TY - JOUR A1 - Herzschuh, Ulrike A1 - Böhmer, Thomas A1 - Li, Chenzhi A1 - Cao, Xianyong A1 - Hébert, Raphaël A1 - Dallmeyer, Anne A1 - Telford, Richard J. A1 - Kruse, Stefan T1 - Reversals in temperature-precipitation correlations in the Northern Hemisphere extratropics during the Holocene JF - Geophysical research letters N2 - Future precipitation levels remain uncertain because climate models have struggled to reproduce observed variations in temperature-precipitation correlations. Our analyses of Holocene proxy-based temperature-precipitation correlations and hydrological sensitivities from 2,237 Northern Hemisphere extratropical pollen records reveal a significant latitudinal dependence and temporal variations among the early, middle, and late Holocene. These proxy-based variations are largely consistent with patterns obtained from transient climate simulations (TraCE21k). While high latitudes and subtropical monsoon areas show mainly stable positive correlations throughout the Holocene, the mid-latitude pattern is temporally and spatially more variable. In particular, we identified a reversal from positive to negative temperature-precipitation correlations in the eastern North American and European mid-latitudes from the early to mid-Holocene that mainly related to slowed down westerlies and a switch to moisture-limited convection under a warm climate. Our palaeoevidence of past temperature-precipitation correlation shifts identifies those regions where simulating past and future precipitation levels might be particularly challenging. Y1 - 2022 U6 - https://doi.org/10.1029/2022GL099730 SN - 0094-8276 SN - 1944-8007 VL - 49 IS - 22 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Andreev, Andrei A1 - Nazarova, Larisa B. A1 - Lenz, Marlene M. A1 - Böhmer, Thomas A1 - Syrykh, Ludmila A1 - Wagner, Bernd A1 - Melles, Martin A1 - Pestryakova, Luidmila A. A1 - Herzschuh, Ulrike T1 - Late Quaternary paleoenvironmental reconstructions from sediments of Lake Emanda (Verkhoyansk Mountains, East Siberia) JF - Journal of quaternary science : JQS N2 - Continuous pollen and chironomid records from Lake Emanda (65 degrees 17'N, 135 degrees 45'E) provide new insights into the Late Quaternary environmental history of the Yana Highlands (Yakutia). Larch forest with shrubs (alders, pines, birches) dominated during the deposition of the lowermost sediments suggesting its Early Weichselian [Marine Isotope Stage (MIS) 5] age. Pollen- and chironomid-based climate reconstructions suggest July temperatures (T-July) slightly lower than modern. Gradually increasing amounts of herb pollen and cold stenotherm chironomid head capsules reflect cooler and drier environments, probably during the termination of MIS 5. T-July dropped to 8 degrees C. Mostly treeless vegetation is reconstructed during MIS 3. Tundra and steppe communities dominated during MIS 2. Shrubs became common after similar to 14.5 ka BP but herb-dominated habitats remained until the onset of the Holocene. Larch forests with shrub alder and dwarf birch dominated after the Holocene onset, ca. 11.7 ka BP. Decreasing amounts of shrub pollen during the Lateglacial are assigned to the Older Dryas and Younger Dryas with T-July similar to 7.5 degrees C. T-July increased up to 13 degrees C. Shrub stone pine was present after similar to 7.5 ka BP. The vegetation has been similar to modern since ca. 5.8 ka BP. Chironomid diversity and concentration in the sediments increased towards the present day, indicating the development of richer hydrobiological communities in response to the Holocene thermal maximum. KW - chironomids KW - environmental reconstructions KW - Late Quaternary KW - pollen Y1 - 2022 U6 - https://doi.org/10.1002/jqs.3419 SN - 0267-8179 SN - 1099-1417 VL - 37 IS - 5 SP - 884 EP - 899 PB - Wiley CY - New York, NY [u.a.] ER - TY - JOUR A1 - Li, Chenzhi A1 - Postl, Alexander K. A1 - Böhmer, Thomas A1 - Cao, Xianyong A1 - Dolman, Andrew M. A1 - Herzschuh, Ulrike T1 - Harmonized chronologies of a global late Quaternary pollen dataset (LegacyAge 1.0) JF - Earth system science data : ESSD N2 - We present a chronology framework named LegacyAge 1.0 containing harmonized chronologies for 2831 pollen records (downloaded from the Neotoma Paleoecology Database and the supplementary Asian datasets) together with their age control points and metadata in machine-readable data formats. All chronologies use the Bayesian framework implemented in Bacon version 2.5.3. Optimal parameter settings of priors (accumulation.shape, memory.strength, memory.mean, accumulation.rate, and thickness) were identified based on information in the original publication or iteratively after preliminary model inspection. The most common control points for the chronologies are radiocarbon dates (86.1 %), calibrated by the latest calibration curves (IntCal20 and SHCal20 for the terrestrial radiocarbon dates in the Northern Hemisphere and Southern Hemisphere and Marine20 for marine materials). The original publications were consulted when dealing with outliers and inconsistencies. Several major challenges when setting up the chronologies included the waterline issue (18.8% of records), reservoir effect (4.9 %), and sediment deposition discontinuity (4.4 %). Finally, we numerically compare the LegacyAge 1.0 chronologies to those published in the original publications and show that the reliability of the chronologies of 95.4% of records could be improved according to our assessment. Our chronology framework and revised chronologies provide the opportunity to make use of the ages and age uncertainties in synthesis studies of, for example, pollen-based vegetation and climate change. The LegacyAge 1.0 dataset, including metadata, datings, harmonized chronologies, and R code used, is openaccess and available at PANGAEA (https://doi.org/10.1594/PANGAEA.933132; Li et al., 2021) and Zenodo (https://doi.org/10.5281/zenodo.5815192; Li et al., 2022), respectively. Y1 - 2022 U6 - https://doi.org/10.5194/essd-14-1331-2022 SN - 1866-3508 SN - 1866-3516 VL - 14 IS - 3 SP - 1331 EP - 1343 PB - Copernics Publications CY - Katlenburg-Lindau ER -