May 15, 2014

POINT OF CONTACT

Principle investigator:
     Kirk L. Clawson
     NOAA Air Resources Laboratory Field Research Division
     1750 Foote Dr.
     Idaho Falls, ID 83402
     Kirk.Clawson@noaa.gov
     (208) 526-2742

README.TXT - Description of Flux Station Data Files

The energy flux station is a permanent installation designed to measure how the shrub-steppe
habitat of the INL interacts with the global energy cycle. It has been operational since 2000. 
For PSB1 it provided an additional site for the evaluation of horizontal homogeneity as 
well as a means of determining energy balance. A suite of measurements were made on two 
separate towers at the flux station and in the soil subsurface.  Measurements of net 
radiation (Kipp&Zonen, NR-LITE-L), air temperature/RH (Visalia, HMP45C), barometric pressure 
(PTB101B), and solar radiation (LI-COR, LI200X-L) were made on one tripod tower.  A Gill 
Model 1210R3 sonic anemometer and an open path LI-7500 infrared gas analyzer (IRGA) are 
mounted on the other tripod tower. This tower was used to measure the fluxes of momentum, 
sensible heat, latent heat, and carbon dioxide.  The anemometer and IRGA are mounted at 
heights of 3.2 and 2.54 m, respectively.   The subsurface sensors made measurements of soil 
temperature (2 and 6 cm; Campbell Scientific, TCAV-L), soil moisture (2.5 cm; Campbell 
Scientific, CS616), and soil heat flux (8 cm; Hukseflux, HFP01SC). The soil heat flux plates 
represent varying degrees of vegetation cover. The energy flux station is located 
approximately 500 m NE of the command center (about 900 mNE of the release location).

The data from the energy flux station is being provided on an as is basis and caution is 
advised in use of the data. However, a similar set of quality assurance calculations as 
those described for the other ARLFRD sonic anemometers in SAGE 13 (see SonicReadme_ARLFRD)
were done for the Gill sonic anemometer and LICOR IRGA data. These were based on Vickers and 
Mahrt (1997) and Aubinet et al. (2000). The calculations were done for 30-minute records 
only. The calculated quality control parameters for the anemometer and IRGA are included in 
the processed data file below for reference although they have not been carefully reviewed. 
In particular, it is noted that the calculated number of “drops” is considered to be 
excessively high and might not be an accurate representation. In any case, the quality 
control parameters provided should be sufficient to screen the data for any obvious problems. 
No quality control review was performed on the soil temperature and heat flux measurements. Turbulence and fluxes measured at the flux station (FLX) sonic anemometer were compared with other sonic anemometer measurements in the study area (see individual IOP discussions).

Data from the energy flux station is provided in two files.
	
The first file that includes all of the measurements made on the first (non-sonic) tower 
and in the soil subsurface. This data file is in comma separated variable (CSV) format with 
fixed length fields.  The data record covers the month of October and provides 5-minute 
averages. The filename is ‘FluxStationPSB1_Tower1_October.CSV’.  The columns in the file are:

1. Year
2. Month
3. Day
4. Hour (MST)
5. Minute
6. Battery Voltage
7. Air Temperature at 2 m (deg C)
8. Relative Humidity at 2 m (%)
9. Solar Radiation (W/m^2)
10. Soil Temperature Location A at 2 cm (deg C)
11. Pressure (mb)
12. Net Radiation (W/m^2)
13. Soil Moisture, 2.5 cm (% by volume)
14. Soil Heat Flux, Plate 1, 8 cm (W/m^2)
15. Soil Heat Flux, Plate 2, 8 cm (W/m^2)
16. Soil Temperature Location B at 6 cm (deg C)
17. Soil Heat Flux, Plate 3, 8 cm (W/m^2)
18. Soil Heat Flux, Plate 4, 8 cm (W/m^2)

The second file (FluxStationPSB1_Tower2_October.csv) contains data processed from the 
sonic anemometer and LI-7500 IRGA and the associated calculated quality control parameters 
for 30-minute records for the month of October. Missing values are indicated by ‘-9999’. In 
the description below, a cycle refers to a single pass through a single record for the 
specified variable during the despiking process. The column headers are:

1. Record – ‘Gjjjhhmm’ where jjj = Julian day and hhmm is the start time of the 30-minute record
2. Sensible heat flux (J/s m^2), with rotation
3. Kinematic heat flux (m K/s), with rotation
4. Sensible heat flux (J/s m^2), 10% correction for non-orthogonal sonic axes
5. Kinematic heat flux (J/s m^2), 10% correction for non-orthogonal sonic axes
6. Sensible heat flux (J/s m^2), 10% correction for non-orthogonal sonic axes and sensor heating (Burba et al. 2008)
7. Latent heat flux (J/s m^2), with rotation
8. Latent heat flux (mmol/s m^2), with rotation
9. Latent heat flux (J/s m^2), 10% correction for non-orthogonal sonic axes and frequency loss
10. Latent heat flux (mmol/s m^2), 10% correction for non-orthogonal sonic axes and frequency loss
11. Latent heat flux (J/s m^2), 10% correction for non-orthogonal sonic axes, frequency loss, and sensor heating
12. Friction velocity u* (m/s), uncorrected
13. Friction velocity u* (m/s), with rotation
14. Friction velocity u* (m/s), corrected for non-orthogonal sonic axes
15. Friction velocity u* (m/s), rotated corrected for non-orthogonal sonic axes
16. z/L
17. z/L with rotation
18. U variance (m^2/s^2), uncorrected
19. V variance (m^2/s^2), uncorrected
20. W variance (m^2/s^2), uncorrected
21. U variance (m^2/s^2), with rotation
22. V variance (m^2/s^2), with rotation
23. W variance (m^2/s^2), with rotation
24. itS_flag1, stationarity flag for sensible heat flux
25. itS_flag2, stationarity flag for sensible heat flux
26. itS_flag3, stationarity flag for sensible heat flux
27. itL_flag1, stationarity flag for latent heat flux
28. itL_flag2, stationarity flag for latent heat flux
29. itL_flag3, stationarity flag for latent heat flux
30. itt_U, integral turbulence flag for wind
31. itt_T, integral turbulence flag for temperature
32. H2O conc, water vapor concentration (mmol/m^3)
33. Count, number of data points in half hour record
34. Flg_count, (‘0’ if 17900 < count < 18100, otherwise ‘1’)
35. Flgspk_w, (‘0’ if fraction of spikes in w < 0.5% for any single cycle, otherwise ‘1’)
36. Flgspk_u, (‘0’ if fraction of spikes in u < 0.5% for any single cycle, otherwise ‘1’)
37. Flgspk_v, (‘0’ if fraction of spikes in v < 0.5% for any single cycle, otherwise ‘1’)
38. Flgspk_t, (‘0’ if fraction of spikes in t < 0.5% for any single cycle, otherwise ‘1’)
39. Flgspk_h2o, (‘0’ if fraction of spikes in h2o < 0.5% for any single cycle, otherwise ‘1’)
40. Flgspk_co2, (‘0’ if fraction of spikes in co2 < 0.5% for any single cycle, otherwise ‘1’)
41. Spkcnt_w, cumulative number of spikes detected in w in ‘Loop_w’ cycles
42. Spkcnt_u, cumulative number of spikes detected in u in ‘Loop_u’ cycles
43. Spkcnt_v, cumulative number of spikes detected in v in ‘Loop_v’ cycles
44. Spkcnt_t, cumulative number of spikes detected in t in ‘Loop_t’ cycles
45. Spkcnt_h2o, cumulative number of spikes detected in h2o in ‘Loop_h2o’ cycles
46. Spkcnt_co2, cumulative number of spikes detected in co2 in ‘Loop_co2’ cycles
47. Loop_w, number of cycles through record to despike w (max=11)
48. Loop_u, number of cycles through record to despike u (max=11)
49. Loop_v, number of cycles through record to despike v (max=11)
50. Loop_t, number of cycles through record to despike t (max=11)
51. Loop_h2o, number of cycles through record to despike h2o (max=11)
52. Loop_co2, number of cycles through record to despike co2 (max=11)
53. W_skw, skewness in w
54. U_skw, skewness in U
55. V_skw, skewness in V
56. T_skw, skewness in T
57. H2O_skw, skewness in H2O
58. CO2_skw, skewness in CO2
59. W_kur, kurtosis in w
60. U_kur, kurtosis in U
61. V_kur, kurtosis in V
62. T_kur, kurtosis in T
63. H2O_kur, kurtosis in H2O
64. CO2_kur, kurtosis in CO2
65. Ampres_w, amplitude resolution test3 w
66. Ampres_u, amplitude resolution test3 u
67. Ampres_v, amplitude resolution test3 v
68. Ampres_t, amplitude resolution test3 t
69. Ampres_h2o, amplitude resolution test3 h2o
70. Ampres_co2, amplitude resolution test3 co2
71. Drops_w, drop test3 w
72. Drops_u, drop test3 u
73. Drops_v, drop test3 v
74. Drops_t, drop test3 t
75. Drops_h2o, drop test3 h2o
76. Drops_co2, drop test3 co2
77. W_mean_hts, haar transform test (soft flag)3 for mean w
78. U_mean_hts, haar transform test (soft flag)3 for mean u
79. V_mean_hts, haar transform test (soft flag)3 for mean v
80. T_mean_hts, haar transform test (soft flag)3 for mean T
81. H2O_mean_hts, haar transform test (soft flag)3 for mean h2o
82. CO2_mean_hts, haar transform test (soft flag)3 for mean co2
83. W_sd_hts, haar transform test (soft flag)3 for standard deviation w
84. U_sd_hts, haar transform test (soft flag)3 for standard deviation u
85. V_sd_hts, haar transform test (soft flag)3 for standard deviation v
86. T_sd_hts, haar transform test (soft flag)3 for standard deviation T
87. H2O_sd_hts, haar transform test (soft flag)3 for standard deviation h2o
88. CO2_sd_hts, haar transform test (soft flag)3 for standard deviation co2
89. W_mean_hth, haar transform test (hard flag)3 for mean w
90. U_mean_hth, haar transform test (hard flag)3 for mean u
91. V_mean_hth, haar transform test (hard flag)3 for mean v
92. T_mean_hth, haar transform test (hard flag)3 for mean T
93. H2O_mean_hth, haar transform test (hard flag)3 for mean h2o
94. CO2_mean_hth, haar transform test (hard flag)3 for mean co2
95. W_sd_hth, haar transform test (hard flag)3 for standard deviation w
96. U_sd_hth, haar transform test (hard flag)3 for standard deviation u
97. V_sd_hth, haar transform test (hard flag)3 for standard deviation v
98. T_sd_hth, haar transform test (hard flag)3 for standard deviation T
99. H2O_sd_hth, haar transform test (hard flag)3 for standard deviation h2o
100. CO2_sd_hth, haar transform test (hard flag)3 for standard deviation co2
101. W_abs, range test flag for w
102. U_abs, range test flag for u
103. V_abs, range test flag for v
104. T_abs, range test flag for t
105. H2O_abs, range test flag for h2o
106. CO2_abs, range test flag for co2
107. RSE_t, relative systematic flux sampling error test value3 for t
108. RSE_h2o, relative systematic flux sampling error test value3 for h2o
109. RSE_co2, relative systematic flux sampling error test value3 for co2
110. RSE_tflg, relative systematic flux sampling error test flag for t 
(‘0’ = pass, ‘1’=fail at test=0.25)
111. RSE_h2oflg, relative systematic flux sampling error test flag for h2o
112. RSE_co2flg, relative systematic flux sampling error test flag for co2
113. RFE_t, relative random flux sampling error test value3 for t
114. RFE_h2o, relative random flux sampling error test value3 for h2o
115. RFE_co2,relative random flux sampling error test value3 for co2
116. RFE_tflg, relative random flux sampling error test flag for t 
(‘0’ = pass, ‘1’=fail at test=0.25)
117. RFE_h2oflg, relative random flux sampling error test flag for h2o
118. RFE_co2flg, relative random flux sampling error test flag for co2
119. RN_t, mesoscale flux trends test value3 for t
120. RN_h2o, mesoscale flux trends test value3 for h2o
121. RN_co2, mesoscale flux trends test value3 for co2
122. RN_tflg, flux trends test flag for t (‘0’ = pass, ‘1’=fail at test=0.25)
123. RN_h2oflg, flux trends test flag for h2o
124. RN_co2flg, flux trends test flag for co2
125. RNU_flg, alongwind relative nonstationarity test3 flag (‘0’=pass, ‘1’=fail at test=0.5)
126. RNV_flg, crosswind relative nonstationarity test3 flag
127. RNS_flg, vector wind relative nonstationarity test3 flag

References

Aubinet,M., Grelle,A., Ibrom,A., Rannik,U., Moncrieff,J., Foken,T., Kowalski,A.S.,
Martin,P.H., Berbigier,P., Bernhofer,C., Clement,R., Elbers,J., Granier,A., 
Grunwald,T., Morgenstern,K., Pilegaard,K., Rebmann,C., Snijders, W., Valentini,R.,
and Vesala,T. (2000) Estimates of the annual net carbon and water exchange of forests: 
the EUROFLUX methodology. Advances in Ecological Research, vol.30, p. 113-175.

Burba,G.G., McDermitt,D.K., Grelle,A.C., Anderson,D.J., and Xu,L. (2008) Addressing the
influence of instrument surface heat exchange on the measurements of CO2 flux from
open-path gas analyzers. Global Change Biology, vol. 14, p. 1854-1876.

Vickers, D., and Mahrt, L., (1997), Quality control and flux sampling problems for tower
and aircraft data. J. Atmos. Oceanic Technol., v. 14, p. 512-526.


