TY - JOUR
T1 - Surface conductance for evapotranspiration of tropical forests
T2 - Calculations, variations, and controls
AU - Tan, Zheng Hong
AU - Zhao, Jun Fu
AU - Wang, Guan Ze
AU - Chen, Meng Ping
AU - Yang, Lian Yan
AU - He, Chun Sheng
AU - Restrepo-Coupe, Natalia
AU - Peng, Shu Shi
AU - Liu, Xue Yan
AU - da Rocha, Humberto R.
AU - Kosugi, Yoshiko
AU - Hirano, Takashi
AU - Saleska, Scott R.
AU - Goulden, Michael L.
AU - Zeng, Jiye
AU - Ding, Fang Jun
AU - Gao, Fu
AU - Song, Liang
N1 - Funding Information:
This study was partly supported by the National Natural Science Foundation of China [grant number NSFC: 41771099 , 41861023 ], the C-Talent Project of Hainan University (to Zheng-Hong Tan) and the candidates of the Young and Middle Aged Academic Leaders of Yunnan Province [ 2019HB040 ].
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/9/15
Y1 - 2019/9/15
N2 - Tropical forests are responsible for the evaporation and transpiration of large quantities of water into the atmosphere annually. Surface conductance (gs) is a poorly understood phenomenon that plays a central role in regulating this evapotranspiration. We studied the calculations, variations, and environmental factors controlling gs based on eddy flux measurements from 10 tropical forest sites that covered a wide range of water gradients across continents. We found that boundary layer conductance (gb) is comparable with aerodynamic conductance for momentum (gaM) and thus, it should not be ignored in estimations of total aerodynamic conductance for water vapor (gaV). Based on the findings, we have made some recommendations for gaM estimation both with and without measurements of turbulence. The seasonal variation of gs is low in humid sites but large in sites with a dry season. A value of 24.8 ± 13.8 mm s−1 was suggested for maximum surface conductance (gsmax) for tropical forests. Both water vapor deficit (D) and radiation (Q) play an important role in controlling gs. The model driven by both D and Q could capture the diurnal variations of gs well and could be implemented in large-scale models in future. We believe the findings of this study could contribute substantially to our understanding of tropical forest gs.
AB - Tropical forests are responsible for the evaporation and transpiration of large quantities of water into the atmosphere annually. Surface conductance (gs) is a poorly understood phenomenon that plays a central role in regulating this evapotranspiration. We studied the calculations, variations, and environmental factors controlling gs based on eddy flux measurements from 10 tropical forest sites that covered a wide range of water gradients across continents. We found that boundary layer conductance (gb) is comparable with aerodynamic conductance for momentum (gaM) and thus, it should not be ignored in estimations of total aerodynamic conductance for water vapor (gaV). Based on the findings, we have made some recommendations for gaM estimation both with and without measurements of turbulence. The seasonal variation of gs is low in humid sites but large in sites with a dry season. A value of 24.8 ± 13.8 mm s−1 was suggested for maximum surface conductance (gsmax) for tropical forests. Both water vapor deficit (D) and radiation (Q) play an important role in controlling gs. The model driven by both D and Q could capture the diurnal variations of gs well and could be implemented in large-scale models in future. We believe the findings of this study could contribute substantially to our understanding of tropical forest gs.
KW - Boundary layer conductance
KW - Energy imbalance correction
KW - Jarvis stomata model
KW - Maximum surface conductance
KW - Penman–Monteith equation
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U2 - 10.1016/j.agrformet.2019.06.006
DO - 10.1016/j.agrformet.2019.06.006
M3 - Article
AN - SCOPUS:85066836462
SN - 0168-1923
VL - 275
SP - 317
EP - 328
JO - Agricultural and Forest Meteorology
JF - Agricultural and Forest Meteorology
ER -