@article{HebertHerzschuhLaepple2022,
  author    = {H{\´e}bert, Rapha{\"e}l and Herzschuh, Ulrike and Laepple, Thomas},
  title     = {Millennial-scale climate variability over land overprinted by ocean temperature fluctuations},
  series = {Nature geoscience},
  volume    = {15},
  journal   = {Nature geoscience},
  number    = {11},
  publisher = {Nature portfolio},
  address   = {Berlin},
  issn      = {1752-0894},
  doi       = {10.1038/s41561-022-01056-4},
  pages     = {899},
  year      = {2022},
  abstract  = {Variations in regional temperature have widespread implications for society, but our understanding of the amplitude and origin of long-term natural variability is insufficient for accurate regional projections. This is especially the case for terrestrial temperature variability, which is currently thought to be weak over long timescales. By performing spectral analysis on climate reconstructions, produced using sedimentary pollen records from the Northern Hemisphere over the last 8,000 years, coupled with instrumental data, we provide a comprehensive estimate of regional temperature variability from annual to millennial timescales. We show that short-term random variations are overprinted by strong ocean-driven climate variability on multi-decadal and longer timescales. This may cause substantial and potentially unpredictable regional climatic shifts in the coming century, in contrast to the relatively muted and homogeneous warming projected by climate models. Due to the marine influence, regions characterized by stable oceanic climate at sub-decadal timescales experience stronger long-term variability, and continental regions with higher sub-decadal variability show weaker long-term variability. This fundamental relationship between the timescales provides a unique insight into the emergence of a marine-driven low-frequency regime governing terrestrial climate variability and sets the basis to project the amplitude of temperature fluctuations on multi-decadal timescales and longer. Temperature variability over land is enhanced by ocean temperature fluctuations on millennial timescales, with implications for regional-scale climate change, according to an analysis of Northern Hemisphere proxy records and observations.},
  language  = {en}
}
@article{HerzschuhBoehmerLietal.2022,
  author    = {Herzschuh, Ulrike and B{\"o}hmer, Thomas and Li, Chenzhi and Cao, Xianyong and H{\´e}bert, Rapha{\"e}l and Dallmeyer, Anne and Telford, Richard J. and Kruse, Stefan},
  title     = {Reversals in temperature-precipitation correlations in the Northern Hemisphere extratropics during the Holocene},
  series = {Geophysical research letters},
  volume    = {49},
  journal   = {Geophysical research letters},
  number    = {22},
  publisher = {American Geophysical Union},
  address   = {Washington},
  issn      = {0094-8276},
  doi       = {10.1029/2022GL099730},
  pages     = {11},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}