SGP/CO2FLX/C1 - Reprocessing User Notes

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.

• WPL H correction to fc(fc_wpl_h)
• Mean horizontal wind speed(mean_rot_u)
• doy
• WPL LE correction to fc(fc_wpl_le)
• variance of variable t(var_t)
• friction velocity(ustar)
• base_time
• variance of variable q(var_q)
• variance of variable c(var_c)
• Corrected sensible heat flux(h)
• theta
• site_elevation
• Mean sonic temperature (t), i.e. virtual temperature(mean_t)
• Mean H2O density(mean_q)
• mean_p
• rotated variance w(var_rot_w)
• rotated variance v(var_rot_v)
• rotated variance u(var_rot_u)
• WPL corrected latent heat flux(le)
• yyyydddhhmmss
• phi
• Mean CO2 density(mean_c)
• site_longitude
• WPL corrected CO2 flux(fc_corr)
• Monin-Obukhov length scale(Lmoni)
• Unit Vector Wind Direction(wdir)
• time_offset
• site_latitude
• zm

• Mean air temperature (lower level)(t_air_lower)
• Mean CO2 density(mean_c)
• z_m_soil_upper
• base_time
• Unit Vector Wind Direction(wdir)
• Average of two upper soil temperature sensors(mean_t_soil_upper)
• phi
• Mean relative humidity (upper level)(rh_upper)
• stderr_mean_m_soil_lower
• z_upper
• Mean air temperature (upper level)(t_air_upper)
• Downwelling longwave hemispheric irradiance; t_rad corrected(r_down_long_hemisp)
• Average of four lower soil moisture sensors(mean_m_soil_lower)
• Total downwelling shortwave radiation (LI-200 sensor)(r_tot)
• doy
• stderr_mean_g_soil
• mean_p
• Mean H2O density(mean_q)
• Mean sonic temperature (t), i.e. virtual temperature(mean_t)
• stderr_mean_t_soil_lower
• Average of four upper soil moisture sensors(mean_m_soil_upper)
• t_rad
• site_elevation
• stderr_mean_t_soil_middle
• Average of two lower soil temperature sensors(mean_t_soil_lower)
• yyyydddhhmmss
• Net solar radiation (NR-lite); t_rad corrected(r_net)
• Mean relative humidity (lower level)(rh_lower)
• rotated variance w(var_rot_w)
• z_lower
• zrad
• rotated variance v(var_rot_v)
• z_t_soil_lower
• rotated variance u(var_rot_u)
• Upwelling shortwave hemispheric irradiance; t_rad corrected(r_up_short_hemisp)
• Average of four soil heat flux probes(mean_g_soil)
• theta
• WPL LE correction to fc(fc_wpl_le)
• site_longitude
• friction velocity(ustar)
• Mean horizontal wind speed(mean_rot_u)
• Average of two middle soil temperature sensors(mean_t_soil_middle)
• zm
• Pressure, atmospheric, at 1-m height, 30-min intervals(bar_pres)
• Downwelling shortwave hemispheric irradiance; t_rad corrected(r_down_short_hemisp)
• WPL H correction to fc(fc_wpl_h)
• WPL corrected latent heat flux(le)
• z_m_soil_lower
• z_t_soil_middle
• Monin-Obukhov length scale(Lmoni)
• site_latitude
• Upwelling longwave hemispheric irradiance; t_rad corrected(r_up_long_hemisp)
• z_t_soil_upper
• time_offset
• Photosynthetic photon flux density (PAR)(ppfd)
• variance of variable t(var_t)
• stderr_mean_m_soil_upper
• stderr_mean_t_soil_upper
• Precipitation, total(precip)
• variance of variable q(var_q)
• WPL corrected CO2 flux(fc_corr)
• variance of variable c(var_c)
• Corrected sensible heat flux(h)
• z_g_soil

• Mean CO2 density(mean_c)
• Mean sonic temperature (t), i.e. virtual temperature(mean_t)
• friction velocity(ustar)
• mean_p
• Mean H2O density(mean_q)
• Unit Vector Wind Direction(wdir)
• zm
• time_offset
• site_latitude
• yyyydddhhmmss
• rotated variance v(var_rot_v)
• rotated variance u(var_rot_u)
• rotated variance w(var_rot_w)
• WPL corrected CO2 flux(fc_corr)
• Corrected sensible heat flux(h)
• variance of variable t(var_t)
• theta
• doy
• base_time
• phi
• site_longitude
• variance of variable q(var_q)
• variance of variable c(var_c)
• Mean horizontal wind speed(mean_rot_u)
• WPL H correction to fc(fc_wpl_h)
• Monin-Obukhov length scale(Lmoni)
• WPL corrected latent heat flux(le)
• site_elevation
• WPL LE correction to fc(fc_wpl_le)

• variance of variable c(var_c)
• zm
• yyyydddhhmmss
• Mean H2O density(mean_q)
• mean_p
• WPL H correction to fc(fc_wpl_h)
• Mean sonic temperature (t), i.e. virtual temperature(mean_t)
• time_offset
• base_time
• site_elevation
• Mean CO2 density(mean_c)
• phi
• variance of variable t(var_t)
• variance of variable q(var_q)
• Monin-Obukhov length scale(Lmoni)
• Unit Vector Wind Direction(wdir)
• site_longitude
• site_latitude
• rotated variance u(var_rot_u)
• rotated variance v(var_rot_v)
• rotated variance w(var_rot_w)
• Mean horizontal wind speed(mean_rot_u)
• doy
• Corrected sensible heat flux(h)
• WPL corrected latent heat flux(le)
• friction velocity(ustar)
• WPL corrected CO2 flux(fc_corr)
• theta
• WPL LE correction to fc(fc_wpl_le)

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 density(mean_c)

• Mean CO2 density(mean_c)

• Mean CO2 density(mean_c)

SGP/CO2FLX/C1 - Reprocess: calibration error

A problem was identified with the calibration of the instrument performed on May 27, 2005. 
A study to correct this bad calibration is underway.

• Mean H2O density(mean_q)
• WPL corrected CO2 flux(fc_corr)
• WPL corrected latent heat flux(le)

SGP/CO2FLX/C1 - Disturbance around site

A bulldozer used to excavate the SGP Tower anchors was right around (within 10 feet) our 
systems.

• WPL corrected CO2 flux(fc_corr)
• Mean CO2 density(mean_c)

• WPL corrected CO2 flux(fc_corr)
• Mean CO2 density(mean_c)

• Mean CO2 density(mean_c)
• WPL corrected CO2 flux(fc_corr)

• WPL corrected CO2 flux(fc_corr)
• Mean CO2 density(mean_c)

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

• zm

SGP/CO2FLX/C1 - Reprocessed: Recalibration

The 4m CO2 flux system was calibrated on May 25, 2005. After the calibration was 
performed, calibration coefficients used to measure CO2 density were not updated. This added an 
OFFSET to the CO2 density measurements.

The data have been reprocessed to address the offset.  The reprocessed data were archived 
in December 2008. Please retrieve the updated files for use in your analysis.

• Mean CO2 density(mean_c)