AmeriFlux
; Annual cycle
; Carbon allocation
; Crop growth
; Crop managements
; Earth system model
; Global perspective
; Growing season
; Land surface models
; Leaf Area Index
; Midlatitudes
; Monitoring stations
; Net ecosystem exchange
; North America
; Plant phenology
; Sensitivity Simulation
; Site observation
; Special algorithms
; Summer precipitation
; Biology
; Carbon dioxide
; Climate models
; Computer simulation
; Earth atmosphere
; Land use
; Oilseeds
; Phenols
; Crops
; cereal
; latent heat flux
; maize
; net ecosystem exchange
; phenology
; soybean
; vegetation
; North America
; Glycine max
; Poaceae
; Zea mays
英文摘要:
The Community Earth System Model, version 1 (CESM1) is evaluated with two coupled atmosphere-land simulations. The CTRL (control) simulation represents crops as unmanaged grasses, while CROP represents a crop managed simulation that includes special algorithms for midlatitude corn, soybean, and cereal phenology and carbon allocation. CROP has a more realistic leaf area index (LAI) for crops than CTRL. CROP reduces winter LAI and represents the spring planting and fall harvest explicitly. At the peak of the growing season, CROP simulates higher crop LAI. These changes generally reduce the latent heat flux but not around peak LAI (late spring/early summer). In midwestern North America, where corn, soybean, and cereal abundance is high, simulated peak summer precipitation declines and agrees better with observations, particularly when crops emerge late as is found from a late planting sensitivity simulation (LateP). Differences between the CROP and LateP simulations underscore the importance of simulating crop planting and harvest dates correctly. On the biogeochemistry side, the annual cycle of net ecosystem exchange (NEE) also improves in CROPrelative to Ameriflux site observations. For a global perspective, the authors diagnose annual cycles of CO2 from the simulated NEE (CO2 is not prognostic in these simulations) and compare against representative GLOBALVIEW monitoring stations. The authors find an increased (thus also improved) amplitude of the annual cycle in CROP. These regional and global-scale refinements from improvements in the simulated plant phenology have promising implications for the development of the CESM and particularly for simulations with prognostic atmospheric CO2.
National Center for Atmospheric Research, Boulder, CO, United States; Oak Ridge National Laboratory, Oak Ridge, TN, United States; Lawrence Berkeley National Laboratory, Berkeley, CA, United States; National Center for Atmospheric Research, Boulder, CO, United States; University of Wisconsin-Madison, Madison, WI, United States
Recommended Citation:
Levis S.,Gordon B. Bonan,Erik Kluzek,et al. Interactive Crop Management in the Community Earth System Model (CESM1): Seasonal influences on land-atmosphere fluxes[J]. Journal of Climate,2012-01-01,25(14)