GEOGRAPHIC INFORMATION

Normal for Yearly EVI for Year 2002 to Present from AQUA

Data Provider Montana Climate Office
Date 01/01/2003 - 01/01/2013
Content Type Downloadable Data
Abstract Normals represent the average condition over a given period of time. The mean and standard deviation of yearly Enhanced Vegetation Index (EVI) are derived and used to calculate the departure from normal as a z-score for year 2002 to present. EVI is an 'optimized' index designed to enhance the vegetation signal with improved sensitivity in high biomass regions and improved vegetation monitoring through a de-coupling of the canopy background signal and a reduction in atmosphere influences. Starting 2000, and after the launch of the two MODIS sensors on Terra (satellite) and Aqua (satellite) by NASA, EVI was adopted as a standard product. The Terra satellite collection encompasses the years 2000 to present. The Aqua satellite collection encompasses the years 2002 to present. The Montana Climate Office tansforms the source MODIS datasets from their native sinusoidal projection to the Montana State Plane coordinate system for the area-of-interest for both the Aqua and Terra MODIS platforms.Technical details for MODIS can be found in the user guide posted at ftp://mco.cfc.umt.edu/resources/MCO/Papers/MODIS_VI_UsersGuide_01_2012.pdf
Purpose The mean for monthly Enhanced Vegetation Index (EVI) for Montana is provided in gridded format. Like the Normalized Difference Vegetation Index (NDVI) many factors affect EVI values like plant photosynthetic activity, total plant cover, biomass, plant and soil moisture, and plant stress. Vegetation indices like EVI make it possible to compare images over time to look for ecologically significant changes. While NDVI is chlorophyll sensitive, the EVI is more responsive to canopy structural variations, including leaf area index (LAI), canopy type, plant physiognomy, and canopy architecture. The two vegetation indices (NDVI and EVI) complement each other and improve upon the detection of vegetation changes and extraction of canopy biophysical parameters. Another difference between NDVI and EVI is that in the presence of snow, NDVI decreases, while EVI increases.
Supplemental Information Processed from HDF raster file source using Python 2.7 code maintained by the Montana Climate Office.
The Montana Climate Office (MCO) provides this product/service for informational purposes only. The MCO did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their purposes. The MCO provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the MCO be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The MCO makes these data and services available as a convenience to the public, and for no other purpose. The MCO reserves the right to change or revise published data and/or services at any time.
Data Access ftp://mco.cfc.umt.edu/evi/aqua/yearly_normals/Readme.html
Distributor Michael D. Sweet Research and Information Systems Specialist Montana Climate Office
32 Campus Drive
Missoula, Montana 59812-0576
Telephone: 406.243.5265
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Fax:
Email: michael.sweet@umontana.edu
Distribution liability The Montana Climate Office (MCO) provides this product/service for informational purposes only. The MCO did not produce it for, nor is it suitable for legal, engineering, or surveying purposes. Consumers of this information should review or consult the primary data and information sources to ascertain the viability of the information for their purposes. The MCO provides these data in good faith but does not represent or warrant its accuracy, adequacy, or completeness. In no event shall the MCO be liable for any incorrect results or analysis; any direct, indirect, special, or consequential damages to any party; or any lost profits arising out of or in connection with the use or the inability to use the data or the services provided. The MCO makes these data and services available as a convenience to the public, and for no other purpose. The MCO reserves the right to change or revise published data and/or services at any time.
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Metadata date 02/13/2015

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