SGP/EBBR/E15 - Soil Moisture Coefficients Incorrect

The soil Moisture coefficients used for E15 were incorrect from the time of
installation of the system in program version 8.  On 9 July 02 parameter 4  (an offset 
value) of program step 136 was changed from 9.5264 to the correct value 0.95264 (this error 
had been made by the vendor). The error masked the real problem (wrong soil type) and 
after 9 July 02 resulted in very low soil moisture measurements.  The coefficients used were 
for coarse sand.  On 28 Sep 04 I visited the E15 site and found the soil type a fine 
sandy clay or fine sandy loam.  I changed the coefficients  at 1509 GMT to those for a very 
fine sandy loam; this produced reasonable soil moistures for the soil type.

The old coefficients in parameters 4 through 9 for step 136 of the program were: 0.95264, 
-6.7859, 36.224, -58.619, 25.073, 4.2278

The new coefficients are: 10.241, -27.943, 49.523, -12.648, -52.643, 38.054

• surface_soil_heat_flux_1
• energy_storage_change_3
• soil_moisture_5
• soil_moisture_2
• energy_storage_change_4
• surface_soil_heat_flux_avg
• energy_storage_change_5
• latent_heat_flux
• surface_soil_heat_flux_5
• surface_soil_heat_flux_2
• soil_moisture_3
• energy_storage_change_1
• surface_soil_heat_flux_4
• surface_soil_heat_flux_3
• energy_storage_change_2
• soil_moisture_1
• soil_moisture_4
• sensible_heat_flux

SGP/EBBR/E15 - 6 Month Checks

Many measurements were incorrect while the AEM was positioned with both aspirators at the 
same height for comparison checks.

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

• temp_air_top
• vapor_pressure_bottom
• rh_top_fraction
• latent_heat_flux
• temp_trh_bottom
• rh_bottom_fraction
• vapor_pressure_top
• bowen_ratio
• temp_trh_top
• temp_air_bottom
• sensible_heat_flux

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

SGP/EBBR/E15  - Wind Speed Frozen Stopped By Ice Storm

An ice storm froze the wind speed sensor to a stopped condition.

The wind speed and residual wind speed measurements are incorrect.

This sensor failure does not affect the sensible and latent heat fluxes.

• wspd_arith_mean

• wspd_vec_mean
• wspd_arith_mean

• wspd_arith_mean
• wspd_vec_mean

SGP/EBBR/E15  - Wind Direction Frozen Stopped By Ice Storm

The wind direction sensor was frozen stopped by ice from a storm.  
The wind direction, sigma_wd, and residual wind speed measurements 
are incorrect.

• wdir_vec_mean_mv

• wdir_vec_mean
• wspd_vec_mean
• wdir_vec_std

• wdir_vec_mean
• wspd_vec_mean
• wdir_vec_std

SGP/EBBR/E15  - Wind Speed Frozen Stopped By Ice

An ice storm froze the wind speed sensor to a stopped condition.

The wind speed and residual wind speed measurements are incorrect.

This sensor failure does not affect the sensible and latent heat fluxes.

• wspd_arith_mean

• wspd_vec_mean
• wspd_arith_mean

• wspd_arith_mean
• wspd_vec_mean

SGP/EBBR/E15  - Wind Direction Frozen Stopped By Ice

The wind direction sensor was frozen stopped by ice from a storm.  
The wind direction, sigma_wd, and residual wind speed measurements 
are incorrect.

• wdir_vec_mean_mv

• wdir_vec_mean
• wspd_vec_mean
• wdir_vec_std

• wdir_vec_mean
• wspd_vec_mean
• wdir_vec_std

SGP/EBBR/E15 - Soil Heat Flows Undermeasured, and Latent and Sensible Heat Fluxes 
Overstimated

Use of the wrong soil type soil moisture coefficients caused soil moisture to be greatly 
undermeasured (a typical wrong value was 4% instead of the correct 17%), soil heat flows 
to be undermeasured, and sensible and latent heat fluxes to be overestimated.

Soil heat flow plate outputs were undermeasured by up to 10%, change of energy storage was 
undermeasured by up to 80% and total soil heat flow was undermeasured by up to 50% as a 
result. This would result in approximately a 5% overestimation of both sensible and 
latent heat fluxes.

• corr_soil_heat_flow_4
• surface_soil_heat_flux_1
• energy_storage_change_3
• soil_moisture_5
• corr_soil_heat_flow_1
• soil_heat_capacity_2
• latent_heat_flux
• corr_soil_heat_flow_2
• surface_soil_heat_flux_5
• surface_soil_heat_flux_2
• soil_heat_capacity_5
• soil_moisture_3
• energy_storage_change_1
• corr_soil_heat_flow_3
• surface_soil_heat_flux_4
• energy_storage_change_2
• surface_soil_heat_flux_3
• soil_heat_capacity_1
• soil_heat_capacity_3
• corr_soil_heat_flow_5
• soil_moisture_2
• energy_storage_change_4
• surface_soil_heat_flux_avg
• energy_storage_change_5
• soil_heat_capacity_4
• sensible_heat_flux
• soil_moisture_4
• soil_moisture_1

SGP/EBBR/E15 - Net Radiation Too Large - Water in Bottom

Water in the bottom dome of the net radiometer made the measurements incorrectly large.  
Sensible and latent heat fluxes were therefore 
incorrect.

• net_radiation_mv

• latent_heat_flux
• sensible_heat_flux
• net_radiation

• net_radiation

SGP/EBBR/E15 - Improved EBBR CR10 Program

Effective 20050329.1900, the EBBR.E15 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 20050329, 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 sgp30ebbrE15.b1 data
stream.  The earlier version of the CR10 program was also used on previous
EBBR datastream names (e.g. sgp30ebbrE15.a1).

• latent_heat_flux
• surface_soil_heat_flux_avg
• sensible_heat_flux

SGP/EBBR/E15 - Average Soil Heat Flux Incorrect

A typo in the version 9 EBBR program caused average soil heat flow to be zero, resulting 
in both sensible and latent heat fluxes being approximately 20 watts per meter squared too 
large during the middle of the day.

• latent_heat_flux
• surface_soil_heat_flux_avg
• sensible_heat_flux

SGP/EBBR/E15 - Soil Set #5 Temperature, Moisture, and Heat Flow Incorrect

Rodents chewed the cables on all three soil set #5 sensors, making the measurements 
incorrect.

• soil_moisture_5_rr
• soil_temp_5_rr
• soil_heat_flow_5_mv

• energy_storage_change_5
• surface_soil_heat_flux_5
• soil_heat_capacity_5
• soil_moisture_5
• corr_soil_heat_flow_5
• soil_heat_flow_5
• soil_temp_5

SGP/EBBR/E15 - metadata corrections

On 20050723, a series of metadata corrections and additions were completed.  These 
metadata changes apply to all EBBR.E15 data collected by ARM back to the installation of the 
instrument in September 1992. Please see the current metadata for correct information.  
These changes do not affect data values or quality.	

The changes are summarized below:
1) Update of "sensor location" information
2) Addition of installation dates for the systems
3) Correction of soil type
4) Correction of soil moisture units (from "by volume" to "gravimetric")

• base time(base_time)

• base time(base_time)

• base time(base_time)

SGP/EBBR/E15 - Net Radiation, Sensible and Latent Heat Fluxes Incorrect.

The top dome of the net radiometer was broken, resulting in net radiations that were too 
small, and thus sensible and latent heat fluxes that were too small.

• net_radiation_mv

• latent_heat_flux
• sensible_heat_flux
• net_radiation

• net_radiation

SGP/EBBR/E15 - Incorrect Sensible and Latent Heat Fluxes

Incorrect gradient measurements and sensible and latent heat fluxes resulted from the AEM 
not exchanging.

• temp_air_left
• temp_air_right

• vapor_pressure_top
• temp_air_top
• vapor_pressure_bottom
• bowen_ratio
• rh_top_fraction
• latent_heat_flux
• temp_trh_top
• temp_trh_bottom
• rh_bottom_fraction
• temp_air_bottom
• sensible_heat_flux

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

SGP/EBBR/E15 - Reprocess: Sensible and Latent Heat Fluxes, Soil Set #2 Sometimes Incorrect

Spikes in soil set #2 sometimes caused sensible and latent heat fluxes to be incorrect.  

There is no electronic connection between the soil set #2 sensors, so it is suspected that 
there was a problem in the soil set #2 cable bundle. A power outage ensued, after which 
the soil set #2 problem did not re-occur.

• corr_soil_heat_flow_2
• latent_heat_flux
• surface_soil_heat_flux_2
• soil_temp_2
• soil_heat_flow_2
• soil_moisture_2
• surface_soil_heat_flux_avg
• energy_storage_change_2
• sensible_heat_flux
• soil_heat_capacity_2

SGP/EBBR/E15 - Wind Speed Sensor Frozen Stopped

Freezing rain froze the wind speed sensor to a stopped condition during the period.

• wspd_arith_mean

• wspd_vec_mean
• wspd_arith_mean

• wspd_arith_mean
• wspd_vec_mean