Vol10 No.5: 812-823
【Title】Validation of Global Land Surface Satellite (GLASS) Downward Shortwave Radiation Product in the Rugged Surface
【Author】JIN Hua-an1, LI Ai-nong1*, BIAN Jin-hu1, ZHANG Zheng-jian1, HUANG Cheng-quan2, LI Meng-xue2
【Addresses】 1 Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China; 2 Department of Geographical Sciences, University of Maryland, College Park, MD 20742, USA
【Citation】JIN Hua-an, LI Ai-nong1, BIAN Jin-hu, ZHANG Zheng-jian, HUANG Cheng-quan, LI Meng-xue (2013) Validation of Global Land Surface Satellite (GLASS) Downward Shortwave Radiation Product in the Rugged Surface. Journal of Mountain Science 10(5): 812-823. DOI: 10.1007/s11629-013-2543-6
【Abstract】The downward shortwave radiation (DSR) is an essential parameter of land surface radiation budget and many land surface models that characterize hydrological, ecological and biogeochemical processes. The new Global LAnd Surface Satellite (GLASS) DSR datasets have been generated recently using multiple satellite data in China. This study investigates the performances of direct comparison approach, which is mostly used for validation of surface insolation retrieved from satellite dataover the plain area, and indirect comparison approach, which needs a fine resolution map of DSR as reference, for validation of GLASS DSR product in time-steps of 1 and 3 hours over three Chinese Ecosystem Research Network sites located in the rugged surface. Results suggest that it probably has a large uncertainty to assess GLASS DSR product using the direct comparison method between GLASS surface insolation and field measurements over complex terrain, especially at Mt. Gongga 3,000 m station with root mean square error of 279.04 and 229.06 W/m2 in time-steps of 1 and 3 hours, respectively. Further improvement for validation of GLASS DSR productin the rugged surface is suggested by generation of a fine resolution map of surface insolation and comparison of the aggregated fine resolution map with GLASS product in the rugged surface. The validation experience demonstrates that the GLASS DSR algorithm is satisfactory with determination coefficient of 0.83 and root mean square error of 81.91W/m2 over three Chinese Ecosystem Research Network sites, although GLASS product overestimates DSR compared to the aggregated fine resolution map of surface insolation.
【Keywords】Downward shortwave radiation; Validation; Complex terrain