HR: 09:25h
AN: H41B-06    [PDF]
TI: Relations Between Albedos and Emissivities From MODIS and ASTER Data Over North African Desert
AU: * Zhou, L
EM: lmzhou@eas.gatech.edu
AF: Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332
AU: Dickinson, R
EM: robted@eas.gatech.edu
AF: Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332
AU: Ogawa, K
EM: kenta@hydrolab.arsusda.gov
AF: USDA/ARS Hydrology and Remote Sensing Lab., Bldg. 007, Rm. 104, BARC-West, Beltsville, MD 20705
AU: Tian, Y
EM: ytian@eas.gatech.edu
AF: Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332
AU: Jin, M
EM: mjin@metosrv2.umd.edu
AF: University of Maryland, 3411 Computer and Space Sciences Building, College Park, MD 20742
AU: Schmugge, T
EM: schmugge@hydrolab.arsusda.gov
AF: USDA/ARS Hydrology and Remote Sensing Lab., Bldg. 007, Rm. 104, BARC-West, Beltsville, MD 20705
AU: Tsvetsinskaya, E
EM: elenat@bu.edu
AF: Boston University, 675 Commonwealth Avenue, Boston, MA 02215
AB: This paper analyzes relations among MODIS surface albedos, ASTER broadband (3-14 $\mu$m) emissivities, and a soil taxonomy map over the arid areas of Algeria, Libya, and Tunisia in North Africa at 30 second (about 1 km) and 2 minute (about 4 km) spatial resolutions. The MODIS albedo data are from 7 spectral bands and 3 broadbands during dust-free seasons and the emissivity data are derived from a linear combination of the waveband emissivities of the ASTER five thermal infrared channels. Both albedo and emissivity data in the study region show similar considerable spatial variability, larger than assumed by most climate models, and such variability is related to the surface types (sands, rock, and soil orders). Emissivity over bare soils exhibits statistically significant correlations with albedos at both broadbands and most of spectral bands and decreases linearly with albedos. Albedo and emissivity are more strongly correlated with each other than either is to the surface types, apparently because of their higher resolution either spatially or in surface mineralogy. This paper provides guidance for the possible inclusion of such correlation to specify albedo and emissivity in climate models.
DE: 1620 Climate dynamics (3309)
DE: 1640 Remote sensing
DE: 3307 Boundary layer processes
DE: 3322 Land/atmosphere interactions
SC: Hydrology [H]
MN: 2003 Fall Meeting