Monin-Obukhov(M-O)similarity theory is an important theoretical basis of the study of the atmospheric surface layer turbulence.Since the surface is always heterogeneous at different scales and in different degrees, temperature(T)is not similar to humidity(q).In order to investigate the dissimilarity of temperature and humidity at different scales and to further understand the turbulent transport process above Jinta Oasis farmland, the data for three heights(3.33,8.41,16.60 m)in sunny day from the“The Oasis System Energy and Water Cycle Field Experiment”over Jinta Oasis farmland was used, which was conducted from 23 May to 18 June in 2005.Firstly, the correlation coefficient of temperature and humidity for every 30-min runs was calculated.Secondly, the frequency distributions of |rTq| in different wind directions and different wind velocity,and the probability distributions of stability with different correlation coefficients for three heights in daytime were analyzed.Thirdly, the spectrum of the correlation coefficient and relative transfer efficiency with Fourier transform under six kinds of correlation coefficient cases(rTq > 0.6,0.3< rTq <0.6,0< rTq < 0.3,<-0.6,-0.6< rTq <-0.3,-0.3< rTq <0)and three kinds of stability conditions (unstable ζ <-0.05,near-neutral -0.05 < ζ <0.05,stable ζ > 0.05) were analyzed in the frequency domain.The results show that the scalar similarity is larger with the lower wind speed at the low level and with the wind speed is between 2 ~-4 m·s-1 at the top level.With the stability closing to near-neutral conditions, the scalar similarity is decreasing.RTq(n)and λn is approximately to a constant in the frequency domain 10-2 < n < 10-1 and 10-1 < n < 100,respectively.With the |rTq| decreasing, the corresponding peak frequency of RTq(n)is decreasing,and the relative transfer efficiency is also decreasing,i.e.,the transfer efficiency of water vapor is increasing,which are caused by the inhibition of heat advection of oasis-desert on heat transport.
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