Schlüsselwörter
(Englisch)
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methane; wetlands; stable isotopes; abrupt climate change; permafrost; tropical floodplains; river deltas
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Forschungsprogramme
(Englisch)
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COST-Action ES0805 - The Terrestrial Biosphere in the Earth System
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Kurzbeschreibung
(Englisch)
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Wetlands are considered to be the single largest natural source of atmospheric methane, accounting for over twenty percent of the annual modern methane budget, and the only source dominated by climate. Improving models of methane release from wetlands was recently highlighted, in a synthesis report on abrupt climate change, as an important area for improvement to better understand the risk associated with abrupt climate change, and is a priority for the TERRABITES COST Action. Additionally, attention has recently been called to the emission of methane associated with thawing permafrost and Yedoma regions due to the immense amount of carbon presently stored in those soils. In light of these concerns, understanding wetland seasonal dynamics, interannual variability, and response to abrupt climate transitions are critical, unresolved questions. Presently available wetland modeling approaches are either unsuitable for simulating wetland area under changing climates due to the use of specified wetland areal extent, or because they are applicable only to certain regions or wetland types and thus not globally applicable. The Dynamic WETland Modeling project (DyWET) will address these issues by evaluation of a new scheme for modeling global wetland area against other models in the TERRABITES COST Action, and using this improved model to simulate wetland methane emissions and the carbon isotope ratio of methane during abrupt climate change events. In performing this work the DyWET project will improve the performance of dynamic global vegetation models (DGVMs) and increase our ability to understand past and future climate change.
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Weitere Hinweise und Angaben
(Englisch)
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Full name of research-institution/enterprise: EPF Lausanne Institute for Environmental Sciences and Technology Station 2
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Partner und Internationale Organisationen
(Englisch)
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AT, BE, BG, CH, DE, DK, ES, FI, FR, GR, IE, IT, LT, LU, NL, NO, PL, SE, UK
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Abstract
(Englisch)
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Wetlands are considered to be the single largest natural source of atmospheric methane (CH4), accounting for over 20% of the annual modern CH4 budget, and the only source dominated by climate. As CH4 is a potent greenhouse gas, improving models of CH4 release from wetlands has been highlighted as an important area for improvement to better understand the risk associated with abrupt climate change. The Dynamic Wetland Modelling During Abrupt Climate Change (DyWET) project approached this challenge with two major activities: 1) development of a dynamic global vegetation model (DGVM) specifically designed to realistically simulate important physical parameters important for accurate simulation of wetland distributions and CH4 fluxes, and 2) creation of a wetland and wetland CH4 model inter-comparison project to determine and promote state-of-the-art approaches amongst the broader modelling community. This project resulted in the development of an improved DGVM that is suitable for time periods distinct from present-day, more realistically simulating important wetland processes, and is capable of long integrations. The project also resulted in the coordination and implementation of the WETland and wetland CH4 Inter-comparison of Models Project (WETCHIMP). This project developed and applied a standard modelling protocol to a series of experiments with 10 state of the art wetland and wetland methane models. A few major findings of WETCHIMP include: 1) inter-model CH4 emission variability is large in both space and time, 2) uniform strong increase in CH4 emissions from sensitivity tests of increased [CO2] with a less uniform response from increased temperature, 3) improved observational datasets are required to better evaluate the models.
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Datenbankreferenzen
(Englisch)
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Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. +41 31 322 74 82 Swiss Project-Number: C09.0054
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