SGP/EBBR - EBBR E20 Data Incorrect from SHF #5

something, since the problem began during J-panel changeout the 4/7/99 PM.
At the 7/21/99 PM, the reference temperature was repaired and reseated.  At
that time the SHF #5 data became correct again; the two events are probably
related only in that other connections, including that of the SHF #5, were
probably reseated at the same time.  The report of the PM activity is not
detailed enough to determine the exact causes and fixes.

The incorrect SHF #5 data can be identified by it being an order of 
magnitude larger than the values from the other soil heat flow sensors.

Affected data are:

5 minute:  none
15 minute: mv_hft5
30 minute: shf5, c_shf5, g5, ave_shf, e, h

• latent heat flux(e)
• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• 5 cm soil heat flow, site 5(shf5)
• soil heat flow, site 5(g5)
• h(h)
• average surface soil heat flow(ave_shf)

• Soil heat flow 5(mv_hft5)

SGP/EBBR - EBBR E20 Thermocouple Data Incorrect

Left and right thermocouple air temperature data are incorrect during the
replacement of the right thermocouple.

Affected data are:

5 minute:  tair_bot, tair_top
15 minute: tai_r, tair_l
30 minute: tair_bot, tair_top, e, h, bowen

• top air temperature(tair_top)
• latent heat flux(e)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• h(h)
• bottom air temperature(tair_bot)

• top air temperature(tair_top)
• bottom air temperature(tair_bot)

• Right air temperature(tair_r)
• Left air temperature(tair_l)

SGP/EBBR - EBBR E20 Right Air Temperature Incorrect

The right air temperature (thermocouple) output was frequently offscale.
Examination of the 15 minute data will clearly show which times are
affected during the period.

The affected data are:

5 minute:  tair_top, tair_bot
15 minute: tair_r
30 minute: tair_top, tair_bot, bowen, h, e

• top air temperature(tair_top)
• latent heat flux(e)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• h(h)
• bottom air temperature(tair_bot)

• top air temperature(tair_top)
• bottom air temperature(tair_bot)

• Right air temperature(tair_r)

SGP/EBBR - EBBR E20 Left Air Temperature Incorrect

Left air temperature (thermocouple) was incorrect during part of the period,
thereby affecting top and bottom air temperature.

The affected data and times are:

5 minute:  tair_top (1935 GMT)
15 minute: tair_l (1945 GMT)
30 minute: tair_top, bowen, e, h (2000 GMT)

• top air temperature(tair_top)
• latent heat flux(e)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• h(h)

• top air temperature(tair_top)

• Left air temperature(tair_l)

SGP/EBBR/E20 - Blown fuse in AEM at E20

On October 30, 1993, before 1300 GMT, the fuse in the AEM (Automatic
Exchange Mechanism) of Meeker, Ok (E20) EBBR blew out.  The AEM remained
nonfunctional until the fuse was replaced just before 1600 GMT on
November 12, 1993.  This situation resulted in the following invalid data:

5 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot,
          vp_top, vp_bot, home

15 minute: rr_thum_r, rr_thum_l, mv_hum_r, mv_hum_l, mv_home, tair_r,
           tair_l

30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot,
           vp_top, vp_bot, bowen, e, h, home_15, home_30


If the biases of the sensors were know, bowen, h, and e could be
recalculated from the 15 minute and/or 5 minute data.  Since we will not
have any idea of what those biases are until an annual calibration of the
sensors can take place (which may be months away), the recalculations
cannot be performed at this time.  Furthermore, it may be invalid to use
sensor biases, if determined too far removed in time, due to the gradual
calibration drift of some of the sensors.

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

• Bottom humidity(hum_bot)
• Temperature of the top humidity chamber(thum_top)
• bottom vapor pressure(vp_bot)
• top air temperature(tair_top)
• Exchange mechanism position indicator (15 to 30 min)(home_30)
• top vapor pressure(vp_top)
• h(h)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Top humidity(hum_top)
• Temperature of bottom humidity sensor chamber(thum_bot)
• latent heat flux(e)
• bottom air temperature(tair_bot)
• Exchange mechanism position indicator (0 to 15 min)(home_15)

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

SGP/EBBR/E22 - Incorrect averaging interval at E22

On November 9, 1993 version 4 of the EBBR program installed at Cordell, OK
(E22) was mistakenly modified in one area during the process of modifying a
calibration in another part of the program.  The mistaken modification was
a change in the execution interval from 30 seconds to 10 seconds.  This
modification remained in the program until November 22, 1993 when it was
discovered and changed back to a 30 second execution interval.  The
modification produced no ill effects as the execution interval only
changes sampling and averaging periods.  A 10 second execution interval
results in three times as many samples being taken, which, when averaged,
should actually produce more accurate results.  Therefore, data quality was
not affected.  This PIF was written only to document the fact that the
mistaken modification was made, and when it was made.

• Soil heat capacity 1(cs1)
• Retrieved pressure profile(pres)
• scalar wind speed(wind_s)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Bottom humidity(hum_bot)
• average surface soil heat flow(ave_shf)
• Reference Thermistor Temperature(tref)
• top vapor pressure(vp_top)
• soil heat flow, site 3(g3)
• 5 cm soil heat flow, site 3(shf3)
• Exchange mechanism position indicator (0 to 15 min)(home_15)
• soil heat flow, site 2(g2)
• Time offset of tweaks from base_time(time_offset)
• wind direction (relative to true north)(wind_d)
• Temperature of bottom humidity sensor chamber(thum_bot)
• 0-5 cm change in soil heat storage with time, site 3(ces3)
• Top humidity(hum_top)
• Dummy altitude for Zeb(alt)
• Soil heat capacity 5(cs5)
• 0-5 cm integrated soil temperature, site 4(ts4)
• Temperature of the top humidity chamber(thum_top)
• volumetric soil moisture, site 5(sm5)
• 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(ces2)
• soil heat flow, site 1(g1)
• net radiation(q)
• 5 cm soil heat flow corrected for soil moisture content, site 2(c_shf2)
• volumetric soil moisture, site 4(sm4)
• h(h)
• volumetric soil moisture, site 3(sm3)
• 5 cm soil heat flow, site 4(shf4)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• bottom air temperature(tair_bot)
• 0-5 cm integrated soil temperature, site 5(ts5)
• soil heat flow, site 5(g5)
• 5 cm soil heat flow, site 1(shf1)
• lat(lat)
• volumetric soil moisture, site 1(sm1)
• 5 cm soil heat flow, site 2(shf2)
• Soil heat capacity 4(cs4)
• 0-5 cm integrated soil temperature, site 2(ts2)
• 5 cm soil heat flow, site 5(shf5)
• 5 cm soil heat flow corrected for soil moisture content, site 1(c_shf1)
• vector wind speed(res_ws)
• base time(base_time)
• volumetric soil moisture, site 2(sm2)
• 0-5 cm integrated soil temperature, site 3(ts3)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• bottom vapor pressure(vp_bot)
• latent heat flux(e)
• 0-5 cm integrated soil temperature, site 2(ts1)
• soil heat flow, site 4(g4)
• top air temperature(tair_top)
• 0-5 cm change in soil heat storage with time, site 2(ces1)
• Exchange mechanism position indicator (15 to 30 min)(home_30)
• Soil heat capacity 3(cs3)
• lon(lon)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• 0-5 cm change in soil heat storage with time, site 5(ces5)
• Soil heat capacity 2(cs2)
• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)

SGP/EBBR/E20 - Reprocess: Questionable data in soil heat fluxes at E20

Soil heat flux probes #4 had been indicating soil heat fluxes that were
higher than the other four probes.  It was decided to replace it.
On November 24, 1993 Soil Heat Flux probe #4 was replaced, resulting in
outputs more similar to the other four probes.  This PIF does not
invalidate previous measurements by the old probe #4, but only indicates
data that is bad as a result of the replacement procedure.  This procedure
resulted in some bad data for the adjoining soil heat flux probes #3 and #5
also.  Bad data for #3 includes the 1600 GMT half hour, and 5 and 15 minute
periods between 1530 and 1600 GMT.  Bad data for #4 includes half hour
times of 1600 through 1900 GMT, with 5 and 15 minute data inbetween those times
being invalid as well.  Bad data for #5 includes half hour times of 1630
and 1700 GMT, with 5 and 15 minute periods inbetween those times being
invalid as well.  Corrupted 30 minute values of shf4, c_shf4, g4, ave_shf, h,
and e, and corrupted 15 minute values of mv_hft4 resulted.  The quantities
shf4, c_shf4, g4, and mv_hft4 are bad data values and are not recoverable.
The other quantities can be recalculated using the remaining functioning
set(s) of soil sensors.

Use the following equations:

ave_shf = (gs summed)/n,

    where n is the number of probes functioning

e = -(q + ave_shf)/(1 + bowen)   where q is net radiation, and bowen is
                                 Bowen Ratio
h = e * bowen

• Soil heat flow 3(mv_hft3)
• Soil heat flow 4(mv_hft4)
• Soil heat flow 5(mv_hft5)

• 5 cm soil heat flow, site 5(shf5)
• soil heat flow, site 5(g5)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• 5 cm soil heat flow, site 4(shf4)
• latent heat flux(e)
• soil heat flow, site 3(g3)
• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• h(h)
• soil heat flow, site 4(g4)
• 5 cm soil heat flow, site 3(shf3)
• 5 cm soil heat flow corrected for soil moisture content, site 3(c_shf3)
• average surface soil heat flow(ave_shf)

SGP/EBBR/E20 - Pressure Sensor Malfunction

Pressure sensor malfunction during attempt to monitor it during Preventative
Maintenance visit.  30 minute values of pressure for 1600 GMT and 1630 GMT,
15 minute values for 1600, 1615, and 1630, and 5 minute values for 1600,
1605, 1610, 1615, 1620, 1625, and 1630 GMT are incorrect.  However, the
range of the incorrect values was such as to not adversely affect flux
measurements.  Some noise was apparently induced in the pressure output
voltage as a result of the monitoring, although it is not known how.

• top vapor pressure(vp_top)
• Retrieved pressure profile(pres)
• bottom vapor pressure(vp_bot)

• bottom vapor pressure(vp_bot)
• top vapor pressure(vp_top)
• Retrieved pressure profile(pres)

• Dummy altitude for Zeb(alt)

SGP/EBBR/E20 - Soil Moisture Probe

Beginning on May 6, 1994, soil moisture probe #3 began a long decline in
output and sensitivity until it stabilized at a low value of around 7, with
virtually no sensitivity at midday (GMT) on May 22, 1994.  The output
remained around this low value until the probe was replaced on June 9,
1994 at 1545 GMT.  Old Probe S/N 92038, New Probe S/N 93003.

• volumetric soil moisture, site 3(sm3)

• Soil moisture 3(r_sm3)

SGP/EBBR/E20 - Fan Stopped, T and RH Biases

Another fan stoppage situation occurred.  This is the fourth one in the
last few months and may indicate a weakening of the fans that aspirate the
temperature, relative humidity housings.  The 15 minute data reveals that
the stoppage occurred at approximately 1300 GMT on September 12.  The left fan
was cleaned out by site operations personnel and began running again at
1847 GMT on September 14.  The 15 minute data during this period shows that
during daytime, the left temperature was greater than the right temperature and
that the left relative humidity was lower than the right relative humidity
(a consequence of greater temperature), irregardless of the positions of the
housings.  The bowen ratio, sensible heat flux and latent heat flux for this
period, as well as all left housing temperatures and relative humidities are
incorrect.  The data values that are incorrect are:

5 minute:  tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot,
           vp_top, vp_bot

15 minute: rr_thum_l, mv_hum_l, tair_l,

30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, thum_bot,
           vp_top, vp_bot, bowen, e, h

Because of the increased frequency of fan stoppage occurrences, I have
submitted a work request to site operations to use the portable vane
anemometer to check the flow of the housing fans on each EBBR and visually
check (and clean if needed) the fans for debris that would restrict the
flow.  Included in this work request are instructions for checking the
performance of the temperature and relative humidity sensors by
manually putting the aspirator housings at the same height for a half hour
period (so that two 15 minute and one half hour comparison result).

The latter part of the work request is prompted by my close inspection of
the Meeker data for the last few weeks.  It is clear that significant
biases have developed in the pairs of temperature and relative humidity
sensors; left thermocouple ~0.5 deg. C greater than right thermocouple,
left relative humidity ~5% lower than right relative humidity.  Biases were
expected in operating the systems over long time periods, and these appear
to be the result of simple offsets, not changes in calibrations.
At this point, I just want to determine how large the offsets are.
Comparison of these offsets between EBBR units, in light of the different
lengths of time that EBBR units and individual sensors have been deployed,
may provide some interesting information on likely offset changes with time.

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

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

• Left air temperature(tair_l)
• Left relative humidity(mv_hum_l)
• Temperature of left humidity sensor chamber(rr_thum_l)

SGP/EBBR/E20 - Soil Moisture Probe Failure

Soil moisture probe #4 went offscale for a short period, for unknown
reasons. However, it may have resulted from Site Operations Preventative
Maintenance activities that were taking place at the time.  The times of
incorrect values are listed below.

30 minute: 1600 GMT; sm4, c_shf4, cs4, ces4, g4, ave_shf, e, h
15 minute: 1600 GMT; r_sm4

• latent heat flux(e)
• Soil heat capacity 4(cs4)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• volumetric soil moisture, site 4(sm4)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• h(h)
• soil heat flow, site 4(g4)
• average surface soil heat flow(ave_shf)

• Soil moisture 4(r_sm4)

SGP/EBBR/E20 - Aspirator Fan Stoppage

During Site Operations Preventative Maintenance activities the left AEM fan
stopped operating.  This affected some of the data being collected.  The
times of incorrect values are listed below.

15 minute: 1530-1715 GMT; tair_l, mv_hum_l, rr_thum_l
30 minute: 1530-1730 GMT; thum_top, thum_bot, tair_top, tair_bot, hum_top,
                          hum_bot, e, h, bowen

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

• Left air temperature(tair_l)
• Left relative humidity(mv_hum_l)
• Temperature of left humidity sensor chamber(rr_thum_l)

SGP/EBBR/E26 - T/RH Check

During the month of November 1994, site operations personnel conducted
field comparisons of the temperature and relative humidity sensors in the
EBBRs and the HMI31 portable T/RH meter (with the removable probe).  As is
reflected in the home signal output, the automatic exchange mechanism was
disabled in order to conduct the checks.

Measurements were taken every 5 minutes, for a half hour each in the
aspirated radiation shields (the HMI31 was inserted into the EBBR aspirated
radiation shield to provide the same aspiration as the EBBR sensors
received).  Measurements of aspirator flow were also recorded.  This
information was provided to the mentor.  The mentor then compared the field
checks with the data recorded by the EBBRs.

The periods of data and data fields that are incorrect because of the checks
are listed below.  Times are those at which the data are reported.


Data Fields

5 minute:  tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot,
           vp_top, vp_bot
15 minute: rr_thum_r, rr_thum_l, mv_hum_r, mv_hum_l, tair_r, tair_l
30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot,
           vp_top, vp_bot, bowen, e, h

5 minute:  1615, 1620, 1625, 1630, 1635, 1640, 1645, 1650, 1655,
           1700, 1705, 1710, 1715, 1720, 1725, 1730, 1735
15 minute: 1615, 1630, 1645, 1700, 1715, 1730, 1745
30 minute: 1630, 1700, 1730, 1800

(EDITOR'S NOTE:  The following analysis refers to all EBBRs installed in Nov 1994)

Results of the T/RH comparisons:
The combined accuracy of the HMI31 and EBBR temperature sensors
(thermocouples or PRTDs) is +/- 0.4 degrees C.  The combined accuracy of the
HMI31 and EBBR RH sensors is +/- 4% for RH less than 80%, and +/- 6% for RH
greater than 80%.  The combined accuracy for each pair of EBBR sensors of
the same type is essentially the same as the quantities stated above.

All of the pairs of EBBR sensors show differences that fall within the
stated combined accuracies.  Although this sounds wonderful, a few of the
differences are close to the combined accuracy, which, because of the small
differences in temperature being measured (normally smaller than the
magnitude of the combined accuracy) could lead to some incorrect estimation
of sensible and latent heat flux.  However, unless there would be substantial
differences of calibration slope of two sensors in a pair, the switching of
height of the sensors every 15 minutes by the automatic exchange mechanism
will remove the offset between the sensors.

The comparisons between the EBBR sensors and the HMI31 T/RH meter showed
much larger differences.  The range of differences were: -2.4 to 0.0 degrees
for the thermocouples, -2.1 to 0.1 degrees for the RH probe PRTDs, and -6.6 to
6.7 percent for the RH sensors.  Six Thermocouples indicated differences from
the HMI31 greater than the combined accuracy.  Seven PRTDs indicated
differences from the HMI31 greater than the combined accuracy.  Four RH
sensors indicated differences from the HMI31 greater than the combined
accuracy.  The temperature differences (for both thermocouples and PRTDs)
were nearly all of one sign; the HMI31 indicated the greater temperature,
which may suggest a bias in the HMI31 temperature measurement, even though
a dozen differences of +/- 0.2 degrees were measured.  Four differences of
zero and only one positive difference (out of 40) were measured.  Thirteen of
the 20 RH differences were positive (HMI31 indicating the lower
RH), with the differences near the level of the combined accuracies being
approximately 50% positive and 50% negative.  It does not appear that the
HMI31 has a RH bias.

Plots of EBBR sensor/HMI31 differences as a function of time from the
installation of the individual sensors (a range of 10 to 30 months in the
field) shows no obvious pattern of sensor drift with time.  This is encouraging.

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

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

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

SGP/EBBR/E20 - Frozen Wind Speed Sensor

On March 7, 1995 freezing rain stopped the cups of the EBBR wind
speed instrument at Meeker, OK (E20).  All 5, 15, and 30
minute data values indicated below are incorrect for the period listed above.

5 minute:  wind_s, res_ws
15 minute: wind_s
30 minute: wind_s, res_ws

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• scalar wind speed(wind_s)

SGP/EBBR/E20 - Reprocess: Soil Temperature Malfunction

During parts of three days, soil temperature probe #4 indicated values
that were either too high or too low, for unknown reasons.  Site
Operations personnel checked connections and repacked the soil around the
probe on 21 July at about 1535 GMT, although ts4 had recovered to proper
values the previous day.

The times of incorrect data and the affected quantities are shown below.
Some of the ts4 values during the listed periods appear to be correct,
although the change in energy storage values appear to indicate otherwise.

18 July: 0400-1400 GMT
19 July: 0430-0500, 0730-1500 GMT
29 July: 0700-1630 GMT

15 minute: rr_ts4

30 minute: ts4, ces4, g4, ave_shf, e, h

Sensible, latent, and soil heat fluxes need to be recalculated using the
change in energy storage of probes 1-3 and 5, as follows.

ave_shf = (g1 + g2 + g3 + g5)/4

e = -(q + ave_shf)/(1 +bowen)

h = -(e + ave_shf +q)

• latent heat flux(e)
• 0-5 cm integrated soil temperature, site 4(ts4)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• h(h)
• soil heat flow, site 4(g4)
• average surface soil heat flow(ave_shf)

• Soil temperature 4(rr_ts4)

SGP/EBBR/E20 - Annual Calibration Changeout

On August 9, 1995 between 0930-2030 GMT, the changeout for annual calibration occurred at 
E20, Meeker, OK.  Soil measurements data should be used with caution for the following 
week at least, as the sensors require time to "settle" into the soil.

• 5 cm soil heat flow corrected for soil moisture content, site 1(c_shf1)
• Soil heat capacity 3(cs3)
• volumetric soil moisture, site 4(sm4)
• volumetric soil moisture, site 2(sm2)
• volumetric soil moisture, site 1(sm1)
• 5 cm soil heat flow, site 1(shf1)
• 0-5 cm integrated soil temperature, site 3(ts3)
• Soil heat capacity 2(cs2)
• 0-5 cm integrated soil temperature, site 4(ts4)
• 5 cm soil heat flow corrected for soil moisture content, site 2(c_shf2)
• Soil heat capacity 5(cs5)
• 0-5 cm integrated soil temperature, site 5(ts5)
• volumetric soil moisture, site 5(sm5)
• 5 cm soil heat flow, site 2(shf2)
• 5 cm soil heat flow, site 5(shf5)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• 0-5 cm integrated soil temperature, site 2(ts2)
• 5 cm soil heat flow, site 4(shf4)
• Soil heat capacity 4(cs4)
• 0-5 cm integrated soil temperature, site 2(ts1)
• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• Soil heat capacity 1(cs1)
• 5 cm soil heat flow, site 3(shf3)
• volumetric soil moisture, site 3(sm3)
• 5 cm soil heat flow corrected for soil moisture content, site 3(c_shf3)

SGP/EBBR/E20 - AEM Home 30 Values Low

The first EBBR to achieve annual calibration changeout was Meeker, Ok, E20.
However, soon after changeout on August 9, 1995, the home 30 value dropped below
15, intermittently, to typically 0.3 to 0.5; this causes a data quality message
to be output in the site operations log as the stated acceptable range for home
30 is 15 to 34.999999.  However, no data is incorrect as a result of this
condition.

No replacement AEM is available, as the changeout kit AEMs are somewhat
different from the initial units.  Site operations hopes to have time to
diagnose the problem on the next PM visit and correct the problem.  At
present, data quality is not jeopardized.

I will submit another DQR or addendum when successful replacement of the
AEM is accomplished.

• soil heat flow, site 1(g1)
• Bottom humidity(hum_bot)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• volumetric soil moisture, site 1(sm1)
• 5 cm soil heat flow, site 1(shf1)
• 0-5 cm integrated soil temperature, site 3(ts3)
• top air temperature(tair_top)
• Exchange mechanism position indicator (15 to 30 min)(home_30)
• top vapor pressure(vp_top)
• 0-5 cm integrated soil temperature, site 4(ts4)
• 5 cm soil heat flow corrected for soil moisture content, site 2(c_shf2)
• soil heat flow, site 4(g4)
• 0-5 cm integrated soil temperature, site 5(ts5)
• average surface soil heat flow(ave_shf)
• volumetric soil moisture, site 5(sm5)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• net radiation(q)
• 0-5 cm change in soil heat storage with time, site 3(ces3)
• 5 cm soil heat flow, site 2(shf2)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Top humidity(hum_top)
• 5 cm soil heat flow, site 5(shf5)
• soil heat flow, site 5(g5)
• soil heat flow, site 2(g2)
• Retrieved pressure profile(pres)
• 0-5 cm change in soil heat storage with time, site 5(ces5)
• Time offset of tweaks from base_time(time_offset)
• Soil heat capacity 4(cs4)
• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• vector wind speed(res_ws)
• Reference Thermistor Temperature(tref)
• volumetric soil moisture, site 3(sm3)
• Exchange mechanism position indicator (0 to 15 min)(home_15)
• 5 cm soil heat flow corrected for soil moisture content, site 1(c_shf1)
• Dummy altitude for Zeb(alt)
• Soil heat capacity 3(cs3)
• volumetric soil moisture, site 4(sm4)
• volumetric soil moisture, site 2(sm2)
• Temperature of the top humidity chamber(thum_top)
• bottom vapor pressure(vp_bot)
• Soil heat capacity 2(cs2)
• soil heat flow, site 3(g3)
• lat(lat)
• Soil heat capacity 5(cs5)
• h(h)
• base time(base_time)
• wind direction (relative to true north)(wind_d)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• 0-5 cm integrated soil temperature, site 2(ts2)
• Temperature of bottom humidity sensor chamber(thum_bot)
• 5 cm soil heat flow, site 4(shf4)
• lon(lon)
• latent heat flux(e)
• 0-5 cm integrated soil temperature, site 2(ts1)
• Soil heat capacity 1(cs1)
• scalar wind speed(wind_s)
• 0-5 cm change in soil heat storage with time, site 2(ces1)
• 5 cm soil heat flow, site 3(shf3)
• bottom air temperature(tair_bot)
• 0-5 cm change in soil heat storage with time, site 2(ces2)
• 5 cm soil heat flow corrected for soil moisture content, site 3(c_shf3)

• vector wind speed(res_ws)
• Dummy altitude for Zeb(alt)
• bottom air temperature(tair_bot)
• base time(base_time)
• Retrieved pressure profile(pres)
• lat(lat)
• wind direction (relative to true north)(wind_d)
• bottom vapor pressure(vp_bot)
• Top humidity(hum_top)
• lon(lon)
• top vapor pressure(vp_top)
• Temperature of the top humidity chamber(thum_top)
• net radiation(q)
• Bottom humidity(hum_bot)
• Time offset of tweaks from base_time(time_offset)
• Reference Thermistor Temperature(tref)
• top air temperature(tair_top)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• Temperature of bottom humidity sensor chamber(thum_bot)
• Home signal(home)
• scalar wind speed(wind_s)

SGP/EBBR/E9 - 3-month Check

During EBBR 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 this period, at least,
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 gradients.  Checks performed before or after the AEM
is disabled also lead to some incorrect data.

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

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

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

SGP/EBBR/E13 - AEM Exchange Stopped in Snow and Freezing Rain

On the night of November 10-11, a north-south line from south central
Kansas through south central Oklahoma received snow and freezing rain and experienced
below freezing temperatures.  This caused the EBBR automatic exchange mechanism (AEM) to
stop exchanging temporarily.   

Note that temperatures, relative humidities, and vapor pressures are not affected; these
are correct as measured, but the height at which the measurements occurred must be
determined from the home signal value.

• latent heat flux(e)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• h(h)

SGP/EBBR/E20 - Soil Heat Flow Zero Under Unchanging Conditions

This DQR is written to inform users of the data that the EBBR soil heat flow
measurements of zero during much of 11 November 1995 at E20, Meeker, OK are
correct values.  Nearly unchanging conditions of net radiation, air
temperature, and soil moisture, plus high wind speeds and near neutral
atmospheric stability, resulted in almost unchanging conditions of
soil temperature and ten and a half hours of zero soil heat flow
output from all soil heat flow plates (some plates outputted zero for
longer than this).  The change in energy storage (determined from the
change in temperature with time of the soil above the plates) was very
nearly zero also during the period of interest.

Such an extended period of zero soil heat flow and the accompanying
unchanging soil and atmospheric conditions is quite rare and therefore
worth noting here in case someone using the data might mistakenly think
that the data is incorrect.

• soil heat flow, site 1(g1)
• Bottom humidity(hum_bot)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• volumetric soil moisture, site 1(sm1)
• 5 cm soil heat flow, site 1(shf1)
• 0-5 cm integrated soil temperature, site 3(ts3)
• top air temperature(tair_top)
• Exchange mechanism position indicator (15 to 30 min)(home_30)
• 0-5 cm integrated soil temperature, site 4(ts4)
• top vapor pressure(vp_top)
• 5 cm soil heat flow corrected for soil moisture content, site 2(c_shf2)
• soil heat flow, site 4(g4)
• 0-5 cm integrated soil temperature, site 5(ts5)
• average surface soil heat flow(ave_shf)
• volumetric soil moisture, site 5(sm5)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• net radiation(q)
• 0-5 cm change in soil heat storage with time, site 3(ces3)
• 5 cm soil heat flow, site 2(shf2)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Top humidity(hum_top)
• 5 cm soil heat flow, site 5(shf5)
• soil heat flow, site 5(g5)
• soil heat flow, site 2(g2)
• Retrieved pressure profile(pres)
• 0-5 cm change in soil heat storage with time, site 5(ces5)
• Time offset of tweaks from base_time(time_offset)
• Soil heat capacity 4(cs4)
• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• vector wind speed(res_ws)
• Reference Thermistor Temperature(tref)
• volumetric soil moisture, site 3(sm3)
• Exchange mechanism position indicator (0 to 15 min)(home_15)
• 5 cm soil heat flow corrected for soil moisture content, site 1(c_shf1)
• Dummy altitude for Zeb(alt)
• Soil heat capacity 3(cs3)
• volumetric soil moisture, site 4(sm4)
• volumetric soil moisture, site 2(sm2)
• Temperature of the top humidity chamber(thum_top)
• bottom vapor pressure(vp_bot)
• Soil heat capacity 2(cs2)
• soil heat flow, site 3(g3)
• lat(lat)
• Soil heat capacity 5(cs5)
• h(h)
• base time(base_time)
• wind direction (relative to true north)(wind_d)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• 0-5 cm integrated soil temperature, site 2(ts2)
• Temperature of bottom humidity sensor chamber(thum_bot)
• 5 cm soil heat flow, site 4(shf4)
• lon(lon)
• latent heat flux(e)
• 0-5 cm integrated soil temperature, site 2(ts1)
• Soil heat capacity 1(cs1)
• 0-5 cm change in soil heat storage with time, site 2(ces1)
• scalar wind speed(wind_s)
• 5 cm soil heat flow, site 3(shf3)
• bottom air temperature(tair_bot)
• 0-5 cm change in soil heat storage with time, site 2(ces2)
• 5 cm soil heat flow corrected for soil moisture content, site 3(c_shf3)

SGP/EBBR/E20 - Temperature/RH Probes Malfunction and Replacement

Beginning on approximately October 1, 1996 the calibration of the temperature 
sensor in one or both T/RH probes began to drift; temperatures started to 
drift higher than the thermocouple probes.  This drift caused the upper and 
lower temperatures measured by the T/RH probe to be 2 to 10 degrees C greater 
than the thermocouple probes.  Comparison with adjacent EBBR sites shows 
that the thermocouples were measuring properly.  The problem affected the vapor 
pressure outputs primarily, making them as much as 1 kPa greater than they 
should be (vapor pressure is calculated from probe temperature and relative 
humidity).  The effect on sensible and latent heat fluxes was negligible, 
although latent heat flux may be overestimated by about 5% presently and 
sensible heat flux underestimated by approximately the same percentage.


Site operations replaced the T/RH probes on 8 May 1996; the new probes are 
performing well. The serial numbers of replaced probes are: Left 632415, 
Right 632356.  New probe serial numbers are: Left 460428, Right 460412.

• null(Raw data stream - documentation not supported)

• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Temperature of the top humidity chamber(thum_top)
• Temperature of bottom humidity sensor chamber(thum_bot)
• bottom vapor pressure(vp_bot)
• latent heat flux(e)
• top vapor pressure(vp_top)
• h(h)

• Temperature of the top humidity chamber(thum_top)
• bottom vapor pressure(vp_bot)
• Temperature of bottom humidity sensor chamber(thum_bot)
• top vapor pressure(vp_top)

• Temperature of right humidity sensor chamber(rr_thum_r)
• Temperature of left humidity sensor chamber(rr_thum_l)

SGP/EBBR/E20 - 3-month check

During EBBR 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 this period, at least,
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 gradients.  Checks performed before or after the AEM
is disabled also lead to some incorrect data.  The period of incorrect
data for the EBBR is listed above; data times affected do not include the
beginning time and do include the ending time (data files are denoted by
the end time).

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

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

SGP/EBBR/E20 - Incorrect Data from Left Humidity Probe

The left humidity probe output started drifting upward at 2145 GMT on 
May 8, 1996 and went offscale (over 105%) at 0200 GMT on May 9, 1996.  The 
output settled at approximately 113% and remained there until the probe was 
replaced on June 19, 1996.  The first correct 15 minute values were at 1630 
GMT on June 19 and the first correct 30 minute values were at 1700 GMT.
During the period of incorrect left probe RH data, the following values 
were incorrect:

15 minute:  mv_hum_l

30 minute: hum_top, hum_bot, vp_top, vp_bot, h, e, bowen.

• latent heat flux(e)
• Bottom humidity(hum_bot)
• top vapor pressure(vp_top)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Top humidity(hum_top)
• h(h)
• bottom vapor pressure(vp_bot)

• Left relative humidity(mv_hum_l)

SGP/EBBR/E4 - EBBR 3 Month Checks - 10 EFs

During EBBR 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 before or after the 
AEM is disabled also lead to some incorrect data.  Incorrect 5, 15 minute and 
half hour data occurs for periods indicated.

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

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

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

SGP/EBBR/E20 - Wind Speed Cups Frozen

Freezing rain, snow, and below freezing conditions during 24 November 
1996 caused the wind speed sensor cups to freeze in a stopped state at E20, 
Meeker, OK.  On 25 November, the cups broke free of the ice and turned freely 
again. 

Measurements affected by the stalled wind speed sensor include:

5 minute:  wind_s, res_ws

15 minute: wind_s

30 minute: wind_s, res_ws

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• scalar wind speed(wind_s)

SGP/EBBR/E20 - Reprocess: E20 Soil Probes #3 Cables Cut

The cables going to #3 soil temperature, moisture, and heat flow probes 
were cut by a mower on 11 June 1997 and were repaired on 16 July 1997.  
Data for the temperature probe was offscale, for the soil moisture probe 
was a constant 10.1 (close to the actual), and for the soil heat flow 
was large negative during the period. 

The following are the data quantities that were affected:

15 minute: rr_ts3, mv_hft3, r_sm3

30 minute: ts3, ces3, shf3, c_shf3, cs3, g3, ave_shf, e, h

Sensible, latent, and soil heat fluxes can be recalculated using the 
values from probes 1, 2, 4, and 5, as follows.

ave_shf = (g1 + g2 + g4 + g5)/4

e = -(q + ave_shf)/(1 +bowen)

h = -(e + ave_shf +q)

• latent heat flux(e)
• soil heat flow, site 3(g3)
• 0-5 cm change in soil heat storage with time, site 3(ces3)
• Soil heat capacity 3(cs3)
• h(h)
• 5 cm soil heat flow, site 3(shf3)
• 5 cm soil heat flow corrected for soil moisture content, site 3(c_shf3)
• average surface soil heat flow(ave_shf)
• 0-5 cm integrated soil temperature, site 3(ts3)

• Soil temperature 3(rr_ts3)
• Soil moisture 3(r_sm3)
• Soil heat flow 3(mv_hft3)

SGP/EBBR/E7 - EBBR Biannual Checks

During EBBR 6-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 before or after the 
AEM is disabled also lead to some incorrect data.  Incorrect 5, 15 minute and 
half hour data occurs for periods indicated.

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

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

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

SGP/EBBR/E26 - EBBR AEMs Not Exchanging (Iced Or Fuse Blown)

The EBBR AEM stopped exchanging because of icing at during this time
period.

The calculations of Bowen ratio, latent heat flux, and sensible heat
flux are incorrect for the time period indicated.  The other
measurements listed  are also incorrect for those times:

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

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

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

SGP/EBBR/E20 - Wind Speed Sensor Frozen

The wind speed sensor was frozen during the period.  

Data values that were incorrect are:

 5 minute: wind_s, res_ws
15 minute: wind_s
30 minute: wind_s, res_ws

• null(Raw data stream - documentation not supported)

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• scalar wind speed(wind_s)

SGP/EBBR/E20 - 3 Month Check

During EBBR 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 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 above.

• Bottom humidity(hum_bot)
• volumetric soil moisture, site 4(sm4)
• Temperature of the top humidity chamber(thum_top)
• bottom vapor pressure(vp_bot)
• top air temperature(tair_top)
• top vapor pressure(vp_top)
• h(h)
• volumetric soil moisture, site 5(sm5)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• Top humidity(hum_top)
• Temperature of bottom humidity sensor chamber(thum_bot)
• latent heat flux(e)
• bottom air temperature(tair_bot)

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

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

SGP/EBBR/E20 - 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 above.

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

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

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

SGP/EBBR/E20 - Wind Speed Incorrect

On 3 July 1998 the cup anemometer lost a cup. Until the cup
assembly was replaced by site ops personnel on 15 July 1998,
wind speed and vector averaged wind speed data were incorrect.
The values affected are listed below.

 5 minute: wind_s, res_ws
15 minute: wind_s
30 minute: wind_s, res_ws

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• scalar wind speed(wind_s)

SGP/EBBR/E20 - Incorrect Data - Cattle Vandalism

Cattle penetrated the electric fence and pulled the aspirator housings
from the AEM.  Thus T/RH/VP and sensible and latent heat fluxes are
incorrect for the period (until 1540 GMT; LE and H through the 30 minute
period ending at 1600 GMT)

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

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

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

SGP/EBBR/E20 - Wind Direction Data Incorrect (revised)

The wind direction sensor was iced stopped by freezing rain, 
resulting in the following values being incorrect:

5 minute:  res_ws, wind_d, sigma_wd
15 minute: mv_wind_d
30 minute: res_ws, wind_d, sigma_wd

• standard deviation of wind direction (sigma theta)(sigma_wd)
• vector wind speed(res_ws)
• wind direction (relative to true north)(wind_d)

• vector wind speed(res_ws)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• wind direction (relative to true north)(wind_d)

• Wind direction (relative to true north)(mv_wind_d)

SGP/EBBR/E20 - Wind Direction Data Incorrect

The wind direction sensor was iced stopped by freezing rain, 
resulting in the following values being incorrect:

5 minute:  res_ws, wind_d, sigma_wd
15 minute: mv_wind_d
30 minute: res_ws, wind_d, sigma_wd

• standard deviation of wind direction (sigma theta)(sigma_wd)
• vector wind speed(res_ws)
• wind direction (relative to true north)(wind_d)

• vector wind speed(res_ws)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• wind direction (relative to true north)(wind_d)

• Wind direction (relative to true north)(mv_wind_d)

SGP/EBBR/E20 - Wind Speed Data Incorrect

The wind speed sensor was iced stopped by freezing rain, 
resulting in the following values being incorrect:

5 minute:  wind_s, res_ws
15 minute: wind_s
30 minute: wind_s, res_ws,

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• scalar wind speed(wind_s)

SGP/EBBR/E20 - Wind Speed Data Incorrect

The wind speed sensor was iced stopped by freezing rain, 
resulting in the following values being incorrect:

5 minute:  wind_s, res_ws
15 minute: wind_s
30 minute: wind_s, res_ws,

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• scalar wind speed(wind_s)

• scalar wind speed(wind_s)

SGP/EBBR/E20 - Data Incorrect

Version 6 of the CR10 program was installed during this period instead of
version 7 (the initial version 7 program did not work).  The calibrations 
and coefficients in version 6 were incorrect; therefore all 
data during this period is of questionable quality and e and h are clearly
incorrect.  The correct version 7 program was installed on 29 Dec 1998.

• null(Raw data stream - documentation not supported)

• Bottom humidity(hum_bot)
• 0-5 cm change in soil heat storage with time, site 4(ces4)
• volumetric soil moisture, site 1(sm1)
• 5 cm soil heat flow, site 1(shf1)
• Exchange mechanism position indicator (15 to 30 min)(home_30)
• 5 cm soil heat flow corrected for soil moisture content, site 2(c_shf2)
• volumetric soil moisture, site 5(sm5)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• net radiation(q)
• 5 cm soil heat flow, site 2(shf2)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• 5 cm soil heat flow, site 5(shf5)
• Top humidity(hum_top)
• soil heat flow, site 5(g5)
• Retrieved pressure profile(pres)
• 0-5 cm change in soil heat storage with time, site 5(ces5)
• Time offset of tweaks from base_time(time_offset)
• volumetric soil moisture, site 3(sm3)
• Exchange mechanism position indicator (0 to 15 min)(home_15)
• Dummy altitude for Zeb(alt)
• volumetric soil moisture, site 2(sm2)
• bottom vapor pressure(vp_bot)
• soil heat flow, site 3(g3)
• h(h)
• Soil heat capacity 5(cs5)
• wind direction (relative to true north)(wind_d)
• 0-5 cm integrated soil temperature, site 2(ts2)
• 0-5 cm integrated soil temperature, site 2(ts1)
• 0-5 cm change in soil heat storage with time, site 2(ces1)
• bottom air temperature(tair_bot)
• 0-5 cm change in soil heat storage with time, site 2(ces2)
• soil heat flow, site 1(g1)
• 0-5 cm integrated soil temperature, site 3(ts3)
• top air temperature(tair_top)
• 0-5 cm integrated soil temperature, site 4(ts4)
• top vapor pressure(vp_top)
• soil heat flow, site 4(g4)
• 0-5 cm integrated soil temperature, site 5(ts5)
• average surface soil heat flow(ave_shf)
• 0-5 cm change in soil heat storage with time, site 3(ces3)
• soil heat flow, site 2(g2)
• Soil heat capacity 4(cs4)
• 5 cm soil heat flow corrected for soil moisture content, site 5(c_shf5)
• vector wind speed(res_ws)
• Reference Thermistor Temperature(tref)
• 5 cm soil heat flow corrected for soil moisture content, site 1(c_shf1)
• Soil heat capacity 3(cs3)
• volumetric soil moisture, site 4(sm4)
• Temperature of the top humidity chamber(thum_top)
• Soil heat capacity 2(cs2)
• lat(lat)
• base time(base_time)
• 5 cm soil heat flow corrected for soil moisture content, site 4(c_shf4)
• Temperature of bottom humidity sensor chamber(thum_bot)
• 5 cm soil heat flow, site 4(shf4)
• lon(lon)
• latent heat flux(e)
• Soil heat capacity 1(cs1)
• scalar wind speed(wind_s)
• 5 cm soil heat flow, site 3(shf3)
• 5 cm soil heat flow corrected for soil moisture content, site 3(c_shf3)

• vector wind speed(res_ws)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• Retrieved pressure profile(pres)
• lat(lat)
• bottom vapor pressure(vp_bot)
• Top humidity(hum_top)
• lon(lon)
• top vapor pressure(vp_top)
• Temperature of the top humidity chamber(thum_top)
• Bottom humidity(hum_bot)
• Time offset of tweaks from base_time(time_offset)
• Temperature of bottom humidity sensor chamber(thum_bot)
• bottom air temperature(tair_bot)
• wind direction (relative to true north)(wind_d)
• net radiation(q)
• Reference Thermistor Temperature(tref)
• top air temperature(tair_top)
• standard deviation of wind direction (sigma theta)(sigma_wd)
• Home signal(home)
• scalar wind speed(wind_s)

• Soil moisture 4(r_sm4)
• Right air temperature(tair_r)
• Soil temperature 5(rr_ts5)
• Left air temperature(tair_l)
• Soil moisture 3(r_sm3)
• Right relative humidity(mv_hum_r)
• Home signal(mv_home)
• Signature(signature)
• base time(base_time)
• Soil heat flow 2(mv_hft2)
• scalar wind speed(wind_s)
• Left relative humidity(mv_hum_l)
• Soil heat flow 1(mv_hft1)
• Soil heat flow 5(mv_hft5)
• Soil moisture 1(r_sm1)
• Reference temperature(rr_tref)
• Dummy altitude for Zeb(alt)
• Soil heat flow 3(mv_hft3)
• Soil heat flow 4(mv_hft4)
• Soil moisture 5(r_sm5)
• Soil moisture 2(r_sm2)
• Temperature of right humidity sensor chamber(rr_thum_r)
• Net radiation(mv_q)
• Soil temperature 1(rr_ts1)
• lat(lat)
• Atmospheric pressure(mv_pres)
• Battery(bat)
• Soil temperature 4(rr_ts4)
• Soil temperature 3(rr_ts3)
• Soil temperature 2(rr_ts2)
• lon(lon)
• Wind direction (relative to true north)(mv_wind_d)
• Time offset of tweaks from base_time(time_offset)
• Temperature of left humidity sensor chamber(rr_thum_l)

SGP/EBBR/E20 - Pressure Low

The pressure sensor values dropped several kPa on 13 January 1999 because 
of a sensor malfunction and remained that way until the sensor was 
replaced on 10 February 1999.  Comparison of the pressure before and after
the problem period shows that Bowen ratio was underestimated by 
approximately 6% during the period, resulting in a 6% overestimation of
latent heat flux and a 6% underestimation of sensible heat flux.  
Adjustment of the flux data during the period by these amounts should be
made by the data user.

• latent heat flux(e)
• top vapor pressure(vp_top)
• ratio of sensible/latent heat fluxes (Bowen ratio)(bowen)
• h(h)
• Retrieved pressure profile(pres)
• bottom vapor pressure(vp_bot)

• bottom vapor pressure(vp_bot)
• top vapor pressure(vp_top)
• Retrieved pressure profile(pres)

• Atmospheric pressure(mv_pres)

SGP/EBBR/E20 - Right Relative Humidity Offset Low

The right relative humidity has been offset low approximately 5%
since the installation of the recalibrated EBBR system on 25 Nov. 1998.  This only
affects the absolute value of the relative humidities used in the flux
calculations; the fluxes themselves are not affected because of the
removal of offsets by the AEM switching.  The right temperature/humidity
probe was replaced on 10 March 1999.

• Temperature of right humidity sensor chamber(rr_thum_r)
• Right relative humidity(mv_hum_r)

SGP/EBBR/E20 - Air Temperature Incorrect

Right air temperature (15 minute) and top and bottom air temperatures 
(5 and 30 minute) during this period are incorrect because the right air
temperature sensor was not working.

• top air temperature(tair_top)
• bottom air temperature(tair_bot)

• top air temperature(tair_top)
• bottom air temperature(tair_bot)

• Right air temperature(tair_r)