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High temporal resolution NDVI phenology from micrometeorological radiation sensors Huemmrich, Karl F.; Black, T. Andrew; Jarvis, Paul G.; McCaughey, J. H.; Hall, Forrest G.

Abstract

The boreal forest is a region characterized by wide swings in temperature and light levels over the course of a year. This seasonal variability strongly effects the vegetation of this biome. Normalized difference vegetation index (NDVI) values were observed at daily timescales for key land cover types of the boreal forest, developing a more detailed description of seasonal changes in NDVI than could be produced from satellite data. NDVI values were calculated from tower-mounted photosynthetically active radiation (PAR) and global solar sensors measuring both incoming and reflected radiation above the canopies at four Boreal Ecosystem-Atmosphere Study (BOREAS) sites. Comparisons were made between the tower-based broadband hemispherical NDVI values and the narrowband nadir-viewed NDVI values from helicopter modular multiband radiometer (MMR). The comparisons indicate that the tower NDVI values are close to the MMR NDVIs in value for the BOREAS sites, but the range in tower NDVIs is not so great as in the MMR NDVIs. In 1996, BOREAS towers operated from before thaw to freeze-up, allowing a complete picture of growing season NDVI for fen, young jack pine, black spruce, and aspen sites. The tower-based NDVI time series display different patterns for each vegetation type, showing the effects of snow cover and vegetation green-up and senescence. Changes in solar zenith angles are shown to have little effect on the seasonal NDVI patterns. An edited version of this paper was published by AGU. Copyright 1999 American Geophysical Union.

Item Metadata

Title
High temporal resolution NDVI phenology from micrometeorological radiation sensors
Creator
Huemmrich, Karl F.; Black, T. Andrew; Jarvis, Paul G.; McCaughey, J. H.; Hall, Forrest G.
Publisher
American Geophysical Union
Date Issued
1999-11
Description
The boreal forest is a region characterized by wide swings in temperature and light levels over the course of a year. This seasonal variability strongly effects the vegetation of this biome. Normalized difference vegetation index (NDVI) values were observed at daily timescales for key land cover types of the boreal forest, developing a more detailed description of seasonal changes in NDVI than could be produced from satellite data. NDVI values were calculated from tower-mounted photosynthetically active radiation (PAR) and global solar sensors measuring both incoming and reflected radiation above the canopies at four Boreal Ecosystem-Atmosphere Study (BOREAS) sites. Comparisons were made between the tower-based broadband hemispherical NDVI values and the narrowband nadir-viewed NDVI values from helicopter modular multiband radiometer (MMR). The comparisons indicate that the tower NDVI values are close to the MMR NDVIs in value for the BOREAS sites, but the range in tower NDVIs is not so great as in the MMR NDVIs. In 1996, BOREAS towers operated from before thaw to freeze-up, allowing a complete picture of growing season NDVI for fen, young jack pine, black spruce, and aspen sites. The tower-based NDVI time series display different patterns for each vegetation type, showing the effects of snow cover and vegetation green-up and senescence. Changes in solar zenith angles are shown to have little effect on the seasonal NDVI patterns. An edited version of this paper was published by AGU. Copyright 1999 American Geophysical Union.
Genre
Article
Type
Text
Language
eng
Date Available
2011-05-25
Provider
Vancouver : University of British Columbia Library
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International
DOI
10.14288/1.0041908
URI
http://hdl.handle.net/2429/34810
Affiliation
Land and Food Systems, Faculty of
Citation
Huemmrich, K. F.; Black, T. Andrew; Jarvis, P. G.; McCaughey, J. H.; Hall, F. G. 1999. High temporal resolution NDVI phenology from micrometeorological radiation sensors. Journal of Geophysical Research Atmospheres 104(D22) 27935-27944
Publisher DOI
10.1029/1999JD900164
Peer Review Status
Reviewed
Scholarly Level
Faculty
Copyright Holder
Black, T. Andrew
Rights URI
http://creativecommons.org/licenses/by-nc-nd/4.0/
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Attribution-NonCommercial-NoDerivatives 4.0 International