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| Titel |
Novel Earth Observation products to characterise wetland extent and methane dynamics: the ESA ALANIS-Methane Project |
| VerfasserIn |
Garry Hayman, Annett Bartsch, Catherine Prigent, Felipe Aires, Michael Buchwitz, John Burrows, Oliver Schneising, Eleanor Blyth, Douglas Clark, Fiona O'Connor, Nicola Gedney |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250058052
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| Zusammenfassung |
| The role of wetlands in the global methane cycle is the subject of much current interest [1,2]. Wetlands are generally accepted as being the largest, but least well quantified, single source of methane (CH4), with emission estimates ranging from 100-231 Tg yr-1 [3,4]. Since the late 1970s, there have been significant inter-annual variations in the growth rate of atmospheric methane, which has been linked to the variability in wetland CH4 emissions [5,6].
Although the emissions of methane from the wetlands and lakes of the boreal region are smaller than those from tropical wetlands, the size and remoteness of the boreal region pose a significant challenge to the quantification of both terrestrial ecosystem processes and their feedbacks to regional and global climate. In recent years, Earth Observation (EO) data have demonstrated the potential to become a major tool for characterizing the main processes and estimating key variables governing the land-atmosphere interface. To this end, the European Space Agency (ESA) has initiated the Atmosphere-LANd Interactions Study (ALANIS), in collaboration with the Integrated Land Ecosystem-Atmosphere Processes Study (iLEAPS). One of the three ALANIS themes is investigating wetland dynamics and methane emissions (denoted ALANIS methane, www.alanis-methane.info).
The ALANIS methane project has a focus on the boreal Eurasia region. There are two main goals: (1) to produce a suite of relevant datasets derived from Earth Observation (EO):
• a regional wetland extent dynamics product characterizing spatial changes of inundated areas over time at low spatial resolution and high time frequency;
• a local wetland extent dynamics product characterizing spatial changes of lake and wetland surface over time at high/medium spatial resolution and low time frequency;
• a snowmelt onset/duration/end product suitable for determining when methane emissions from wetland restart after the winter season;
• a freeze onset product suitable for determining when lake/wetland methane emissions stop after the summer season; and,
• atmospheric column CH4 concentrations.
and (2) to use these (and other) EO products to evaluate and improve the Joint UK Land Environment Simulator (JULES, http://www.jchmr.org/jules), a state-of-the-art land surface model.
An overview of the project and example results will be given.
1. Bloom, A.A., Palmer, P.I., Fraser, A., Reay, D.S. & Frankenberg, C. (2010). Large-scale controls of methanogenesis inferred from methane and gravity spaceborne data. Science, 327, 322-325
2. Ringeval, B., de Noblet-Ducoudre, N., Ciais, P., Bousquet, P., Prigent, C., Papa, F. & Rossow, W.B. (2010). An attempt to quantify the impact of changes in wetland extent on methane emissions on the seasonal and interannual time scales. Global Biogeochemical Cycles, 24, GB2003.
3. Wuebbles, D.J. & Hayhoe, K. (2002). Atmospheric methane and global change, Earth Science Reviews, 57, 177-210.
4. Mikaloff Fletcher, S.E. Tans, P.P., Bruhwiler, L.M., Miller, J.B., & Heimann, M. (2004). CH4 sources estimated from atmospheric observations of CH4 and its 13C/12C isotopic ratios: 1. Inverse modelling of source processes. Global Biogeochemical Cycles, 18, GB4004.
5. Bousquet, P. & 17 others (2006). Contribution of anthropogenic and natural sources to atmospheric methane variability, Nature, 443, 439-443.
6. Fiore, A.M., Horowitz, L.W., Dlugokencky, E.J. & West, J.J. (2006). Impact of meteorology and emissions on methane trends, 1990-2004, Geophysical Research Letters, L12809. |
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