The influence of surface roughness and turbulence on heat fluxes from an oil palm plantation in Jambi, Indonesia

[摘要] Oil palm plantations are expanding vastly in Jambi, resulted in altered surface roughness and turbulence characteristics, which may influence exchange of heat and mass. Micrometeorological measurements above oil palm canopy were conducted for the period 2013-2015. The oil palms were 12.5 years old, canopy height 13 meters and 1.5 years old canopy height 2.5 m. We analyzed the influence of surface roughness and turbulence strenght on heat (sensible and latent) fluxes by investigating the profiles and gradient of wind speed, and temperature, surface roughness (roughness length, zo, and zero plane displacement, d), and friction velocity u∗. Fluxes of heat were calculated using profile similarity methods taking into account atmospheric stability calculated using Richardson number Ri and the generalized stability factor ζ. We found that roughness parameters (zo, d, and u∗) directly affect turbulence in oil palm canopy and hence heat fluxes; they are affected by canopy height, wind speed and atmospheric stability. There is a negative trend of d towards air temperature above the oil palm canopy, indicating the effect of plant volume and height in lowering air temperature. We propose studying the relation between zero plane displacement d with a remote sensing vegetation index for scaling up this point based analysis.

[发布机构] Agrometeorology Division, Department of Geophysics and Meteorology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University (IPB), Darmaga Campus, Indonesia^1;University of Goettingen, Faculty of Forest Sciences, Büsgenweg 2, Göttingen; 37077, Germany^2;University of Granada, Department of Ecology, Avda. Fuente Nueva s/n, Granada; 18071, Spain^3

[效力级别] 生态环境科学

[关键词] Atmospheric stability;Generalized stability factors;Micrometeorological measurements;Oil palm plantations;Profile similarities;Roughness parameters;Turbulence characteristics;Zero-plane displacement