Ch inafl UX CO 2. ( ChinaFLUX), AmeriFLUX EUROFLUX A siaflux. Vol110, No15 Oct1, 2008 GEO2INFORMATION SC IENCE , ), MATLAB.

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1 GEO2INFORMATION SC IENCE Vol110, No15 Oct1, 2008 Ch inafl UX CO 2 1, 2, 1, 1, 3, 1, 1, 1, 1, 1 (1, ; 2, ; 3, ) : CO 2, CO 2, MATLAB, GU I,, (ChinaFLUX) 30m in CO 2, /,, ChinaFLUX : ; ChinaFLUX; MATLAB; 1,,,,,, / (QA /QC),,, [ 1 5 ], AmeriFLUX EUROFLUX A siaflux, [ 6 12 ],,,, ED IS2 OL, Bayreuth TK2, CarbonEurope PE2WAVE [ ],,,, ( ChinaFLUX),,,, ( 30 CO 2 ), MATLAB, GU I,,, : ; : : ( ), (CERN ) : ( ),, E2mail: sp ring_ lee@ hotmail1com

2 ChinaFLUX AmeriFLUX EuroFLUX A siaflux, 30m in,, CO 2, CO 2 ( 1),, / (QA /QC), u 3 ChinaFLUX FLUXNET [ 1, 4, ] 1 ChinaFLUX Fig1 1 Flow of ChinaFLUX data p rocessing 211,, 30m in,, CO 2, 30m in CO 2 (N EE) : N EE = F c + F c_ W PL + F s (1), F c, F c_ W PL W PL, F s (1),, 0, [ 1, ] B C D, A = B CD,, u v w = A T u m v m w m (2) u v w, m, T CO 2 F c =w c, w (m s - 1 ), c CO 2 (mg m - 3 ), (2) W PL

3 5 : ChinaFLUX CO CO 2, W ebb2pearman2leuning (W PL), CO 2 [ 1, ] : F c_ W PL = m a c w v + (1 + m a v ) c m v a m v a T w T (3), CO 2, a c v CO 2 (mg m - 3 ) ; m a m v ( g mol - 1 ) ; (3) T ( K), CO 2,, ( F s ) N EE [ 1, ] CO 2 F s : F s = ( c / t) h (4), c CO 2 (mgco 2 m - 3 s - 1 ), t (1800 s), h (m) 212 / ( QA /QC) CO 2, u 3 :,,, : CO 2, - 3 3mg m - 2 s - 1,, :,,, [ 16 ],, d i = (N EE i - N EE i - 1 ) - (N EE i N EE i ) ( i = 1, 2,, ), d i i, M d + ( z MAD ) > d i > M d - ( z MAD ) (5), M d N EE ; MAD =m edian ( d i - M d ) ; z, z, z u 3 :,, u 3 ( u 3 N EE ) [ 17 ] u 3, N EE u 3 [ ],, u 3, u 3 u 3 [ 16 ], 6, 20 u 3, 99%, u 3 u 3 ( r < 014) u 3 u 3 6 u 3 213,,,, [ 2, 3 ],

4 [ 6, 10, 24 ],,, : (, 4 15 ) 7 14 [ 1 3 ] : X h, k = X h, k = ( i- n /2,, i+n /2) (6), h ( = 1,, 48), i = n,, ( d - n + 1), n,, d, k : ( ) N EE,, N EE N EE : N EE, N EE M ichaelis2menten [ 1 3 ] : N EE = Q PPFD F GPP, sat - F + R E, day (7) Q PPFD F GPP, sat, Q PPFD ( mol m - 2 s - 1 ),, F GPP, sa t, F R E, day ( molco 2 m - 2 s - 1 ), L loyd & Taylor [ 1 3 ] :, F R E, n igh t = F R E, T ref e [ E 0 (1 / ( T ref - T 0 ) - 1 / ( T K - T 0 ) ) ] (8) F R E, n igh t, N EE; T ref ( K) ; F R E, T ref T ref ; T 0 ( K) ; T K ( K) E 0 F R E, T ref, Sm ish M isterlich A rrhenius Van t Hoff [ 1 ], N EE, :, MATLAB, ;, Reichstein [ 21 ], E 0 L loyd & Tay2 lor, R ref 214 N EE R e ( ) GEE ( ) GEE R e N EE, 30m in, GEE R e,, R e N EE,,,,, N EE R e GEE;,, Re =N EE [ 1, 19, 25, 26 ] 30m in, N EE R e GEE, ( g C m - 2 ) 3 311,,, (1) : Chin2 aflux ChinaFLUX ORACLE, ODBC,

5 5 : ChinaFLUX CO ( ) 4 ; (, ) 3 ( ),, ;, ( 3) Excel (2) QA /QC, ( 2) W PL u 3,,,, 3, Fig13 Gap filling of m issing data,,, N EE, 30m in GEE R e,, 30m in (3) (4),,,,, N EE GEE Re,,,, ( MATLAB 4, ) N EE ; MDV, 2 Fig12 Account of flow flux and QA /QC 4 Fig14 D isp lay of the result

6 , MATLAB,,,, MATLAB lsqcurvefit, MATLAB,,,, 312, V isual Basic /C + +, Java, Matlab, Matlab AP I, ( inv) ( size),, Matlab GU I,, [ 27 ] (1) GU I MATLAB 6, GU I W indows,, Matlab, GU I GU I 1fig 1m, (2) MATLAB MATLAB, MATLAB MATLAB, ( SQL ),, O ra2 cle, Sybase, M icrosoft SQL Server Inform ix, ChinaFLUX ORACLE, ODBC, (3) MATLAB MATLAB, 4 CO 2, ChinaFLUX , ( ) N EE GEE 2003 CO 2,, 39m 2003 ( 5 ), 5cm ( 6), N EE CO Fig15 Downloading data 6 Fig16 Choosing meteorological data

7 5 : ChinaFLUX CO CO 2 W PL ( 39m ) N EE, N EE ( [ ] ) ( Z = 515, 13 ) u 3 ( u ) 7-9 N EE Fig19 Final result of N EE, N EE GEE R e 10 N EE R e GEE gC m - 2 y gC m - 2 y gC m - 2 y - 1 [ 19, 25, 26, 28 ] 7 N EE Fig17 N EE after QA /QC ( 8) 5cm, M ichaelis2menten L loyd & Taylor N EE, ( 10, E , R ref 8 ) 9, Fig110 Flux data at 2003 Q ianyanzhou site,,, ( 11) 8 Fig18 Non2linear gap filling method 11 Fig111 Exp lanation of data p rocessing

8 MATLAB 711, GU I, ChinaFLUX, :, ; ChinaFLUX, ;, ;, MATLAB CO 2,,,, [ 1 ], 1. :, [ 2 ] Falge E, Baldocchi D D, O lson R, et al. Gap2filling strategies for defensible annual sum s of net ecosystem ex2 change. Agricultural and Forest Meteorology, 2001, (107) : [ 3 ] Falge E, Baldocchi D D, O lson R, et al. Gap2filling strategies for long2term energy flux data sets. Agricultural and ForestMeteorology, 2001, (107) : [ 4 ] A siaflux. g g g g [ 5 ] AubinetM, Grelle A. Estimates of the annual net carbon and water exchange of European forests: The EUROFLUX methodology. Advanced in Ecological Research, 2000, (30) : [ 6 ] Makoto Ooba, Takashi H irano. Comparisons of gap2filling methods for carbon flux dataset: A combination of a genet2 ic algorithm and an artificial neural network. Ecological Modelling, 2006, (198) : [ 7 ] H iroki Iwata, Yadvinder Malhi. Gap2filling measurements of carbon dioxide storage in trop ical rainforest canopy air2 space. Agricultural and Forest M eteorology, 2005, (132) : [ 8 ] J Ruppert, M M auder. Innovative gap2filling strategy for annual sum s of CO 2 net ecosystem exchange. Agricultural and ForestMeteorology, 2006, (138) : [ 9 ] Baldocchi D. A ssessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystem s: Past, p resent and future. Global Change B iology, 2003, (9) : [ 10 ] Dafeng Hui, Shiqiang W an, Bo Su, et al. Gap2filling m issing data in eddy covariance measurements using mul2 tip le imputation (M I) for annual estimations. Agricul2 tural and ForestMeteorology. 2004, (121) : [ 11 ],,. (ChinaFLUX). D, 2006, 36 ( ) : [ 12 ],,.. D, 2004, 34 ( ) : [ 13 ] http: / / gaia. agraria. unitus. it/ database / eddyp roc / [ 14 ] http: / /www. geos. ed. ac. uk / abs/ research /m icrom2 et/ edisol/ [ 15 ] http: / /www. bitoek. uni - bayreuth. de /mm / en / soft2 ware / software / software_ dl. php? id_ obj = [ 16 ],,. ChinaFLUX. D, 2004, 34 ( ) : [ 17 ],,.., 2007, 22 ( 8) : [ 18 ],,.., 2007, 28 (3) : [ 19 ],,.. D, 2006, 36 ( ) : [ 20 ],,.. D, 2004, 34 ( ) : [ 21 ] D Papale, M Reichstein E. Towards a more harmonized p rocessing of eddy covariance CO 2 fluxes: A lgorithm s and uncertainty estimation. B iogeosciences D iscuss, 2006, (3) : [ 22 ],,. ( China FLUX) CO 2. D, 2006, 36 ( ) : [ 23 ],,. / CO 2., 2004, 19 (4) : [ 24 ],,.

9 5 : ChinaFLUX CO ChinaFLUX CO 2. D, 2006, 36 ( I), [ 25 ],,.. D, 2006, 36 ( ) : [ 26 ],,.. D, 2006, 36 ( ) : [ 27 ] D1Hanselman, B1L ittlefield. MATLAB 7. :, [ 28 ],,. CO 2. D, 2004, 34 ( ) : The D esign and Applica tion of CO 2 Flux Da ta Processing System a t Ch inafl UX L I Chun 1, 2, HE Honglin 2, L IU M in 2, 3, SU W en 2, FU Yuling 2, ZHANG Leim ing 2, W EN Xuefa 2, YU Guirui 2 (1. Tianjin M eteorological B ureau, Tianjing , China; 2. Institute of Geographic Sciences and N atural Resources Research, CAS, B eijing , China; 3. N anjing N orm al U niversity College of Geographical Sciences, N anjing , China) Abstract: The standardized p rocessing of observed CO 2 flux data and issue of high grade data p roduct are the p re2 condition and foundation of researches at CO 2 Flux and its related field. However, there are a system of p roblem s when we p rocess these observed flux data, such as tedious p rocessing, unified m ethods and lag of p rocessing. In order to solve these p roblem s, we choose MATLAB as development toolkit. Through making a use of its powerful mathematical computation functions and visible GU I technology, and through making an integration of current flux data p rocessing methods, we developed the p rocessing system of observed flux data at ChinaFLUX w ith independ2 ent intellectual p roperty rights. The p rocessing object is to observe CO 2 flux data with half2hour interval. The main p rocessing step s included turbulent flux computation, quality control/ quality assurance of observed data, gap fill2 ing of m issing data, separation and computation of carbon flux exchange at different time scales and so on. On the basis of current researches at ChinaFLUX, we imp roved the algorithm s of abnormal data rejection, u 3 threshold determ ination and nonlinear gap 2filling method, which we considered to be op timal. The outputs of NEE, GEE and Re at Q ianyanzhou Flux Tower at ChinaFlux are gc m - 2 y - 1, gc m - 2 y - 1 and gc m - 2 y - 1, which are sim ilar to other research results. This system, with high automaticity and visual2 ization, can p rovide a valid p latform for p rocessing observed CO 2 flux data. Key words: p rocessing system of observed flux data; ChinaFLUX; MATLAB; standardization