Preliminary Analysis of Near-Surface Flux Data from Meteorological Gradient Observation Tower in Shenzhen

Eddy covariance system is the most common observation instrument for measuring turbulent transport flux near surface.Based on the eddy flux data observed by meteorological gradient pyramid in Shiyan Area of Shenzhen from September 2017 to February 2018, the near-surface momentum, sensible heat, latent heat and CO₂ fluxes in autumn and winter are analyzed, and the following conclusions are drawn. The diurnal variation of near-surface momentum fluxes is consistent in autumn and winter.In autumn, the sensible heat flux near surface is less than that in winter, but the latent heat flux is much larger in autumn, which causes the total heat flux to be larger in autumn than in winter. It may be related to the changes of underlying surface property, such as soil moisture. The daily average of CO₂ fluxes in autumn and winter is negative, indicating that this area is a carbon sink, and the negative value of CO₂ is lower in autumn, which may be related to the flourishing vegetation.