Spatial variations in evapotranspiration over East Asian forest sites. I. Evapotranspiration and decoupling coefficient

  • Khatun Rehana
    Graduate School of Bioagricultural Sciences, Nagoya University
  • Ohta Takeshi
    Graduate School of Bioagricultural Sciences, Nagoya University
  • Kotani Ayumi
    Graduate School of Bioagricultural Sciences, Nagoya University
  • Asanuma Jun
    Terrestrial Environment Research Center, Tsukuba University
  • Gamo Minoru
    National Institute of Advanced Industrial Science and Technology
  • Han Shijie
    Institute of Applied Ecology, Chinese Academy of Sciences
  • Hirano Takashi
    Graduate School of Agriculture, Hokkaido University
  • Nakai Yuichiro
    Forestry and Forest Products Research Institute
  • Saigusa Nobuko
    National Institute for Environmental Studies
  • Takagi Kentaro
    Field Science Center for Northern Biosphere, Hokkaido University
  • Wang Huimin
    Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences
  • Yoshifuji Natsuko
    Graduate School of Agriculture, Kyoto University

Description

Evapotranspiration (ET) is not only a vital component of water budget, but also plays an important role in the energy budget of the earth-atmospheric system, ultimately driving many regional and global scale climatological processes. This paper describes the ET characteristics and factors controlling ET across the 17 forest sites in East Asia (2°S to 64°N latitude). ET was measured using the eddy covariance technique at each site. Daytime dry-canopy data for the growing season were used in this study. Growing season mean ET gradually decreased as latitude increased, with a range of 4.4 to 1.2 mm d−1. The growing season mean decoupling coefficient (Ω) ranged from 0.42 to 0.11 across the studied sites. At low-latitude forest sites, Ω was close to 0.50, indicating that the bulk surface was partially decoupled from the atmosphere and ET was strongly controlled by net radiation and vapour pressure deficit. At high-latitude forest sites, Ω was low (∼0.12), indicating that the bulk surface was well coupled to the atmosphere and ET was mainly controlled by surface conductance. The value of Ω was determined mainly by the ratio of aerodynamic conductance to surface conductance across the studied forests of East Asia.<br>

Journal

  • Hydrological Research Letters

    Hydrological Research Letters 5 83-87, 2011

    Japan Society of Hydrology and Water Resources (JSHWR) / Japanese Association of Groundwater Hydrology (JAGH) / Japanese Association of Hydrological Sciences (JAHS) / Japanese Society of Physical Hydrology (JSPH)

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Details 詳細情報について

  • CRID
    1390282680265460736
  • NII Article ID
    130002125899
  • DOI
    10.3178/hrl.5.83
  • ISSN
    18823416
  • Text Lang
    en
  • Data Source
    • JaLC
    • Crossref
    • CiNii Articles
    • KAKEN
    • OpenAIRE
  • Abstract License Flag
    Disallowed

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