SGP/SMOS/E8 - Snow depth sensor removed; data reported as missing

The snow depth sensor was removed from service.  The program was changed so that -9999 is 
entered into the datastream.

• Time of Minimum Snow Depth(time_min_snow)
• Maximum Snow Depth(max_snow)
• Minimum Snow Depth(min_snow_depth)
• Time of Maximum Snow Depth(time_max_snow)

• snow_sen
• Snow, depth, 30-min intervals(snow)

• snow_sen
• Snow, depth, 30-min intervals(snow)

SGP/SWATS/E8 - Sensor failure, 15cm W

The temperature rise readings from the 15-cm depth on the west profile are incorrect. This 
also causes the matric potential and water content data to be incorrect.

Instrument removed from service 20091110.

• Volumetric Water Content, West Profile(watcont_W)
• Sensor Temperature Rise, West Profile(trise_W)
• Soil Water Potential, West Profile(soilwatpot_W)

SGP/EBBR/E8 - Improved EBBR CR10 Program

Effective 20050322.1730, the EBBR.E8 CR10 program was revised to improve 
the quality of the primary measurements as follows:
   
1) An RMS procedure is used to determine max and min limits of acceptable
soil heat flow.  This is applied to the individual soil sets.  Measurements
outside the limits are rejected and the measurements within the limits are
used to calculate the average soil heat flow.
   
2) Max and min limits are used to determine incorrect values of net
radiation, sensible heat flux (h), latent heat flux (e), and automatic
exchange mechanism (AEM) signal.  If AEM signal is outside the limits, h 
and e are set to 999s.  If net radiation is outside the limits, h and e are 
set to 999s. If h or e are outside the limits, h and e are set to 999s.
   
Virtually no incorrect soil measurement will affect the primary 
measurements of h and e.
   
By setting h and e to 999s, it can be easily seen that the primary 
variables are incorrect; no other interpretation is possible.
   
Prior to 20050322, the improved CR10 program was NOT in effect.  DQRs have
been submitted for known instances of incorrect soil measurements which
affected the quality of the primary measurements of h and e.
   
Note: the DQR begin date is the begin date of the sgp30ebbrE8.b1 data
stream.  The earlier version of the CR10 program was also used on previous
EBBR datastream names (e.g. sgp30ebbrE8.a1).

• Heat flux, sensible, at 1.5-m height, 30-min intervals(sensible_heat_flux)
• Average soil heat flow at the surface(surface_soil_heat_flux_avg)
• Heat flux, latent, at 1.5-m height, 30-min intervals(latent_heat_flux)

SGP/EBBR/E8 - 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):

0-224, 314-360

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.

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

SGP/SWATS/E8 - Sensor failure, 35cm W

The sensor installed at 35 cm at the west profile has produced questionable data ince it 
was installed back in 1996.  Once the sensor began to stabilize at 17:00 GMT on 07/20/99, 
it has produced questionable or incorrect values of temperature rise.  From 07/20/99 to 
the present date, 35cm W temperature rise values have stayed within a range of 
approximately 0.8-2.0 C, while the sensor from the 35cm E profile has produced an approximate range 
of 1.5-4.0 C.

In addition, the calibration for this sensor is so bad it is not possible to correct it 
using field data.  The range of temperature rise values produced by this sensor is too 
limited to reliably re-calibrate the instrument.  Under the old ARM calibration for SWATS, 
the calibrated reference temperature change should fall within a range of 1.45-4.00 C (the 
new range is 1.38-3.96 C).  For this sensor, the reference temperature change has fallen 
within an approximate range of 0.2-1.7 C and the calibration is actually adjusting the 
trise measurements in the wrong direction.  

Therefore, all temperature rise, matric potential and water content data 
are all highly suspect from the 35cm W sensor.

The soil temperature data appear to be OK.

Instrument removed from service 20091110.

• Volumetric Water Content, West Profile(watcont_W)
• Sensor Temperature Rise, West Profile(trise_W)
• Soil Water Potential, West Profile(soilwatpot_W)