运用OLS线性回归和计算EBR能量平衡比率的方法,以当雄草原站2003~2005年的通量数据为基础,对西藏高寒草原的能量平衡闭合状况进行了研究。研究结果表明,当雄草原站存在着能量不完全闭合的现象,OLS线型回归斜率偏低。生长季能量闭合状况好于非生长季,白天好于夜晚,晴天好于阴天和雨雪天气。随后对能量不闭合的原因进行了初步分析。将潜热通量、显热通量以及土壤热通量的时间提前后,能量闭合程度提高。得出结论,由于热量传输速率的差别,在很大程度上影响了能量的闭合。其他原因如采样的误差与仪器的误差、高频和低频的损失、其他能量项的忽略、平流的损失,也造成了部分能量的不闭合。
Through adopting the means of OLS Linearity return and calculating EBR energy balance,and based on the three-year flux amount data of Damxung rangeland station,we conducted a research on the energy balance closure aiming at the Tibet Plateau alpine meadow.The results show that,there exists a phenomenon of in-complete closure of energy and the slope of OLS curve is relatively low.The closure condition of energy balance in growing season is better than that in non-growing season;day-time is better than night;fine day is better than windy,rainy or snowy days.Later on,we have an analysis on the reason in energy in-closure.When the time of latent heat fluxes,sensible heat fluxes and soil heat fluxes is advanced,the closure condition of energy balance is improved.We draw a conclusion that the difference in the rate of heat transference has a great impact on the energy balance closure.Other reasons as the deviations in samples and instrument,the loss of high frequency and low frequency,the ignorance of some energy item and loss of advection have also contributed to the in-closure of energy balance.
[1] Baldocch iD, Falge E, Gu, et a l. FLUXNET: A new tool to study the temporal and spatia l variab ility of ecosystem-scale carbon d ioxide, w ater vapor and en ergy flux den sit ies[J] . Bu ll. Am. Me teorol. Soc. , 2001, 82: 2415-2434.
[2] And erson D E, V erm a S B, Rosenb erg N J. Eddy correlationm easurem en ts ofCO2, latent h eat and sens ible heat fluxes o-ver a crop su rface[J]. B ound. -Lay. M eteorol. , 1984, 29: 263-272.
[3] W ilsonK, Goldstein A, et a l. En ergy balance closure at FLUXNET s ites[J]. Ag ricul tura l and F orestM eteorology, 2002, 113: 223-243.
[4] 李正泉, 于贵瑞, 等. 中国通量观测网络(Ch inaFLUX)能量平衡闭合状况的评价[J]. 中国科学D辑, 2004, 34(增刊 (): 46~ 56. [LI Zheng-qu an, YU Gui-ru,i et a l. En ergy balance closure at Ch inaFLUX sites. Science In C hina, S er. D Ea rth S ciences, 2005, 48(z1): 51-62.]
[5] 吴家兵, 关德新, 等. 东北阔叶红松林能量平衡特征[J]. 生态学报, 2004, 25 (10): 21～26. [WU Jia-b ing, GUAN De-x in, e t al. Characterist ic of the energy balan ce in b road-leaved K orean p in e forest of n orth eastern Ch ina. A cta E colog ica S inica, 2005, 25 (10): 21-26.]
[6] 刘允芬, 于贵瑞, 等. 红壤丘陵区人工林能量平衡闭合研究[J] . 林业科学, 2006, 42 (2): 13～20. [L IU Yun-fen, YU Gu i-ru,i et a l. Study on surface energy balance closure of a con iferous forest p lantation in red earth h il ly area. S cien tia Si l-vae S in icae, 2006, 42(2): 13-20.]
[7] 徐玲玲, 张宪洲, 等. 青藏高原高寒草甸生态系统净二氧化碳交换量特征[J] . 生态学报, 2005, 25 (8): 1948~ 1952. [XU L ing-ling, ZHANG X ian-zhou, e t al. Net ecosystem carbon d ioxid e exch ange of alp inem eadow in th eT ibetan Plateau from Augus t to O ctob er. A cta Ecologica S inica, 2005, 25 (8): 1948-1952.]
[8] M ahrt L. Flux sam pl ing errors for aircraft and tow ers[J]. A tm os. Ocean. T echnol. , 1998, 15: 416-429.
[9] Gu J, Sm ith E A, M erritt JD. Testing energy balan ce closu re w ithGOES-retrieved net rad iation and inm easu red eddy cor-relat ion fluxes in BOREAS [J]. J. Geophy s. R es. , 1999, 104 (D22): 27881-27893.
[10] S tann ard D I, B lanford JH, et al. Interpretation of su rface flux m easurem ents in heterogen eous terrain during the M on-soon% 90 experim ent[J] . W ater R esou r. R es. , 1994, 30(5): 1227-1239.
[11] Moncrieff JB, M ah liY, Leun ing R. The p ropagation of errors in long-term m easurem en ts of land-atm osphere fluxes of car-bon and w ater[J]. G lob. Change B iol. , 1996, 2: 231-240.
[12] M eek D W, PruegerH. Solu tions for th ree regression prob lem s comm on ly found inm eteorological data analys is[A] . In: Proceed ings of the 23rd Con ference on Agricu lturalForestM eteorology[C] . Am ericanM eteorological Society, A lbuquer-que, NM, Novem ber 2-6, 1998. 141-145.
[13] VanLoonW K P, BastingsHM H, MoorsE J. C alib ration of soil heat flux sen sors[J] . Ag ric. F or. M eteorol. , 1998, 92: 1-8.
[14] Mayocch i C L, B ristow K L. Soil su rface heat f lux: som e general questions and comm en ts onm easurem en ts[J] . Ag ric. F or. Me teorol. , 1995, 75: 43-50.
[15] Moore C J, Fisch G. E stim ating heat storage in Am azonian trop ical forest[J]. Ag ric. F or. M e teorol. , 1986, 38: 147-169.
[16] Leun ing R, JuddM J. The relat ive m erits of op en and closed path analyses for m easu rem en t of eddy f luxes[J] . G lobal Change B iology 2, 1996: 241-253.
[17] Paw U K T, Ba ldocch iD D, e t al. Corrections of eddy covariance m easu rem en ts incorporat ing both advect ive ef fects and den sity fluxes[J] . Bound.-Lay. M eteorol. , 1997: 487-511.
[18] M cM illen R T. An eddy correlation techn ique w ith extended app licab ility to non-s im ple terra in[J] . Bound. -L ay. M eteo-rol. , 1988, 43: 231-245.
