HR: 0800h
AN: B31B-0217 [Abstracts]
TI: Understanding the TVX Relationship between NDVI and Surface Temperature for the Varying Landscape of
Oklahoma
AU: Nagol, J
EM: jotreddy@yahoo.com
AF: University of Toledo, 2801 W. Bancroft St.
Department of Geography and Planning, Toledo, OH 43606
United States
AU: * Czajkowski, K P
EM: kczajko@utnet.utoledo.edu
AF: University of Toledo, 2801 W. Bancroft St.
Department of Geography and Planning, Toledo, OH 43606
United States
AU: Stadler, S
EM: steve.stadler@okstate.edu
AF: Oklahoma State University, 207 Scott Hall
Geography Department
Oklahoma State University
, Stillwater, OK 74078-4073
United States
AU: Goward, S N
EM: sgoward@umd.edu
AF: University of Maryland, Department of Geography
2181 LeFrak Hall
University of Maryland, College Park, MD 20782
United States
AU: Mather, S
EM: smather@utnet.utoledo.edu
AF: University of Toledo, 2801 W. Bancroft St.
Department of Geography and Planning, Toledo, OH 43606
United States
AB:
The relationship between the Normalized Difference Vegetation Index (NDVI) and surface skin temperature (Ts), the
Temperature-Vegetation Index (TVX), generally exhibits a negative relationship where vegetation has a high NDVI and low
temperature and bare soil has a low NDVI and higher temperature. This relationship has been utilized to study air
temperature, soil moisture and surface moisture conditions as part of biospheric and hydrologic studies. A form of this
relationship is part of the MOD 16 MODIS Evaporative Fraction (EF) product. We have found that the TVX relationship
exhibits unusual behavior in some situations. We derived TVX slope and air temperature estimations using AVHRR data and
compared the output to data from the Oklahoma Mesonet for the period of May 6 to August 20, 1999. This study shows that
positive NDVI/Ts slopes were possibly caused by subpixel water bodies. In addition, NDVI/Ts slopes become increasingly
negative after winter wheat harvest in July in Central Oklahoma producing errors in air temperature estimation up to 30 K.
The largest errors occurred as a drought intensified through August.
DE: 3360 Remote sensing
DE: 3307 Boundary layer processes
DE: 1812 Drought
DE: 0315 Biosphere/atmosphere interactions
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting