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| Titel |
Contribution of oceanic and vegetation feedbacks to Holocene climate change in monsoonal Asia |
| VerfasserIn |
A. Dallmeyer, M. Claussen, J. Otto |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 6, no. 2 ; Nr. 6, no. 2 (2010-04-07), S.195-218 |
| Datensatznummer |
250003444
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| Publikation (Nr.) |
 copernicus.org/cp-6-195-2010.pdf |
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| Zusammenfassung |
| The impact of vegetation-atmosphere and ocean-atmosphere interactions on the
mid- to late Holocene climate change as well as their synergy is studied for
different parts of the Asian monsoon region, giving consideration to the
large climatic and topographical heterogeneity in that area. We concentrate
on temperature and precipitation changes as the main parameters describing
monsoonal influenced climates. For our purpose, we analyse a set of coupled
numerical experiments, performed with the comprehensive Earth system model
ECHAM5/JSBACH-MPIOM under present-day and mid-Holocene (6 k) orbital
configurations (Otto et al., 2009b). The temperature change caused by the
insolation forcing reveals an enhanced seasonal cycle, with a pronounced
warming in summer (0.58 K) and autumn (1.29 K) and a cooling in the other
seasons (spring: -1.32 K; winter: -0.97 K). Most of this change can be
attributed to the direct response of the atmosphere, but the ocean, whose
reaction has a lagged seasonal cycle (warming in autumn and winter, cooling
in the other seasons), strongly modifies the signal. The simulated
contribution of dynamic vegetation is small and most effective in winter,
where it slightly warms the near-surface atmosphere (approx. 0.03 K). The
temperature difference attributed to the synergy is on average positive, but
also small. Concerning the precipitation, the most remarkable change is the
postponement and enhancement of the Asian monsoon (0.46 mm/day in summer,
0.53 mm/day in autumn), mainly related to the direct atmospheric response. On
regional average, the interactive ocean (ca. 0.18 mm/day) amplifies the
direct effect, but tends to weaken the East Asian summer monsoon and
strongly increases the Indian summer monsoon rainfall rate (0.68 mm/day). The
influence of dynamic vegetation on precipitation is comparatively small
(<0.04 mm/day). The synergy effect has no influence, on average. |
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