HR: 0800h
AN: C21A-1062    [Abstracts]
TI: A New Approach For Snow Coverage Monitoring Using Simulated Aqua MODIS Band 6
AU: * Wang, L
EM: lwang2@gmu.edu
AF: School of Computational Science (SCS),George Mason University, MS 5CS, fairfax,VA, 22030
AU: Qu, J J
EM: jqu@scs.gmu.edu
AF: School of Computational Science (SCS),George Mason University, MS 5CS, fairfax,VA, 22030
AU: Qu, J J
EM: jqu@scs.gmu.edu
AF: Biosphere Science Branch NASA/GSFC, 614.4, Greenbelt,MD, 20771
AU: Xiong, X
EM: Xiaoxiong.Xiong-1@nasa.gov
AF: Biosphere Science Branch NASA/GSFC, 614.4, Greenbelt,MD, 20771
AU: Hao, X
EM: xhao1@gmu.edu
AF: School of Computational Science (SCS),George Mason University, MS 5CS, fairfax,VA, 22030
AU: Xie, Y
EM: yxie2@gmu.edu
AF: School of Computational Science (SCS),George Mason University, MS 5CS, fairfax,VA, 22030
AU: Che, N
EM: nianzeng_che@ssaihq.com
AF: Science System And Application, Inc(SSAI), 10201 Greenbelt Road, Lanham,MD, 20706
AB: The Moderate Resolution Imaging Spectroradiometer (MODIS) is a key research instrument for the NASA Earth Observing System (EOS). It was successfully launched onboard the Terra satellite in December 1999 and Aqua satellite in May 2002. Both MODIS instruments have been working well except that fifteen of the twenty detectors in Aqua MODIS band 6 are non-functional or noisy. The stripping in Aqua MODIS band 6 caused by the non-functional or noisy detectors has been a serious problem because band 6 is the primary band for MODIS snow products. To continue monitoring global snow coverage, the MODIS scientists have been using Aqua MODIS band 7 instead of band 6 to compute the Normalized Difference Snow Index (NDSI). Since snow has similar reflectance characteristics in MODIS bands 6 and 7 relative to other bands, band 7 has been considered as a reasonable replacement for band 6 in snow mapping and snow monitoring. However, it was found that the MODIS snow reflectance is typically a few percent lower in band 7 than in band 6. This difference affects the NDSI with higher NDSI values of snow when band 7 is used. And it appears that the change to band 7 from band 6 has resulted in subtle changes in the ability to detect clouds and snow in some situations. Therefore it is necessary to further investigate the relationship between MODIS band 6 and band 7, and possibly identify another alternative for NDSI retrieval as a replacement for band 6. In our preliminary investigations we have developed and validated a feasible algorithm to map Aqua MODIS band 6 based on the relationship between Terra MODIS band 6 and band 7. We will describe this algorithm in this paper and discuss its applications in retrieving Aqua MODIS NDSI. The Aqua NDSI values generated using simulated Aqua MODIS band 6 data as well as band 7 data are collected, analyzed, and compared with Terra snow maps. The approach for snow coverage monitoring proposed in this paper is valuable to determine the effects of the switch to band 7 and to find another alternative for Aqua MODIS NDSI retrieval. It is also helpful to keep the continuity and consistence of MODIS snow products.
DE: 0736 Snow (1827, 1863)
DE: 1895 Instruments and techniques: monitoring
SC: Cryosphere [C]
MN: Fall Meeting 2005