, *GEOCHEMICAL modeling, *CARBON isotopes, *ALUMINUM alloys, *ALKALINE earth metals
Abstract

Palaeoclimate information on multiple climate variables at different spatiotemporal scales is becoming increasingly important to understand environmental and societal responses to climate change. A lack of high-quality reconstructions of past hydroclimate has recently been identified as a critical research gap. Speleothems, with their precise chronologies, widespread distribution, and ability to record changes in local to regional hydroclimate variability, are an ideal source of such information. Here, we present a new version of the Speleothem Isotopes Synthesis and AnaLysis database (SISALv3), which has been expanded to include trace element ratios and Sr isotopes as additional, hydroclimate-sensitive geochemical proxies. The oxygen and carbon isotope data included in previous versions of the database have been substantially expanded. SISALv3 contains speleothem data from 365 sites from across the globe, including 95 Mg/Ca , 85 Sr/Ca , 52 Ba/Ca , 25 U/Ca , 29 P/Ca , and 14 Sr-isotope records. The database also has increased spatiotemporal coverage for stable oxygen (892) and carbon (620) isotope records compared with SISALv2 (which consists of 673 and 430 stable oxygen and carbon records, respectively). Additional meta information has been added to improve the machine-readability and filtering of data. Standardized chronologies are included for all new entities along with the originally published chronologies. Thus, the SISALv3 database constitutes a unique resource of speleothem palaeoclimate information that allows regional to global palaeoclimate analyses based on multiple geochemical proxies, permitting more robust interpretations of past hydroclimate and comparisons with isotope-enabled climate models and other Earth system and hydrological models. The database can be accessed at 10.5287/ora-2nanwp4rk (Kaushal et al., 2024). [ABSTRACT FROM AUTHOR]

Published
2024
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12. Polymeric micelles loaded in situ gel with prednisolone acetate for ocular inflammation: development and evaluation

Author

Kaushal, Nikita, primary, Kumar, Manish, additional, Tiwari, Abhishek, additional, Tiwari, Varsha, additional, Sharma, Kamini, additional, Sharma, Ajay, additional, Marisetti, Arya Lakshmi, additional, Gupta, Madan Mohan, additional, Kazmi, Imran, additional, Alzarea, Sami I, additional, Almalki, Waleed Hassan, additional, and Gupta, Gaurav, additional

Published
2023
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14. Climatic and cave settings influence on drip water fluorescent organic matter with implications for fluorescent laminations in stalagmites.

Author

Endres, Laura Sibylla, Jacquin, Céline, González-Lemos, Saúl, Rodríguez-Rodríguez, Laura, Sliwinski, Jakub, Kaushal, Nikita, Kost, Oliver, and Stoll, Heather Marie

Subjects
SPELEOTHEMS, STALACTITES & stalagmites, CARBON content of water, DISSOLVED organic matter, VEGETATION dynamics, BEDROCK, CAVES, FLUORESCENCE spectroscopy
Abstract

Speleothem fluorescence can provide insights into past vegetation dynamics and stalagmite chronology. However, its origin and especially the formation of fluorescent laminations in stalagmites are poorly understood. We conducted a year-long monthly monitoring of drip water fluorescence in La Vallina Cave (northern Iberian Peninsula) and compared the results to drip water chemistry and active speleothems from the same sites. Drip waters were analyzed using fluorescence spectroscopy and parallel factor analysis (PARAFAC). The resulting five-component model indicates contributions from vegetation, microbial activity, and bedrock. Intra-site fluorescence variability is mainly influenced by changes in overlying vegetation, water reservoir time, and respiration rates. Contrary to prevailing views, we find no systematic increase in drip water fluorescence during rainy conditions across drip sites and seasonal variations in drip water fluorescence are absent at a location where present-day speleothem layers form. Our findings challenge the notion of a higher abundance of humic-like fluorescence during the rainy season as the primary cause for layer formation and suggest additional controls on drip water fluorescence, such as bedrock interaction and microbial reprocessing. We also propose that growth rate may control the dilation of the fluorescence signal in stalagmites, indicating other potential mechanisms for fluorescent layer formation. [ABSTRACT FROM AUTHOR]

Published
2024
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15. The SISAL webApp: exploring the speleothem climate and environmental archives of the world.

Author

Hatvani, István Gábor, Kern, Zoltán, Tanos, Péter, Wilhelm, Micah, Lechleitner, Franziska A., and Kaushal, Nikita

Subjects
SPELEOTHEMS, DATABASES, ISOTOPIC analysis, TRACE elements, COMPUTER programming education, DATA mining, SQL
Abstract

We present the 'SISAL webApp'—a web-based tool to query the Speleothem Isotope Synthesis and AnaLysis (SISAL) database. The software provides an easy-to-use front-end interface to mine data from the SISAL database while providing the SQL code alongside as a learning tool. It allows for simple and increasingly complex querying of the SISAL database based on various data and metadata fields. The SISAL webApp version currently hosts SISALv2 of the database with 691 records from 294 sites, 512 of which have standardized chronologies. The SISAL webApp has sufficient flexibility to host future versions of the SISAL database, which may include allied speleothem information such as trace elements and cave-monitoring records. The SISAL webApp will increase accessibility to the SISAL database while also functioning as a learning tool for more advanced ways of querying paleoclimate databases. The SISAL webApp is available at http://geochem.hu/SISAL_webApp. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Phase 4 of PAGES 2k: Hydroclimate of the Common Era

Author

Falster, Georgina, primary, Sayani, Hussein, additional, Orsi, Anais, additional, McGregor, Helen, additional, Kaushal, Nikita, additional, Jonkers, Lukas, additional, Jones, Matthew, additional, Henley, Benjamin, additional, Eggleston, Sarah, additional, and Atwood, Alyssa, additional

Published
2023
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19. Update to the SISAL speleothem database -- links to monitoring data, additional palaeoenvironmental proxies and enhanced accessibility

Author

Kaushal, Nikita, primary, Wilhelm, Micah, additional, Lechleitner, Franziska, additional, Braun, Kerstin, additional, Rehfeld, Kira, additional, Gabor Hatvani, Istvan, additional, Tanos, Peter, additional, Ritzau, Magdalena, additional, Skiba, Vanessa, additional, Azennoud, Khalil, additional, Gabor Szucs, Jozsef, additional, Kern, Zoltan, additional, Burstyn, Yuval, additional, and Ait Brahim, Yassine, additional

Published
2023
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24. SISALv3: A global speleothem stable isotope and trace element database.

Author

Kaushal, Nikita, Lechleitner, Franziska A., Wilhelm, Micah, Bühler, Janica C., Braun, Kerstin, Brahim, Yassine Ait, Azennoud, Khalil, Baker, Andy, Burstyn, Yuval, Comas-Bru, Laia, Goldsmith, Yonaton, Harrison, Sandy P., Hatvani, István G., Rehfeld, Kira, Ritzau, Magdalena, Skiba, Vanessa, Stoll, Heather M., Szűcs, József G., Treble, Pauline C., and Azevedo, Vitor

Subjects
*DATABASES, *STABLE isotopes, *TRACE elements, *GEOCHEMICAL modeling, *EVIDENCE gaps, *CARBON isotopes, *ALKALINE earth metals
Abstract

Paleoclimate information on multiple climate variables at different spatiotemporal scales is increasingly important to understand environmental and societal responses to climate change. A lack of high-quality reconstructions of past hydroclimate has recently been identified as a critical research gap. Speleothems, with their precise chronologies, widespread distribution, and ability to record changes in local to regional hydroclimate variability, are an ideal source of such information. Here we present a new version of the Speleothem Isotopes Synthesis and AnaLysis database (SISALv3), which has been expanded to include trace element ratios and Sr-isotopes as additional, hydroclimate-sensitive geochemical proxies. The oxygen and carbon isotope data included in previous versions of the database have been substantially expanded. SISALv3, contains speleothem data from 364 sites from across the globe, including 94 Mg/Ca, 83 Sr/Ca, 51 Ba/Ca, 25 U/Ca, 29 P/Ca and 14 Sr-isotope records. The database also has increased spatiotemporal coverage for stable oxygen (831) and carbon (588) isotope records compared to SISALv2. Additional meta information has been added to improve machine-readability and filtering of data. Standardized chronologies are included for all new entities together with the originally published chronologies. The SISALv3 database thus constitutes a unique resource of speleothem paleoclimate information that allows regional-to-global paleoclimate analyses based on multiple geochemical proxies, allowing more robust interpretations of past hydroclimate and comparisons with isotope-enabled climate models and other earth system and hydrological models. [ABSTRACT FROM AUTHOR]

Published
2023
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25. QbD-based rivastigmine tartrate-loaded solid lipid nanoparticles for enhanced intranasal delivery to the brain for Alzheimer's therapeutics

Author

Arora, Deepshi, primary, Bhatt, Shailendra, additional, Kumar, Manish, additional, Verma, Ravinder, additional, Taneja, Yugam, additional, Kaushal, Nikita, additional, Tiwari, Abhishek, additional, Tiwari, Varsha, additional, Alexiou, Athanasios, additional, Albogami, Sarah, additional, Alotaibi, Saqer S., additional, Mittal, Vineet, additional, Singla, Rajeev K., additional, Kaushik, Deepak, additional, and Batiha, Gaber El-Saber, additional

Published
2022
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26. Announcing Phase 4 of PAGES 2k: Hydroclimate of the Common Era

Author

Henley, Benjamin, primary, Eggleston, Sarah, additional, Kaushal, Nikita, additional, Atwood, Alyssa, additional, Bothe, Oliver, additional, Falster, Georgy, additional, Jones, Matthew, additional, Jonkers, Lukas, additional, Konecky, Bronwen, additional, Linderholm, Hans, additional, Martrat, Belen, additional, McGregor, Helen, additional, Orsi, Anais, additional, Phipps, Steven, additional, and Sayani, Hussein, additional

Published
2022
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28. Paleoclimatology and Paleoceanography Perspectives on Integrated, Coordinated, Open, Networked (ICON) Science

Author

Belem, Andre, primary, Bell, Tomoko, additional, Burdett, Heidi, additional, Ibarra, Daniel Enrique, additional, Kaushal, Nikita, additional, Keenan, Benjamin, additional, Klimaszewski-Patterson, Anna, additional, Mette, Madelyn, additional, Naeher, Sebastian, additional, Onafeso, Olumide D, additional, Panmei, Champoungam, additional, Ratnayake, Amila Sandaruwan, additional, and Truax, Olivia, additional

Published
2021
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29. Evaluating model outputs using integrated global speleothem records of climate change since the last glacial

Author

Comas-Bru, Laia, Harrison, Sandy P., Werner, Martin, Rehfeld, Kira, Scroxton, Nick, Veiga-Pires, Cristina, Ahmad, Syed Masood, Brahim, Yassine Ait, Mozhdehi, Sahar Amirnezhad, Arienzo, Monica, Atsawawaranunt, Kamolphat, Baker, Andy, Braun, Kerstin, Breitenbach, Sebastian, Burstyn, Yuval, Chawchai, Sakonvan, Columbu, Andrea, Deininger, Michael, Demeny, Attila, Dixon, Bronwyn, Hatvani, Istvan Gabor, Hu, Jun, Kaushal, Nikita, Kern, Zoltan, Labuhn, Inga, Lachniet, Matthew S., Lechleitner, Franziska A., Lorrey, Andrew, Markowska, Monika, Nehme, Carole, Novello, Valdir F., Oster, Jessica, Perez-Mejias, Carlos, Pickering, Robyn, Sekhon, Natasha, Wang, Xianfeng, Warken, Sophie, Atkinson, Tim, Ayalon, Avner, Baldini, James, Bar-Matthews, Miryam, Bernal, Juan Pablo, Boch, Ronny, Borsato, Andrea, Boyd, Meighan, Brierley, Chris, Cai, Yanjun, Carolin, Stacy, Cheng, Hai, Constantin, Silviu, Couchoud, Isabelle, Cruz, Francisco, Denniston, Rhawn, Dragusin, Virgil, Duan, Wuhui, Ersek, Vasile, Finné, Martin, Fleitmann, Dominik, Fohlmeister, Jens, Frappier, Amy, Genty, Dominique, Holzkamper, Steffen, Hopley, Philip, Johnston, Vanessa, Kathayat, Gayatri, Keenan-Jones, Duncan, Koltai, Gabriella, Li, Ting-Yong, Lone, Mahjoor Ahmad, Luetscher, Marc, Mattey, Dave, Moreno, Ana, Moseley, Gina, Psomiadis, David, Ruan, Jiaoyang, Scholz, Denis, Sha, Lijuan, Smith, Andrew Christopher, Strikis, Nicolas, Treble, Pauline, Unal-Imer, Ezgi, Vaks, Anton, Vansteenberge, Stef, Voarintsoa, Ny Riavo G., Wong, Corinne, Wortham, Barbara, Wurtzel, Jennifer, Zhang, Haiwei, Voarintsoa, Ny Riavo, Earth Observatory of Singapore, Comas-Bru L., Harrison S.P., Werner M., Rehfeld K., Scroxton N., Veiga-Pires C., Ahmad S.M., Brahim Y.A., Mozhdehi S.A., Arienzo M., Atsawawaranunt K., Baker A., Braun K., Breitenbach S., Burstyn Y., Chawchai S., Columbu A., Deininger M., Demeny A., Dixon B., Hatvani I.G., Hu J., Kaushal N., Kern Z., Labuhn I., Lachniet M.S., Lechleitner F.A., Lorrey A., Markowska M., Nehme C., Novello V.F., Oster J., Perez-Mejias C., Pickering R., Sekhon N., Wang X., Warken S., Atkinson T., Ayalon A., Baldini J., Bar-Matthews M., Bernal J.P., Boch R., Borsato A., Boyd M., Brierley C., Cai Y., Carolin S., Cheng H., Constantin S., Couchoud I., Cruz F., Denniston R., Dragusin V., Duan W., Ersek V., Finne M., Fleitmann D., Fohlmeister J., Frappier A., Genty D., Holzkamper S., Hopley P., Johnston V., Kathayat G., Keenan-Jones D., Koltai G., Li T.-Y., Lone M.A., Luetscher M., Mattey D., Moreno A., Moseley G., Psomiadis D., Ruan J., Scholz D., Sha L., Smith A.C., Strikis N., Treble P., Unal-Imer E., Vaks A., Vansteenberge S., Voarintsoa N.R.G., Wong C., Wortham B., Wurtzel J., and Zhang H.

Subjects
010506 paleontology, Climate Research, 010504 meteorology & atmospheric sciences, δ18O, lcsh:Environmental protection, Climate Change, Stratigraphy, Speleothem, Climate change, F800, PMIP4 CONTRIBUTION, Geology [Science], 01 natural sciences, Klimatforskning, STABLE-ISOTOPE VARIATIONS, lcsh:Environmental pollution, Time windows, ddc:550, Meteorology & Atmospheric Sciences, lcsh:TD169-171.8, Speleothem Records, GENERAL-CIRCULATION MODEL, ASIAN MONSOON, Glacial period, Geosciences, Multidisciplinary, DELTA-O-18 WATER ISOTOPE, Baseline (configuration management), lcsh:Environmental sciences, 0105 earth and related environmental sciences, lcsh:GE1-350, Global and Planetary Change, geography, Coupled model intercomparison project, Science & Technology, geography.geographical_feature_category, Paleontology, Geology, GROWTH FREQUENCY VARIATIONS, NORTH-ATLANTIC, OXYGEN-ISOTOPE, 13. Climate action, Climatology, lcsh:TD172-193.5, Physical Sciences, Spatial ecology, Environmental science, Institut für Geowissenschaften, ATMOSPHERIC CIRCULATION, HIGH-RESOLUTION
Abstract

Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data-model comparisons. Here, we illustrate this using 456 globally distributed speleothem delta O-18 records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data-model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on delta O-18 values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices. European Geosciences Union - W2017/413; Irish Centre for Research in Applied Geosciences (iCRAG); European Association of Geochemistry (Early Career Ambassadors program 2017); Quaternary Research Association UK; Navarino Environmental Observatory, Stockholm University; University College Dublin, Savillex (UK) - SF1428; Ibn Zohr University, Morocco; University of Reading; European Research Council - 694481; Natural Environment Research Council (JPI-Belmont project "PAleao-Constraints on Monsoon Evolution and Dynamics (PACMEDY)"); Geological Survey Ireland - 2017-SC-056; Royal Irish Academy; Deutsche Forschungsgemeinschaft - RE3994/2-1; Past Global Changes (PAGES) programme; info:eu-repo/semantics/publishedVersion

Published
2019
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30. A data–model approach to interpreting speleothem oxygen isotope records from monsoon regions

Author

Parker, Sarah E., Harrison, Sandy P., Comas-Bru, Laia, Kaushal, Nikita, LeGrande, Allegra N., Werner, Martin, Parker, Sarah E., Harrison, Sandy P., Comas-Bru, Laia, Kaushal, Nikita, LeGrande, Allegra N., and Werner, Martin

Abstract

Reconstruction of past changes in monsoon climate from speleothem oxygen isotope (δ18O) records is complex because δ18O signals can be influenced by multiple factors including changes in precipitation, precipitation recycling over land, temperature at the moisture source, and changes in the moisture source region and transport pathway. Here, we analyse > 150 speleothem records of the Speleothem Isotopes Synthesis and AnaLysis (SISAL) database to produce composite regional trends in δ18O in monsoon regions; compositing minimises the influence of site-specific karst and cave processes that can influence individual site records. We compare speleothem δ18O observations with isotope-enabled climate model simulations to investigate the specific climatic factors causing these regional trends. We focus on differences in δ18O signals between the mid-Holocene, the peak of the Last Interglacial (Marine Isotope Stage 5e) and the Last Glacial Maximum as well as on δ18O evolution through the Holocene. Differences in speleothem δ18O between the mid-Holocene and the Last Interglacial in the East Asian and Indian monsoons are small, despite the larger summer insolation values during the Last Interglacial. Last Glacial Maximum δ18O values are significantly less negative than interglacial values. Comparison with simulated glacial–interglacial δ18O shows that changes are principally driven by global shifts in temperature and regional precipitation. Holocene speleothem δ18O records show distinct and coherent regional trends. Trends are similar to summer insolation in India, China and southwestern South America, but they are different in the Indonesian–Australian region. Redundancy analysis shows that 37 % of Holocene variability can be accounted for by latitude and longitude, supporting the differentiation of records into individual monsoon regions. Regression analysis of simulated precipitation δ18O and climate variables show significant relationships between global Holocene monsoon δ1

Published
2021

33. The Iso2k database: a global compilation of paleo-δ18O and δ2H records to aid understanding of Common Era climate

Author

Konecky, Bronwen, Mckay, Nicholas, Churakova (sidorova), Olga, Comas-Bru, Laia, Dassié, Émilie, Delong, Kristine L., Falster, Georgina, Fischer, Matt, Jones, Matthew, Jonkers, Lukas, Kaufman, Darrell S., Leduc, Guillaume, Managave, Shreyas, Martrat, Belen, Opel, Thomas, Orsi, Anais, Partin, Judson, Sayani, Hussein, Thomas, Elizabeth R., Thompson, Diane, Tyler, Jonathan J., Abram, Nerilie J., Atwood, Alyssa, Cartapanis, Olivier, Conroy, Jessica, Curran, Mark, Dee, Sylvia, Deininger, Michael, Divine, Dmitry V., Kern, Zoltán, Porter, Trevor J., Stevenson, Samantha, von Gunten, Lucien, Braun, Kerstin, Carré, Matthieu, Incarbona, Alessandro, Kaushal, Nikita, Klaebe, Robert M., Kolus, Hannah R., Mortyn, Peter Graham, Moy, Andrew D., Roop, Heidi A., Sicre, Marie-Alexandrine, Yoshimura, Kei, Department of Earth and Planetary Sciences [St Louis], Washington University in Saint Louis (WUSTL), School of Earth Sciences & Environmental Sustainability, Northern Arizona University [Flagstaff], Siberian Federal University (SibFU), Swiss Federal Institute for Forest, Snow and Landscape Research WSL, School of Archaeology, Geography and Environmental Sciences (SAGES), University of Reading (UOR), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), LSU - Department of Geography and Anthropology [Baton Rouge], Louisiana State University (LSU), Australian Nuclear Science and Technology Organisation [Australie] (ANSTO), University of Nottingham, UK (UON), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Earth and Climate Science Department [IISER Pune], Indian Institute of Science Education and Research Pune (IISER Pune), Department of Environmental Chemistry [Barcelona], Spanish National Research Council (CSIC), Alfred Wegener Institute for Polar and Marine Research (AWI), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of Texas at Austin [Austin], School of Earth and Atmospheric Sciences [Atlanta], Georgia Institute of Technology [Atlanta], University at Buffalo [SUNY] (SUNY Buffalo), State University of New York (SUNY), Department of Geosciences [Tucson], University of Arizona, Department of Earth Sciences [Adelaide], University of Adelaide, Research School of Earth Sciences and Centre of Excellence for Climate Extremes, Australian National University (ANU), Department of Earth, Ocean, and Atmospheric Sciences, Florida State University [Tallahassee] (FSU), Oeschger Centre for Climate Change Research (OCCR), University of Bern, Institute of Geological Sciences [Bern], Department of Geology, University of Illinois at Urbana-Champaign [Urbana], University of Illinois System-University of Illinois System, Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, Rice University [Houston], Institute of Geosciences [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Norwegian Polar Institute, Institute for Geological and Geochemical Research, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Department of Geography and Planning [University of Toronto], University of Toronto, Faculty of the Bren School of Environmental Science and Management, University of California [Santa Barbara] (UCSB), University of California-University of California, Past Global Changes International Project Office (PAGES), Past Global Changes International Project Office, Institute of Human Origins, Department of Anthropology, Variabilité à long terme du climat de l'océan (VALCO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Department of Earth and Marine Sciences [Palermo], Università degli studi di Palermo - University of Palermo, Department of Earth Sciences [Oxford], University of Oxford [Oxford], The University of Adelaide, School of Earth and Environmental Sustainability, Institut de Ciencia i Tecnologia Ambientals (ICTA), Universitat Autònoma de Barcelona (UAB), University of Washington [Seattle], Variabilité de l'Océan et de la Glace de mer (VOG), Institute of Industrial Science (IIS), The University of Tokyo (UTokyo), Swiss Academy of SciencesNational Science Foundation (NSF)Chinese Academy of SciencesNSF-AGS1805141NSF-AGS PRF1433408PalMod, the German paleoclimate modeling initiativeFederal Ministry of Education & Research (BMBF), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Geosciences [University of Arizona], Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and University of Oxford

Subjects
[SDU]Sciences of the Universe [physics], [SDE.MCG]Environmental Sciences/Global Changes, [SDE]Environmental Sciences
Abstract

International audience; Reconstructions of global hydroclimate during the Common Era (CE; the past ∼2000 years) are important for providing context for current and future global environmental change. Stable isotope ratios in water are quantitative indicators of hydroclimate on regional to global scales, and these signals are encoded in a wide range of natural geologic archives. Here we present the Iso2k database, a global compilation of previously published datasets from a variety of natural archives that record the stable oxygen (δ18O) or hydrogen (δ2H) isotopic compositions of environmental waters, which reflect hydroclimate changes over the CE. The Iso2k database contains 759 isotope records from the terrestrial and marine realms, including glacier and ground ice (210); speleothems (68); corals, sclerosponges, and mollusks (143); wood (81); lake sediments and other terrestrial sediments (e.g., loess) (158); and marine sediments (99). Individual datasets have temporal resolutions ranging from sub-annual to centennial and include chronological data where available. A fundamental feature of the database is its comprehensive metadata, which will assist both experts and nonexperts in the interpretation of each record and in data synthesis. Key metadata fields have standardized vocabularies to facilitate comparisons across diverse archives and with climate-model-simulated fields. This is the first global-scale collection of water isotope proxy records from multiple types of geological and biological archives. It is suitable for evaluating hydroclimate processes through time and space using large-scale synthesis, model–data intercomparison and (paleo)data assimilation. The Iso2k database is available for download at https://doi.org/10.25921/57j8-vs18 (Konecky and McKay, 2020) and is also accessible via the NOAA/WDS Paleo Data landing page: https://www.ncdc.noaa.gov/paleo/study/29593 (last access: 30 July 2020).

Published
2020
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34. Coral skeletal luminescence records changes in terrigenous dissolved organic matter (tDOM) parameters in tropical coastal waters

Author

Martin, Patrick, primary, Kaushal, Nikita, additional, Tanzil, Jani, additional, Sanwlani, Nivedita, additional, Yang, Liudongqing, additional, Zhou, Yongli, additional, Cherukuru, Nagur, additional, Sahar, Syamil, additional, Müller, Moritz, additional, Mujahid, Aazani, additional, Lee, Jen Nie, additional, and Goodkin, Nathalie, additional

Published
2021
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37. Contributors

Author

Ahmed, S.M., Azadi, Elham, Bansal, Ishita, Behranvand, Vajiheh, Binod, Parameswaran, Chauhan, Priya, Chawla, Shashi, Demirci, Sahin, Diwan, Anchita, Ganesh Kumar, Baskaran, Gizer, S. Gorkem, Gopal, Dharshini, Goyal, Kartika, Gulati, Shikha, Hussain, Chaudhery Mustansar, Kadeppagari, Ravi-Kumar, Kailasa, Suresh Kumar, Kandasamy, Ruckmani, Kaushal, Nikita, Krishnaswami, Venkateshwaran, Kumar, Manish, Kumar, Sanjay, Kumari, Beena, Kumari, Sweta, Kurt, Saliha B., Latha, M.S., Madhavan, Aravind, Mallakpour, Shadpour, Mansour, N.A., Maruthamuthu, Vijayalakshmi, Mehta, Vaibhavkumar N., Melappa, Govindappa, Misra, Shashi Kiran, Mondal, Shibsankar, Mongia, Ayush, Narayanrao, Kulkarni Akshay, Pandey, Annu, Pandey, Ashok, Pathak, Kamla, Paul, Swastik, Philip, Eapen, Polat, Osman, Prajapati, Vimalkumar S., Prakash, K.S., Priyadarshini, E., Rai, Prateek, Rajagopal, Rampriya Alagarsamy, Raut, Shishir, Raval, Juhi B., Reshmy, R., Rohit, Jigneshkumar V., Roy, Subhasis, Sadek, E.M., Saha, Ankit, Sahiner, Mehtap, Sahiner, Nurettin, Shah, Chirantan, Shah, Manan, Shah, Vraj, Sharma, Nandini, Shikha, Sindhu, Raveendran, Singh, Parinita, Skariyachan, Sinosh, Suner, Selin S., Thomas, Deepa, Unni, Rekha, Vaisakh, P.H., and Vijayan, Sneha

Published
2023
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39. The Indian Summer Monsoon from a Speleothem d18O Perspective – a Review

Author

Kaushal, Nikita, Breitenbach, Sebastian F. M., Lechleitner, Franziska A., Sinha, Ashish, Tewari, Vinod C., Ahmad, Syed Masood, Berkelhammer, Max, Band, Shraddha, Yadava, Madhusudan, Ramesh, Rengaswamy, and Henderson, Gideon M.

Subjects
earth_sciences_other
Abstract

As one of the most prominent seasonally recurring atmospheric circulation patterns, the Asian Summer Monsoon (ASM) plays a vital role for the life and livelihood of about a third of the global population. Changes in the strength and seasonality of the ASM significantly affect the region, yet the drivers of change and the varied regional responses of the ASM are not well understood. In the last two decades, there have been a number of studies reconstructing the ASM using stalagmite-based proxies such as oxygen isotopes (18O). Such reconstructions allow examination of the drivers and responses, increasing monsoon predictability. In this review paper, we focus on stalagmite 18O records from India at the proximal end of the ASM region. Indian stalagmite 18O records show well dated, high amplitude changes in response to the dominant drivers of the ASM on orbital to multi-centennial timescales and indicate the magnitude of monsoon variability in response to these drivers. We examine Indian stalagmite records collated in SISAL_v1 (version 1) database (http://researchdata.reading.ac.uk/139/) and support the database with a summary of record quality and regional climatic interpretations of the 18O record during different climate states. We highlight current debates and suggest the most useful time periods (climatic events) and locations for further work using tools such as data-model comparisons, spectral analysis methods, multi-proxy investigations and monitoring work

Published
2018

40. The SISAL database

Author

Atsawawaranunt, Kamolphat, Comas-Bru, Laia, Mozhdehi, Sahar Amirnezhad, Deininger, Michael, Harrison, Sandy P., Baker, Andy, Boyd, Meighan, Kaushal, Nikita, Ahmad, Syed Masood, Brahim, Yassine Ait, Arienzo, Monica, Bajo, Petra, Braun, Kerstin, Burstyn, Yuval, Chawchai, Sakonvan, Duan, Wuhui, Hatvani, Istvan Gabor, Hu, Jun, Kern, Zoltan, Labuhn, Inga, Lachniet, Matthew, Lechleitner, Franziska A., Lorrey, Andrew, Perez-Mejias, Carlos, Pickering, Robyn, Scroxton, Nick, Atkinson, Tim, Ayalon, Avner, Baldini, James, Bar-Matthews, Miriam, Pablo Bernal, Juan, Breitenbach, Sebastian, Boch, Ronny, Borsato, Andrea, Cai, Yanjun, Carolin, Stacy, Cheng, Hai, Columbu, Andrea, Couchoud, Isabelle, Cruz, Francisco, Demeny, Attila, Dominguez-Villar, David, Dragusin, Virgil, Drysdale, Russell, Ersek, Vasile, Finne, Martin, Fleitmann, Dominik, Fohlmeister, Jens Bernd (Dr.), Frappier, Amy, Genty, Dominique, Holzkamper, Steffen, Hopley, Philip, Kathayat, Gayatri, Keenan-Jones, Duncan, Koltai, Gabriella, Luetscher, Marc, Li, Ting-Yong, Lone, Mahjoor Ahmad, Markowska, Monika, Mattey, Dave, McDermott, Frank, Moreno, Ana, Moseley, Gina, Nehme, Carole, Novello, Valdir F., Psomiadis, David, Rehfeld, Kira, Ruan, Jiaoyang, Sekhon, Natasha, Sha, Lijuan, Sholz, Denis, Shopov, Yavor, Smith, Andrew, Strikis, Nicolas, Treble, Pauline, Unal-Imer, Ezgi, Vaks, Anton, Vansteenberge, Stef, Veiga-Pires, Cristina, Voarintsoa, Ny Riavo, Wang, Xianfeng, Wong, Corinne, Wortham, Barbara, Wurtzel, Jennifer, and Zong, Baoyun

Subjects
ddc:550, Institut für Geowissenschaften
Abstract

Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide "out-of-sample" evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (delta O-18, delta C-13) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data.

Published
2018

41. The SISAL database: a global resource to document oxygen and carbon isotope records from speleothems

Author

Atsawawaranunt, Kamolphat, Comas-Bru, Laia, Amirnezhad Mozhdehi, Sahar, Deininger, Michael, Harrison, Sandy P., Baker, Andy, Boyd, Meighan, Kaushal, Nikita, Ahmad, Syed Masood, Ait Brahim, Yassine, Arienzo, Monica, Bajo, Petra, Braun, Kerstin, Burstyn, Yuval, Chawchai, Sakonvan, Duan, Wuhui, Hatvani, István Gábor, Hu, Jun, Kern, Zoltán, Labuhn, Inga, Lachniet, Matthew, Lechleitner, Franziska A., Lorrey, Andrew, Pérez-Mejías, Carlos, Pickering, Robyn, Scroxton, Nick, Atkinson, Tim, Ayalon, Avner, Baldini, James, Bar-Matthews, Miriam, Bernal, Juan Pablo, Breitenbach, Sebastian, Boch, Ronny, Borsato, Andrea, Cai, Yanjun, Carolin, Stacy, Cheng, Hai, Columbu, Andrea, Couchoud, Isabelle, Cruz, Francisco, Demény, Attila, Domínguez-Villar, David, Drăgusin, Virgil, Drysdale, Russell, Ersek, Vasile, Finné, Martin, Fleitmann, Dominik, Fohlmeister, Jens, Frappier, Amy, Genty, Dominique, Holzkämper, Steffen, Kathayat, Gayatri, Keenan-Jones, Duncan, Koltai, Gabriella, Luetscher, Marc, Li, Ting-Yong, Lone, Mahjoor Ahmad, Markowska, Monika, Mattey, Dave, McDermott, Frank, Moreno, Ana, Moseley, Gina, Nehme, Carole, Novello, Valdir F., Psomiadis, David, Rehfeld, Kirah, Ruan, Jiaoyang, Sekhon, Natasha, Sha, Lijuan, Scholz, Denis, Shopov, Yavor, Strikis, Nicolás, Treble, Pauline, Ünal-İmer, Ezgi, Vaks, Anton, Vansteenberge, Stef, Veiga-Pires, Cristina, Voarintsoa, Ny Riavo, Wang, Xianfeng, Wong, Corinne, Wortham, Barbara, Wurtzel, Jennifer, and Zong, Baoyun

Abstract

Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide “out-of-sample” evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (δ18O, δ13C) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data. The compiled data are available at http://dx.doi.org/10.17864/1947.147 .

Published
2018

42. A data-model approach to interpreting speleothem oxygen isotope records from monsoon regions on orbital timescales.

Author

Parker, Sarah E., Harrison, Sandy P., Comas-Bru, Laia, Kaushal, Nikita, LeGrande, Allegra N., and Werner, Martin

Abstract

Reconstruction of past changes in monsoon climate from speleothem oxygen isotope (δ[sup 18]O) records is complex because δ[sup 18]O signals can be influenced by multiple factors including changes in precipitation, precipitation recycling over land, temperature at the moisture source and changes in the moisture source region and transport pathway. Here, we analyse > 150 speleothem records from version 2 of the Speleothem Isotopes Synthesis and Analysis (SISAL) database to produce composite regional trends in δ[sup 18]O in monsoon regions; compositing minimises the influence of site-specific karst and cave processes that can influence individual site records. We compare speleothem δ[sup 18]O observations with isotope-enabled climate model simulations to investigate the specific climatic factors causing these regional trends. We focus on differences in δ[sup 18]O signals between interglacial (mid-Holocene and Last Interglacial) and glacial (Last Glacial Maximum) states, and on δ[sup 18]O evolution through the Holocene. Differences in speleothem δ[sup 18]O between the mid-Holocene and Last Interglacial in the East Asian and Indian monsoons are small, despite the larger summer insolation values during the Last Interglacial. Last Glacial Maximum δ[sup 18]O values are significantly less negative than interglacial values. Comparison with simulated glacial-interglacial δ[sup 18]O shows that changes are principally driven by global shifts in temperature and regional precipitation. Holocene speleothem δ[sup 18]O records show distinct and coherent regional trends. Trends are similar to summer insolation in India, China and southwestern South America, but different in the Indonesian-Australian region. Redundancy analysis shows that 37 % of Holocene variability can be accounted for by latitude and longitude, supporting the differentiation of records into individual monsoon regions. Regression analysis of simulated precipitation δ[sup 18]O and climate variables show that global Holocene monsoon δ[sup 18]O trends are driven by changes in precipitation, atmospheric circulation and (to a lesser extent) source area temperature, whilst precipitation recycling is non-significant. However, there are differences in regional scale mechanisms; there are clear relationships between changes in precipitation and in δ[sup 18]O for India, southwestern South America and the Indonesian-Australian regions, but not for the East Asian monsoon. Changes in atmospheric circulation contributes to δ[sup 18]O trends in the East Asian, Indian and Indonesian-Australian monsoons, and a weak source area temperature effect is observed over southern and central America and Asia. Precipitation recycling is influential in southwestern South America and southern Africa. Overall, our analyses show that it is possible to differentiate the impacts of specific climatic mechanisms influencing precipitation δ[sup 18]O and use this analysis to interpret changes in speleothem δ[sup 18]O. [ABSTRACT FROM AUTHOR]

Published
2020
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43. The Indian Summer Monsoon from a Speleothem δ18O Perspective—A Review

Author

Kaushal, Nikita, primary, Breitenbach, Sebastian F. M., additional, Lechleitner, Franziska A., additional, Sinha, Ashish, additional, Tewari, Vinod C., additional, Ahmad, Syed Masood, additional, Berkelhammer, Max, additional, Band, Shraddha, additional, Yadava, Madhusudan, additional, Ramesh, Rengaswamy, additional, and Henderson, Gideon M., additional

Published
2018
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44. The Indian Summer Monsoon from a Speleothem d18O Perspective – a Review

Author

Kaushal, Nikita, primary, Breitenbach, Sebastian F. M., additional, Lechleitner, Franziska A., additional, Sinha, Ashish, additional, Tewari, Vinod C., additional, Ahmad, Syed Masood, additional, Berkelhammer, Max, additional, Band, Shraddha, additional, Yadava, Madhusudan, additional, Ramesh, Rengaswamy, additional, and Henderson, Gideon M., additional

Published
2018
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47. The SISAL database: a global resource to document oxygen and carbon isotope records from speleothems

Author

Atsawawaranunt, Kamolphat, Comas-Bru, Laia, Mozhdehi, Sahar Amirnezhad, Deininger, Michael, Harrison, Sandy P., Baker, Andy, Boyd, Meighan, Kaushal, Nikita, Ahmad, Syed Masood, Brahim, Yassine Ait, Arienzo, Monica, Bajo, Petra, Braun, Kerstin, Burstyn, Yuval, Chawchai, Sakonvan, Duan, Wuhui, Hatvani, Istvan Gabor, Hu, Jun, Kern, Zoltan, Labuhn, Inga, Lachniet, Matthew, Lechleitner, Franziska A., Lorrey, Andrew, Perez-Mejias, Carlos, Pickering, Robyn, Scroxton, Nick, Atkinson, Tim, Ayalon, Avner, Baldini, James, Bar-Matthews, Miriam, Pablo Bernal, Juan, Breitenbach, Sebastian, Boch, Ronny, Borsato, Andrea, Cai, Yanjun, Carolin, Stacy, Cheng, Hai, Columbu, Andrea, Couchoud, Isabelle, Cruz, Francisco, Demeny, Attila, Dominguez-Villar, David, Dragusin, Virgil, Drysdale, Russell, Ersek, Vasile, Finné, Martin, Fleitmann, Dominik, Fohlmeister, Jens, Frappier, Amy, Genty, Dominique, Holzkamper, Steffen, Hopley, Philip, Kathayat, Gayatri, Keenan-Jones, Duncan, Koltai, Gabriella, Luetscher, Marc, Li, Ting-Yong, Lone, Mahjoor Ahmad, Markowska, Monika, Mattey, Dave, McDermott, Frank, Moreno, Ana, Moseley, Gina, Nehme, Carole, Novello, Valdir F., Psomiadis, David, Rehfeld, Kira, Ruan, Jiaoyang, Sekhon, Natasha, Sha, Lijuan, Sholz, Denis, Shopov, Yavor, Smith, Andrew, Strikis, Nicolas, Treble, Pauline, Unal-Imer, Ezgi, Vaks, Anton, Vansteenberge, Stef, Veiga-Pires, Cristina, Voarintsoa, Ny Riavo, Wang, Xianfeng, Wong, Corinne, Wortham, Barbara, Wurtzel, Jennifer, Zong, Baoyun, Veiga-Pires, C., Atsawawaranunt, Kamolphat, Comas-Bru, Laia, Amirnezhad Mozhdehi, Sahar, Deininger, Michael, Harrison, Sandy P., Baker, Andy, Boyd, Meighan, Kaushal, Nikita, Ahmad, Syed Masood, Ait Brahim, Yassine, Arienzo, Monica, Bajo, Petra, Braun, Kerstin, Burstyn, Yuval, Chawchai, Sakonvan, Duan, Wuhui, Hatvani, István Gábor, Hu, Jun, Kern, Zoltán, Labuhn, Inga, Lachniet, Matthew, Lechleitner, Franziska A., Lorrey, Andrew, Pérez-Mejías, Carlo, Pickering, Robyn, Scroxton, Nick, and Tim Atkinso, Avner Ayalon, James Baldini, Miriam Bar-Matthews, Juan Pablo Bernal, Sebastian Breitenbach, Ronny Boch, Andrea Borsato, Yanjun Cai, Stacy Carolin, Hai Cheng, Andrea Columbu, Isabelle Couchoud, Francisco Cruz, Attila Demény, David Dominguez-Villar, Virgil Dragusin, Russell Drysdale, Vasile Ersek, Martin Finné, Dominik Fleitmann, Jens Fohlmeister, Amy Frappier, Dominique Genty, Steffen Holzkämper, Philip Hopley, Gayatri Kathayat, Duncan Keenan-Jones, Gabriella Koltai, Marc Luetscher, Ting-Yong Li

Subjects
010506 paleontology, Climate Research, 010504 meteorology & atmospheric sciences, Climate change, Speleothem, F800, 010502 geochemistry & geophysics, computer.software_genre, 01 natural sciences, Klimatforskning, Cave, Paleoclimatology, lcsh:Environmental sciences, 0105 earth and related environmental sciences, lcsh:GE1-350, geography, geography.geographical_feature_category, Database, Stable isotope ratio, speleothems, PALEOCLIMATOLOGIA, lcsh:QE1-996.5, lcsh:Geology, Metadata, 13. Climate action, General Earth and Planetary Sciences, Environmental science, Climate model, computer, Chronology
Abstract

Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide “out-of-sample” evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (δ18O, δ13C) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data. The compiled data are available at https://doi.org/10.17864/1947.147.

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48. The Indian Summer Monsoon from a Speleothem \delta$^{18}$O Perspective -- A Review.

Author

Kaushal, Nikita, Breitenbach, Sebastian F.M., Lechleitner, Franziska A., Sinha, Ashish, Tewari, Vinod C., Ahmad, Syed M., Berkelhammer, Max, Band, Shraddha, Yadava, Madhusudan, Ramesh, Rengaswamy, and Henderson, Gideon M.

Subjects
*OXYGEN isotopes, *ATMOSPHERIC circulation, *MONSOONS, *CARBONATE rocks, *CARBON isotopes, *STABLE isotope analysis
Abstract

As one of the most prominent seasonally recurring atmospheric circulation patterns, the Asian summer monsoon (ASM) plays a vital role for the life and livelihood of about one-third of the global population. Changes in the strength and seasonality of the ASM significantly affect the ASM region, yet the drivers of change and the varied regional responses of the ASM are not well understood. In the last two decades, there were a number of studies reconstructing the ASM using stalagmite-based proxies such as oxygen isotopes (\delta$^{18}$O). Such reconstructions allow examination of ASM drivers and responses, increasing monsoon predictability.In a review study [1], we focus on stalagmite \delta$^{18}$O records from India at the proximal end of the larger ASM region. Stalagmite-based time series are available from a number of caves in northern, northeastern and south Indian caves, as well as from the Andaman Islands. Despite widespread occurrence of carbonate rocks, data is lacking for Central and western India (the Vindhayans and Thar Desert), and Pakistan. We examine Indian stalagmite records collated in the Speleothem Isotope Synthesis and AnaLysis version 1 database [1] and support the database with a summary of record quality and regional climatic interpretations of the \delta$^{18}$O record during different climate states. Indian stalagmite \delta$^{18}$O records show well-dated, high-amplitude changes in response to the dominant drivers of the ASM on orbital to multi-centennial timescales, and indicate the magnitude of monsoon variability in response to these drivers.We suggest the most useful time periods (climatic events) and locations for further work using tools such as data-model comparisons, spectral analysis methods, multi-proxy investigations, and monitoring.References[1] Kaushal, N., Breitenbach, S.F.M., Lechleitner, F.A., Sinha, A., Tewari, V.C., Ahmad, S.M., Berkelhammer, M., Band, S., Yadava, M., Ramesh, R. and Henderson, G.M.: The Indian Summer Monsoon from a Speleothem $\delta^{18}$O Perspective -- A Review. Quaternary, 1, 29, https://doi.org/10.3390/quat1030029, 2018.\\[2] Atsawawaranunt, K., Comas-Bru, L., Amirnezhad Mozhdehi, S., Deininger, M., Harrison, S. P., Baker, A., Boyd, M., Kaushal, N., Ahmad, S. M., Ait Brahim, Y., Arienzo, M., Bajo, P., Braun, K., Burstyn, Y., Chawchai, S., Duan, W., Hatvani, I. G., Hu, J., Kern, Z., Labuhn, I., Lachniet, M., Lechleitner, F. A., Lorrey, A., P\'{e}rez-Mej\'{\i}as, C., Pickering, R., Scroxton, N., and SISAL Working Group Members: The SISAL database: a global resource to document oxygen and carbon isotope records from speleothems, Earth Syst. Sci. Data, 10, 1687-1713, https://doi.org/10.5194/essd-10-1687-2018, 2018. [ABSTRACT FROM AUTHOR]

Published
2019

49. A Review on Polymeric Nanostructured Micelles for the Ocular Inflammation-Main Emphasis on Uveitis.

Author

Kaushal N, Kumar M, Singh A, Tiwari A, Tiwari V, and Pahwa R

Subjects
Humans, Drug Carriers, Polymers, Solvents, Inflammation drug therapy, Micelles, Uveitis drug therapy
Abstract

Background: Various types of nano-formulations are being developed and tested for the delivery of the ocular drug. They also have anatomical and physiological limitations, such as tear turnover, nasal lachrymal waste, reflex squinting, and visual static and dynamic hindrances, which pose challenges and delay ocular drug permeation. As a result of these limitations, less than 5% of the dose can reach the ocular tissues., Objective: The basic purpose of designing these formulations is that they provide prolonged retention for a longer period and can also increase the course time., Methods: To address the aforementioned issues, many forms of polymeric micelles were developed. Direct dissolving, dialysis, oil-in-water emulsion, solvent evaporation, co-solvent evaporation, and freeze-drying are some of the methods used to make polymeric nano micelles., Results: Their stability is also very good and also possesses reversible drug loading capacity. When the drug is given through the topical route, then it has very low ocular bioavailability., Conclusion: The definition and preparation process of polymeric micelles and anti-inflammatory drugs used in uveitis and the relation between uveitis and micelles are illustrated in detail., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Published
2023
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