مرکز منطقه ای اطلاع رساني علوم و فناوري - Variations of Foliage Chlorophyll fAPAR and Foliage Non-Chlorophyll fAPAR (fAPAR<formula formulatype="inline"> <img src="/images/tex/21101.gif" alt="_{\\rm chl}"> </formula>, fAPAR<formula formulatype="inline"> <img src="/images/tex/21102.gif" alt="

Title :

Variations of Foliage Chlorophyll fAPAR and Foliage Non-Chlorophyll fAPAR (fAPAR $_{\\rm chl}$ , fAPAR $_{\\rm</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Author : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>Qingyuan Zhang ; Middleton, Elizabeth M. ; Yen-Ben Cheng ; Landis, David R.</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Author_Institution : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>Univ. Space Res. Assoc., Columbia, MD, USA</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Volume : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>6</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Issue : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>5</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>fYear : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>2013</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Firstpage : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>2254</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Lastpage : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>2264</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Abstract : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>In the last three decades, substantial advancements have been made in understanding the global carbon cycle. Some of these advancements involve using the fraction of absorbed photosynthetically active radiation (fAPAR) by an entire canopy (fAPAR<sub>canopy</sub>) and/or the Normalized Difference Vegetation Index (NDVI) in modeling studies. In spite of these advancements, large uncertainties still remain. Zhang (Remote Sens. Environ., 2005) [1] tried to mitigate some of these uncertainties with the concept of using fAPAR that is restricted to the foliage chlorophyll (fAPAR<sub>chl</sub>) instead of the entire canopy. In this current study, we calculated fAPAR<sub>canopy</sub>, fAPAR<sub>chl</sub>, and foliage non-chlorophyll fAPAR (fAPAR<sub>non-hl</sub>) for the Harvard Forest using a radiative transfer model and multi-temporal Earth Observing One (EO-1) Hyperion satellite images. The canopy-level proportions of foliar chlorophyll and non-chlorophyll absorption were determined at different seasons (spring, summer, autumn) in an effort to demonstrate temporal variations of three plant functional types: deciduous forest, coniferous forest, and grass. Comparisons were made for NDVI versus fAPAR<sub>canopy</sub> and for the Enhanced Vegetation Index (EVI) versus fAPAR<sub>chl</sub>. In addition, EO-1 Hyperion images were utilized to simulate these new fAPAR<sub>canopy</sub>, fAPAR<sub>chl</sub>, and fAPAR<sub>non-chl</sub> products at 60 m as prototypes for the proposed NASA HyspIRI satellite spectrometer. These products should prove useful for future terrestrial carbon cycle and ecosystem studies.</div> </div> <div class='row'> <div class='leftDiv labelDiv col-xs-4 col-sm-2 fullRecLabelEnglish'>Keywords : </div><div class='valueDiv leftDirection leftAlign col-xs-8 col-sm-10 fullRecValueEnglish'>hyperspectral imaging; photosynthesis; radiative transfer; vegetation mapping; EO-1 Hyperion images; Harvard Forest; NASA HyspIRI satellite spectrometer; coniferous forest; deciduous forest; ecosystem; enhanced vegetation index; foliage chlorophyll fAPAR variations; foliage nonchlorophyll fAPAR variations; fraction of absorbed photosynthetically active radiation; grass; multitemporal Earth Observing One Hyperion satellite images; normalized difference vegetation index; radiative transfer model; terrestrial carbon cycle; Atmospheric modeling; Biological system modeling; MODIS; Poles and towers; Spatial resolution; Springs; Vegetation mapping; fAPAR<formula formulatype=$ $_{rm chl}$; fAPAR$_{rm canopy}$; fAPAR$_{rm nonmathchar "702D chl}$ ; terrestrial carbon cycle; vegetation photosynthesis;