Characterization and intercomparison of global moderate resolution leaf area index (LAI) products: Analysis of climatologies and theoretical uncertainties
2013
Fang, Hongliang | Jiang, Chongya | Li, Wenjuan | Wei, Shanshan | Baret, Frédéric | Garcia-Haro, Javier | Liang, Shunlin | Liu, Ronggao | Pinty, Bernard | Xiao, Zhiqiang | Zhu, Zaichun | Sondra, CentraleSupélec, Université Paris-Saclay (COmUE) (SONDRA) ; ONERA-CentraleSupélec-Université Paris Saclay (COmUE) | Department of Electrical and Computer Engineering [Univ. Singapore] ; National University of Singapore (NUS) | University of Illinois at Urbana-Champaign [Urbana] (UIUC) ; University of Illinois System | PHysicochimie des Electrolytes et Nanosystèmes InterfaciauX (PHENIX) ; Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Chinese Academy of Geological Sciences [Beijing] (CAGS) ; Ministry of Land and Resources (MLR) | Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH) ; Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Universitat de València = University of Valencia (UV) | University of Maryland [College Park] (UMD) ; University System of Maryland | Joint Research center ; European Commission | School of Geography, State Key Laboratory of Remote Sensing Science ; Beijing Agricultural University | Boston University [Boston] (BU) | Hundred Talent Program of the Chinese Academy of Sciences; National Natural Science Foundation of China [41171333]; State Program for High-Tech Research and Development [2009AA122100]; National Basic Research Program of China (973 Program) [2007CB714407]; National Basic Research Program of China [2010CB950701]
International audience
اظهر المزيد [+] اقل [-]إنجليزي. [1] Leaf area index (LAI) is a critical variable for land surface and climate modeling studies. Several global LAI products exist, and it is important to know how these products perform and what their uncertainties are. Five major global LAI products—MODIS, GEOV1, GLASS, GLOBMAP, and JRC-TIP—were compared between 2003 and 2010 at a 0.01 spatial resolution and with a monthly time step. The daily Land-SAF product was used as a regional reference in order to evaluate the performance of other global products in Africa. Cross-sensor LAI conversion equations were derived for different biome types. Product uncertainties were assessed by looking into the product quantitative quality indicators (QQIs) attached to MODIS, GEOV1, and JRC-TIP. MODIS, GEOV1, GLASS, and GLOBMAP are generally consistent and show strong linear relationships between the products (R 2 > 0.74), with typical deviations of < 0.5 for nonforest and < 1.0 for forest biomes. JRC-TIP, the only effective LAI product, is about half the values of the other LAI products. The average uncertainties and relative uncertainties are in the following order: MODIS (0.17, 11.5%) < GEOV1 (0.24, 26.6%) < Land-SAF (0.36, 37.8%) < JRC-TIP (0.43, 114.3%). The highest relative uncertainties usually appear in ecological transition zones. More than 75% of MODIS, GEOV1, JRC-TIP, and Land-SAF pixels are within the absolute uncertainty requirements (AE 0.5) set by the Global Climate Observing System (GCOS), whereas more than 78.5% of MODIS and 44.6% of GEOV1 pixels are within the threshold for relative uncertainty (20%). This study reveals the discrepancies mainly due to differences between definitions, retrieval algorithms, and input data. Future product development and validation studies should focus on areas (e.g., sparsely vegetated and savanna areas) and periods (e.g., winter time) with higher uncertainties. Citation: Fang, H., et al. (2013), Characterization and intercomparison of global moderate resolution leaf area index (LAI) products: Analysis of climatologies and theoretical uncertainties,
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل Institut national de la recherche agronomique