 |
| Titel |
Wetland methane modelling over the Scandinavian Arctic: Performance of current land-surface models |
| VerfasserIn |
Garry Hayman, Aurélien Quiquet, Nicola Gedney, Douglas Clark, Andrew Friend, Charles George, Catherine Prigent |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250098178
|
| Publikation (Nr.) |
 EGU/EGU2014-13828.pdf |
|
|
|
|
|
| Zusammenfassung |
| Wetlands are generally accepted as being the largest, but least well quantified, single natural
source of CH4, with global emission estimates ranging from 100-231 Tg yr-1 [1] and for
which the Boreal and Arctic regions make a significant contribution [2, 3]. The recent review
by Melton et al. [4] has provided a summary of the current state of knowledge on the
modelling of wetlands and the outcome of the WETCHIMP model intercomparison
exercise. Melton et al. found a large variation in the wetland areas and associated
methane emissions from the participating models and varying responses to climate
change.
In this paper, we report results from offline runs of two land surface models over
Scandinavia (JULES, the Joint UK Land Environment Simulator [5, 6] and HYBRID8 [7]),
using the same driving meteorological dataset (CRU-NCEP) for the period from January
1980 to December 2010. Although the two land surface models are very different, both
models have used a TOPMODEL approach to derive the wetland area and have similar
parameterisations of the methane wetland emissions.
We find that both models give broadly similar results. They underestimate the wetland
areas over Northern Scandinavia, compared to remote sensing and map-based datasets of
wetlands [8]. This leads to lower predicted methane emissions compared to those observed on
the ground and from aircraft [9]. We will present these findings and identify possible reasons
for the underprediction. We will show the sensitivity to using the observed wetland areas to
improve the methane emission estimates.
References
[1] Denman, K., et al.,: Couplings Between Changes in the Climate System and Biogeochemistry, In
Climate Change 2007: The Physical Science Basis, Contribution of Working Group I to the Fourth
Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press,
United Kingdom, 2007; [2] Smith, L. C., et al.: Siberian peatlands a net carbon sink and global
methane source since the early Holocene, Science, 303, 353-356, doi:10.1126/science.1090553,
2004; [3] Zhuang, Q., et al.: CO2 and CH4 exchanges between land ecosystems and the
atmosphere in northern high latitudes over the 21st century, Geophysical Research Letters, 33,
doi:10.1029/2006gl026972, 2006; [4] Melton, J.R., et al.: Present state of global wetland extent and
wetland methane modelling: conclusions from a model inter-comparison project (WETCHIMP),
Biogeosciences, 10, 753-788, doi:10.5194/bg-10-753-2013, 2013; [5] Best, M. J., et al.: The
Joint UK Land Environment Simulator (JULES), model description - Part 1: Energy and
water fluxes, Geoscientific Model Development, 4, 677-699, doi:10.5194/gmd-4-677-2011,
2011; [6] Clark, D.B., et al.: The Joint UK Land Environment Simulator (JULES), Model
description - Part 2: Carbon fluxes and vegetation. Geoscientific Model Development, 4, 701-722,
doi:10.5194/gmd-4-701-2011, 2011; [7] Friend, A.D., and N.Y. Kiang: Land surface model
development for the GISS GCM: Effects of improved canopy physiology on simulated climate. J.
Climate, 18, 2883-2902, doi:10.1175/JCLI3425.1, 2005; [8] Prigent, C., et al.: Changes in land surface
water dynamics since the 1990s and relation to population pressure, Geophys. Res. Lett., 39,
L08403, doi:10.1029/2012GL051276, 2012; [9] O’Shea, S., et al.: Methane and carbon dioxide
fluxes from the European Arctic wetlands during the MAMM project, paper in preparation. |
|
|
|
|
|
|