SGP/EBBR/E26 - Spark Gap Bad, Pressure Incorrect

In a trip to E26, I found that a bad spark gap through which the barometer was powered was 
causing pressure measurements to be incorrect.  The pressure readings oscillated with 
the voltage of the EBBR battery.  During daytime the voltage and thus the pressure would 
increase and vice versa during dark hours.

Apparently only the positive side of the power supply was properly connected through the 
spark gap and thus the voltage received by the pressure sensor was lower than required to 
power it properly.  Under this condition the perssure measurement varies with voltage 
level.  The pressure measurements therefore had a diurnal signature and usually were 
incorrect.  

The decreased pressure during most times would cause latent heat flux to be slightly 
overestimated and sensible heat flux to be slightly underestimated.

• Atmospheric pressure(mv_pres)

• Retrieved pressure profile(pres)

• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• latent heat flux(e)
• Retrieved pressure profile(pres)
• h(h)

SGP/EBBR/E26 - Soil Temperature #4 and Soil Heat Flow #4 Incorrect

The soil temperature and soil heat flow probes for set #4 was pulled 
partially out of the ground.  This caused soil temperature #4 to be too high and soil heat 
flow #4 to be too low.  The error is not so great as to cause a large error in the 
sensible and latent heat fluxes.

• latent heat flux(e)
• 5 cm soil heat flow, site 4(shf4)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• Soil heat capacity 4(cs4)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• soil heat flow, site 4(g4)
• h(h)
• 0-5 cm integrated soil temperature, site 4(ts4)

SGP/EBBR/E26 - 6 Month Checks

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

• Temperature of right humidity sensor chamber(rr_thum_r)
• Right air temperature(tair_r)
• Left air temperature(tair_l)
• Right relative humidity(mv_hum_r)
• Temperature of left humidity sensor chamber(rr_thum_l)
• Left relative humidity(mv_hum_l)

• bottom air temperature(tair_bot)
• Bottom humidity(hum_bot)
• Top humidity(hum_top)
• Temperature of the top humidity chamber(thum_top)
• bottom vapor pressure(vp_bot)
• top air temperature(tair_top)
• Temperature of bottom humidity sensor chamber(thum_bot)
• top vapor pressure(vp_top)

• top air temperature(tair_top)
• Temperature of bottom humidity sensor chamber(thum_bot)
• h(h)
• latent heat flux(e)
• top vapor pressure(vp_top)
• Bottom humidity(hum_bot)
• bottom vapor pressure(vp_bot)
• Top humidity(hum_top)
• bottom air temperature(tair_bot)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Temperature of the top humidity chamber(thum_top)

SGP/EBBR/E26 - Incorrect soil type coefficients used

The soil type coefficents for soil moisture were incorrect from the day
of the system installation on, making soil moisture values too large.

As a result, soil heat flows were overmeasured, and sensible and latent heat fluxes were 
underestimated.

• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• Soil heat capacity 1(cs1)
• soil heat flow, site 1(g1)
• Soil heat capacity 4(cs4)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• volumetric soil moisture, site 5(sm5)
• h(h)
• volumetric soil moisture, site 2(sm2)
• latent heat flux(e)
• 0-5 cm change in soil heat storage with time, site 5(ces5)
• soil heat flow, site 2(g2)
• volumetric soil moisture, site 3(sm3)
• 5 cm soil heat flow corrected for soil moisture content, site 2(c_shf2)
• 5 cm soil heat flow corrected for soil moisture content, site 1(c_shf1)
• Soil heat capacity 5(cs5)
• volumetric soil moisture, site 4(sm4)
• 0-5 cm change in soil heat storage with time, site 3(ces3)
• soil heat flow, site 5(g5)
• volumetric soil moisture, site 1(sm1)
• Soil heat capacity 3(cs3)
• Soil heat capacity 2(cs2)
• average surface soil heat flow(ave_shf)
• 5 cm soil heat flow corrected for soil moisture content, site 3(c_shf3)
• 0-5 cm change in soil heat storage with time, site 2(ces1)
• soil heat flow, site 3(g3)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• soil heat flow, site 4(g4)
• 0-5 cm change in soil heat storage with time, site 2(ces2)

SGP/EBBR/E26 - Improved EBBR CR10 Program

Effective 20050331.1700, the EBBR.E26 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 20050331, 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 sgp30ebbrE26.b1 data
stream.  The earlier version of the CR10 program was also used on previous
EBBR datastream names (e.g. sgp30ebbrE26.a1).
~

• latent heat flux(e)
• h(h)
• average surface soil heat flow(ave_shf)

SGP/EBBR/E26 - metadata corrections

On 20050723, a series of metadata corrections and additions were completed.  These 
metadata changes apply to all EBBR.E26 data collected by ARM back to the installation of the 
instrument in June 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 moisture units (from "by volume" to "gravimetric")

• base time(base_time)

• base time(base_time)

• base time(base_time)