Data Quality Reports for Session: 102641 User: bjharm Completed: 11/14/2006


TABLE OF CONTENTS

DQR IDSubjectData Streams Affected
D040217.2SGP/CO2/C1 - Reprocessing User Notessgp30co2flx4mC1.b1, sgp30co2flx25mC1.b1, sgp30co2flx60mC1.b1, sgp30co2flx4mmetC1.b1
D040217.3SGP/CO2/C1 - Reprocessing User Notessgp30co2flx4mmetC1.b1
D040505.5SGP/CO2/C1 - Longwave Radiation Incorrectsgp30co2flx4mmetC1.b1
D041026.1SGP/CO2/C1 - Reprocess: Unitssgp30co2flx4mC1.b1, sgp30co2flx25mC1.b1, sgp30co2flx60mC1.b1
D041103.1SGP/CO2/C1 - Mean CO2 density incorrect, CO2 flux suspectsgp30co2flx60mC1.b1
D050316.1SGP/CO2/C1 - Reprocessed: User Notessgp30co2flx4mmetC1.b1
D051116.2SGP/CO2/C1 - downwelling longwave hemispheric irradiance incorrectsgp30co2flx4mmetC1.b1
D051116.3SGP/CO2/C1 - Soil Temperature measurementssgp30co2flx4mmetC1.b1
D060107.1SGP/CO2/C1 - Reprocess: calibration errorsgp30co2flx4mC1.b1
D060510.1SGP/CO2/C1 - Met stand was movedsgp30co2flx4mmetC1.b1


DQRID : D040217.2
Start DateStart TimeEnd DateEnd Time
12/18/2002000002/17/20040000
Subject:
SGP/CO2/C1 - Reprocessing User Notes
DataStreams:sgp30co2flx4mC1.b1, sgp30co2flx25mC1.b1, sgp30co2flx60mC1.b1, sgp30co2flx4mmetC1.b1
Description:
Format Changes:
  To comply with archive standards, the name of the unlimited dimention variable in the 
cdf level b1 files was changed from 'record' to 'time'. This does not affect data quality.
Measurements:sgp30co2flx60mC1.b1:
  • height of tower base from sea level(site_elevation)
  • corrected sensible heat flux(h)
  • latitude of instument location(site_latitude)
  • mean value of IRGA pressure(mean_p)
  • variance of variable c(var_c)
  • Date and time in alternate form(yyyydddhhmmss)
  • mean sonic temperature (t), i.e. virtual temperature(mean_t)
  • mean horizontal wind speed(mean_rot_u)
  • Time offset of tweaks from base_time(time_offset)
  • variance of variable q(var_q)
  • rotated variance v(var_rot_v)
  • fractional day of the year(doy)
  • Vertical angle of wind(phi)
  • rotated variance w(var_rot_w)
  • Monin-Obukhov length scale(Lmoni)
  • rotated variance u(var_rot_u)
  • Unit Vector Wind Direction(wdir)
  • friction velocity(ustar)
  • additive WPL LE correction to c flux(fc_wpl_le)
  • additive WPL H correction to c flux(fc_wpl_h)
  • Time offset from base_time(base_time)
  • rotation to zero w(theta)
  • longitude of instument location(site_longitude)
  • mean co2 concentration (c)(mean_c)
  • height of instument from tower base(zm)
  • variance of variable t(var_t)
  • WPL corrected CO2 flux(fc_corr)
  • mean water vapor concentration (q)(mean_q)
  • WPL corrected latent heat flux(le)

sgp30co2flx4mC1.b1:
  • mean value of IRGA pressure(mean_p)
  • variance of variable c(var_c)
  • variance of variable t(var_t)
  • WPL corrected latent heat flux(le)
  • mean horizontal wind speed(mean_rot_u)
  • Vertical angle of wind(phi)
  • Monin-Obukhov length scale(Lmoni)
  • variance of variable q(var_q)
  • height of instument from tower base(zm)
  • longitude of instument location(site_longitude)
  • additive WPL LE correction to c flux(fc_wpl_le)
  • mean sonic temperature (t), i.e. virtual temperature(mean_t)
  • mean water vapor concentration (q)(mean_q)
  • corrected sensible heat flux(h)
  • additive WPL H correction to c flux(fc_wpl_h)
  • Date and time in alternate form(yyyydddhhmmss)
  • Unit Vector Wind Direction(wdir)
  • mean co2 concentration (c)(mean_c)
  • rotated variance w(var_rot_w)
  • Time offset from base_time(base_time)
  • rotated variance u(var_rot_u)
  • rotated variance v(var_rot_v)
  • rotation to zero w(theta)
  • WPL corrected CO2 flux(fc_corr)
  • latitude of instument location(site_latitude)
  • Time offset of tweaks from base_time(time_offset)
  • friction velocity(ustar)
  • height of tower base from sea level(site_elevation)
  • fractional day of the year(doy)

sgp30co2flx25mC1.b1:
  • Time offset from base_time(base_time)
  • Monin-Obukhov length scale(Lmoni)
  • WPL corrected latent heat flux(le)
  • variance of variable t(var_t)
  • rotated variance u(var_rot_u)
  • Date and time in alternate form(yyyydddhhmmss)
  • rotated variance v(var_rot_v)
  • Vertical angle of wind(phi)
  • Unit Vector Wind Direction(wdir)
  • longitude of instument location(site_longitude)
  • latitude of instument location(site_latitude)
  • WPL corrected CO2 flux(fc_corr)
  • height of instument from tower base(zm)
  • variance of variable q(var_q)
  • friction velocity(ustar)
  • variance of variable c(var_c)
  • additive WPL LE correction to c flux(fc_wpl_le)
  • mean value of IRGA pressure(mean_p)
  • rotated variance w(var_rot_w)
  • mean sonic temperature (t), i.e. virtual temperature(mean_t)
  • fractional day of the year(doy)
  • mean co2 concentration (c)(mean_c)
  • rotation to zero w(theta)
  • mean horizontal wind speed(mean_rot_u)
  • height of tower base from sea level(site_elevation)
  • corrected sensible heat flux(h)
  • additive WPL H correction to c flux(fc_wpl_h)
  • mean water vapor concentration (q)(mean_q)
  • Time offset of tweaks from base_time(time_offset)

sgp30co2flx4mmetC1.b1:
  • average of four lower soil moisture sensors(mean_m_soil_lower)
  • standard error of mean_t_soil_middle note maximum of two values used in
    calculation(stderr_mean_t_soil_middle)
  • average of two middle soil temperature sensors(mean_t_soil_middle)
  • Time offset of tweaks from base_time(time_offset)
  • corrected sensible heat flux(h)
  • additive WPL H correction to c flux(fc_wpl_h)
  • rotated variance v(var_rot_v)
  • precipitation accumulated between outputs, 3-hr accumulation(precip)
  • additive WPL LE correction to c flux(fc_wpl_le)
  • rotated variance u(var_rot_u)
  • rotation to zero w(theta)
  • standard error of mean_t_soil_lower note maximum of two values used in
    calculation(stderr_mean_t_soil_lower)
  • fractional day of the year(doy)
  • WPL corrected CO2 flux(fc_corr)
  • depth of soil heat flux probes(z_g_soil)
  • height of radiation instruments(zrad)
  • net solar radiation (NR-lite)(r_net)
  • depth of lower m soil probesp(z_m_soil_lower)
  • standard error of mean_m_soil_upper(stderr_mean_m_soil_upper)
  • mean co2 concentration (c)(mean_c)
  • height of lower RH/T sensor(z_lower)
  • Date and time in alternate form(yyyydddhhmmss)
  • mean water vapor concentration (q)(mean_q)
  • variance of variable c(var_c)
  • depth of middle t soil probesm(z_t_soil_middle)
  • height of instument from tower base(zm)
  • photosynthetic photon flux density (PAR)(ppfd)
  • barometric pressure(bar_pres)
  • upwelling longwave hemispheric irradiance t_rad corrected(r_up_long_hemisp)
  • latitude of instument location(site_latitude)
  • mean air temperature, upper level(t_air_upper)
  • average of two lower soil temperature sensors(mean_t_soil_lower)
  • Unit Vector Wind Direction(wdir)
  • standard error of mean_t_soil_upper note maximum of two values used in
    calculation(stderr_mean_t_soil_upper)
  • mean horizontal wind speed(mean_rot_u)
  • mean sonic temperature (t), i.e. virtual temperature(mean_t)
  • upwelling shortwave hemispheric irradiance t_rad corrected(r_up_short_hemisp)
  • mean relative humidity, lower level(rh_lower)
  • mean air temperature, lower level(t_air_lower)
  • rotated variance w(var_rot_w)
  • WPL corrected latent heat flux(le)
  • mean value of IRGA pressure(mean_p)
  • downwelling shortwave hemispheric irradiance t_rad corrected(r_down_short_hemisp)
  • friction velocity(ustar)
  • Time offset from base_time(base_time)
  • height of upper RH/T sensor(z_upper)
  • height of tower base from sea level(site_elevation)
  • variance of variable q(var_q)
  • standard error of mean_g_soil(stderr_mean_g_soil)
  • radiometer body temperature (for longwave correction)(t_rad)
  • longitude of instument location(site_longitude)
  • variance of variable t(var_t)
  • downwelling longwave hemispheric irradiance t_rad corrected(r_down_long_hemisp)
  • average of four upper soil moisture sensors(mean_m_soil_upper)
  • average of up to four soil heat flux sensors(mean_g_soil)
  • total downwelling shortwave radiation (LI-200 sensor)(r_tot)
  • depth of upper t soil probesm(z_t_soil_upper)
  • depth of upper m soil probesm(z_m_soil_upper)
  • Vertical angle of wind(phi)
  • depth of lower t soil probesm(z_t_soil_lower)
  • mean relative humidity, upper level(rh_upper)
  • standard error of mean_m_soil_lower(stderr_mean_m_soil_lower)
  • average of two upper soil temperature sensors(mean_t_soil_upper)
  • Monin-Obukhov length scale(Lmoni)


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DQRID : D040217.3
Start DateStart TimeEnd DateEnd Time
12/18/2002000012/18/20030000
Subject:
SGP/CO2/C1 - Reprocessing User Notes
DataStreams:sgp30co2flx4mmetC1.b1
Description:
A subset of the radiation measurements had an incorrect gain applied to raw data in period 
from 20021218-20031218.  To correct for this, a multiplicative correction factor of 1.11 
were applied to raw data used for the following variables:

r_down_short_hemisp
r_down_long_hemisp
r_up_short_hemisp
r_up_long_hemisp

Note that the long wave variables are computed by adding the black body thermal radiation 
from the radiometer body to each of the long wave signals.  Hence, the multiplicative 
correction is applied to the raw long wave fluxes before adding in the flux from the 
radiometer body.
Measurements:sgp30co2flx4mmetC1.b1:
  • downwelling shortwave hemispheric irradiance t_rad corrected(r_down_short_hemisp)
  • upwelling longwave hemispheric irradiance t_rad corrected(r_up_long_hemisp)
  • upwelling shortwave hemispheric irradiance t_rad corrected(r_up_short_hemisp)
  • downwelling longwave hemispheric irradiance t_rad corrected(r_down_long_hemisp)


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DQRID : D040505.5
Start DateStart TimeEnd DateEnd Time
12/18/2003000004/28/20041900
Subject:
SGP/CO2/C1 - Longwave Radiation Incorrect
DataStreams:sgp30co2flx4mmetC1.b1
Description:
Long wave radiation values (r_up_long_hemisp, r_down_long_hemisp) are bad 
due to correction with bad radiometer body temperature (t_rad) resulting
from a wiring issue.
Measurements:sgp30co2flx4mmetC1.b1:
  • radiometer body temperature (for longwave correction)(t_rad)
  • upwelling longwave hemispheric irradiance t_rad corrected(r_up_long_hemisp)
  • downwelling longwave hemispheric irradiance t_rad corrected(r_down_long_hemisp)


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DQRID : D041026.1
Start DateStart TimeEnd DateEnd Time
12/18/2002000010/12/20042359
Subject:
SGP/CO2/C1 - Reprocess: Units
DataStreams:sgp30co2flx4mC1.b1, sgp30co2flx25mC1.b1, sgp30co2flx60mC1.b1
Description:
Mean CO2 density units are incorrectly labeled as umol m-3. Units should be labeled as 
mmol m-3.
Measurements:sgp30co2flx60mC1.b1:
  • mean co2 concentration (c)(mean_c)

sgp30co2flx4mC1.b1:
  • mean co2 concentration (c)(mean_c)

sgp30co2flx25mC1.b1:
  • mean co2 concentration (c)(mean_c)


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DQRID : D041103.1
Start DateStart TimeEnd DateEnd Time
10/13/2004190010/20/20041800
Subject:
SGP/CO2/C1 - Mean CO2 density incorrect, CO2 flux suspect
DataStreams:sgp30co2flx60mC1.b1
Description:
A problem was identified with the calibration of the instrument over the time period 
October 12, 2004 to October 20, 2004. The offset of the instrument is known to be incorrect 
over this time frame, and a study of the gain of the instrument is underway.
Measurements:sgp30co2flx60mC1.b1:
  • mean co2 concentration (c)(mean_c)
  • WPL corrected CO2 flux(fc_corr)


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DQRID : D050316.1
Start DateStart TimeEnd DateEnd Time
12/18/2002000003/15/20052359
Subject:
SGP/CO2/C1 - Reprocessed: User Notes
DataStreams:sgp30co2flx4mmetC1.b1
Description:
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.
Measurements:sgp30co2flx4mmetC1.b1:
  • photosynthetic photon flux density (PAR)(ppfd_up)
  • total downwelling shortwave radiation (LI-200 sensor)(r_tot)


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DQRID : D051116.2
Start DateStart TimeEnd DateEnd Time
04/28/2004190011/16/20050000
Subject:
SGP/CO2/C1 - downwelling longwave hemispheric irradiance incorrect
DataStreams:sgp30co2flx4mmetC1.b1
Description:
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.
Measurements:sgp30co2flx4mmetC1.b1:
  • downwelling longwave hemispheric irradiance t_rad corrected(r_down_long_hemisp)


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DQRID : D051116.3
Start DateStart TimeEnd DateEnd Time
12/18/2002000011/16/20050000
Subject:
SGP/CO2/C1 - Soil Temperature measurements
DataStreams:sgp30co2flx4mmetC1.b1
Description:
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.
Measurements:sgp30co2flx4mmetC1.b1:
  • 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)


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DQRID : D060107.1
Start DateStart TimeEnd DateEnd Time
05/27/2005000001/06/20062359
Subject:
SGP/CO2/C1 - Reprocess: calibration error
DataStreams:sgp30co2flx4mC1.b1
Description:
A problem was identified with the calibration of the instrument performed on May 27, 2005. 
A study to correct this bad calibration is underway.
Measurements:sgp30co2flx4mC1.b1:
  • WPL corrected CO2 flux(fc_corr)
  • mean water vapor concentration (q)(mean_q)
  • WPL corrected latent heat flux(le)


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DQRID : D060510.1
Start DateStart TimeEnd DateEnd Time
04/11/2006153004/19/20061500
Subject:
SGP/CO2/C1 - Met stand was moved
DataStreams:sgp30co2flx4mmetC1.b1
Description:
Ameriflux program (Hank Loescher from Oregon state university) visits the site to 
intercompare his instruments with our 4m flux system.
The met stand was moved by 30 feet and consequently:
1. Soil moisture sensors were disconnected,
2. Soil temperature sensors were disconnected,
3. Soil heat plates were disconnected,
4. The true direction of the anemometer boom was 230 degrees instead of the regular 270 
degrees.
Measurements:sgp30co2flx4mmetC1.b1:
  • average of two lower soil temperature sensors(mean_t_soil_lower)
  • average of four upper soil moisture sensors(mean_m_soil_upper)
  • Unit Vector Wind Direction(wdir)
  • average of four lower soil moisture sensors(mean_m_soil_lower)
  • average of two middle soil temperature sensors(mean_t_soil_middle)
  • average of up to four soil heat flux sensors(mean_g_soil)
  • average of two upper soil temperature sensors(mean_t_soil_upper)


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