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Titel |
Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles |
VerfasserIn |
V. Haverd, M. R. Raupach, P. R. Briggs, J. G. Canadell, P. Isaac, C. Pickett-Heaps, S. H. Roxburgh, E. Gorsel, R. A. Viscarra Rossel, Z. Wang |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 3 ; Nr. 10, no. 3 (2013-03-25), S.2011-2040 |
Datensatznummer |
250018169
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Publikation (Nr.) |
copernicus.org/bg-10-2011-2013.pdf |
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Zusammenfassung |
Information about the carbon cycle potentially constrains the water cycle,
and vice versa. This paper explores the utility of multiple observation sets to
constrain a land surface model of Australian terrestrial carbon and water
cycles, and the resulting mean carbon pools and fluxes, as well as their
temporal and spatial variability. Observations include streamflow from 416
gauged catchments, measurements of evapotranspiration (ET) and net ecosystem
production (NEP) from 12 eddy-flux sites, litterfall data, and data on
carbon pools. By projecting residuals between observations and corresponding
predictions onto uncertainty in model predictions at the continental scale,
we find that eddy flux measurements provide a significantly tighter
constraint on continental net primary production (NPP) than the other data
types. Nonetheless, simultaneous constraint by multiple data types is
important for mitigating bias from any single type.
Four significant results emerging from the multiply-constrained model are
that, for the 1990–2011 period: (i) on the Australian continent, a
predominantly semi-arid region, over half the water loss through ET
(0.64 ± 0.05) occurs through soil evaporation and bypasses plants
entirely; (ii) mean Australian NPP is quantified at 2.2 ± 0.4
(1σ) Pg C yr−1; (iii) annually cyclic ("grassy") vegetation
and persistent ("woody") vegetation account for 0.67 ± 0.14 and
0.33 ± 0.14, respectively, of NPP across Australia; (iv) the average
interannual variability of Australia's NEP (±0.18 Pg C yr−1,
1σ) is larger than Australia's total anthropogenic greenhouse gas
emissions in 2011 (0.149 Pg C equivalent yr–1), and is dominated by
variability in desert and savanna regions. |
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