Abstract – Using Moderate Resolution Imaging

• Main Authors: P. S. A. Beck A, S. R. Karlsen B, A. Skidmore C, L. Nilsen A, K. A. Høgda B
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: phenology; downy birch; maximum value composites; MODIS; Fennoscandia
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.141.3682; http://www.isprs.org/publications/related/ISRSE/html/papers/261.pdf

vegetation index (NDVI) data, we mapped the onset of spring in the years 2000-2004 in Fennoscandia. First, NDVI maximum value composite (MVC) time series were filtered and smoothed to remove noise. Next, pixel specific NDVI thresholds were calibrated using field observations of budburst in Betula pubescens Ehrh. (n = 81). This method achieves modest agreement between the predicted and observed dates (RMSE = 13 days). The resulting maps show that the arrival of spring varies by more than two months within the study area and by more than a month between years. We illustrate how MODIS NDVI images track phenological patterns in great detail and can be used to monitor the effects of ongoing climate change.