TY - JOUR
T1 - Characterization of seasonal variation of forest canopy in a temperate deciduous broadleaf forest, using daily MODIS data
AU - Zhang, Qingyuan
AU - Xiao, Xiangming
AU - Braswell, Bobby
AU - Linder, Ernst
AU - Ollinger, Scott
AU - Smith, Marie Louise
AU - Jenkins, Julian P.
AU - Baret, Fred
AU - Richardson, Andrew D.
AU - Moore, Berrien
AU - Minocha, Rakesh
N1 - Funding Information:
We would like to thank Dr. Marvin E. Bauer and the anonymous referees whose careful reviews resulted in a more meaningful analysis and a much improved manuscript. The study was supported by NASA Earth System Science Graduate Fellowship (NGT5-30477 for Q. Zhang), NASA Earth Observation System Interdisciplinary Science project (NAG5-10135) and NASA Carbon Cycle Science Project (CARBON-0000-1234). Field data of the study site are from the long-term research studies at the Bartlett Experimental Forest under the support of the U.S. Department of Agriculture, Forest Service, Northeastern Research Station.
PY - 2006/12/15
Y1 - 2006/12/15
N2 - In this paper, we present an improved procedure for collecting no or little atmosphere- and snow-contaminated observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The resultant time series of daily MODIS data of a temperate deciduous broadleaf forest (the Bartlett Experimental Forest) in 2004 show strong seasonal dynamics of surface reflectance of green, near infrared and shortwave infrared bands, and clearly delineate leaf phenology and length of plant growing season. We also estimate the fractions of photosynthetically active radiation (PAR) absorbed by vegetation canopy (FAPARcanopy), leaf (FAPARleaf), and chlorophyll (FAPARchl), respectively, using a coupled leaf-canopy radiative transfer model (PROSAIL-2) and daily MODIS data. The Markov Chain Monte Carlo (MCMC) method (the Metropolis algorithm) is used for model inversion, which provides probability distributions of the retrieved variables. A two-step procedure is used to estimate the fractions of absorbed PAR: (1) to retrieve biophysical and biochemical variables from MODIS images using the PROSAIL-2 model; and (2) to calculate the fractions with the estimated model variables from the first step. Inversion and forward simulations of the PROSAIL-2 model are carried out for the temperate deciduous broadleaf forest during day of year (DOY) 184 to 201 in 2005. The reproduced reflectance values from the PROSAIL-2 model agree well with the observed MODIS reflectance for the five spectral bands (green, red, NIR1, NIR2, and SWIR1). The estimated leaf area index, leaf dry matter, leaf chlorophyll content and FAPARcanopy values are close to field measurements at the site. The results also showed significant differences between FAPARcanopy and FAPARchl at the site. Our results show that MODIS imagery provides important information on biophysical and biochemical variables at both leaf and canopy levels.
AB - In this paper, we present an improved procedure for collecting no or little atmosphere- and snow-contaminated observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The resultant time series of daily MODIS data of a temperate deciduous broadleaf forest (the Bartlett Experimental Forest) in 2004 show strong seasonal dynamics of surface reflectance of green, near infrared and shortwave infrared bands, and clearly delineate leaf phenology and length of plant growing season. We also estimate the fractions of photosynthetically active radiation (PAR) absorbed by vegetation canopy (FAPARcanopy), leaf (FAPARleaf), and chlorophyll (FAPARchl), respectively, using a coupled leaf-canopy radiative transfer model (PROSAIL-2) and daily MODIS data. The Markov Chain Monte Carlo (MCMC) method (the Metropolis algorithm) is used for model inversion, which provides probability distributions of the retrieved variables. A two-step procedure is used to estimate the fractions of absorbed PAR: (1) to retrieve biophysical and biochemical variables from MODIS images using the PROSAIL-2 model; and (2) to calculate the fractions with the estimated model variables from the first step. Inversion and forward simulations of the PROSAIL-2 model are carried out for the temperate deciduous broadleaf forest during day of year (DOY) 184 to 201 in 2005. The reproduced reflectance values from the PROSAIL-2 model agree well with the observed MODIS reflectance for the five spectral bands (green, red, NIR1, NIR2, and SWIR1). The estimated leaf area index, leaf dry matter, leaf chlorophyll content and FAPARcanopy values are close to field measurements at the site. The results also showed significant differences between FAPARcanopy and FAPARchl at the site. Our results show that MODIS imagery provides important information on biophysical and biochemical variables at both leaf and canopy levels.
KW - Atmosphere contamination
KW - Bartlett Experimental Forest
KW - FAPAR
KW - MODIS
KW - Markov Chain Monte Carlo (MCMC) method
KW - PROSPECT
KW - Phenology
KW - SAIL-2
KW - Snow
UR - http://www.scopus.com/inward/record.url?scp=33751231745&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33751231745&partnerID=8YFLogxK
U2 - 10.1016/j.rse.2006.06.013
DO - 10.1016/j.rse.2006.06.013
M3 - Article
AN - SCOPUS:33751231745
SN - 0034-4257
VL - 105
SP - 189
EP - 203
JO - Remote Sensing of Environment
JF - Remote Sensing of Environment
IS - 3
ER -