In:
Climate of the Past, Copernicus GmbH, Vol. 17, No. 3 ( 2021-05-26), p. 1091-1117
Abstract:
Abstract. We investigate the climate impact of reduced dust during the mid-Holocene using
simulations with the IPSL model. We consider simulations where dust is
either prescribed from an IPSL PI simulation or from CESM simulations
(Albani et al., 2015). In
addition, we also consider an extreme mid-Holocene case where dust is
suppressed. We focus on the estimation of the dust radiative effects and the relative responses of the African and Indian monsoon, showing how local dust forcing or orography affect atmospheric temperature profiles, humidity and precipitation. The simulated mid-Holocene climate is statistically different
in many regions compared to previous mid-Holocene simulations with the IPSL
models. However, it translates to only minor improvements compared to
palaeoclimate reconstructions, and the effect of dust has little impact on
mid-Holocene model skill over large regions. Our analyses confirm the
peculiar role of dust radiative effect over bright surfaces such as African
deserts compared to other regions, brought about by the change of sign of
the dust radiative effect at the top of atmosphere for high surface albedo.
We also highlight a strong dependence of results on the dust pattern. In
particular, the relative dust forcing between West Africa and the Middle East
impacts the relative climate response between India and Africa and between
Africa, the western tropical Atlantic and the Atlantic meridional
circulation. It also affects the feedback on the Atlantic Ocean thermohaline
circulation. Dust patterns should thus be better constrained to fully
understand the changes in the dust cycle and forcing during the mid-Holocene,
which also informs on the potential changes in key dust feedbacks in the
future.
Type of Medium:
Online Resource
ISSN:
1814-9332
DOI:
10.5194/cp-17-1091-2021
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2021
detail.hit.zdb_id:
2217985-9
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