Zobrazeno 1 - 10
of 344
pro vyhledávání: '"Paul J, Valdes"'
Autor:
Caitlyn R. Witkowski, Anna S. von der Heydt, Paul J. Valdes, Marcel T. J. van der Meer, Stefan Schouten, Jaap S. Sinninghe Damsté
Publikováno v:
Nature Communications, Vol 15, Iss 1, Pp 1-9 (2024)
Abstract Constraining the relationship between temperature and atmospheric concentrations of carbon dioxide (pCO2) is essential to model near-future climate. Here, we reconstruct pCO2 values over the past 15 million years (Myr), providing a series of
Externí odkaz:
https://doaj.org/article/a2b92b21484147e78157381fce2cda18
Autor:
Martin H. Trauth, Asfawossen Asrat, Markus L. Fischer, Peter O. Hopcroft, Verena Foerster, Stefanie Kaboth-Bahr, Karin Kindermann, Henry F. Lamb, Norbert Marwan, Mark A. Maslin, Frank Schaebitz, Paul J. Valdes
Publikováno v:
Nature Communications, Vol 15, Iss 1, Pp 1-9 (2024)
Abstract The transition from a humid green Sahara to today’s hyperarid conditions in northern Africa ~5.5 thousand years ago shows the dramatic environmental change to which human societies were exposed and had to adapt to. In this work, we show th
Externí odkaz:
https://doaj.org/article/3f3e52f12dcc48b381e3f6c4402c43f7
Autor:
Irene Malmierca‐Vallet, Louise C. Sime, Paul J. Valdes, Marlene Klockmann, Guido Vettoretti, John Slattery
Publikováno v:
Geophysical Research Letters, Vol 51, Iss 13, Pp n/a-n/a (2024)
Abstract Greenland ice core records feature Dansgaard–Oeschger (D‐O) events, which are abrupt warming episodes followed by gradual cooling during ice age climate. The three climate models used in this study (CCSM4, MPI‐ESM, and HadCM3) show spo
Externí odkaz:
https://doaj.org/article/4b057760d5e24e0f9a6e94f1f9ed2ab7
Publikováno v:
Nature Communications, Vol 14, Iss 1, Pp 1-11 (2023)
Abstract The Sahara region has experienced periodic wet periods over the Quaternary and beyond. These North African Humid Periods (NAHPs) are astronomically paced by precession which controls the intensity of the African monsoon system. However, most
Externí odkaz:
https://doaj.org/article/001b0d7e59074a0eba58b67c55bb1955
Autor:
Xinwen Zhang, Uriel Gélin, Robert A. Spicer, Feixiang Wu, Alexander Farnsworth, Peirong Chen, Cédric Del Rio, Shufeng Li, Jia Liu, Jian Huang, Teresa E. V. Spicer, Kyle W. Tomlinson, Paul J. Valdes, Xiaoting Xu, Shitao Zhang, Tao Deng, Zhekun Zhou, Tao Su
Publikováno v:
Nature Communications, Vol 13, Iss 1, Pp 1-10 (2022)
Spines are an important physical defense for many plant species. Here, the authors describe seven different spine morphologies from the Eocene of central Tibet associated with regional aridification and expansion of herbivorous mammals.
Externí odkaz:
https://doaj.org/article/9d58631e6b374a828437a334d2ddada8
Autor:
Andrew D. Wickert, Carlie Williams, Lauren J. Gregoire, Kerry L. Callaghan, Ruža F. Ivanović, Paul J. Valdes, Lael Vetter, Carrie E. Jennings
Publikováno v:
Geophysical Research Letters, Vol 50, Iss 10, Pp n/a-n/a (2023)
Abstract Climatic warming following the Last Glacial Maximum caused the southern Laurentide Ice Sheet (LIS) to begin ∼2,000‐year cycles of retreat and readvance whose cause remains ambiguous. By developing a marine‐calibrated chronology of sout
Externí odkaz:
https://doaj.org/article/ebbf8936d67149d6880efef554d6de0e
Publikováno v:
Geophysical Research Letters, Vol 50, Iss 1, Pp n/a-n/a (2023)
Abstract During abrupt climate changes of the last glacial period paleorecords show large amplitude changes in the dust cycle. We use Earth System model simulations to evaluate processes operating across these events. Idealized Heinrich stadial‐lik
Externí odkaz:
https://doaj.org/article/22f6ce7cb9e24caeb11574987c7f9d24
Publikováno v:
Scientific Data, Vol 8, Iss 1, Pp 1-18 (2021)
Measurement(s) temperature • precipitation • cloud cover • net primary productivity Technology Type(s) computational modeling technique Factor Type(s) atmospheric carbon dioxide • orbital parameters • land surface type (ocean, land, land ic
Externí odkaz:
https://doaj.org/article/b78005f64224410e82a0105133cfa581
Autor:
Peter O Hopcroft, Paul J Valdes
Publikováno v:
Environmental Research Letters, Vol 17, Iss 8, p 085001 (2022)
The ‘Greening’ and subsequent desertification of the Sahara during the early to mid-Holocene is a dramatic example of natural climate change. We analyse a suite of simulations with a newly palaeo-conditioned configuration of the HadCM3 coupled mo
Externí odkaz:
https://doaj.org/article/9ac91644da97483997d29018900baff7
Autor:
Michael P. Erb, Charles S. Jackson, Anthony J. Broccoli, David W. Lea, Paul J. Valdes, Michel Crucifix, Pedro N. DiNezio
Publikováno v:
Nature Communications, Vol 9, Iss 1, Pp 1-10 (2018)
Periodic changes in the tilt of the Earth’s axis alter the distribution of incoming solar radiation. Here, the authors show that the temperature response to this forcing seemingly differs in models and Antarctic ice cores, with a better agreement r
Externí odkaz:
https://doaj.org/article/9f3e3f7fc040403b80ce8eb06874a05c