SGP/EBBR - EBBR E9 Anemometer Frozen, Wind Speed Incorrect

The anemometer cups were frozen stalled.

The following values were therefore incorrect:

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

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

• scalar wind speed(wind_s)

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

SGP/EBBR - EBBR E9 Net Radiation Incorrect

The net radiometer top dome was broken and water had entered.  Net 
radiation values are therefore incorrect during the period.

The affected data are:

5 minute:  q
15 minute: mv_q
30 minute: q, h, e

• net radiation(q)

• Net radiation(mv_q)

• net radiation(q)
• h(h)
• latent heat flux(e)

SGP/EBBR/E9 - Invalid wind speed frozen sensor

On February 23, 1994 the EBBR wind speed sensor at E9, Ashton, KS was
frozen to a stationary condition by ice.  It broke free in strong winds on
February 24, 1994.  Invalid data for the time period indicated is:

30 minute: wind_s, res_ws

15 minute: wind_s

5 minute: wind_s, res_ws.

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

• scalar wind speed(wind_s)

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

SGP/E9/EBBR - AEM Malfunction

EDITOR'S NOTE:  This DQR refers, in part, to data collected prior to the
begin date of regular ARM data.  During the first month covered by this
DQR, the EBBR.E9 data were not archived with standard ARM names.  The data
are therefore not readily available, but can be made available by special
request.  The total period covered by the problem documented here is
930615.0000-940322.1643.

The AEM at E9 frequently did not function properly during the time period
stated.  Please see the notes in the EBBR platform describing home signal
conditions for which certain of the data fields are suspect.  The newly
installed AEM is performing properly so far.

The files could be flagged, but it is up to the user to read the
platform notes concerning the condition of the home signal and then
view the quality of the data accordingly.  I would be at my terminal full-
time in attempting to list all days and times and data fields that are
affected by the numerous AEM malfunctions.  Furthermore, I have done so
previously in several PIFs that I will reference here for information:
P931101.4, P931115.2, P940105.2, P940211.3

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

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

SGP/EBBR/E9 - AEM failure

The Automatic Exchange Mechanism would not function.  It was decided to
take the unit back to SGP CART to try to repair it.  A spare AEM was not
available for a replacement, so the aspirated radiation shields housing
temperature and humidity gradient sensors were attached to the EBBR
framework, one meter apart vertically, with the right side in the lower
position.  The housings remained this way for two weeks.  During this time
period, home signal, sensible heat flux, and latent heat flux values are
incorrect.  Significant reprocessing would be required to obtain correct
fluxes, and that would be possible only if one assumed that offsets in the
sensor calibrations are negligible; that is a very debatable assumption
considering that the EBBR system is already half a year past due for
calibration.

• h(h)
• Exchange mechanism position indicator (15 to 30 min)(home_30)
• Exchange mechanism position indicator (0 to 15 min)(home_15)
• latent heat flux(e)

SGP/EBBR/E9 - Reprocess: Soil Heat Flow Sensor Failure

Failure of soil heat flow sensor #5 at E9, Ashton, KS resulted in incorrect
data values for 6 fields for much of the period of time listed above.  The
soil heat flow values from #5 were so large (in the absolute) that it
deleteriosly affected the soil heat flux average and the sensible and
latent heat fluxes.  The fields affected were:

30 minute: shf5, c_shf5, g5, ave_shf, e, h

15 minute: mv_hft5.

I list only the 30 minute times affected below; it can be assumed that the
15 minute value contained in the half hour are incorrect.  Sensor #5 was
replaced at 1545 GMT on June 28.  Old S/N 923029, new S/N 923092.  Half hour
1600 GMT is missing due to having to reload the CR10 program with a new shf5
calibration.  Sensible and latent heat fluxes can be recomputed by averaging
soil heat flow sensors 1-4; use the following equations:

ave_shf = (g1 + g2 + g3 + g4)/4

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

h = e * bowen,

where g is total soil heat flow, q is net radiation, and bowen is Bowen
Ratio.

Affected half hours:

Date          Times (GMT)

6/15    2130, 2300, 2330
6/16    0000, 0030, 2130-2330
6/17    0000-1530, 1900, 1930
6/18    0200-2330
6/19    All
6/20    All
6/21    All
6/22    All
6/23    All
6/24    All
6/25    0000-1930, 2300, 2330
6/26    All
6/27    All
6/28    0000-1600

• Soil heat flow 5(mv_hft5)

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

SGP/EBBR/E9 - Malfunctioning Wind Dir Sensor, Incorrect SM2 Results

It has been reported previously that a malfunction of the wind direction
sensor resulting in zero or 135 degree outputs can cause the soil moisture
#2 sensor to read offscale.  The two sensors are attached to a multiplexer
pair.  The manufacturer of the multiplexer and data acquisition system have
not been able to explain how our instrument configuration can cause this
effect.  Shortly after 0030 GMT on August 20, 1994 significant rainfall
occurred, being reflected in more than a doubling of soil moisture within
an hour.  During the time period listed above, the wind direction sensor
mulfunctioned (apparently caused by water in the wind direction sensor
electronics), causing the following data fields to be incorrect:

5 minute:  res_ws, wind_d, sigma_wd

15 minute: mv_wind_dir

30 minute: res_ws, wind_d, sigma_wd.

During part of the listed period, Soil Moisture #2 was also incorrect,
being offscale; during those times the following 30 minute data is also
incorrect:

30 minute: sm2, c_shf2, ave_shf, cs2, ces2, g2, h, e.

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

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

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

SGP/EBBR/E9 - Reprocess: Soil Heat Flux Out of Range

For an unknown reason, soil heat flux sensor #5 indicated too small a value
for the period listed above.  This resulted in an incorrect average of soil
heat flow for the five sets of soil heat flow plates, and therefore
incorrect e (latent heat flux) and h (sensible heat flux) in the 30 minute
data.  The following data values are incorrect:

15 minute: mv_hft5

30 minute: shf5, c_shf5, ave_shf, g5, e, h

The latent and sensible heat flux can be recalculated by using only soil
heat flows 1 through 4 to calculate the average soil heat flow,

ave_shf = (g1 + g2 + g3 + g4)/4

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

h = -(e + ave_shf + q).

• Soil heat flow 5(mv_hft5)

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

SGP/EBBR/E9 - Hail Damage to Net Radiometer and Wind Speed Sensor

Golf ball size hail was reported for the Ashton site for early August 20,
1994.  It damaged the wind speed sensor and the net radiometer shortly
before 0130 GMT.  The following data fields are to be flagged as incorrect
for the periods listed above (resultant wind speed has already been
indicated as incorrect in a previous DQR that documented the malfunction of
the wind direction sensor):

5 minute:  wind_s, res_ws, q

15 minute: wind_s, mv_q

30 minute: wind_s, res_ws, q, h, e.

Note that h and e are also incorrect as a consequence of q being incorrect.

• scalar wind speed(wind_s)
• vector wind speed(res_ws)
• net radiation(q)

• scalar wind speed(wind_s)
• Net radiation(mv_q)

• vector wind speed(res_ws)
• net radiation(q)
• h(h)
• scalar wind speed(wind_s)
• latent heat flux(e)

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/E9 - Reprocess: Soil Heat Flow Sensor 5 Incorrect Data

Soil heat flow sensor #5 periodically outputted incorrect values from
mid-August 1994 until mid-January 1995.  The output often indicated large
negative heat flow.  The sensor was replaced on January 23, 1995, even
though the previous week of data was correct.  The data affected (and thus
incorrect) includes:

15 minute: mv_hft5
30 minute: shf5, c_shf5, g5, ave_shf, e, h.

The dates and times (GMT) of incorrect values are listed below.  Only half
hour times are listed.

08/19/94  1700-2300
10/13/94  1800-2330
10/14/94  0000-1500
10/17/94  2030-2100
10/28/94  2030-2230
12/20/94  0630-2330
12/21/94  0000-2330
12/22/94  0000-2330
12/23/94  0000-0530
12/26/94  1700-2330
12/27/94  0000-0130, 1630
01/02/95  0600-2330
01/03/95  0000-2330
01/04/95  0000-2330
01/05/95  0000-1700, 2200-2330
01/06/95  0000-2330
01/07/95  0000-2330
01/08/95  0000-2330
01/09/95  0000-0230, 0900-2330
01/10/95  0000-2330
01/11/95  0000-2330
01/12/95  0000-2330
01/13/95  0000-2330
01/14/95  0000-0400, 0800-2330
01/15/95  0000-0300, 1200-2330
01/16/95  0000-1600

The latent and sensible heat fluxes can be recalculated by using only soil
heat flows 1 through 4 to calculate the average soil heat flow,

ave_shf = (g1 + g2 + g3 + g4)/4

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

h = -(e + ave_shf + q)

• Soil heat flow 5(mv_hft5)

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

SGP/EBBR/E9 - Radiation Shield Problem

The left radiation shield was off during the period of time above.  Close
inspection of the 15 minute data was required to detect when the shield
fell off.  As is often the case in such a situation, the 30 minute data
does not adequately indicate such a failure.  A radiation shield has fallen off
of an EBBR before, apparently a result of vibration of the AEM during
exchanges.  All air and humidity probe temperatures (except the reference
temperature), relative humidities, vapor pressures, Bowen ratio, sensible heat
flux, and latent heat flux during this period are considered to be incorrect.

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

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

SGP/EBBR/E9 - Stopped Ventilation Fan

On April 18, 1995, a site operator discovered the right aspirator ventilation
fan of the EBBR to be stopped.  Inspection of the data indicates that this
condition began early in the GMT day.  Interpretation of the start time of
the condition is made more difficult by a slight bias low in absolute
temperature in comparison to the left temperature probe.  Lack of ventilation
of the temperature and relative humidity sensors attached to the AEM results
in incorrect measurements of air temperature and relative humidity by the
right aspirator probes, and therefore all quantities calculated from them,
including sensible and latent heat fluxes, are incorrect as well.
The quantities that are incorrect for the period above are:

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

15 minute: rr_thum_r, mv_hum_r, tair_r

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

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

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

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

SGP/EBBR/E9 - Frozen Wind Speed Sensor

On March 7, 1995 freezing rain stopped the cups of the EBBR wind
speed instrument at Ashton, KS (E9).  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

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

• scalar wind speed(wind_s)

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

SBP/EBBR/E9 - Reprocess: Soil Heat Flow Sensor 5 Incorrect Data

Soil heat flow sensor #5 periodically outputted incorrect values during the
period above.  The output often indicated large negative heat flow.  The
sensor connections were tightened on March 20, 1995, which seems to have
corrected the problem.  The data affected (and thus incorrect) includes:

15 minute: mv_hft5
30 minute: shf5, c_shf5, g5, ave_shf, e, h.

The dates and times (GMT) of incorrect values are listed below.  Only half
hour times are listed.

03/10/95  2130
03/11/95  0100-0600, 1530-2330
03/12/95  0000-1930
03/13/95  0500
03/16/95  1830-2330
03/17/95  0000-2330
03/18/95  0000-1100
03/19/95  2100-2330
03/20/95  0000-0400, 1530-1700

The latent and sensible heat fluxes can be recalculated by using only soil
heat flows 1 through 4 to calculate the average soil heat flow,

ave_shf = (g1 + g2 + g3 + g4)/4

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

h = -(e + ave_shf + q)

• Soil heat flow 5(mv_hft5)

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

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/E9 - Annual calibration changeout

On November 15, 1995 the changeout for annual calibration occurred at E9,
Ashton, KS.  SEBS unit 4 was removed and unit 6 was installed.  Between
1230 and 2100 GMT no data was collected; data during this period is missing.

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

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

SGP/EBBR/E9 - Wind Speed Cups Frozen

Freezing rain, snow, and below freezing conditions during 23 January 
1996 caused the wind speed sensor cups to freeze in a stopped state at E9, 
Ashton, KS.  Site operations personnel removed the ice from the cups later 
in the day to allow them to turn 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

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

• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• 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.  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).

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

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

SGP/EBBR/E9 - Air Temperature Thermocouples Incorrect

Both air temperature thermocouples were offscale, for unknown reasons, for 
1500 GMT for both 15 and 30 minute air temperature values.

The malfunction of the air temperature thermocouples results in incorrect Bowen 
ratio, sensible heat flux, and latent heat flux during the period above. 

The data values that are affected are:

5 minute:  tair_top, tair_bot

15 minute: tair_r, tair_l

30 minute: tair_top, tair_bot, bowen, e, and h

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

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

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

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/E9 - Temperature Portion of T/RH Probe

The Temperature portion of the right T/RH probe indicated too high a 
temperature for nearly 11 months.  I twice placed work requests to have the 
probe replaced, but no spares were available.  Spares recently became 
available and I placed a new work request to have the probe changed.  The 
replacement occurred on 18 June 1997; this fixed the problem.  The main 
results of the high temperatures were probe top and bottom temperatures
(used only for the calculation of vapor pressure) and vapor pressures that 
were too large.  Furthermore, this caused latent heat flux to be reported 
to be too large, and therefore sensible heat flux was reported to be too 
small.  Recalculation of the fluxes using thermocouple temperatures to 
calculate vapor pressure would be quite time consuming and would have to
assume that the thermocouple temperature and probe temperature were nearly 
the same.

The EBBR procedures have been changed to include comparison of the 
thermocouple and probe temperatures to make it easier for the site 
operators to detect this condition.

The data affected (and thus incorrect) includes:

15 minute: rr_thum_r 
30 minute: thum_top, thum_bot, vp_top, vp_bot, e, h, bowen.

• Battery(bat)
• Dummy altitude for Zeb(alt)
• Soil heat flow 3(mv_hft3)
• Temperature of right humidity sensor chamber(rr_thum_r)
• Soil heat flow 4(mv_hft4)
• Soil heat flow 5(mv_hft5)
• lon(lon)
• Soil heat flow 1(mv_hft1)
• Soil heat flow 2(mv_hft2)
• base time(base_time)
• lat(lat)

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

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/E9 - Wind Direction Sensor Malfunction

During numerous intermittent times during the period listed, the wind direction
sensor at E9, Ashton, KS malfunctioned, putting out a value of 135.  The
sensor was replaced on 30 September 1997, at 1550 GMT.  All wind direction data
with values of 135 during the period listed should be considered incorrect.
The affected data are:

 5 minute: res_ws, wind_d, sigma_d

15 minute: mv_wind_d

30 minute: res_ws, wind_d, sigma_d

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

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

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

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/E2 - EBBR Net Radiometer Domes Pierced, Water Inside - Data Affected

The upper dome of the EBBR net radiometers was punctured.
After the puncture, water collected in the top and/or bottom dome.  The
water was removed and the dome was replaced during PM visits. 

 In some cases, the puncture and water resulted in incorrect data. 
Comparison with net radiation values from surrounding EBBR sites and the
SIRS is neccesary to determine if the EBBR net radiation data 
are correct or incorrect.

It is often difficult to tell from the data when the punctures occurred,
but they would have existed for no more than 2 weeks, since the domes
are checked during each two-weekly PM visit.

Incorrect net radiation data results in the latent heat flux and
sensible heat flux also being incorrect.

• Net radiation(mv_q)

• net radiation(q)

• latent heat flux(e)
• net radiation(q)
• h(h)

SGP/EBBR/E9 - Wind Speed Sensor Frozen

The wind speed sensor was frozen stalled during this period. 

Data values that were affected are:

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

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

• null(Raw data stream - documentation not supported)

• scalar wind speed(wind_s)

• vector wind speed(res_ws)
• 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 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.

• 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/E9 - 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.

• 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/E9 - Wind Direction Data Incorrect

The wind direction sensor stopped working correctly, resulting in the
following values being affected:

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

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

• null(Raw data stream - documentation not supported)

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

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

SGP/EBBR/E9 - EBBR E9 Net Radiometer Dome Broken, Flux Data Incorrect

Incorrect Net Radiation values resulted in incorrect sensible and 
latent heat fluxes. Affected values are:

5 minute:   q
15 minute:  mv_q
30 minute:  q, e, h

• net radiation(q)

• null(Raw data stream - documentation not supported)

• Net radiation(mv_q)

• net radiation(q)
• h(h)
• latent heat flux(e)

SGP/EBBR/E9 - 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,

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

• null(Raw data stream - documentation not supported)

• scalar wind speed(wind_s)

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

SGP/EBBR/E9 - 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,

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

• null(Raw data stream - documentation not supported)

• scalar wind speed(wind_s)

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

SGP/EBBR/E9 - Wind Speed Incorrect

The wind speed sensor lost two of the three cups.  Flux data is not 
affected.  The data values affected are:

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

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

• null(Raw data stream - documentation not supported)

• scalar wind speed(wind_s)

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

SGP/EBBR/E9 - Right Aspirator Not Working

The result of the right aspirator not working was a reduction in measured
temperature gradient and thus a reduction in estimated sensible heat flux
and an increase in latent heat flux.  The fluxes could be in error by as
much as 10%.  Reported right air and humidity probe temperatures, top and 
bottom air and humidity probe temperatures, right relative humidity, and 
top and bottom vapor pressure are affected.

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

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