TY - GEN A1 - Dallmeyer, Anne A1 - Claussen, Martin A1 - Wang, Yongbo A1 - Herzschuh, Ulrike T1 - Spatial variability of Holocene changes in the annual precipitation pattern BT - a model-data synthesis for the Asian monsoon region T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - This study provides a detailed analysis of the mid-Holocene to present-day precipitation change in the Asian monsoon region. We compare for the first time results of high resolution climate model simulations with a standardised set of mid-Holocene moisture reconstructions. Changes in the simulated summer monsoon characteristics (onset, withdrawal, length and associated rainfall) and the mechanisms causing the Holocene precipitation changes are investigated. According to the model, most parts of the Indian subcontinent received more precipitation (up to 5 mm/day) at mid-Holocene than at present-day. This is related to a stronger Indian summer monsoon accompanied by an intensified vertically integrated moisture flux convergence. The East Asian monsoon region exhibits local inhomogeneities in the simulated annual precipitation signal. The sign of this signal depends on the balance of decreased pre-monsoon and increased monsoon precipitation at mid-Holocene compared to present-day. Hence, rainfall changes in the East Asian monsoon domain are not solely associated with modifications in the summer monsoon circulation but also depend on changes in the mid-latitudinal westerly wind system that dominates the circulation during the pre-monsoon season. The proxy-based climate reconstructions confirm the regional dissimilarities in the annual precipitation signal and agree well with the model results. Our results highlight the importance of including the pre-monsoon season in climate studies of the Asian monsoon system and point out the complex response of this system to the Holocene insolation forcing. The comparison with a coarse climate model simulation reveals that this complex response can only be resolved in high resolution simulations. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 905 KW - Asian monsoon KW - holocene KW - precipitation KW - climate modelling KW - moisture reconstructions Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-432771 SN - 1866-8372 IS - 905 ER - TY - GEN A1 - Dallmeyer, Anne A1 - Claussen, Martin A1 - Ni, Jian A1 - Cao, Xianyong A1 - Wang, Yongbo A1 - Fischer, Nils A1 - Pfeiffer, Madlene A1 - Jin, Liya A1 - Khon, Vyacheslav A1 - Wagner, Sebastian A1 - Haberkorn, Kerstin A1 - Herzschuh, Ulrike T1 - Biome changes in Asia since the mid-Holocene BT - An analysis of different transient Earth system model simulations T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - The large variety of atmospheric circulation systems affecting the eastern Asian climate is reflected by the complex Asian vegetation distribution. Particularly in the transition zones of these circulation systems, vegetation is supposed to be very sensitive to climate change. Since proxy records are scarce, hitherto a mechanistic understanding of the past spatio-temporal climate-vegetation relationship is lacking. To assess the Holocene vegetation change and to obtain an ensemble of potential mid-Holocene biome distributions for eastern Asia, we forced the diagnostic biome model BIOME4 with climate anomalies of different transient Holocene climate simulations performed in coupled atmosphere-ocean(-vegetation) models. The simulated biome changes are compared with pollen-based biome records for different key regions. In all simulations, substantial biome shifts during the last 6000 years are confined to the high northern latitudes and the monsoon-westerly wind transition zone, but the temporal evolution and amplitude of change strongly depend on the climate forcing. Large parts of the southern tundra are replaced by taiga during the mid-Holocene due to a warmer growing season and the boreal treeline in northern Asia is shifted northward by approx. 4 degrees in the ensemble mean, ranging from 1.5 to 6 degrees in the individual simulations, respectively. This simulated treeline shift is in agreement with pollen-based reconstructions from northern Siberia. The desert fraction in the transition zone is reduced by 21% during the mid-Holocene compared to pre-industrial due to enhanced precipitation. The desert-steppe margin is shifted westward by 5 degrees (1-9 degrees in the individual simulations). The forest biomes are expanded north-westward by 2 degrees, ranging from 0 to 4 degrees in the single simulations. These results corroborate pollen-based reconstructions indicating an extended forest area in north-central China during the mid-Holocene. According to the model, the forest-to-non-forest and steppe-to-desert changes in the climate transition zones are spatially not uniform and not linear since the mid-Holocene. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 643 KW - Last Glacial Maximum KW - Eastern Continental Asia KW - summer monsoon precipitation KW - PMIP2 coupled simulations KW - Global Vegetation Model KW - northern high‐latitudes KW - Holocene climate change KW - Tibetan Plateau KW - environmental changes KW - Inner Mongolia Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-418755 SN - 1866-8372 IS - 643 SP - 107 EP - 134 ER -