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Harvard Forest REU Symposium Abstract 2012

• Title: Using Webcam Imagery to Study Forest Phenology on a Global Scale
• Author: Hannah E Skolnik (Johns Hopkins University)
• Abstract:

  The earth’s climate has been changing steadily getting warmer. There is no evidence that this will cease and as such, it is most important to study the ramifications of this heating trend. Growing season length can be a good indicator for how the earth’s natural systems are responding to global warming. There are two traditional ways to track growing season length, however these options either require significant methodological improvement (e.g. satellite remote sensing) or are subjective (e.g. human observations of when leaves begin to grow and die). The goal of this summer’s project has been to explore a more innovative method to track tree phenology. We have been using the technique of near-surface remote sensing, using freely available webcam images pulled off the Internet. The photos have all come from the AMOS (Archive of Many Outdoor Scenes) archive, a collection of many thousands of outdoor webcams compiled by Washington University in St. Louis. We had the opportunity to use 90 million images from over 1,800 geolocated webcams around the world. We analyzed the data by classifying the utility of the sites, based on how much the camera moves and how much/what type of vegetation is in the view. We then calculated the relative greenness values, or Green Chromatic Coordinate (GCC). This is graphed to show how the leaves are responding temporally over a season so we can then estimate the onset of Spring and the onset of Autumn. By monitoring phenology in ecosystems, we can quantify the effect of climate change on the natural world, which brings us one step closer to understanding how humans are altering their environment.

• Research Category: Ecological Informatics and Modelling; Group Projects