Back to Search
Start Over
A model-data comparison of gross primary productivity: Results from the North American Carbon Program site synthesis
- Source :
- Journal of Geophysical Research: Biogeosciences, Journal of Geophysical Research: Biogeosciences, American Geophysical Union, 2012, 117 (G3), pp.n/a-n/a. ⟨10.1029/2012JG001960⟩, Journal of Geophysical Research: Biogeosciences, 2012, 117 (G3), pp.n/a-n/a. ⟨10.1029/2012JG001960⟩, JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
- Publication Year :
- 2012
- Publisher :
- HAL CCSD, 2012.
-
Abstract
- Accurately simulating gross primary productivity (GPP) in terrestrial ecosystem models is critical because errors in simulated GPP propagate through the model to introduce additional errors in simulated biomass and other fluxes. We evaluated simulated, daily average GPP from 26 models against estimated GPP at 39 eddy covariance flux tower sites across the United States and Canada. None of the models in this study match estimated GPP within observed uncertainty. On average, models overestimate GPP in winter, spring, and fall, and underestimate GPP in summer. Models overpredicted GPP under dry conditions and for temperatures below 0 degrees C. Improvements in simulated soil moisture and ecosystem response to drought or humidity stress will improve simulated GPP under dry conditions. Adding a low-temperature response to shut down GPP for temperatures below 0 degrees C will reduce the positive bias in winter, spring, and fall and improve simulated phenology. The negative bias in summer and poor overall performance resulted from mismatches between simulated and observed light use efficiency (LUE). Improving simulated GPP requires better leaf-to-canopy scaling and better values of model parameters that control the maximum potential GPP, such as epsilon(max) (LUE), V-cmax (unstressed Rubisco catalytic capacity) or Jmax (the maximum electron transport rate).
- Subjects :
- NET ECOSYSTEM PRODUCTIVITY
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere
SUB-ALPINE FOREST
ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS
STOMATAL CONDUCTANCE
SOIL-MOISTURE
DIOXIDE FLUXES
GLOBAL VEGETATION MODEL
CO2 EXCHANGE
Earth and Environmental Sciences
Settore BIO/07 - ECOLOGIA
BOREAL FORESTS
INTERANNUAL VARIABILITY
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
ComputingMilieux_MISCELLANEOUS
HIGH-ELEVATION
Subjects
Details
- Language :
- English
- ISSN :
- 21698953 and 01480227
- Database :
- OpenAIRE
- Journal :
- Journal of Geophysical Research: Biogeosciences, Journal of Geophysical Research: Biogeosciences, American Geophysical Union, 2012, 117 (G3), pp.n/a-n/a. ⟨10.1029/2012JG001960⟩, Journal of Geophysical Research: Biogeosciences, 2012, 117 (G3), pp.n/a-n/a. ⟨10.1029/2012JG001960⟩, JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
- Accession number :
- edsair.dedup.wf.001..fb7a11ba3d53f3957c3fb4e3ae0dc412