DOI: 10.1016/j.jag.2016.05.005
Scopus记录号: 2-s2.0-84997795123
论文题名: Consistency of vegetation index seasonality across the Amazon rainforest
作者: Maeda E ; E ; , Moura Y ; M ; , Wagner F ; , Hilker T ; , Lyapustin A ; I ; , Wang Y ; , Chave J ; , Mõttus M ; , Aragão L ; E ; O ; C ; , Shimabukuro Y
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2016
卷: 52 起始页码: 42
结束页码: 53
语种: 英语
英文关键词: BRDF effect
; EVI
; GEP
; MAIAC
; MODIS
; NDVI
; Phenology
; Seasonality
Scopus关键词: algorithm
; bidirectional reflectance
; MODIS
; NDVI
; phenology
; rainforest
; remote sensing
; seasonality
; Amazonia
英文摘要: Vegetation indices (VIs) calculated from remotely sensed reflectance are widely used tools for characterizing the extent and status of vegetated areas. Recently, however, their capability to monitor the Amazon forest phenology has been intensely scrutinized. In this study, we analyze the consistency of VIs seasonal patterns obtained from two MODIS products: the Collection 5 BRDF product (MCD43) and the Multi-Angle Implementation of Atmospheric Correction algorithm (MAIAC). The spatio-temporal patterns of the VIs were also compared with field measured leaf litterfall, gross ecosystem productivity and active microwave data. Our results show that significant seasonal patterns are observed in all VIs after the removal of view-illumination effects and cloud contamination. However, we demonstrate inconsistencies in the characteristics of seasonal patterns between different VIs and MODIS products. We demonstrate that differences in the original reflectance band values form a major source of discrepancy between MODIS VI products. The MAIAC atmospheric correction algorithm significantly reduces noise signals in the red and blue bands. Another important source of discrepancy is caused by differences in the availability of clear-sky data, as the MAIAC product allows increased availability of valid pixels in the equatorial Amazon. Finally, differences in VIs seasonal patterns were also caused by MODIS collection 5 calibration degradation. The correlation of remote sensing and field data also varied spatially, leading to different temporal offsets between VIs, active microwave and field measured data. We conclude that recent improvements in the MAIAC product have led to changes in the characteristics of spatio-temporal patterns of VIs seasonality across the Amazon forest, when compared to the MCD43 product. Nevertheless, despite improved quality and reduced uncertainties in the MAIAC product, a robust biophysical interpretation of VIs seasonality is still missing. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/80029
Appears in Collections: 气候变化事实与影响
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作者单位: University of Helsinki, Department of Geosciences and Geography, P.O. Box 68, Helsinki, Finland; National Institute for Space Research (INPE), Avenida dos Astronautas 1758, São Jose dos Campos-SP, Brazil; Oregon State University, College of Forestry, Corvallis, OR, United States; University of Southampton, Department of Geography and Environment, Highfield Rd, SO17 1BJSouthampton, United Kingdom; NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD, United States; University of Maryland, Baltimore County, 1000 Hilltop Cir, Baltimore, MD, United States; CNRS & Université Paul Sabatier UMR 5174, Laboratoire Evolution et Diversité Biologique, Toulouse, France
Recommended Citation:
Maeda E,E,, Moura Y,et al. Consistency of vegetation index seasonality across the Amazon rainforest[J]. International Journal of Applied Earth Observation and Geoinformation,2016-01-01,52