SGP/PGS/C1 - Reprocessing User Notes

Precise Gas System (pgs) daily b1 files should have a dimension of 480, corresponding to a 
measurement every 3 minutes. Previously submitted files had a dimension of 481, the last 
time step of each individual file being mistakenly repeated.

• 90% confidence limit of co2ppm(co2ppm_se)
• Pressure of channel 2(pres2)
• reading of CO2 in mV(co2mv)
• reference CO2 reading in mV(ref)
• calibration coefficient 1 (quadratic fit)(coeff1)
• calibration coefficient 3 (quadratic fit)(coeff3)
• longitude of instrument tower(site_longitude)
• pressure inside the IRGA box measured by the pressure controller(pres_ctrlr)
• Temperature in refigerator(t_refrig)
• flow rate measured by the mass flow controller(flow_rate)
• calibration coefficient 2 (quadratic fit) 90% confidence limit(coeff2_se)
• p-value of co2 readings during the last 30sec of 3min period of raw data(co2mv_slope_pval)
• MFRSR channels(channel)
• Number of measurements for indicated channel(nmeas)
• calculated concentration of CO2(co2ppm)
• latitude of instrument tower(site_latitude)
• calibration coefficient 2 (quadratic fit)(coeff2)
• Second level of QC, see reject_flag_explanation global attribute(reject_flag)
• Pressure of channel 1(pres1)
• Date and time in alternate form(yyyymmddhhmmss)
• height of base of instrument tower(site_elevation)
• Slope of CO2 readings during last 30sec of 3min period of raw data(co2mv_slope)
• flag indicating which channel isotope sample was taken from(iso)
• base time(base_time)
• Pressure of channel 3(pres3)
• calibration coefficient 3 (quadratic fit) 90% confidence limit(coeff3_se)
• 90% confidence limint of co2mv_slope(co2mv_slope_se)
• temperature of the IRGA(t_irga)
• adjusted CO2(adj)
• r-squared of quadratic fit(r2)
• Pressure of channel 4(pres4)
• calibration coefficient 1 (quadratic fit) 90% confidence limit(coeff1_se)
• First level of QC, see warn_flag_explanation global attribute(warn_flag)
• standard deviation of co2mv(co2mv_se)

SGP/CO2FLX/C1 - Reprocess: Units

Mean CO2 density units are incorrectly labeled as umol m-3. Units should be labeled as 
mmol m-3.

• mean co2 concentration (c)(mean_c)

• mean co2 concentration (c)(mean_c)

• mean co2 concentration (c)(mean_c)

SGP/CO2FLX/C1 - Reprocessed: User Notes

Replacement of LI-200 sensor (total downwelling shortwave radiation, variable r_tot) by a 
new LI-190 sensor (upwelling photosynthetic photon flux density, variable ppfd_up).

The new LI-190 sensor was:
- installed on December 9, 2004. 
- being tested from December 9, 2004 to December 22, 2004.
- operational after December 22, 2004.

Consequently:
1. variable "r_tot" is filled with missing values (qc_r_tot = 1) after December 9, 2004,
2. variable "ppfd_up" is filled with missing values (qc_ppfd_up = 1) prior December 22, 
2004.

• photosynthetic photon flux density (PAR)(ppfd_up)
• total downwelling shortwave radiation (LI-200 sensor)(r_tot)

SGP/CO2FLX/C1 - downwelling longwave hemispheric irradiance incorrect

A problem was identified with the downwelling longwave hemispheric irradiance (variable 
"r_down_long_hemisp") calibration of our Kipp & Zonen CNR1 radiometer. The offset of the 
instrument is believed to be incorrect over the specified time frame, and a correction of 
the problem is underway.

• downwelling longwave hemispheric irradiance t_rad corrected(r_down_long_hemisp)

SGP/CO2FLX/C1 - Soil Temperature measurements

Current data quality check (qc) procedure does not catch spikes in soil temperature 
measurements. A new qc procedure is being tested and will improve the current procedure.

• average of two lower soil temperature sensors(mean_t_soil_lower)
• average of two middle soil temperature sensors(mean_t_soil_middle)
• average of two upper soil temperature sensors(mean_t_soil_upper)

SGP/PGS/C1 - Suspicious 2m data

KNF pump for 2m height (channel 1) started to leak on July 22, 2004 and sampled air was 
consequently "contaminated" by indoor air. The pump was replaced on August 19, 2005.

• 90% confidence limit of co2ppm(co2ppm_se)
• calculated concentration of CO2(co2ppm)

SGP/PGS/C1 - Updated files

Dew point temperature (dpt) sensor (Vaisala DMT 142) was added to the system on May 24, 
2005 to assess water trapping system efficiency. Consequently, variable "dpt" is filled 
with missing values (-999.99) prior measurements start date (May 24, 2005).

• 90% confidence limit of co2ppm(co2ppm_se)
• Pressure of channel 2(pres2)
• reading of CO2 in mV(co2mv)
• reference CO2 reading in mV(ref)
• calibration coefficient 1 (quadratic fit)(coeff1)
• calibration coefficient 3 (quadratic fit)(coeff3)
• longitude of instrument tower(site_longitude)
• pressure inside the IRGA box measured by the pressure controller(pres_ctrlr)
• Temperature in refigerator(t_refrig)
• flow rate measured by the mass flow controller(flow_rate)
• calibration coefficient 2 (quadratic fit) 90% confidence limit(coeff2_se)
• p-value of co2 readings during the last 30sec of 3min period of raw data(co2mv_slope_pval)
• MFRSR channels(channel)
• Number of measurements for indicated channel(nmeas)
• calculated concentration of CO2(co2ppm)
• latitude of instrument tower(site_latitude)
• calibration coefficient 2 (quadratic fit)(coeff2)
• Second level of QC, see reject_flag_explanation global attribute(reject_flag)
• Pressure of channel 1(pres1)
• Date and time in alternate form(yyyymmddhhmmss)
• height of base of instrument tower(site_elevation)
• Slope of CO2 readings during last 30sec of 3min period of raw data(co2mv_slope)
• flag indicating which channel isotope sample was taken from(iso)
• base time(base_time)
• Pressure of channel 3(pres3)
• calibration coefficient 3 (quadratic fit) 90% confidence limit(coeff3_se)
• 90% confidence limint of co2mv_slope(co2mv_slope_se)
• temperature of the IRGA(t_irga)
• adjusted CO2(adj)
• r-squared of quadratic fit(r2)
• Pressure of channel 4(pres4)
• calibration coefficient 1 (quadratic fit) 90% confidence limit(coeff1_se)
• First level of QC, see warn_flag_explanation global attribute(warn_flag)
• standard deviation of co2mv(co2mv_se)

SGP/CO2FLX/C1 - downwelling longwave hemispheric irradiance incorrect

Downwelling longwave radiation measurements (variable "r_down_long_hemisp") are bad due to 
a wiring issue. Users should not use the downwelling longwave hemispheric irradiance 
during this period. The downwelling shortwave and longwave radiation at CF is also available 
from the Broadband Radiometer Station (BRS).

• downwelling longwave hemispheric irradiance t_rad corrected(r_down_long_hemisp)

SGP/CO2FLX/C1 - Reprocess: 4m instruments height

The height of the 4m instruments is 4.8 m and not 4.65 m as shown in b1 datastream

• height of instument from tower base(zm)