Japan Geoscience Union Meeting 2016

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International Session (Oral)

Symbol A (Atmospheric and Hydrospheric Sciences) » A-CG Complex & General

[A-CG10] Earth and Planetary satellite observation projects Part II: Satellite Earth Environment Observation

Tue. May 24, 2016 10:45 AM - 12:15 PM 303 (3F)

Convener:*Riko Oki(Japan Aerospace Exploration Agency), Tadahiro Hayasaka(Graduate School of Science, Tohoku University), Kaoru Sato(Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo), Masaki Satoh(Atmosphere and Ocean Research Institute, The University of Tokyo), Yoshiaki HONDA(Center for Environmental Remote Sensing, Chiba University), Kenlo Nasahara(Faculty of Life and Environmental Sciences, University of Tsukuba), Takashi Nakajima(Tokai University, School of Information Science & Technology, Dept. of Human & Information Science), Taikan Oki(Institute of Industrial Science, The University of Tokyo), Tsuneo Matsunaga(Center for Environmental Measurement and Analysis, National Institute for Environmental Studies), Yukari Takayabu(Atmosphere and Ocean Research Institute, the University of Tokyo), Hiroshi Murakami(Earth Observation Research Center, Japan Aerospace Exploration Agency), Hajime Okamoto(Kyusyu University), Gail Skofronick Jackson(NASA Goddard Space Flight Center), Paul Chang(NOAA College Park), David Crisp(Jet Propulsion Laboratory, California Institute of Technology), Chair:David Crisp(Jet Propulsion Laboratory), Tatsuya Yokota(National Institute for Environmental Studies)

11:15 AM - 11:30 AM

[ACG10-21] Satellite Retrieval of Overstory and Understory Leaf Area Index in High Northern Forests

*Wei Yang1, Hideki Kobayashi2, Kenlo Nishida Nasahara3 (1.Center for Environmental Remote Sensing, Chiba University, 2.Japan Agency for Marine-Earth Science and Technology, 3.University of Tsukuba)

Keywords:Satellite Remote Sensing, Leaf Area Index, Northern Forests

Leaf area index (LAI), defined as one-half the total green leaf are per unit of horizontal ground surface area, is a crucial input parameter for global carbon cycle modeling. Since carbon fixed through net primary productivity has different residence times for different components, the LAI for overstory and understory vegetation in forest ecosystems need to be treated differently in carbon cycle modeling. Currently, satellite remote sensing is the only feasible technique to measure the LAI at a continental and/or global scale over a long periods of multiple years. However, there are no existing satellite products that provide simultaneous estimation of overstory and understory leaf area index (LAIo and LAIu) at present. Consequently, we proposed an integrating look-up table (LUT) method to remotely estimate the LAIo and LAIu for boreal forests, where are encountering rapider temperature change than other areas. In the newly proposed method, the understory normalized vegetation difference index (NDVIu) is first retrieved from multiple satellite observations by using a semi-empirical method. Then the LAIu is estimated from the retrieved NDVIu through searching a LUT generated by radiative transfer simulation for understory vegetation. In order to estimate the LAIo, a new land-cover map of forest types, which classifies the boreal forests as low, medium and high types, is generated by using a wall-to-wall canopy height product to replace the conventional global land-cover maps. The LUTs containing angles, LAIu, LAIo, and corresponding reflectance at red and near-infrared bands are generated for each forest type by running a radiative transfer model. Specifically, the forest landscape parameters are determined by an empirical forest structure model. Moreover, the retrieved NDVIu is used as an ancillary information to constrain the relationship between LAIo and canopy reflectance. The validation results showed acceptable accuracy based on our filed measurement at interior Alaska, America.