Large-scale features of Last Interglacial climate: results from evaluating the <i>lig127k</i> simulations for the Coupled Model Intercomparison Project (CMIP6)–Paleoclimate Modeling Intercomparison Project (PMIP4)
<p>The modeling of paleoclimate, using physically based tools, is increasingly seen as a strong out-of-sample test of the models that are used for the projection of future climate changes. New to the Coupled Model Intercomparison Project (CMIP6) is the Tier 1 Last Interglacial experiment for 1...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-01-01
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| Series: | Climate of the Past |
| Online Access: | https://cp.copernicus.org/articles/17/63/2021/cp-17-63-2021.pdf |
| Summary: | <p>The modeling of paleoclimate, using physically based tools, is
increasingly seen as a strong out-of-sample test of the models that are used
for the projection of future climate changes. New to the Coupled Model
Intercomparison Project (CMIP6) is the Tier 1
Last Interglacial experiment for 127 000 years ago (<i>lig127k</i>), designed to
address the climate responses to stronger orbital forcing than the
<i>midHolocene</i> experiment, using the same state-of-the-art models as for the future and
following a common experimental protocol. Here we present a first analysis
of a multi-model ensemble of 17 climate models, all of which have completed
the CMIP6 DECK (Diagnostic, Evaluation and Characterization of Klima) experiments. The equilibrium climate sensitivity (ECS) of
these models varies from 1.8 to 5.6 <span class="inline-formula"><sup>∘</sup></span>C. The seasonal character of
the insolation anomalies results in strong summer warming over the Northern
Hemisphere continents in the <i>lig127k</i> ensemble as compared to the CMIP6 <i>piControl</i> and
much-reduced minimum sea ice in the Arctic. The multi-model results indicate
enhanced summer monsoonal precipitation in the Northern Hemisphere and
reductions in the Southern Hemisphere. These responses are greater in the
<i>lig127k</i> than the CMIP6 <i>midHolocene</i> simulations as expected from the larger insolation anomalies
at 127 than 6 ka.</p>
<p>New synthesis for surface temperature and precipitation, targeted for 127 ka, have been developed for comparison to the multi-model ensemble. The
<i>lig127k</i> model ensemble and data reconstructions are in good agreement for summer
temperature anomalies over Canada, Scandinavia, and the North Atlantic and
for precipitation over the Northern Hemisphere continents. The model–data
comparisons and mismatches point to further study of the sensitivity of the
simulations to uncertainties in the boundary conditions and of the
uncertainties and sparse coverage in current proxy reconstructions.</p>
<p>The CMIP6–Paleoclimate Modeling Intercomparison
Project (PMIP4) <i>lig127k</i> simulations, in combination with the proxy record, improve
our confidence in future projections of monsoons, surface temperature, and
Arctic sea ice, thus providing a key target for model evaluation and
optimization.</p> |
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| ISSN: | 1814-9324 1814-9332 |