Imperial College London

Professor Iain Colin Prentice

Faculty of Natural SciencesDepartment of Life Sciences (Silwood Park)

Chair in Biosphere and Climate Impacts
 
 
 
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Contact

 

+44 (0)20 7594 2482c.prentice

 
 
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Location

 

2.3Centre for Population BiologySilwood Park

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Summary

 

Publications

Citation

BibTex format

@article{Cleator:2020:10.5194/cp-16-699-2020,
author = {Cleator, SF and Harrison, SP and Nichols, NK and Prentice, IC and Roulstone, I},
doi = {10.5194/cp-16-699-2020},
journal = {Climate of the Past},
pages = {699--712},
title = {A new multivariable benchmark for Last Glacial Maximum climate simulations},
url = {http://dx.doi.org/10.5194/cp-16-699-2020},
volume = {16},
year = {2020}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - We present a new global reconstruction of seasonal climates at the Last Glacial Maximum (LGM, 21 000 years BP) made using 3-D variational data assimilation with pollen-based site reconstructions of six climate variables and the ensemble average of the PMIP3—CMIP5 simulations as a prior (initial estimate of LGM climate). We assume that the correlation matrix of the uncertainties in the prior is both spatially and temporally Gaussian, in order to produce a climate reconstruction that is smoothed both from month to month and from grid cell to grid cell. The pollen-based reconstructions include mean annual temperature (MAT), mean temperature of the coldest month (MTCO), mean temperature of the warmest month (MTWA), growing season warmth as measured by growing degree days above a baseline of 5 C (GDD5), mean annual precipitation (MAP), and a moisture index (MI), which is the ratio of MAP to mean annual potential evapotranspiration. Different variables are reconstructed at different sites, but our approach both preserves seasonal relationships and allows a more complete set of seasonal climate variables to be derived at each location. We further account for the ecophysiological effects of low atmospheric carbon dioxide concentration on vegetation in making reconstructions of MAP and MI. This adjustment results in the reconstruction of wetter climates than might otherwise be inferred from the vegetation composition. Finally, by comparing the uncertainty contribution to the final reconstruction, we provide confidence intervals on these reconstructions and delimit geographical regions for which the palaeodata provide no information to constrain the climate reconstructions. The new reconstructions will provide a benchmark created using clear and defined mathematical procedures that can be used for evaluation of the PMIP4–CMIP6 entry-card LGM simulations and are available at https://doi.org/10.17864/1947.244 (Cleator et al., 2020b).
AU - Cleator,SF
AU - Harrison,SP
AU - Nichols,NK
AU - Prentice,IC
AU - Roulstone,I
DO - 10.5194/cp-16-699-2020
EP - 712
PY - 2020///
SN - 1814-9324
SP - 699
TI - A new multivariable benchmark for Last Glacial Maximum climate simulations
T2 - Climate of the Past
UR - http://dx.doi.org/10.5194/cp-16-699-2020
UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000524489800002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR - https://cp.copernicus.org/articles/16/699/2020/
UR - http://hdl.handle.net/10044/1/89889
VL - 16
ER -