Abstract: Based on the data from August 13^th to November 12^th, 2014, observed at Kizil Sue mountain ecological observatory in Kyrgyzstan, this research analyzed the day and month variation characteristics of the turbulent flux and the effective energy. Besides, this paper used two methods, difference value of energy balance(D)and the energy balance ratio(EBR), to analyze the energy closure of the study area and its month's variation characteristics. The geographical coordinates of the study area, which is located on the southeast of the Isser Lake, were 78.202°E, 42.191°N. The vegetation of the study area was the typical grassland, but there were some tall and dense forests around the study area. The types of the vegetation were complicated. And the study area was more typical. So analyzing the energy and material exchanging rule of the region was beneficial to the sustainable development of the water resources and the ecological environment of the region. Two tools including the eddy covariance technique and the auxiliary meteorological observation system were used for data collecting. The water and heat flux data and turbulent data were collected by the eddy covariance technique, while the data of the net radiation(R_n)and the soil heat flux were collected by the auxiliary meteorological observation system which collected the precipitation data at the same time. The precipitation data did be a standard for getting rid of the flux data. The results show that:the turbulent flux's and the effective energy's day variation characteristics presented unimodal pattern. The monthly mean values reduced evidently through months. Besides, the energy closure changed as the months changed. Through the observation of the energy balance in the study area from August 13^th, 2014 to November 11^th, 2014, we found that the area's energy was not closed, and the inaccurate calculation for the soil heat flux was one of the main factors that could lead the energy to imbalance. By the method of residual energy balance(D), we found that D was beyond 0 from 8∶00 to 16∶00 during the period of observation, the energy kept the balance at about 8∶00 and 16∶00. Through the method of the energy balance ratio(EBR), results show that the degree of energy balance was about 75% in the whole period of observation, and the best degree of energy balance was 0.85 in October, in August, it was 0.75, and 0.7 in September. The energy closure degree in this paper cloud be used as one standard of the regional carbon flux data evaluation, and thus could lay foundation for the study of regional carbon exchange in the future.

Key words: energy balance, latent heat flux, sensible heat flux, eddy covariance