SGP/EBBR - Incorrect Units for Soil Heat Capacity (cs1, cs2, cs3, cs4, cs5) in 30EBBR 
Header

The units for Soil Heat Capacity (cs1, cs2, cs3, cs4,
cs5) in the EBBR 30 minute netcdf header have been 
incorrect from the beginning of processing the data
into netcdf files.  The correct units are MJ/m^3/C.
   
This does not affect the data quality.

(NOTE: The actual begin date of some of these data streams
 is as early as 7/4/93.  This DQR applies to all 30m EBBR
 data.)

• soil_heat_capacity_5
• soil_heat_capacity_4
• soil_heat_capacity_2
• soil_heat_capacity_3
• soil_heat_capacity_1

• soil_heat_capacity_1
• soil_heat_capacity_2
• soil_heat_capacity_3
• soil_heat_capacity_4
• soil_heat_capacity_5

• soil_heat_capacity_1
• soil_heat_capacity_2
• soil_heat_capacity_5
• soil_heat_capacity_3
• soil_heat_capacity_4

• soil_heat_capacity_1
• soil_heat_capacity_2
• soil_heat_capacity_3
• soil_heat_capacity_4
• soil_heat_capacity_5

• soil_heat_capacity_2
• soil_heat_capacity_1
• soil_heat_capacity_5
• soil_heat_capacity_4
• soil_heat_capacity_3

• soil_heat_capacity_1
• soil_heat_capacity_2
• soil_heat_capacity_3
• soil_heat_capacity_4
• soil_heat_capacity_5

• soil_heat_capacity_5
• soil_heat_capacity_4
• soil_heat_capacity_3
• soil_heat_capacity_2
• soil_heat_capacity_1

• soil_heat_capacity_1
• soil_heat_capacity_5
• soil_heat_capacity_4
• soil_heat_capacity_3
• soil_heat_capacity_2

• soil_heat_capacity_3
• soil_heat_capacity_2
• soil_heat_capacity_5
• soil_heat_capacity_4
• soil_heat_capacity_1

• soil_heat_capacity_2
• soil_heat_capacity_3
• soil_heat_capacity_4
• soil_heat_capacity_5
• soil_heat_capacity_1

SGP/EBBR/E13 - Wind Direction Dependency of Surface Fluxes and General Data Quality 
Information

Beginning in FY2006, Data Quality Reports are not written for missing 
data or for situations when qc flags clearly show that the data is 
incorrect (this is true for most of the conditions listed below).  
DQRs are written for periods when data is incorrect, when the situation 
is not represented by qc flags in the data, and it's not obvious that 
the data should have been flagged as incorrect.

The EBBR data is only useful for particular wind directions at each 
Extended Facility.  Please use the following resources to help in 
interpreting the EBBR data.

1) qc flags in the EBBR data.

2) Instrument Mentor Monthly Summaries (IMMS) at http://www.db.arm.gov/IMMS/

3) SGP EF Surface Conditions Observations (EFSCO) at 
http://198.124.96.210:591/sfc_cond1/default.htm

4) Surface fluxes are valid only for the following wind directions
(in degrees):

0-52, 142-194, 328-360

Note that there are wind directions at most sites for which the fetch
is insufficient and therefore EBBR data is invalid.  Appropriate 
fetch was determined from a 1/40 measurement height to fetch ratio, 
resulting in a required minimum fetch of 120 m.  Particular attention 
should be paid to the limited valid wind directions for the Central 
Facility EBBR.  The surface vegetation type for the EBBRs is grazed 
or ungrazed grassland (refer to the EFSCO for state).

5) Some conditions that commonly cause the EBBR primary measurements to 
be incorrect or missing follow:

a) Sensible and latent heat fluxes are not accurate during times when 
the Automatic Exchange Mechanism (AEM) is not functioning properly.  
The AEM switches the gradient measuring instrumentation between the 
top and bottom positions every 15 minutes; this reduces the effects of 
instrument offsets.  Sometimes the AEM does not reach it's full extent 
of travel, resulting in the home signal being zero.  

b) Sensible and latent heat fluxes are sometimes incorrect when surface 
soil heat flow is out of range, as seen in the average soil heat flux 
(ave_shf).

c) Very light winds may be seen at nights for brief periods. Wind 
direction flops around a lot during low wind conditions (< 1.5 m/s) 
and is often unreliable during those periods.

d) Missing data periods occur at times; this is usually a site data 
system collection/communication problem; it can also occur during 
replacement of the system with a newly calibrated unit.  Missing data 
is sometimes filled in later from manual or automatic re-collection of 
the data.

• Wind speed vector mean(wspd_vec_mean)
• Heat flux, sensible, at 1.5-m height, 30-min intervals(sensible_heat_flux)
• corr_soil_heat_flow_4
• home_signal_30
• corr_soil_heat_flow_3
• energy_storage_change_4
• energy_storage_change_5
• corr_soil_heat_flow_5
• corr_soil_heat_flow_2
• Heat flux, latent, at 1.5-m height, 30-min intervals(latent_heat_flux)
• corr_soil_heat_flow_1
• temp_air_bottom
• Wind direction, vector, lower, 1-min avg(wdir_vec_mean)
• surface_soil_heat_flux_5
• Average soil heat flow at the surface(surface_soil_heat_flux_avg)
• lon
• temp_air_top
• temp_trh_top
• base_time
• soil_heat_flow_1
• soil_moisture_1
• soil_heat_flow_3
• soil_moisture_2
• soil_heat_flow_2
• soil_heat_flow_5
• soil_heat_flow_4
• energy_storage_change_1
• soil_moisture_5
• energy_storage_change_3
• soil_moisture_3
• energy_storage_change_2
• soil_moisture_4
• time_offset
• Barometric Pressure(atmos_pressure)
• temp_reference
• vapor_pressure_top
• soil_heat_capacity_1
• soil_temp_2
• soil_heat_capacity_5
• soil_temp_1
• soil_heat_capacity_4
• soil_heat_capacity_3
• soil_heat_capacity_2
• home_signal_15
• soil_temp_5
• soil_temp_4
• soil_temp_3
• Wind speed, lower, 1-min avg(wspd_arith_mean)
• wdir_vec_std
• bowen_ratio
• surface_soil_heat_flux_3
• alt
• surface_soil_heat_flux_4
• surface_soil_heat_flux_1
• surface_soil_heat_flux_2
• rh_bottom_fraction
• lat
• vapor_pressure_bottom
• Radiation, net(net_radiation)
• temp_trh_bottom
• rh_top_fraction

SGP/EBBR/E13 - Six Month Checks

During EBBR 6 month checks (formally called 3 month checks) the Automatic 
Exchange Mechanism is disabled (reflected by home signals near zero) so that
the two aspirator units can be placed at the same height.  The measurements
during these periods do not produce correct outputs of bowen ratio (bowen), 
sensible heat flux (h), or latent heat flux (e), nor do the air temperature
and relative humidity measurements indicate correct gradients.  Checks 
performed just before or after the AEM is disabled also lead to some 
incorrect data.  Incorrect 5, 15 minute and half hour data occurs for the 
period indicated.

• rh_left_mv
• temp_trh_left_rr
• temp_air_left
• temp_air_right
• temp_trh_right_rr
• rh_right_mv

• temp_air_top
• rh_top_fraction
• vapor_pressure_top
• temp_trh_top
• vapor_pressure_bottom
• rh_bottom_fraction
• temp_air_bottom
• temp_trh_bottom

• Heat flux, sensible, at 1.5-m height, 30-min intervals(sensible_heat_flux)
• vapor_pressure_top
• Heat flux, latent, at 1.5-m height, 30-min intervals(latent_heat_flux)
• temp_air_bottom
• temp_air_top
• bowen_ratio
• temp_trh_top
• rh_bottom_fraction
• vapor_pressure_bottom
• temp_trh_bottom
• rh_top_fraction

SGP/EBBR/E13 - Net Radiation Incorrect - Water in Bottom Dome

Water entered the net radiometer top dome through a hole made, probably,
by migrating birds (this happens every Spring and Autumn) and accumulated
in the bottom dome.  This causes nighttime net radiations to be too large
and daytime net radiations to be too small.  The data is therefore incorrect.

• net_radiation_mv

• Radiation, net(net_radiation)

• Radiation, net(net_radiation)