Publications Found: 36
Similarity Theory For Local And Spatially Averaged Momentum Fluxes
Nakamura, R., Mahrt, L.

Tower and aircraft data from a number of field studies are analyzed to: (1) estimate the roughness lengths for local and area-averaged momentum fluxes over various surface types; (2) examine the applicability of the ψ-stability formulations of Paulson and Dyer for momentum fluxes; (3) investigate the possibility …

Journal: Agricultural And Forest Meteorology, Volume 108 (4): 265-279 (2001), ISBN . DOI: 10.1016/s0168-1923(01)00250-7 Sites: CA-Man, CA-Oas, CA-Obs, CA-Ojp, CA-SJ3

The Seasonal Water And Energy Exchange Above And Within A Boreal Aspen Forest
Blanken, P., Black, T., Neumann, H., den Hartog, G., Yang, P., Nesic, Z., Lee, X.

The seasonal water and energy exchange of a boreal aspen forest underlain by a hazelnut understory is described. Measurements of above-aspen latent and sensible heat, short-wave and net radiation, and photosynthetically active radiation are compared to those measured above the hazelnut understory. Understory radiation measurements …

Journal: Journal Of Hydrology, Volume 245 (1-4): 118-136 (2001), ISBN . DOI: 10.1016/s0022-1694(01)00343-2 Sites: CA-Oas

Nocturnal Mixing In A Forest Subcanopy
Mahrt, L., Lee, X., Black, A., Neumann, H., Staebler, R.

The vertical structure of the flow in the old aspen canopy in BOREAS is examined in terms of thermocouple profiles and sonic anemometers above, within, and below the aspen canopy. The data are composited for different periods in order to isolate seasonal changes of the canopy and sun angle. On clear nights, a strong surface …

Journal: Agricultural And Forest Meteorology, Volume 101 (1): 67-78 (2000), ISBN . DOI: 10.1016/s0168-1923(99)00161-6 Sites: CA-Oas

Remote Sensing Of Photosynthetic-Light-Use Efficiency Of Boreal Forest
Nichol, C. J., Huemmrich, K. F., Black, T., Jarvis, P. G., Walthall, C. L., Grace, J., Hall, F. G.

Using a helicopter-mounted portable spectroradiometer and continuous eddy covariance data we were able to evaluate the photochemical reflectance index (PRI) as an indicator of canopy photosynthetic light-use efficiency (LUE) in four boreal forest species during the Boreal …

Journal: Agricultural And Forest Meteorology, Volume 101 (2-3): 131-142 (2000), ISBN . DOI: 10.1016/s0168-1923(99)00167-7 Sites: CA-Man, CA-Oas, CA-Obs, CA-Ojp

Micrometeorology, Biophysical Exchanges And NEE Decomposition In A Two-Story Boreal Forest — Development And Test Of An Integrated Model
Gu, L., Shugart, H. H., Fuentes, J. D., Black, T., Shewchuk, S. R.

An integrated model of canopy micrometeorology and exchanges of mass and energy was developed and tested for a two-story boreal forest. Roles of different elements of this forest ecosystem in determining net ecosystem exchanges (NEEs) of sensible heat, water vapor and CO2 were analyzed by using the model. In this model, …

Journal: Agricultural And Forest Meteorology, Volume 94 (2): 123-148 (1999), ISBN . DOI: 10.1016/s0168-1923(99)00006-4 Sites: CA-Oas

Diurnal And Annual Exchanges Of Mass And Energy Between An Aspen-Hazelnut Forest And The Atmosphere: Testing The Mathematical Model Ecosys With Data From The BOREAS Experiment
Grant, R. F., Black, T. A., den Hartog, G., Berry, J. A., Neumann, H. H., Blanken, P. D., Yang, P. C., Russell, C., Nalder, I. A.

There is much uncertainty about the net carbon (C) exchange of boreal forest ecosystems, although this exchange may be an important part of global C dynamics. To resolve this uncertainty, net C exchange has …

Journal: Journal Of Geophysical Research: Atmospheres, Volume 104 (D22): 27699-27717 (1999), ISBN . DOI: 10.1029/1998jd200117 Sites: CA-Oas

Modeling BRFAnd Radiation Regime Of Boreal And Tropical Forests
Gastellu-Etchegorry, J., Guillevic, P., Zagolski, F., Demarez, V., Trichon, V., Deering, D., Leroy, M.

Monitoring of forest evolution and functioning with remote sensing depends on canopy BRF (bidirectional reflectance factor) sensitivity to biophysical parameters and to canopy PAR (photosynthetically active radiation) regime. Here, we study the canopy BRF of a tropical (Sumatra) …

Journal: Remote Sensing Of Environment, Volume 68 (3): 281-316 (1999), ISBN . DOI: 10.1016/s0034-4257(98)00119-9 Sites: CA-Oas, CA-Obs, CA-Ojp

Effects Of Climatic Variability On The Annual Carbon Sequestration By A Boreal Aspen Forest
Chen, W. J., Black, T. A., Yang, P. C., Barr, A. G., Neumann, H. H., Nesic, Z., Blanken, P. D., Novak, M. D., Eley, J., Ketler, R. J., Cuenca, R.

To evaluate the carbon budget of a boreal deciduous forest, we measured CO2 fluxes using the eddy covariance technique above an old aspen (OA) forest in Prince Albert National Park, Saskatchewan, Canada, in 1994 and 1996 as part of the Boreal Ecosystem-Atmosphere Study (BOREAS). We found that the OA forest is a strong …

Journal: Global Change Biology, Volume 5 (1): 41-53 (1999), ISBN . DOI: 10.1046/j.1365-2486.1998.00201.x Sites: CA-Oas

Sap Flow In Trembling Aspen: Implications For Stomatal Responses To Vapor Pressure Deficit
Hogg, E. H., Hurdle, P. A.

We monitored sap flow and estimated diurnal changes in transpiration rates of two trembling aspen (Populus tremuloides Michx.) stands, located in the southern boreal forest and aspen parkland of Saskatchewan, Canada. In both stands during the peak growing season (June and July), sap flow during the day (0700–1700 h local …

Journal: Tree Physiology, Volume 17 (8-9): 501-509 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.501 Sites: CA-Oas

Simulating Forest Productivity And Surface-Atmosphere Carbon Exchange In The BOREAS Study Region
Kimball, J. S., Thornton, P. E., White, M. A., Running, S. W.

A process-based, general ecosystem model (BIOME–BGC) was used to simulate daily gross primary production, maintenance and heterotrophic respiration, net primary production and net ecosystem carbon exchange of boreal aspen, jack pine and black spruce stands. Model simulations of daily net carbon exchange of the ecosystem (NEE) explained …

Journal: Tree Physiology, Volume 17 (8-9): 589-599 (1997), ISBN . DOI: 10.1093/treephys/17.8-9.589 Sites: CA-Man, CA-Oas, CA-Obs, CA-Ojp