RT Journal Article
T1 A new bootstrap technique to quantify uncertainty in estimates of ground surface temperature and ground heat flux histories from geothermal data
A1 Cuesta-Valero, Francisco José
A1 Beltrami, Hugo
A1 Gruber, Stephan
A1 García-García, Almudena
A1 González Rouco, Jesús Fidel
AB Estimates of the past thermal state of the land surface are crucial to assess the magnitude of current anthropogenic climate change as well as to assess the ability of Earth System Models (ESMs) to forecast the evolution of the climate near the ground, which is not included in standard meteorological records. Subsurface temperature reacts to long-term changes in surface energy balance - from decadal to millennial time scales - thus constituting an important record of the dynamics of the climate system that contributes, with low-frequency information, to proxy-based paleoclimatic reconstructions. Broadly used techniques to retrieve past temperature and heat flux histories from subsurface temperature profiles based on a singular value decomposition (SVD) algorithm were able to provide robust global estimates for the last millennium, but the approaches used to derive the corresponding 95 % confidence interval were wrong from a statistical point of view in addition to being difficult to interpret. To alleviate the lack of a meaningful framework for estimating uncertainties in past temperature and heat flux histories at regional and global scales, we combine a new bootstrapping sampling strategy with the broadly used SVD algorithm and assess its performance against the original SVD technique and another technique based on generating perturbed parameter ensembles of inversions. The new bootstrap approach is able to reproduce the prescribed surface temperature series used to derive an artificial profile. Bootstrap results are also in agreement with the global mean surface temperature history and the global mean heat flux history retrieved in previous studies. Furthermore, the new bootstrap technique provides a meaningful uncertainty range for the inversion of large sets of subsurface temperature profiles. We suggest the use of this new approach particularly for aggregating results from a number of individual profiles, and to this end, we release the programs used to derive all inversions in this study as a suite of codes labeled CIBOR v1: Codes for Inverting BORholes, version 1.
PB Copernicus Gesellschaft MBH
SN 1991-959X
YR 2022
FD 2022-10-28
LK https://hdl.handle.net/20.500.14352/73256
UL https://hdl.handle.net/20.500.14352/73256
LA eng
NO © Author(s)2022. This research has been supported by the Alexander von Humboldt-Stiftung (Research Fellowship grant), the Canada Research Chairs Program, and the Natural Sciences and Engineering Research Council of Canada Discovery Grants (NSERC DG 140576948 and 2020-04783).
NO Alexander von Humboldt-Stiftung (Research Fellowship grant)
NO Canada Research Chairs Program
NO Natural Sciences and Engineering Research Council of Canada Discovery
DS Docta Complutense
RD 10 abr 2025