Description of flux data for WLEF in WLEFyyyy_flux.txt

Missing or invalid data is reported as -999. 
Time is recorded at the beginning of average period. 
The average interval is 60 minutes. 

Prepared by Chuixiang Yi on August 30, 2000. Modified by Chuixiang Yi to add the preferred latent and sensible heat fluxes to this file on September 28, 2001. If you find any problem please contact with Chuixiang Yi through cxyi@essc.psu.edu or call at 814-865-9617.

Column		Name		Description					Unit

1		year		year						year
2		month		month						month
3		day		day of month					day
4		LST		Local standard Time (CST)			hour
5		jday		Julian day					day
6		fjday		fractional Julian day				day
7		FCst_30m 	RCS* for CO2 below 30 m				(umol m-2 s-1)
8		FCst_122m	RCS* for CO2 below 122 m			(umol m-2 s-1)
9		FCst_396m	RCS* for CO2 below 396 m			(umol m-2 s-1)
10		FCtb_30m 	turbulence flux of CO2 at 30 m			(umol m-2 s-1)
11		FCtb_122m	turbulence flux of CO2 at 122 m			(umol m-2 s-1)
12		FCtb_396m	turbulence flux of CO2 at 396 m			(umol m-2 s-1)
13		neec_30m	neec_30m = FCst_30m + FCtb_30m			(umol m-2 s-1)
14		neec_122m	neec_122m = FCst_122m + FCtb_122m		(umol m-2 s-1)
15		neec_396m	neec_396m = FCst_396m + FCtb_396m		(umol m-2 s-1)
16		pref_neec	preferred neec***				(umol m-2 s-1)
17		pref_cflag	neec flag**
18		FQst_30m 	RCS* for H2O below 30 m				(W m-2)
19		FQst_122m	RCS* for H2O below 122 m			(W m-2)
20		FQst_396m	RCS* for H2O below 396 m			(W m-2)
21		FQtb_30m 	turbulence flux of H2O at 30 m			(W m-2)
22		FQtb_122m	turbulence flux of H2O at 122 m			(W m-2)
23		FQtb_396m	turbulence flux of H2O at 396 m			(W m-2)
24		neeq_30m	neeq_30m = FQst_30m + FQtb_30m			(W m-2)
25		neeq_122m	neeq_122m = FQst_122m + FQtb_122m		(W m-2)
26		neeq_396m	neeq_396m = FQst_396m + FQtb_396m		(W m-2)
27		pref_neeq	preferred neeq***				(W m-2)
28		pref_qflag	neeq flag**
29		FTst_30m 	RCS* for temperature below 30 m			(W m-2)
30		FTst_122m	RCS* for temperature below 122 m		(W m-2)
31		FTst_396m	RCS* for temperature below 396 m		(W m-2)
32		FTtb_30m 	turbulence flux of temperature at 30 m		(W m-2)
33		FTtb_122m	turbulence flux of temperature at 122 m		(W m-2)
34		FTtb_396m	turbulence flux of temperature at 396 m		(W m-2)
35		neet_30m	neet_30m = FTst_30m + FTtb_30m			(W m-2)
36		neet_122m	neet_122m = FTst_122m + FTtb_122m		(W m-2)
37		neet_396m	neet_396m = FTst_396m + FTtb_396m		(W m-2)
38		pref_neet	preferred neet***				(W m-2)
39		pref_qflag	neet flag**
40		Ust_30m		friction velocity at 30 m			(m s-1)
41		Ust_122m	friction velocity at 122 m			(m s-1)
42		Ust_396m	friction velocity at 396 m			(m s-1)


* RCS= the rate of change of a variable x storage, x is c for CO2, q for water vapor mixing ratio, 
t for temperature.

** -999. of flags denotes no data and the rest numbers indicate which level neex=FXst+FXtb is used. 
For example, 2 refers to 30 m; 4 refers to 122 m; 6 refers to 396 m; 5 refers to average for 122 m 
and 396 m levels.

*** Note for the preferred neex, x can be c (CO2), q (H2O) and t (temperature).
The flux values were computed from observations on the WLEF-TV transmitter tower. Because of the 
multiple-level and high-altitude flux and mixing ratio data, as well as a clearing around the base 
of the tower, an algorithm has been developed that selects one or more of the multiple net ecosystem 
exchange measurements for each hourly flux value.  Data are taken from 122 and 396 m under strongly 
unstable conditions(surface heat flux is larger than or equal 100 (W/m2)), and from 30m under slightly
unstable to stable conditions. If these preferred levels are missing, data is taken from any existing 
turbulent flux level. One and two missing holes are interpolated in preferred neex. The CO2 storage 
flux missing gap from 21 July to 17 August of 1999 was filled by monthly diurnal average taking 15-day 
data before and after the gap. In the FTst calculation, missing temperature data were filled  by Dr. 
Niall Hanan.