Summary:

A newly developed ground-based canopy imaging system called an MVI was tested and used by the BOREAS TE-06 team to collect measurements of the canopy gap fraction (sky fraction), canopy gap-size distribution (size and frequency of gaps between foliage in canopy), branch architecture, and leaf angle distribution (fraction of leaf area in specific leaf inclination classes assuming azimuthal symmetry). Measurements of the canopy gap-size distribution are used to derive canopy clumping indices that can be used to adjust indirect LAI measurements made in nonrandom forests. These clumping factors will also help to describe the radiation penetration in clumped canopies more accurately by allowing for simple adjustments to Beer's law. Measurements of the above quantities were obtained at BOREAS NSA OJP site in IFC-2 in 1994, at the SSA OA in July 1995, and at the SSA OBS and SSA OA sites in IFC-2 in 1996. Modeling studies were also performed to further validate MVI measurements and to gain a more complete understanding of boreal forest canopy architecture. By using MVI measurements and Monte Carlo simulations, clumping indices as a function of zenith angle were derived for the three main boreal species studied during BOREAS.

A guide document which includes more information about this data set can be found at https://daac.ornl.gov/data/boreas/TE/te6mltvg/comp/TE06_Multi_Veg_Imager.txt .

ORNL DAAC maintains information on the entire BOREAS Project.

Data Citation

Cite this data set as follows:

Kucharik, C. J., and J. M. Norman. 1998. BOREAS TE-06 Multiband Vegetation Imager Data. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. https://doi.org/10.3334/ORNLDAAC/331.

References:

Chen, J.M. and J. Cihlar. 1995. Quantifying the effect of canopy architecture on optical measurements of leaf area index using two gap size analysis methods. IEEE Trans. Geosci. Remote Sens., 33: 777-787.

Chen, J.M., P.M. Rich, S.T. Gower, J.M. Norman, and S. Plummer, 1997. Leaf area index of boreal forests: Theory, techniques, and measurements. J. Geophys. Res., BOREAS Special Issue.

Kucharik, C.J. 1997. Characterizing the radiation regime in nonrandom forest canopies. Ph.D. Thesis, University of Wisconsin-Madison, 308 pp.

Kucharik, C.J., J.M. Norman, and S.T. Gower, 1997b. Measurements of leaf orientation, light distribution, and sunlit leaf area in boreal aspen. Submitted to Agricultural and Forest Meteorology.

Kucharik, C.J., J.M. Norman, and S.T. Gower, 1998a. Measurements of leaf orientation, light distribution, and sunlit leaf area in a boreal aspen forest. Agricultural and Forest Meteorology 91(1-2): 127-148.

Kucharik, C.J., J.M. Norman, and S.T. Gower, 1998b. Measurements of branch area and adjusting leaf area index indirect measurements. Agricultural and Forest Meteorology, 91 (1-2): 69-88.

Kucharik, C.J., J.M. Norman, L.M. Murdock, and S.T. Gower. 1997a. Characterizing canopy nonrandomness with a Multiband Vegetation Imager (MVI). J. Geophys. Res., BOREAS Special Issue.

Sellers, P. and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94)

Sellers, P. and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96)

Sellers, P. and F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue.

Sellers, P. and F. Hall., K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94).

Sellers, P. and F. Hall., K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96).

Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and early results from the 1994 field year. Bulletin of the American Meteorological Society. 76(9): 1549-1577.

Zhang, T., R. Ramakrishnan, and M. Livny. 1996. BIRCH: An efficient data clustering method for very large databases. In Proc. of ACM SIGMOD International Conf. on Data Management, June 1996, Montreal, Canada.

Data Format:

For information on Parameter/Variable Names, Variable Description/Definition, Units of Measurement, and Data File Format see this companion file https://daac.ornl.gov/data/boreas/TE/te6mltvg/comp/te6mltvg.def

Document Information:

12-Oct-1998 (data citation revised on 25-Sep-2002)

Document Review Date:

12-Oct-1998

Document Curator:

webmaster@daac.ornl.gov

Document URL:

https://daac.ornl.gov