Proxy surrogate reconstructions for Europe and the estimation of their uncertainties

<p>Combining proxy information and climate model simulations reconciles these sources of information about past climates. This, in turn, strengthens our understanding of past climatic changes. The analogue or proxy surrogate reconstruction method is a computationally cheap data assimilation ap...

Full description

Bibliographic Details
Main Authors: O. Bothe, E. Zorita
Format: Article
Language:English
Published: Copernicus Publications 2020-02-01
Series:Climate of the Past
Online Access:https://www.clim-past.net/16/341/2020/cp-16-341-2020.pdf
_version_ 1819084282444906496
author O. Bothe
E. Zorita
author_facet O. Bothe
E. Zorita
author_sort O. Bothe
collection DOAJ
description <p>Combining proxy information and climate model simulations reconciles these sources of information about past climates. This, in turn, strengthens our understanding of past climatic changes. The analogue or proxy surrogate reconstruction method is a computationally cheap data assimilation approach, which searches in a pool of simulated climate states the best fit to proxy data. We use the approach to reconstruct European summer mean temperature from the 13th century until present using the Euro 2k set of proxy records and a pool of global climate simulation output fields. Our focus is on quantifying the uncertainty of the reconstruction, because previous applications of the analogue method rarely provided uncertainty ranges. We show several ways of estimating reconstruction uncertainty for the analogue method, which take into account the non-climate part of the variability in each proxy record.</p> <p>In general, our reconstruction agrees well at multi-decadal timescales with the Euro 2k reconstruction, which was conducted with two different statistical methods and no information from model simulations. In both methodological approaches, the decades around the year 1600&thinsp;CE were the coldest. However, the approaches disagree on the warmest pre-industrial periods. The reconstructions from the analogue method also represent the local variations of the observed proxies. The diverse uncertainty estimates obtained from our analogue approaches can be locally larger or smaller than the estimates from the Euro 2k effort. Local uncertainties of the temperature reconstructions tend to be large in areas that are poorly covered by the proxy records. Uncertainties highlight the ambiguity of field-based reconstructions constrained by a limited set of proxies.</p>
first_indexed 2024-12-21T20:45:59Z
format Article
id doaj.art-d3bb4bf57c9b4fd6b91f9b19f4f96bec
institution Directory Open Access Journal
issn 1814-9324
1814-9332
language English
last_indexed 2024-12-21T20:45:59Z
publishDate 2020-02-01
publisher Copernicus Publications
record_format Article
series Climate of the Past
spelling doaj.art-d3bb4bf57c9b4fd6b91f9b19f4f96bec2022-12-21T18:50:49ZengCopernicus PublicationsClimate of the Past1814-93241814-93322020-02-011634136910.5194/cp-16-341-2020Proxy surrogate reconstructions for Europe and the estimation of their uncertaintiesO. BotheE. Zorita<p>Combining proxy information and climate model simulations reconciles these sources of information about past climates. This, in turn, strengthens our understanding of past climatic changes. The analogue or proxy surrogate reconstruction method is a computationally cheap data assimilation approach, which searches in a pool of simulated climate states the best fit to proxy data. We use the approach to reconstruct European summer mean temperature from the 13th century until present using the Euro 2k set of proxy records and a pool of global climate simulation output fields. Our focus is on quantifying the uncertainty of the reconstruction, because previous applications of the analogue method rarely provided uncertainty ranges. We show several ways of estimating reconstruction uncertainty for the analogue method, which take into account the non-climate part of the variability in each proxy record.</p> <p>In general, our reconstruction agrees well at multi-decadal timescales with the Euro 2k reconstruction, which was conducted with two different statistical methods and no information from model simulations. In both methodological approaches, the decades around the year 1600&thinsp;CE were the coldest. However, the approaches disagree on the warmest pre-industrial periods. The reconstructions from the analogue method also represent the local variations of the observed proxies. The diverse uncertainty estimates obtained from our analogue approaches can be locally larger or smaller than the estimates from the Euro 2k effort. Local uncertainties of the temperature reconstructions tend to be large in areas that are poorly covered by the proxy records. Uncertainties highlight the ambiguity of field-based reconstructions constrained by a limited set of proxies.</p>https://www.clim-past.net/16/341/2020/cp-16-341-2020.pdf
spellingShingle O. Bothe
E. Zorita
Proxy surrogate reconstructions for Europe and the estimation of their uncertainties
Climate of the Past
title Proxy surrogate reconstructions for Europe and the estimation of their uncertainties
title_full Proxy surrogate reconstructions for Europe and the estimation of their uncertainties
title_fullStr Proxy surrogate reconstructions for Europe and the estimation of their uncertainties
title_full_unstemmed Proxy surrogate reconstructions for Europe and the estimation of their uncertainties
title_short Proxy surrogate reconstructions for Europe and the estimation of their uncertainties
title_sort proxy surrogate reconstructions for europe and the estimation of their uncertainties
url https://www.clim-past.net/16/341/2020/cp-16-341-2020.pdf
work_keys_str_mv AT obothe proxysurrogatereconstructionsforeuropeandtheestimationoftheiruncertainties
AT ezorita proxysurrogatereconstructionsforeuropeandtheestimationoftheiruncertainties