Open AccessBasic characteristics of canopy turbulence in a homogeneous rice paddy
Author(s) -
Hong Jinkyu,
Kim Joon,
Miyata Akira,
Harazono Yoshinobu
Publication year - 2002
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2002jd002223
Subject(s) - canopy , turbulence , atmospheric sciences , kurtosis , environmental science , skewness , eddy covariance , meteorology , physics , ecosystem , mathematics , ecology , statistics , biology
To assess the interactions of key ecosystems with the overlying atmosphere, it is fundamental to understand the turbulence structure within and above their canopies. Rice is a staple crop particularly in Asia, and, yet, information on canopy turbulence of this vital food resource is limited by the scarcity of field measurement. The purpose of this study was to examine whether rice canopy shows an organized turbulence structure and, if so, whether such coherent structure scales to the patterns found in other canopies. Using the field data obtained during the 1996 International Rice Experiment (IREX96), we computed turbulence statistics such as mean, standard deviation, covariance, skewness, kurtosis, and turbulence length scales. When appropriately scaled with canopy height and friction velocity, these turbulence statistics showed coherent structures, which agreed well within the ranges of those reported for other canopies. Both quadrant and spectrum analyses confirmed that the intermittent and energetic eddies with length scale of the order of canopy height dominated the transfer processes within and above rice canopy. Such results were further substantiated by the countergradient fluxes observed during the IREX96. Furthermore, within‐canopy turbulence became more intermittent under stable conditions.