The PMIP4 contribution to CMIP6 – Part 3: The last millennium, scientific objective, and experimental design for the PMIP4 <i>past1000</i> simulations
The pre-industrial millennium is among the periods selected by the Paleoclimate Model Intercomparison Project (PMIP) for experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6) and the fourth phase of the PMIP (PMIP4). The <i>past1000</i> tran...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2017-11-01
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Series: | Geoscientific Model Development |
Online Access: | https://www.geosci-model-dev.net/10/4005/2017/gmd-10-4005-2017.pdf |
Summary: | The pre-industrial millennium is among the periods selected by the
Paleoclimate Model Intercomparison Project (PMIP) for experiments
contributing to the sixth phase of the Coupled Model Intercomparison Project
(CMIP6) and the fourth phase of the PMIP (PMIP4). The <i>past1000</i>
transient simulations serve to investigate the response to (mainly) natural
forcing under background conditions not too different from today, and to
discriminate between forced and internally generated variability on
interannual to centennial timescales. This paper describes the motivation and
the experimental set-ups for the PMIP4-CMIP6 <i>past1000</i> simulations,
and discusses the forcing agents orbital, solar, volcanic, and land use/land
cover changes, and variations in greenhouse gas concentrations. The
<i>past1000</i> simulations covering the pre-industrial millennium from 850
Common Era (CE) to 1849 CE
have to be complemented by <i>historical</i> simulations (1850 to 2014 CE)
following the CMIP6 protocol. The external forcings for the <i>past1000</i>
experiments have been adapted to provide a seamless transition across these
time periods. Protocols for the <i>past1000</i> simulations have been
divided into three tiers. A default forcing data set has been defined for the
Tier 1 (the CMIP6
<i>past1000</i>) experiment. However, the PMIP community has maintained the
flexibility to conduct coordinated sensitivity experiments to explore
uncertainty in forcing reconstructions as well as parameter uncertainty in
dedicated Tier 2 simulations. Additional experiments (Tier 3) are defined to
foster collaborative model experiments focusing on the early instrumental
period and to extend the temporal range and the scope of the simulations.
This paper outlines current and future research foci and common analyses for
collaborative work between the PMIP and the observational communities
(reconstructions, instrumental data). |
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ISSN: | 1991-959X 1991-9603 |