A technique for improving MODIS standard snow products for snow cover monitoring over Eastern Turkey

Daily snow cover maps at 500 m resolution are available from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on NASA's Terra and Aqua satellites. However, information of the ground can only be obtained during clear sky conditions. In addition, the spectral similarity between clouds and snow in the visible part of the spectrum causes some ambiguities in separation of them. The dynamic behavior of clouds with their tendency to move faster often enables discrimination between cloud and snow, since snow remains relatively stationary. In this study, a daily merging methodology to combine Terra and Aqua based snow maps are proposed, and the benefits of this combination are evaluated. The methodology was tested for Eastern Turkey covering the period from December 2002 to March 2003. Merged maps derived from the standard daily snow maps from Terra (MOD10A1) and Aqua (MYD10A1) reduce the cloud cover present in any one image alone, provide better representation of the surface snow cover, and indicate better agreement with ground snow measurements than when either one is used alone. For “on the ground data date” analyses yielded 31% match ratios for MOD10A1 and MYD10A1, whereas combined images enabled 38%. One- to 2-day temporal window shifting enabled further 7% and 5% improvements in match ratios, respectively. The maximum improvement of 25% was achieved in January of 2003. The proposed methodology provides an easy and effective way to improve snow cover maps with little effort and provides fewer cloud-contaminated images for snow monitoring, for hydrology, and water resource management.

[1]  Ivan Csiszar,et al.  Automated Monitoring of Snow Cover over North America with Multispectral Satellite Data , 2000 .

[2]  David A. Robinson.  Hemispheric snow cover from satellites , 1993 .

[3]  Zuhal Akyürek,et al.  Using MODIS snow cover maps in modeling snowmelt runoff process in the eastern part of Turkey , 2005 .

[4]  D. Lettenmaier,et al.  Assimilating remotely sensed snow observations into a macroscale hydrology model , 2006 .

[5]  Z. Pu,et al.  MODIS/Terra observed seasonal variations of snow cover over the Tibetan Plateau , 2007 .

[6]  R. Dickinson,et al.  Analysis of leaf area index products from combination of MODIS Terra and Aqua data , 2006 .

[7]  R. G. Crane,et al.  Satellite discrimination of snow/cloud surfaces , 1984 .

[8]  Hongjie Xie,et al.  Evaluation of MODIS snow cover and cloud mask and its application in Northern Xinjiang, China , 2008 .

[9]  Richard Fernandes,et al.  Validation of VEGETATION, MODIS, and GOES + SSM/I snow‐cover products over Canada based on surface snow depth observations , 2003 .

[10]  N. DiGirolamo,et al.  MODIS snow-cover products , 2002 .

[11]  Jan M. H. Hendrickx,et al.  Statistical evaluation of remotely sensed snow-cover products with constraints from streamflow and SNOTEL measurements , 2005 .

[12]  D. Hall,et al.  Development of methods for mapping global snow cover using moderate resolution imaging spectroradiometer data , 1995 .

[13]  D. Hall,et al.  Accuracy assessment of the MODIS snow products , 2007 .

[14]  J. Dozier.  Spectral Signature of Alpine Snow Cover from the Landsat Thematic Mapper , 1989 .

[15]  Dan Tarpley,et al.  Mapping and monitoring of the snow cover fraction over North America , 2003 .

[16]  G. Gesell,et al.  An algorithm for snow and ice detection using AVHRR data An extension to the APOLLO software package , 1989 .

[17]  Günter Blöschl,et al.  Spatio‐temporal combination of MODIS images – potential for snow cover mapping , 2008 .

[18]  Matthew Rodell,et al.  Updating a Land Surface Model with MODIS-Derived Snow Cover , 2004 .

[19]  Andrew G. Klein,et al.  Validation of daily MODIS snow cover maps of the Upper Rio Grande River Basin for the 2000–2001 snow year , 2003 .

[20]  Andreas Stoffel,et al.  Synergy of in situ and space borne observation for snow depth mapping in the Swiss Alps , 2007, Int. J. Appl. Earth Obs. Geoinformation.

[21]  Dennis P. Lettenmaier,et al.  Evaluation of the snow‐covered area data product from MODIS , 2003 .

[22]  A. Gruen,et al.  Operational snow mapping using multitemporal Meteosat SEVIRI imagery , 2007 .

[23]  Mark A. Templin,et al.  Validation of the MODIS snow product and cloud mask using student and NWS cooperative station observations in the Lower Great Lakes Region , 2006 .