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Monitoring Seasonal Albedo and Vegetation Phenology with the V006 Daily MODIS BRDF/albedo Product
Zhuosen
Wang, University of Massachusetts Boston, wangzhs@bu.edu
Crystal
Schaaf, University of Massachusetts Boston, crystal.schaaf@umb.edu
(Presenter)
Alan
Strahler, Boston University, alan@bu.edu
Xiaoyang
Zhang, ERT at NOAA/NESDIS/STAR, xiaoyang.zhang@noaa.gov
Yanmin
Shuai, NASA/GSFC, yanmin.shuai@ertcorp.com
Yan
Liu, University of Massachusetts Boston, yan.liu@umb.edu
Qingsong
Sun, Boston University, sqs@bu.edu
The effects of rapidly changing events such as vegetation phenology and seasonal snowfall play important roles in the annual terrestrial energy and carbon cycles and serve as indicators of climate change. The timing of vegetation greenup and senescence impacts essential ecosystem processes while the duration of snow-free periods (particularly at high northern latitudes) has affected the composition and extent of vegetation. The MODerate resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF), Albedo, and Nadir BRDF-Adjusted Reflectance (NBAR) products have been providing cloud free measures of snow cover extent and of vegetation productivity and phenology for more than 13 years. The standard MODIS MCD43 products make use of the linear “kernel-driven” RossThick-LiSparse Reciprocal (RTLSR) BRDF model to describe the reflectance anisotropy of each land pixel at a 500-m gridded resolution over the globe. In the past this multi-day product was only retrieved every 8 days, which limited its ability to capture rapidly changing events such as ephemeral snow fall and snow melt and vegetation emergence and senescence. A daily version of the MODIS product is now available in the Collection V006 reprocessing. The algorithm still uses all MODIS reflectance observations acquired during a 16-day period but utilizes a moving window to improve upon the 8-day temporal resolution of the previous versions. Individual observations are weighted by their quality, observation coverage, and proximity to the production date of interest. These standard V006 NASA data products will allow daily monitoring of albedo and land surface change phenomena. In this study, we monitor the seasonal snow cover and vegetation phenology dynamics over a number of spatially representative instrumented tower sites.
Presentation Type: Poster
Session: Poster Session 1-B
(Tue 4:30 PM)
Associated Project(s):
Poster Location ID: 9
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